Biological Pathways to Improve Pest Control in Agriculture

Gupta, Manika

Biological Pathways to Improve Pest Control in Agriculture

Summary

India is especially suitable for agricultural products, its vast plains containing alluvial soil with rich natural contents. The major economy of India is based on agricultural products. The green revolution in India brought high hopes for Indian farmers. Several new scientific information helped crop production to grow by leaps and bounds: the more researches, the more intricacies. Further knowledge of pests makes scientists consider several new solutions. The use of chemicals was immediately adopted to decimate the population of pests and, at first, good results were obtained. But later on, harmful effects of the pesticides became known. It was realized later on that the regular use of chemicals in pesticides is extremely dangerous for human health.
Generally, chemical pesticides are used to curb the harmful effects of insects and pests. But the immediate gain of this process has an adverse effect on the environment in the long run. Regular use of chemicals leads to insecticide resistance. Then, biodiversity is distributed by pest resurgence and pesticide residues. So, the immediate gain of one generation creates serious problems for the next generation.
To sustain agriculture towards its natural mode some new solutions are to be traced. The solution to reduce pesticides is present in the preference for biological management. Predators and parasitoids may be used as natural enemies. In order to gain control over the thrips pests by less harmful means for the agricultural crops, more research work needs to be done. Certain other methods have to be explored in favour of the environment, biodiversity and other useful flora and fauna. We need to maintain the tritrophic interactions in which eating relationships between several species may be traced for biological control.

Excerpt

Gupta, Manika: Biological Pathways to Improve Pest Control in Agriculture, Hamburg,

Anchor Academic Publishing 2017

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Acknowledgement

God is great and mighty to make, without whose will nothing can move

in the world. Human efforts achieve success only when God smiles on them.

As a human I thought of doing something in the field of my studies related to

thrips population on chilli plants and biological methods to control it so that

yield loss occurring to the farmers of the chilli field may be checked and at the

same time harms caused by the chemicals in the pest management may be

saved. Really it was due to God's grace upon me that I could complete my

adventure.

God helps those who help themselves. As a novice researcher, I went

to Dr. Virendra Kumar, Associate Professor, Dept. of Zoology and he agreed

to guide me in the present research endeavour. Words fail to express the

gratitude I owe to him. It was he who showed me the right path in the course

of this research work and unreservedly afforded time whenever I needed it.

His valuable suggestions and tips to carry on the research work made me

reach the present stage of completion of the project.

I am also thankful to other faculty members of the Department of

Zoology, D.S. College, Aligarh namely Dr. Anjana Agrawal, Dr. Sheeba,

Mr. Vinay Kumar, Ms. Parul Yadav, Dr. Meera Singh, Dr. P.C. Agrawal, Dr.

R.K. Agrawal, Dr. R.K. Goel, Dr. T.C. Agrawal and Dr. P.K. Gupta, who gave

fruitful suggestions time to time during the progress of the present research

work.

My thanks and gratitude to Dr. S.K. Goel, Head, Department of

Mathematics, D.S. College, Aligarh are released spontaneously at this

juncture as it was he who showed me a simple and effective method of

drawing statistical conclusions for the confirmation of the stated problem.

I offer my special thanks to Dr. Mahesh Chandra, Assistant Professor,

Dept. of Zoology, P.C. Bagla College, Hathras who has specialities in

research programmes and works as the chief editor of several journals. It was

under the benefit of his abilities freely extendable to me that the present

research thesis got the current shape. He supported me by providing relevant

material and technique to bring finishing touch in my thesis.

I shall be failing in my duty if I do not extend my gratitude to Dr. Sarang

Savalekar [Ph.D. in Termite Management, Director Paramount Pest

Consultants Pvt. Ltd., Partner Pest Consultants, President of Pest

Management Association (India)] with whom I had frequent on-line

consultations about the progress of my research thesis. His constant support,

encouragement and kind faith in me always boosted me and kept me focus

towards the goal. It was the help of this gentleman with a big heart that I could

achieve high standard in the preparation of my thesis. Dr. Sarang Savalekar is

working in Termite Management and has high aptitude for research.

I am highly thankful to Dr. Vivek Kumar, University of Florida, who

provided me a number of relevant taxonomic images of thrips which I used

for the beautification of my thesis. I am also thankful to Dr. Antoon Loomans,

Netherlands who helped me in taxonomical identification and examination of

morphological biology of natural enemies selected for our research.

I must extend my gratitude to the journals `Bionotes', `Nature and

Environment', `Annals of Zoology' and `Annals of Natural Sciences' which

gave space to my research papers during the progress of the present

research work.

My thanks go to different libraries, like Maulana Azad Library, A.M.U.,

D.S. College Library, Aligarh, The British Council Library, Google Online

Library and Wiley Online Library wherefrom I picked up material relevant to

my research. I am also thankful to different websites freely available for

visiting and downloading. I owe a great deal to IARI, New Delhi and NBAIR,

Bangalore (Agricultural Institutes) which supplied to me natural enemies of

thrips for getting practical results of my thesis.

I am also thankful to different farmers of the localities mentioned in the

thesis, who gave permission to hold experiments in their fields. I am also

thankful to Mr. Ravi Mittal who with his extraordinary computer skills made the

ugly looking manuscript of the thesis into a beautiful volume as it looks now.

The last, but not the least, the support of my family should not go

unnoticed and uncared for. I am highly grateful to my father Dr. Hem Prakash,

Head, Dept. of English, D.S. College, Aligarh and my mother Smt. Abha

Varshney who helped me financially, morally and emotionally during the

progress of the research work. My younger brother Er. Akash and my

younger sister Ms. Shreya Varshney also deserve my thanks as they with all

naughty activities teased me time to time and again ignited my interest for the

research work in ironic comments.

(Manika Gupta)

Abstract

India is the heaven of agricultural products, its vast plains contain

alluvial soil with rich natural contents. Major economy of India is based on

agricultural products. Green revolution in India brought high hopes for Indian

farmers. Several new scientific information helped crop production to grow by

leaps and bounds. The more researches, the more intricacies. Further

knowledge of pests makes scientists think about several other solutions. Use

of chemicals was immediately adopted to curve the population of pests and

good results were also obtained. But later on, harmful effects of the pesticides

were also known. It was realized later on that the regular use of chemicals in

pesticides creates danger for human health. A kind of ecological disturbance

is caused unnecessarily. Over the next three decades, production of food

grains in India was increased at least 2 million tonnes in order to meet the

food demand of the growing population. Today, further prospects of raising

agricultural production in the manner as in the recent past appear to be

severally constrained. Land frontiers are becoming limited and opportunities

to bring additional land under cultivation are being bedimmed.

Over the last 10-15 years, S. dorsalis has rapidly become a major pest

of chilli pepper and Solanaceous plants. It has gained prominence in several

tropical regions of the world. Due to cryptic small size and thigmotactic

behaviour it is not easily detectable and harms caused, it continues to affect

chilli production and quality. S. dorsalis was known to infest a wide variety of

host plants. It causes damage by extracting the contents of the cells and

tissues of their host plant. This leads to necrosis of feeding in the forms of

scars, leaves distortion, distortion of buds, flowers and young fruits. In order to

maintain economic feasibility, it is necessary to find effective means of

biological control, so as to maintain the standards of commercialization. In this

study, it is suggested the biological approach is a cost-effective technology.

The magnitude of the net benefits of this technology would depend on the

type of input which is used in biological management package and its

applications. Biological management is akin to a new technology and

knowledge intensive. It requires method of perfect application before it is

transferred to the farmers. Our research study indicates, some alternatives to

check the growth of harmful pests for the crop of chilli. It is true that the

natural control through biological methods may not kill cent percent insects

harming the chilli plants. But, we have to attain that level which does not affect

the growth at economic level and also gives healthy production of the fruits of

chilli. We have to think about the final market quality of the crop in order to

make it economically viable. For this purpose, most effective management

has to be done to see the good results of biological methods through natural

enemies; predators and parasitoids in the Insect Pest Management.

Contents

Chapter-1

Introduction

1-47

1.1

Preamble

1.2

Statement of the Problem

1.3

Research Objectives

1.4

Scope of Research Work

1.5

Organization

1.6

Research Hypothesis

Chapter-2

Review of Literature

48-85

2.1

Historical Resume

Chapter-3

Research Methodology

86-100

3.1

Research Methodology for Survey and

Sampling

3.2

Collection of Natural Enemies from

Different Outfields

3.3

Rearing of Sampled Insects

3.4

Establishment of Research Laboratory

3.5

Laboratory Bioassays

3.6

Methods of Stock Collection

3.7

Taxonomic Research Study

3.8

Laboratory Processes

3.9

Research Methodology for Cultivation

of Chilli Plants

3.10

Biological Controlled Experiments of

Thrips Under Net House Conditions

Chapter-4

Experimental Analysis

101-236

4.1

Population Fluctuation

104

4.2

Sampling of Natural Enemies During

Year 2014-15

108

4.3

Biological Controlled Experiments

Under Net House Conditions

124

4.4

Results of Biological Controlled

Experiments During the Year 2014-15

and 2015-16

180

4.5

Statistical Analysis of Biological

Controlled Experiments

194

4.6

Discussion

212

4.7

Discussion of Biological Controlled

Experiments

217

Chapter-5

Observation

237-275

5.1

Thysanopterans on Chilli Crop in

District Aligarh of Western Uttar

Pradesh

238

5.2

Occurrence and Damage of Thrips on

Chilli Crop

241

5.3

Pest Investigation by the Monitoring

Observation on Chilli Crop

245

5.4

Weather Influences on Insects

248

5.5

Taxonomy of Scirtothrips dorsalis

249

5.6

Biology of Scirtothrips dorsalis

257

5.7

Life Cycle of S. dorsalis

258

5.8

Taxonomy and Biology of Natural

Enemies of Thrips

263

Chapter-6

Summary and Conclusion

276-325

6.1

Summary and Conclusion

277

6.2

Recommendation

307

6.3

Future Scope

311

6.4

Popularization : May Reach at Gross

Root Level Need

314

6.5

General Suggestions : Through Our

Entire Research

315

6.6

Limitations : Over Restrain the Growth

of Harmful Pests

319

6.7

The "Pros and Cons" of Biological

Control

322

Bibliography

326-343

Appendices

List of Figures, Charts, Tables and Graphs

Total No. of

Count

Figures

Charts

Tables

Graphs

______________________________________________

Chapter-1

Introduction

______________________________________________

1.1 Preamble

1.2 Statement of the Problem

1.3 Research

Objectives

1.4 Scope

Research

Work

1.5 Organization

1.6 Research

Hypothesis

______________________________________________

Chapter-1

Introduction

1.1 Preamble

Agriculture : Extensive Background

From decades, agriculture

has an extensive background. Its

association with needful food crops

is of vital significance. Agricultural

activity is famous for its farming

including forestry, marketing and

distribution of crops. All these are

acknowledged as a part

of current agriculture status. It will be better to explain the whole system as

the production and then distribution of the products among the people for its

proper utilization in human needs. In India, Agriculture is a vital activity. It will

be better to explain it as the backbone of our country. It also provides great

opportunities in the field of self employment and labour employment.

Agriculture : Known as Source of Livelihood

The word agriculture has its origin in Latin language. Its adaptation in

middle English gave its modern meaning. Two words "ager" and "culturo"

went into its making. From "ager" we mean "field" and from "culturo" we

understand cultivation which tends to mean "growing". At present it plays a

tremendous role in the human efforts to use natural resources for the

betterment of human life. It is the main source of livelihood of many people. It

contributes a lot in the production of commodities; including food, fiber, forest

and horticultural crops to maintain the quality of life.

Agricultural Contribution: To National Revenue

Agriculture contributes a lot in the economy of the most of the countries

of the world. India is prominent country based on agriculture.

It deserves the second rank worldwide on the basis of the farm input

and other life forms for food, bio-fuel, medicinal products etc. In India,

Figure 1.1 : Agriculture : Is the Backbone

| Chapter 1 | Introduction

agricultural production prepares the backbone of the country and place an

important role in its economy. Its share in the Gross Domestic Products

prepares the economic health of the country.

Figure 1.2 : Economic Health by GDP Share

Role of Agriculture

Agriculture has a broad range and acts as a main source for

sustenance of human life. The sector of agriculture also provides fodder for

domestic animals. Really, agriculture is the main source for several industries

also - cotton industry, jute fibre industry, tobacco industry and further edible

oils and non-edible industries, all use raw materials coming from agricultural

products in India.

Figure 1.3 : Agriculture : The Basis of Human Survival

Economic Importance of Agriculture

We may find out economic importance of agriculture in its value

towards fair and sustainable food products such as rice, wheat, potato,

| Chapter 1 | Introduction

tomato, onion, beans, cotton, maize, millets and pulses and also chilli pepper

which are present in the form of food grains. These basic and useful crops are

the basis of our healthy diet.

In the developing countries agriculture is the main source of livelihood

in rural areas. Today, the people of the world are conscious about eco-system

and healthy-environment endangered by pollution and other damages.

Agriculture provides a fruitful ground for the sustainability of healthy

environment. Still the field of agriculture plays a dominant role in the overall

economic, scenario and it is more a `way of life' than a `mode of business.'

Figure 1.4 : Agriculture : Source for sustenance of human life

It is worthwhile to remember the following words of a thinker, "When it

is understood that one losses joy and happiness in the attempt posses them,

the essence of natural farming will be realized. The ultimate goal of farming is

not the growing of crops, but the cultivation and perfection of human beings."

The Chilli: Life and Soul of Indian Dishes

Pepper, Chilli, Chile or Chilli belongs to the

family Solanaceae. It is being cultivated throughout the

country for thousands of years.

Figure 1.5 : The Chilli

| Chapter 1 | Introduction

Its use is still relevant despite many changes in the food habits of the

people. The genus Capsicum has direct link to a divergent group of plants

which are famous for its intense pungent taste. It is derived from the Greek

word i.e. Kapsima means `to bite'. In India, we have several varieties of chilli

with exclusive qualities of divergent breeds.

Taxonomic Position of Chilli

Kingdom

Plantae

Division

Magnoliophyta

Class

Magnoliopsida

Order

Solanales

Family

Solanaceae

Genus

Capsicum

Species

annuum

World Scenario of Chilli

As per the estimations based on different researchers, it is concluded

that the area of chilli production all over the world around 105 million hectare.

In the total area of chilli production about 7 million tonnes of chilli is produced

all over the world. The notable countries of chilli production are India,

Pakistan, Indonesia, Korea, Sri Lanka and Turkey. It is used as a potent spice

all over the world and in the total trade of spices in the world about 16% is

covered by chilli. Its expensive use in spices is making it an impatient item of

trade. Christopher Columbus, who discovered America in the last decade of

century was the first European to use chilli in the taste of food.

Figure 1.6 : World Scenario of Chilli

| Chapter 1 | Introduction

History Expansion

Chilli crop is not of Asian origin. It was brought to Asia in sixtenth

century when Spanish and Portugese adventures discovered Asian countries

like India and Indonesia. In 1498, chilli was brought to India by the Portuguese

explorer Vasco-de-Gama. Soon, chilli became an important ingredient in

Indian cuisine.

Economic Importance of Chilli with Potential Health Benefits

Chilli is an important agricultural crop. Its popularity among its

increasing number of users has made it a crop of economic importance.

Besides its nutritional value it is also used in medicines. Unripe fruits are

green in colour, but after the process of ripening, they attain the shade of red

colour. Green chillies are sometimes usefully applied for natural colours. They

are also used as antioxidant compounds. Wide range spectrum of vitamins (A,

C, B, E and P) is also found in this excellent crop. This crop is also rich with

group of compounds like castonoids, capsaicinoids and phenolic. It is

worthwhile to note that these compounds which are very essential for our

immune system are largely present in fruit of Capsicum.

From the morphological point of view the chilli plant has dark green or

purple leaves. It develops a natural crown of white colour and attains the

growth upto 1.5 meters. The fruits of chilli are utilized in various ways at

various stages. Fleshy pepper of large size is used and consumed as fresh

vegetable. Dry fruits of chilli are used directly as well as by turning them into

powder for the purpose of spices. Chilli is also liked for its aroma and sharp

acidic flavour. Really it has gained wide spread popularity due to its multiple

uses.

The pungency of Capsicum annuum is due to its active constituent

Capsaicin. It is recognized as a powerful stimulant with no narcotic effect.

Figure 1.7 : White Colour Flower

Figure 1.8 : Large Fleshy Pepper

| Chapter 1 | Introduction

It is worthwhile to remember the following words of a thinker:

"Chilli is one of the great peasant foods. Its contribution has made to

world cuisine. Eaten with corn bread, sweet onion, sour cream, it

contains all five of the elements deemed essential by the sages of the

orient, sweet, sour, salty, pungent and bitter.

Apart from traditional and culinary uses it can play a major role in

therapeutic and pharmacological actions. These actions create prominent role

as Immunity Booster.

Chilli : Acting as a Useful Agent

x They are recognized as useful agents for the benefit of human health.

x They serve as anticancer, anti-ulcer, analgesic, and anti-inflammatory,

anti epileptic and anti-haemorrhoidal agents.

x Further analysis of the ingredients of Capsicum shows that it is helpful

in the management of Burns, Psoriasis, Chronic Migraine, Heart

disorders and Diabetes.

x The nutrients like Ascorbic acid and Pro-vitamin A are also found in it.

Chemical Analysis of Chilli

Chilli is an all time vegetable. It makes an integral component all over

the world in preparing cuisines of better taste. However, in India and Mexico,

it is largely used as a spice as well as vegetable. In preparing its chemical

analysis it has been found that its dried pod yields of 100 gm contains 160

calories of energy in which we find Carbohydrates 36 gm, Protein 18 gm, Fat

16 gm, Iron 31mg, Niacin 2.5 mg, Vitamin A 640 I.U. and Vitamin C 40 mg.

Table 1.1

Nutritional Value of Chilli (Capsicum)

Value (Per 100 gms.) (Chillies)

Parameters

x Moisture

87.700 gm

x Protein

2.900 gm

x Fat

0.600 gm

x Minerals

1.000 gm

x Fibre

6.800 gm

x Carbohydrates

3.000 gm

x Energy

29.000 keg

x Calcium

30.000 mg

x Phosphorous

80.000 mg

x Iron

4,400 mg

| Chapter 1 | Introduction

Vitamins

Carotene

175.000

Thiamine

0.190 mg

Riboflavin

0.390 mg

Niacin

0.900 mg

Vitamin C

111.000 mg

Minerals & Trace Elements

, K

, Mg

, Cu

, Mn

, Mo

, Zn

Oxalic acid

Caloric Value

Chilli (Dry) : 297

Chilli (Green) : 229

Chilli is called as Wonder Spice

Chilli is considered as

commercial vegetable-cum-spice

crops. Different varieties of Chilli are

Capsicum annuum, Capsicum

frutescens, Capsicum chinense,

Capsicum baccatum and Capsicum

pubescens etc. They are cultivated for varied uses namely vegetables,

pickles, spices and condiments. So, it is popularly called `a wonder spice'.

We need it in our daily life and enjoy its taste from mild to tingling and even

explosively hot.

"Chilli is one of those marvellous simple, elemental, all important and

fundamental concepts that has been elaborated out of all recognition;

rather like justice, or objective reality.

Important Growing States of Chilli in India

Karnataka

Andhra Pradesh

Orissa

Rajasthan

Maharashtra

West Bengal

Tamil Nadu

Uttar Pradesh

Western Uttar Pradesh : Famous for Bountiful Resources

Our area of research is in Western Uttar Pradesh, which is famous for

its fertile soil, abundant water, and varied climate, cold wet and hot. In

Western Uttar Pradesh agriculture is known as vital source of `State Wealth'

as far as the production of chilli is concerned. It contributes 10% of the total

output of chilli in India.

Figure 1.9 : Chilli : `A Wonder Spice'

| Chapter 1 | Introduction

Our observation areas are the villages around the district Aligarh

namely, Tappal, Jalali, Kayamganj, Sumera and Talib Nagar. In these

areas chilli is grown at a large scale. These areas contribute a lot in the chilli

production of the western Uttar Pradesh. On the basis of the available data it

was found that the productivity level of this crop in these areas is very low. It

comes to 392 kg ha

-1

, which is very thin in comparison to the other parts of

India and still very poor on the touchstone of the international benchmark level

of 5000 kg ha

-1

. It further ignites our research to find out means to increase its

productivity level by saving its damage by thrips and other harmful pests.

Growth Production of Chilli

Chilli is widely cultivated throughout the warm temperate, tropical and

sub-tropical countries. Archaeologists believe that Capsicum was used as a

food as long as 9,000 years ago. It was first used as a decorative item and

later as food stuff and then was used in medicine. Chilli is known as a

`favourite item' in the use of cooking, curries, breads and appetizers. Although

India is one of the biggest producers of chilli but the productivity rates and

quality are not yet satisfactory. Whereas the beneath marks level of chilli is

set at 5000 kg ha

-1

in the international market. India is at 1500 kg ha

-1

level. In

order to compete in the international market effective measures are to be

taken to increase its productivity and quality level.

In India

In India, the production of chilli is popular in all its corners, but there are

several states which do not produce as much chilli as they consume. The

production of chilli is found at large scale in those states, where climate is

generally hot and dry. Its pungency level is better realized in such states of

tropical areas. It is further marked on the lines of the received data that during

2012-2013, India produced around 13 lakh tons of red chilli. Chilli production

for the 2014-15 crop years is estimated to be around 13 lakh tons as against

11.5 lakh ton produced during 2013-14. The total area of chilli cultivation

increased to 8.06 lakh hectare from 7.48 lakh hectare.

The Chilli Ecosystem: Prone to Heavy Infestation

Vegetables play a major role in the farming of chilli crops. But such

crops are heavily infected by pests during certain circumstances. Chilli is a

simple crop and even ordinary farmers with lesser technical know how can

| Chapter 1 | Introduction

cultivate and grow it. Cosmetic damage largely affects the chilli fruits, which is

directly proportional to yield loss. On the other hand, pests cause indirect

damage in the form of several deformities on twigs, leaves, buds, flowers and

affect the growth of the plant. High densities of pest's population cause an

immediate loss in quality in a short period of time. In the studies of Lewis

(1997) it has been found that the crop of chilli has been extensively damaged

by insects and pests.

Figure 1.10 : The Chilli Eco-System

Anyone engaged in agricultural, horticultural or medicinal entomology

needs to know something about the insects which commonly affect plants,

animals or humans. The effects may be beneficial or harmful. Beneficial

effects need to be improved upon whereas harmful insects need to be

controlled.

Chilli is an important commercial vegetable-cum spice crop. This crop

is known to harbour more than 50 insects and 2 mite pests. Scirtothrips

dorsalis is the major constraints for higher productivity of chilli and its yields.

These pests suck and attack the crop at seedling stage itself and continue till

first harvest, causing severe losses upto 34%.

| Chapter 1 | Introduction

Insect Pest Management

Regular

studies

environmental

concerns have revealed varieties of

insects and their behavioural patterns. It is on the basis of such studies that

certain methods are evolved to curb the growth of insects. Basic foundation of

insect-pest management is based on a detailed knowledge of the crop-

ecosystem. Both the harmful and beneficial aspects of insect impact are

recognized. Thus, entomologists have progressed in their knowledge of the

chilli agro ecosystem and the related interactions.

A better side of the knowledge is related to the relative value of the

beneficial insects and it is increasingly recognized.

Reduced Yield Quality By Insect and Pests

In the field of agricultural studies an insect is counted and classified as

pest on the basis of the damage it causes to the crop by reducing the yield to

the extent that it becomes a cause of worry to the farmers and growers of the

crop.

Figure 1.11 : The Pest : Thrips

Pest

The term `pest' is very subjective and varied accordingly to several

criteria. Of course, it is a living being in the ecosystem and its presence and

rapid breeding causes annoyance to crops in the way of its healthy growth. In

this way, from the agricultural view point an insect which does not cause

damage to crops as a whole is kept out from the list of pests animals. So

many insects belong to generally accepted pest species but the individual

| Chapter 1 | Introduction

populations are not always counted as pests and not recognized as economic

pests.

From among the numerous pests, we have to recognize certain pests

which cause substantial damage to the crop and on the basis of that damage

we would like to call them pest species and their value is placed upon these

consequences by human society.

The damage to the crop is first seen on the physiology of the plant

such as twisting of leaves, discolouring of leaves and tissue, breaking on

leaves and then it directly affects the quantity and quality of the fruits.

The Arthropod Complex: In Chilli Ecosystem

Large complex of Insects and their species is found in chilli

ecosystems. Wherever the crop is grown a few pests are of economic

significance. The large number of insects creates major pest fauna of chilli

including thrips, whiteflies, aphids, mites, caterpillars etc.

Figure 1.12 : The Arthropod Complex

| Chapter 1 | Introduction

Chart 1.1

Classification of Insects*

Insecta

Apterygota

Pterygota

¾ Thysanura

¾ Diplura

¾ Protura

Exopterygota Endopterygota

¾ Collembola

(hemimetabola)

(holometabola)

¾ Ephemeroptera

¾ Odonata

¾ Placoptera

¾ Gryllabattodea

¾ Orthoptera

¾ Phasmida

¾ Dermaptera

¾ Embioptera

¾ Dictyoptera

¾ Isoptera

¾ Zoraptera

¾ Pscoptera

¾ Mallophaga

¾ Siphunculata

¾ Hemiptera

¾ Thysanoptera*

¾ Neuroptera

¾ Mecoptera

¾ Lepidoptera

¾ Trichoptera

¾ Diptera

¾ Siphanoptera

¾ Hymenoptera

¾ Coleoptera

¾ Strepsiptera

O R D E

| Chapter 1 | Introduction

Thysanoptera: Recorded as opportunistic

species

Homogenous group of insects have been

recorded as the opportunistic species, they are

famous for their characteristic wings having long

fringe with less nervature. Thysanopteran adults

are only a few mm long and they readily fly and

easily migrate into and around the protected

crops under green houses. Thysanopterans have peculiar piercing and

sucking types mouth parts with vestigial right mandiable, protursible bladder

like structure at the apex of tarsal of leg.

till

now

the two suborders `Tubulifera' and `Terebrantia' have been

recorded under which more than 5,000 species and 8 families have been

found. The families are:

x Merothripidae

x Aeolothripidae

x Heterothripidae

x Adiheterothripidae

x Thripidae

x Uzelothripidae

x Fauriellidae

x Phlaeothripidae

Thrips : Fall in order Thysanoptera

Minute insects i.e. Thrips fall in the order Thysanoptera and Family

Thripidae. They show exploiting behaviour intermittently. Thrips plays an

active role as a pest of several crops and causes substantial damage.

Thripidae family is found throughout the world and comprise more than 200

genera.

Origin and Distribution of Thrips pest

The word `Thrips' has been derived from a Greek word which means

`Woodworm'. Thrips also refers to "Fringed Wing Insects, Bladder footed

insects, Storm flies, Thunder flies, Thunder blights and Corn lice." Due to

fringed nature of wings, they come in the order Thysanoptera.

Figure 1.13 :

Thysanopteran Thrips Adult

| Chapter 1 | Introduction

Thrips have their primary and independent status. Systematic studies on

these groups have been extensive.

Biological Diversity

Large number of thrips species is considered as pests, and affects the

plants in commercial value. They are widely distributed. They are most

abundant in the tropics. Near about 8,000 species have been recorded all

over the world. About 5,000 species have been studied with perfect details

about their life history and natural habits. They spread in far and distant

regions with the movement of the wind currents. Some species have also

been reported upto the snow limit of the Himalayas. Under favourable

conditions, many species have capability to multiply fast and their increasing

population becomes the cause of irritations to the human world.

Chilli Thrips :Scirtothrips dorsalis

Scientific Name

Scirtothrips dorsalis

Year

1919

Comman Name

Chilli Thrips

Other Scientific Names

x Anaphothrips andreae

x Heliothrips minutissimus

x Neophysopus fragariae

Distribution: S. dorsalis is distributed in all those countries of Asia

where chilli is grown. Countries like Indonesia, Bangladesh, Pakistan, Japan,

Korea, China, Sri Lanka, Taiwan, Thailand and Philippines, all are affected by

the infestation of S. dorsalis.

Origin: There are divergent views about the origin of chilli. One thing is

certain that it became popular in Asian countries only after the Spanish and

Portugese adventurers came here in 16

century. According to current

studies, it is believed that the origin of chilli may be traced in Indonesia much

before it became popular after the adventurers of Spanish and Portugese

explorers. So, it is concluded that the chilli plant was present in Indonesia but

its utility was not recognized in the past as much as it was recognized in the

century by the western explorers who encouraged its large scale

production for the betterment of cuisine taste. South Asian countries became

| Chapter 1 | Introduction

the largest producers due to favourable climate to this crop. Moreover, the

better effect of its pungency is brought about by the prevailing climate

conditions in South Asia. Then it became popular in Africa and other

continents.

In this manner, S. dorsalis, the pest infecting the chilli plant is not

known to be sure from which source it originated. It is found in several other

crops also. On the basis of polyphagy nature they act as pestilent. From the

view point of agriculture there are several hosts on which they grow as

pestilent. Thrips exploit host plants and thus they become thicker and thicker

and consequently change the landscape of agricultural fauna. Throughout the

contiguous region of South Eastern Asia, chilli thrips has spread rapidly.

Its Hosts: There are uncertainities about the original host of

S. dorsalis. In India, this species is found in plants of castor, pepper, cotton,

tea and even in mango and peanuts. This pest is found in the new world also

and has been traced in more than 100 plants of about forty families. The main

wild host plants in which S. dorsalis is found belonging to Solanaceae and

Fabaceae family. Pepper also comes within their ranges. Under the pressures

of trade and globalization, thrips continued expanding through their range.

Host Damage

Thrips become serious pests as they cause wide spread damage to the

host plant. Their immediate effect is seen as cosmetic infestation on the

leaves. They feed on plant tissues by their mouth parts and its result is seen

in the form of tissue scarification and depletion of host plant. Thrips prefers

young plant tissue. They damage the host plant by their direct feeding on

leaves and then on flowers and fruits. They also cause damage by

transmitting viruses which aggravate contamination of the products. Thrips

are phytophagous, or sometimes they show the characteristics of omnivorous

herbivores. They frequently encounter an array of possible host plants and

additionally, they prefer their oviposition of eggs on them.

| Chapter 1 | Introduction

Feeding Injury

Chilli

thrips,

S. dorsalis does not feed on mature host tissues; it feeds

on young fruit calyx and leaves. Thrips feeding on delicate plant organs can

create silvery scarring on leaves. This early damage to plant growth can lead

to malformation of the fruits. It is the result of feeding injury caused by

S. dorsalis on the host plant that the photosynthetic activity is also affected

and the final result is significant yield loss.

Figure 1.14 : Deformities on Chilli Leaves

The infestation usually starts from seedling stage, although the severe

infestation appears in the stage of vegetation. Thrips possess piercing and

sucking mouthparts by which, they feeds and cause damage. They suck the

epidermal cells of the host plant and cause necrosis and distortion of leaves,

buds, flowers and fruits. In this manner tender leaves and buds become

brittle.

Thrips are not very impressive due to its morphological nature in

contrast to our better known insects. Thrips are found averaging in size at 1-2

mm. Vast majorities of thrips species are plant feeders.

Figure 1.15 : Thrips

1-2mm in s

ize

| Chapter 1 | Introduction

Life History : A Simple Process

Most of the thrips attacking their host plants have a simple life history.

Thrips grow at six stages, which may be enumerated like this - first step is

egg. Second and third stages are larval which are non-feeding. The forth

stage is prepupal. The fifth is pupate stage and the sixth and the final stage is

adult through the phenomenon of metamorphosis. Under favourable

environment the young attain full growth in 7-10 days.

Thrips are known as weak fliers. They do not travel long distances. But

they are spread at long distances by air currents. Thrips population is mostly

hidden in the ventral surface of the leaf. Nymphs as well as adults suck the

cell sap mostly from the ventral surface of the leaf. As a result, the infested

leaf loses its vitality and becomes curled or twisted.

The growing importance of chilli thrips compels the academic world to

carry more and more researches in this field so that the major problems

posed by thrips may be countered and effective solutions may be traced.

Thrips infested host plant which almost failed to produce any fruits or

produced very minimum number of deformed fruits.

Figure 1.16 : Developmental Stages of Thrips

It is also seen that in the protected crops most of the adults are

females. Males are rarely found to have full growth. Actually, males are not

needed for fertilization. Thrips are gregarious in nature and the large numbers

often concentrated on the same leaf or flower.

| Chapter 1 | Introduction

Economic Importance

Thrips are opportunist species for many scientists, agriculturists and

entomologists, exploring intermittently and occurring in environment. These

are mostly phytophagous and distributed universally in most ornamental crops

and native plants. Phytophagous thrips mostly feed on the tender leaves and

feeding areas are not restricted to leaves alone but may also extend to almost

all parts of their hosts. They readily fly and can easily migrate into and around

the greenhouses. Therefore, it is very difficult to control the population growth

of thrips. The host range of thrips is not limited to certain few. It has its habitat

in variety of host plants.

The population of thrips grows rapidly during the warmer parts of the

year. In this manner, several generations of thrips overlap during the growing

season. The population of thrips does not grow in the rainy season or during

chilly winters with less than 4

C temperature. Warm and dry season is the

appropriate season for abundant infestation of thrips.

General Introduction of Chilli Thrips

Adult thrips

: 0.5 1.2mm long

Definitive Identification

: ~40-80 x magnification

Eggs

: Microscopic, generally eggs are about

0.070 mm wide and a few may be found

0.075 mm long. It is in about six to eight

days that the 9 eggs of the thrips develop.

Thereafter these eggs grow into two larval

stages which are technically called I and II

instars. The larval stage remains for six/

seven days.

Prepupal Period

: Short time period approximately Twenty

four hours

Pupalperiod

: 2-3 days

General Appearance The

Larvae

: Offwhite in colour

| Chapter 1 | Introduction

The Adults

: The adult thrips develop into yellow and

grayish colours when they are seen

through microscope. Sometimes sketchy

stripes are also seen on the dorsal surface

adjacent to the meeting point of abdominal

segments.

Life Cycle

: Thrips shows a rapid life-cycle. The total

life cycle of thrips is about 20 days and

sometimes even lesser.

Duration

: We find their rapid growth as one female

oviposits more than hundred eggs at the

rate of 3/4 eggs per day.

The Nymphs

: (a) It takes two to seven days in the

hatching of the nymphs at the stage of the

first two instars. They carry on through

pseudopodal stages. We can call them

prepupa and pupa stages.

(b) These developments take place on

leaves or flowers as the infestation of

thrips continues in the crop.

Characteristic Feature

: The plant of chilli, above the ground is

attacked by the infestation of thrips and

damage occurs.

Metamorphosis

: Thrips show a simple metamorphosis.

They do not actually pupate but the pupate

stages are known as pseudopodal stages

because they are akin to pupal stage. Of

course, it results through the process of

simple metamorphosis.

Risk of Chemical Pesticides

Generally chemical pesticides are used to curb the harmful effects of

insects and pests. But, the immediate gain in this process has adverse effect

| Chapter 1 | Introduction

on the environment in the long run. Regular use of chemicals leads to

insecticide resistance. Then, biodiversity is distributed by pest resurgence and

pesticide residues. So the immediate gain of one genration become serious

problems for the next generation, hence risk for the future.

Figure 1.17 : Agricultural practices heavily based on chemical pesticides

Pest

Resurgence:

Resurgence is the term which is applied in the

matter of sudden increase in the number of pest population. It occurs when

pests become habitual of resisting the pesticides. There is gradual decline in

the treatment effect and at the later stage, rapid recovery of pests comes to

the fore after initial suppression of them by chemicals.

Use of chemicals leads to several other problems in human life. It leads

to residual toxicity in fruits and vegetables and pollution of water in the long

run. It also causes harm to the predators and parasitoids which are beneficial

to the crop in the scheme of nature. When these natural enemies of the pests

are eliminated with the use of chemicals, there is always danger to the crop

as the next problem of the outbreak of secondary pests also stares in our

face.

On the basis of the scientific study of the applied chemicals, it is

understood that the pesticides have in them toxic heavy metals, which are

harmful in the long run. It is true that these chemicals have immediate effect

of killing on the pests. But at the same time these chemicals also kill the

natural enemies of these pests. Repeated use of chemical pesticides can

benefit farmers in the pest control, but in the long run they become more

harmful than even the original pests. The scheme of nature is disturbed. The

gradual process of pest control with the natural enemies is checked and the

| Chapter 1 | Introduction

rhythm of biodiversity is broken. Having looked at the immediate gains in the

crop, the farmers are tempted to have the repeated use of them and this

widespread use of chemicals creates adverse effects on the environment and

consequently upon human health.

It was in 1960's that Rachel Carson published "Silent Spring" and tried

to awaken humanity against the perils the pesticides might bring to the human

world. She warned against indiscriminate use of chemicals in pest control.

Now, it is realized that the continuous use of pesticides leads to altering the

genetic make up of pests also and they become pesticide resistant in the long

run.

It is the cause of worry that the use of pesticides in India is increasing

at fast rate. It is estimated that every year there is increase of 2.5% annually

from 1970 till today. Of the 96000 tonnes of pesticides produced in the

country, about two thirds are used in the field of agriculture.

So, the continuous use of these pesticides in various regions of India

adversely affects the plants and animal species.

Lack of Government Seriousness

Regular studies against the use of pesticides have created concern at

the government levels also Central Government of India was forced to ban a

number of pesticides in the field of agriculture as the harmful effects of the

pesticides on human health were brought to light. But these attempts of the

government remained mostly on paper. Despite the law of ban in their use,

many of these pesticides are available in the market and the farmers who are

tempted to use them for immediate gains can easily get them for use in

agricultural crops. There is not strict enforcement of law of ban. These

loopholes in the system of governance are having demonic face to annihillate

the wide propensities of human health.

The government agencies are not very serious in regulating the use of

pesticides. The people in the government do not pay much attention towards

what is happening at the lower level where the sellers and dealers of

pesticides attract the farmers far beyond the limit in the use of pesticides for

immediate gains. Whatever feeble law is available for its restriction is not

implemented forcefully due to corruption among the authorities. The dealers

and sellers of pesticides can easily get freedom of keeping and selling even

| Chapter 1 | Introduction

the banned pesticides. There is hardly any system of guiding the local farmers

who are the actual growers and producers of the crops. The ignorant farmers

very easily come under attraction of immediate gains when they are told about

the large scale benefit of a particular pesticide generally possessed for sale

and as canvassed by the local dealers. Further, there is no enforceable law of

registration and regulations for the sale of pesticides. Every "TOM, DICK AND

HARRY" having a fancy of opening sale shop of pesticides and agro products

can easily begin his trade and can supply harmful pests in the farmer's active

world.

Biological Control Measures: A Wide Spreading Encouraging

Programme

If we study the history of pest control, we find that chemical insecticides

began to be used in 1940's. These pesticides were prepared on synthetic

basis and were relatively easy in use. For a very long duration these

chemicals were considered safe and effective means of pest management.

But, later on ill effects of these pesticides were realized. There were hazards

to the applicator as well as to those people who inhaled their wasps in the

process of spraying. Further, it was also realized that these pesticides also

produced a few ill features in the soil and water and finally affected the wild

life as a whole.

The organic standards are also brought down by synthetic chemicals. If

one kind of pest is restrained by chemicals, the other kinds of pests having

resistance to these synthetic chemicals began to develop. In these hazardous

situations many farmers and gardeners began to explore those methods

which could reduce the ill effects of the pesticides.

Biological control of pesticides is a safe alternative. This method may

replace pesticides and can bring good results both ways at economic

threshold and on environmental issues. It is a safe method in which a living

organism is used against another living organism in the scheme of nature

where killing is the means of survival. In the biological control it is discovered

which the natural enemies of the harmful pests are. In this manner, the natural

enemies of thrips reduce the population of these pests in natural manner and

save the crop from harmful effects. It is most successful management

| Chapter 1 | Introduction

approach. In the simplest definition as given by International Biological

Programme, biological control is "using biota to reduce biota."

Biological

control

thus

beneficial

in both ways. It helps the farmers

and does not injure environment. It is, of course, cost effective as well as

environmentally safest.

Pest : It is a kind of organism which grows a living being and its

multiple growth causes damage to plant.

Biological control is a method in which one living organism, which is

harmful to the crop, is made food by another living organism. It is the

adherence to the scheme of nature that the harmful organisms are kept a low

levels, of course at Economic Threshold Level.

Economic Threshold

Economic threshold is related to the economic value of the crop, of

course, a beneficial ratio between the cost of production and the cost gained

in yield. It may be defined as the level of control of the pests at economically

viable cost to reduce the pest population so as to save economic injury to

the crop.

Biological control is now gaining prominance among agricultural

scientists and it is now an interesting area of entomological research. It is the

safest method in both natural and man made things. It also saves eco-system

from further injury. The net result of natural biological control is based on the

presumption that the earth is green and plants can produce biomass enough

to sustain other forms of life.

It is from the time immemorial, say some 500 million years that

evolution of the eco-system is maintained by reducing the pest population in a

natural way in the scheme of nature without any intervention of others in

artificial way. Human knowledge of this naturally controlled eco-system led to

the application of certain natural agents to control the harmful organism. On

the basis of this knowledge anthropod biological control was used by using

predatory ants about 300 years ago.

Having been fatigued by the synthetic chemicals in the pest

management, recent pest management is further looking with hopes on

biological control. It is recognized as the most sustainable method in the

modern times. It is cheapest as well as safest. It is expected that biological

control methods will attract about 40% agricultural area by 2050.

| Chapter 1 | Introduction

For the success of biological control a fair and accurate knowledge of

the pest behaviour and the behaviour of their natural enemies is essential. It is

on the basis of accurate knowledge of the different organisms related to the

crop and the environment that the biological control can be made

economically viable and with negligible risk to the eco system.

Biological control is a sub-discipline of applied ecology. To adequately

practice it, one should have a firm understanding of population and

behavioural ecology. Without any systematic and proper identification of

insect pests, and their associations of natural enemies, biological control as a

science would fail to function.

There are three basic approaches of biological control strategies :

(i) Importation; sometimes called Classical Biological Control;

(ii) Augmentation; (iii) Conservation.

x Finding new useful natural enemies

x Releasing additional natural enemies when those naturally present are

not in adequate quantity.

x Enhancing the effectiveness of beneficial organisms of protecting them

from harmful effects and providing them with necessary habitat and

other resources

So, biological control of arthropods can be defined as, "The study and

uses of Parasites, Predators and Pathogens for the regulation of host (pest)

densities."

Importation Biological Approach

It involves the introduction of a pest's natural enemies to a new locality,

where they do not occur naturally. Release of natural enemies and these can

permanently establish in new areas for an effective control measures.

This is usually done by government authorities. Importation or classical

biological control usually targets introduced (non-native) pests, most of which

arrive here without the natural enemies.

Native pests which are not adequately controlled by existing natural

enemies may also be the target of this classical approach.

"Classical Biological control is the process of finding natural

enemies of invasive pest and importing and establishing these

natural enemies to control the pest-reuniting old enemies."

| Chapter 1 | Introduction

Augmentative Approach

Augmentation involves the

supplemental release of natural enemies.

This approach is boosting the naturally,

occurring population of natural enemies.

Augmentation of Natural Enemies

typically involves the purchase and release

of natural enemies that are already present

in India but may not be numerous enough

to adequately control pests in a particular location. The goal of augmentative

biological control is to temporarily increase the number of natural enemies,

and, hence the level of biological control for the target pest.

In this approach, a few natural enemies may be released at a critical

time of the season. It is called as inoculative release. Sometimes millions may

be released and it is called as inundative release.

Conservative Biological Control

The conservation of existing natural enemies in an environment is the

third method of biological pest control. This control refers to the use of

indigenous predators and parasitoids, usually against native pests. Natural

enemies are already adopted to the habitat and to the target pest. Their

conservation can be simple and cost effective. Various measures are

implemented to enhance the abundance of the natural enemies and their

activities. This includes the manipulation of the crop microclimate, creation of

overwintering refuges, increasing the availability of alternative hosts and prey,

and providing essential food resources such as flowers for adult parasitoids.

Natural Enemies: Known for their Enormous Value

The Predators, Parasites and Pathogens of pests that are used in

biological control management are a large component of world's biodiversity.

These natural enemies are of enormous value to the sustainable agriculture,

where they can often eliminate the need for pesticide input. Natural enemies

introduced to the environment are capable of sustaining themselves and they

are also known for their self-perpetuating behaviour and thus they continue to

reduce the pest population. Biological control is a particular method of

Figure 1.18 : Augmentative

Release of Natural Enemies

| Chapter 1 | Introduction

exploiting nature against nature and to get desired effect through beneficial

organism i.e. natural enemies.

Figure 1.19 : The Natural Enemies of Pest's

Predators and Parasitoids: As a Miracle

Biological control is an applied field of natural phenomenon, the

strategy of bringing natural agents to feed upon the damage causing pests

and thus to reduce damage to tolerable levels. This term may be used to

denote one of the major ecological sources of nature.

Practically, all living species are attacked by natural enemies

parasites, predators or pathogens which feed on them in one way or the

other. Indeed, many potentially injurious pests are kept at very low levels and

never reach economic pest proportions due to the effective action of naturally

occurring natural enemies without deliberate intervention by man.

Figure 1.20 : A Predator

Figure 1.21 : A Parasitoid

| Chapter 1 | Introduction

All plant and animal species are the objects of attack by some or other

natural agents for their natural habits of attaining food for the perpetuation of

their lives. The impact of these natural enemies ranges from a temporary or

minor effect to the death of the host or prey. Predators and parasites are

animals that feed on other animals. They show the entomopathogenic nature.

Effective biological control may be achieved through their utilization. The term

predation is composed of a broad base of animal

o plant (herbivore)

predation supporting the complex web of animal

o animal (carnivore)

predation. The terms predator and parasite have had a long history of usage.

Predators

"A predator is a free-living organism throughout its life. It preys upon

other organisms for its food." In the broad sense predation is one of the major

ways of life in the animal kingdom. Many ecologists have studied on animal-

prey relationships for many years. Predation is common among insects and

many of our successful cases of biological control have been through

predators. Many species show predation habit on both immatures and adults,

but some as certain species are predaceous and feed on larvae.

Predators require food to complete their life cycle and for this purpose

they attack their preys and devour thrips. They are basically chewers or

suckers. Some insect orders are almost exlcusively predators. Predators

share the following distinguished features :

1. They are usually larger than prey.

2. They feed on a wide range of animals and mostly they are not host

specific.

3. Death to the victim is caused immediately after capture.

4. Adults or young may be predatory.

5. They are known for their activeness in capturing and eating their pest

and other predators.

Parasitoids

Insect parasitoids have immature life stages and they develop by

feeding on a single host and devour the host for their survival. Adult

parasitoids have their independent nature and free living. On the basis of their

behaviour and nature of feeding and living they may also be called parasites.

| Chapter 1 | Introduction

A particular life stage of a species is attacked by parasitoids in their exercise

of getting food for their survival. Parasitism may occur at any trophic level of a

food chain. These are organisms which lay eggs in or on the bodies of their

hosts and complete their life cycle on host bodies as a result of which hosts

die. They show their major characteristics as follows:

x They have special choice in choosing their hosts to feed on.

x They are keen in killing their host which are bigger in size.

x Females are more active and make search for the host.

x After the search of the host the females lay their eggs near it so that

food for the larvae may be available at their growth.

x Adults have free living whereas the immature ones remain near the

host.

Amblyseius cucumeris or Neoseilus cucumeris

Commonly called

: Predatory Mites

Distribution

: Cosmopolitan and distributed through North

America, Europe, Australia, New Zealand

Common Hosts

: Among the common hosts, we may trace

Aphids, small caterpillars, thrips, psyllids,

mites, leafhopper nymphs etc.

Common Habitats

: They live and find growth in pastures, field

margins, and habitats with herbaceious and

shrubby flowering plants.

Size

Nymphs

: 0.5 2mm

Adults

: 1-2mm, (i) pear shaped and tan coloured, (ii)

Eggs are generally round in character and

visually transparent. The size of an egg is

about 0.14 cm.

Note: Females of N. cucumeris are

undistinguishable from other species. The

two species can only be separated by adult

males. The eggs laid by this species can

tolerate low humidity and develop rapidly.

| Chapter 1 | Introduction

Metamorphosis

: Both the nymphs and adults are predatory

and develop through metamorphosis.

Generations per year

: 2-3

Characteristics

x A. cucumeris is a predator and it feeds on

small arthropod preys. For their survival

this species consumes two to ten thrips

per day. Within their life span of 30 days,

one consumes more than hundred thrips.

x Suppose thrips population reduces, then

they continue to feed on pollen and spider

mites.

x At the time of application of predators ratio

of 1:2 must be kept between the attacker

and prey.

x Neoseiulus moves freely at long distances

and feeds on young thrips.

Monitoring

x 10-15x hand lens must be applied for

inspection.

x Mostly they are found on the underside of

leaves along their veins. They are

sometimes seen inside the petals of

flowers.

x It is a biocontrol agent widely used for the

elimination of thrips, not of one species,

but of several species in greenhouses

through preventive, mass releases.

Macrotracheiliella nigra (Minute Pirate Bug)

Family

: Anthocoridae

Distribution

: The anthocoridae family, popularly known for

causing more damage has minute pirate

bugs which are also called flower bugs.

There are many species and more than 500

are known worldwide.

| Chapter 1 | Introduction

Habit and Habitat

: They are cryptic in nature and keep their

habitats in galls. They are also seen in the

open surface in the environment proper for

their growth.

Feeding Habit

x They feed on the plant material.

x Frequently they feed on chitnised

arthropod.

x Minute pirate bugs are feed on insect

eggs and smaller thrips and these

predators are beneficial to our purpose.

x These predators are beneficial as

biological control agents.

x They enter a reproductive diapause in late

fall.

Common Hosts

x Feeds on the eggs of the corn earthworm,

mites and thrips.

x Anthocorids are often predacious.

Size

: Anthocorids are 1.5 5mm long.

Morphological Features

x They are oval in shape and their flat

bodies are often patterned in black and

white.

x They are soft and elongated.

x Their forehead is extended forward.

x Their antennae are longer than the head

and they can be properly viewed.

x Their mouth is designed in such a manner

that they can easily suck by piercing their

mouth part. They have digestive enzymes

to consume the available food.

Ceranisus menes and Thripobius semiluteus

Family

: Eulophidae

Distribution

: Cosmopolitan

In about 300 generate, more than 4300

species are described.

| Chapter 1 | Introduction

Feeding Habit

x Generally larvae does not feed but in a

few species it is also found feeding on

plants.

x It attacks on second instar larva.

x It attacks those thrips which are generally

yellow and whitish in colour. It turns black

and swells around head after sucking and

when the parasite wasp matures.

Diagnostic Features

x Gaster at base is yellow or light brown.

x C. menes females of this species may

have either a yellow or partly brown

metasoma and shows coloration.

x C. menes can record for at least 20

generations on thrips species.

x T. semiluteus can decline thrips

population about 60% of larvae.

x Having been shipped in the pupal stage,

the wasps should be held at 65

-75

attain to adult stage.

x Highly mobile adults may be found

moving hither and thither in the net house

in search of their preys, the thrips.

x Monitoring of the wasp growth and their

reproduction must be done with keen

observation on immature thrips.

x Eulophids are separable from most other

chalcidoidea by the possession of only

four tarsomeres. On each leg a small,

straight protibial spur, and by antennae

with two to four funicle segments.

Development

x In about three weeks, the development

takes place from egg to adult, if the

temperature and environment is

favourable to their growth.

| Chapter 1 | Introduction

Details

Pages
Type of Edition: Erstausgabe
Year: 2017
ISBN (PDF): 9783960676898
ISBN (Softcover): 9783960671893
File size: 25.4 MB
Language: English
Publication date: 2017 (September)
Keywords: biological control natural enemies augmentation sustainable agriculture Parasitoid tritrophic Biodiversity Chilli thrips Agriculture in India Green revolution Entomology

Author

Manika Gupta (Author)

Biological Pathways to Improve Pest Control in Agriculture

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Author

Manika Gupta (Author)