Summary
The influence of insects on human life – destructive and beneficial – can be traced back to prehistoric days until now. Agricultural entomology concerns itself with the study of insects associated with various aspects of agriculture. It deals with the study of both beneficial and detrimental insects. Insects that are detrimental to agriculture are commonly known as insect pests. The bulk of agricultural entomology deals with the control of those. Insect pest control is now conducted through integrated pest management (IPM) principles that aim to be sustainable in the use of resources and environmentally friendly. IPM requires plenty of experience and knowledge and combines all available methods of control. Prevention is also an important component of IPM programs.
In India, agriculture is the main occupation of the majority of people. The most important natural enemies of agricultural crops are insects, plant diseases, weeds and weather conditions. Out of this, insects are the greatest competitors of man in the struggle for existence. In the present topic the various kinds of pest will be studied in broad sense/view.
In India, agriculture is the main occupation of the majority of people. The most important natural enemies of agricultural crops are insects, plant diseases, weeds and weather conditions. Out of this, insects are the greatest competitors of man in the struggle for existence. In the present topic the various kinds of pest will be studied in broad sense/view.
Excerpt
Table Of Contents
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knocking down insect pests with high water pressure), and chemical control, giving preference to
products that are less harmful to humans and the environment. In IPM, control begins by
knowing the insects that affect the agricultural crops. The first step in insect control is the correct
identification of the insect, making taxonomy an important part of any pest control strategy. It is
very important to study also the biology of the insect pest, since control may be more efficient at
certain times of the insect life cycle; for example, in scale insects, chemical control is generally
more effective when the insects are in their first instar (or first growth stage), just after hatching
from the egg, because they are more vulnerable as they are smaller and have not developed a
protective scale cover at this time. Once they grow older, scale insects produce a waxy cover that
makes them less susceptible to pesticides.
In IPM, control measures should be undertaken only when necessary. This can be achieved by
closely monitoring the insect populations in the field, through visual observation of crops or by
the use of monitoring traps, etc. Once the relationship between damage and pest population
densities are established, an economic threshold can be defined, where control measures should
be started so that the potential pest population will not exceed the economic injury level. An
insect should be considered a pest only when its damage exceeds the economic injury level;
before that point it is a just a potential pest. There are many insects in the field, but not all insects
require control as most do not cause harm and some are beneficial. Prevention is an important
component of IPM programs, because by preventing potential pests there is no need of control at
all. Cultural control methods such as crop rotation, the use of pest-resistant varieties, or using
pest-free plantings, are some common methods of prevention. At a larger scale, prevention can be
done also at points of entry, for example, quarantine inspections at airports and ports prevent the
entrance of exotic pests to a country. The study of agricultural entomology involves all the basic
principles of agronomy, insect ecology, life history and behavior, insect taxonomy, insect
physiology, toxicology and other fields of general and applied entomology.
In India, agriculture is the main occupation of the majority of people. The major cash crops are
sugarcane, cotton, citrus, groundnut, tobacco, potato etc. Apart from these coffee, tea, cashew nut,
mango, grapes, oranges, various kinds of vegetables and flowers etc. Besides this major crops are
sorghum, wheat, rice, maize, millets and many legumes are also cultivated on large scale as they
have increasing market value but the most important natural enemies of agricultural crops are
insects, plant diseases, weeds and weather conditions. Out of this insects are most successful
group of animals even in the adverse climatic conditions therefore, they are greatest competitors
of man in the struggle for existence. The insects which cause damage to crop plants are called as
Agricultural Pest. In the present topic we will study the various kinds of pest in broad sense/view.
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I. GENERAL CONCEPT DEFINITION AND TYPES OF PEST
(A) PEST Derived from French word `Peste' and Latin term `Pestis' meaning plague or
contagious disease.
- Pest is any animal which is noxious, destructive or troublesome to man or his interests.
- A pest is any organism which occurs in large numbers and conflict with man's welfare,
convenience and profit.
- A pest is an organism which harms man or his property significantly or is likely to do so
(Woods, 1976).
- Insects are pests when they are sufficiently numerous to cause economic damage (Debacli,
1964).
- Pests are organisms which impose burdens on human population by causing
(i) Injury to crop plants, forests and ornamentals.
(ii) Annoyance, injury and death to humans and domesticated animals.
(iii) Destruction or value depreciation of stored products.
- Pests include insects, nematodes, mites, snails, slugs, etc. and vertebrates like rats, birds,
etc.
- Depending upon the importance, pests may be agricultural forest, household, medical,
aesthetic and veterinary pests.
(B) CONCEPT OF PEST
Pest can be defined as any organism (animal or plant) whose population increases to such an
extent as to cause economic losses to crops or a nuisance and health hazard to man and his
livestock or possessions will be declared as a pest. The attack of pest to the agricultural crops
cause economic loss to farmer. According to Edwards and Heath (1964) the pest is said to be
"Economic Pest" if any pest causes at least 5% or more loss to the crops. The amount of
damage caused to a crop is called as "Economic damage". The lowest pest population
density which causes damage is called as "Economic Injury Level". This varies from crop to
crop, area to area and season to season. For calculating the Economic Injury Level (EIL)
includes four parameters:
(i) Cost of control
(ii) The market value of the crop
(iii) The yield loss attributable to a unit number of insects.
(iv) The effectiveness of the control.
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Stern et. al. (1959) called the density of pest population at which control measures should be
started to prevent increase in pest population from reaching the economic injury level is
called as `Economic Threshold'.
(C) TYPES OF PESTS
Insect pest are capable of feeding an almost all types of organic matter. The insects can cause
damage to crop plants in the field, fruit plants, stored food and even the property. The pests
can cause even health problems to man and his animals. Based on the host which they affect
the pests are classified as following
1. Agricultural Crop Pests
Each and every agricultural crops are infested by number of pests that cause severe damage.
Pest constitute a large number of insects attacking the various crop plants. The immature
stages or adults insects are either foliage feeders or saps suckers. These insects bears chewing
and sucking type of mouth parts. They may be internal feeders or borers or sub-terranean
inhabitants. The important crops like jowar, bajara, wheat, cotton, sugarcane, etc. are attacked
by pests like stem borer, shoot fly, Deccan wingless grasshopper, armyworms, flea beetles,
aphids, leafhoppers mites, jowar midge fly, etc. The cabbage worms, semi-loopers, potato
beetles, etc., possess chewing type mouth parts. They chew and shallow the external parts of
the plants. While some insects i.e. blister beetle feed on pollens, petals of bajara etc. thus
causing severe damage.
Sugarcane is an important cash crop cultivated widely in Maharashtra. This single crop is
infested by sugarcane stem borer, shoot borer moth, root borer, pyrilla, mealy bug, scale
insects etc. The cutworms, leafhoppers, potato tuber moth, epilachna beetles, mites, aphids
and thrips cause injuries to potato crop and vegetables in field as well as in the storage. The
cabbage leaf miner and cabbage caterpillars spoil the cabbage crop seriously. The Rhinoceros
beetle, mango stem borer, brinjal fruit borer, ber fruit borer infesting the variety of fruits in
the field as well as in the storage. The Thrips, Aphids, flea beetles, etc. damage grapes,
resulting to great economic loss; if not controlled properly. The chickoo moth and rhinoceros
beetles cause damage to chickoo and to coconuts. Thus, large number of pest organisms
cause serious damage to many agricultural crop plants if not controlled properly.
Agricultural Pests can have direct or indirect effect on agricultural plants/crops as following:
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(a) Direct effect
The direct effect of pests is mainly due to their feeding on the crop plants, through biting,
piercing or sucking mouth parts to feed on the crop accordingly.
(i) Leaf eaters like adults and nymphs, larvae of zonocerus, caterpillar larvae reduce the leaf
area and adversely affect the plant growth.
(ii) Stem borers and hoot flies make tunnels in the stem and disturb the conduction
mechanism of the plant i.e. Antherigona in Maize, Disphya in coffee.
(iii) Some pests attack the buds at the growing points and prevent the branching and growth
of the stem. i.e. Chilo zonellus in Jowar and Earias in cotton.
(iv) In some plants, the pests causes the immature fruit fall i.e. Mango fruit fly, ridge fly.
(v) The pests attack the flowers and damage the crop e.g. Tassel beetle of Maize.;
(vi) In some plants like maize, black maize beetle, destroy the absorbing tissue of root
leading inhibit growth. Some insects consume stored food, underground tubers, etc. affect
growth i.e. potato beetle.
(vii) Number of sucking insects suck cell sap from the crop plants in large quantities and
results in loss of vigor of the plant. For example, Bemisia (white fly) on cotton, Aphids on
many vegetable plants.
(viii) Some pest suck sap from flower and reduce the seed setting i.e. coffee Lygus bugs.
(ix) Premature nut fall is seen in coconut because of coconut hug and scales insects causes
premature leaf fall.
(x) Some sucking insect inject toxins into the host body which results in distortion, gall
formation, necrosis of leaves, etc. in the host e.g. Lygus bugs in cotton.
(xi) Dysdercus sucks cell sap of cotton leading vitality of plants.
(b) Indirect Effects
(i) Agricultural pests effects, delay the crop maturity and harvest. These pests not only cause
loss of production but also cause decline of qualify, nutritional value, discoloration and
market value.
(ii) The insects cause damage also act as transmission agents to transfer the pathogenic fungi,
bacteria or viruses which leads secondary effects on the crop plants. For example,
platygasteri wasp transmit coffee leaf rust, viral diseases like mosaic virus disease and
curling leaf of cotton.
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2. Household Pests
The diverse environments around us are very attractive to insects, including lawns, flowers,
shrubs, parks, industrial complexes and dwellings. Pests that infest dwellings are commonly
referred to as household pests (insects). Household insects are direct concern to man, his
possessions and his immediate environment.
Insects such as cockroaches, crickets, houseflies, fruit flies, weevils, ants (red and black), and
silver fish, etc. which contaminate eatable food and spoil it or transmitting disease causing
agents are commonly placed under this group. The insects like cloth moths, carpet beetle,
furniture beetles cause damage to property (human-possessions) are also belongs to
household pest. Thus, all types of insect which are unwanted guests in the dwellings of man,
which cause damage to human holdings and his health are called as household pests.
3. Storage Grain Pests
The storage of food grains has been a long practice with cultivators and traders. Considerable
losses both in quality and quantity of food grains take place in storage due to number of
factors. Organisms like insects, mites, rodents, fungi and bacteria are directly responsible for
causing loss in stored products. It is estimated that about 74Q% stored grains are lost every
year due to stored grain pest in India.
The stored food grains, seeds, fruits, nuts, etc. are infected by the internal borer insects in the
Kothis, godowns and warehouses are most injurious of all insects. The borers can attack
them, even during the harvesting stage in the farm land itself. The grain weevils (pulse beetle,
rice weevils), moths. Red rust flour beetle, etc. cause a major damage to stored cereals
(wheat, rice, bajara, barley, corn, oat, millets, etc.) and pulses (lentils, peas, beans, gram, etc.)
respectively. Mainly the insects spoil the stored food grains and render them unfit for human
consumption, sowing purposes. The stored grain pest can be differentiated into two types viz.
(i) Primary type: This group of pests cause damage to intact grains i.e. uncrushed state.
(ii) Secondary type: This group of pests feed or attack the broken or crushed grains.
4. Structural Pests
Structural pests are those harmful insects which cause damage to wooden frames, doors,
furniture, fencing posts, library books, stored papers, cardboards, and all other wooden
articles and components of buildings are referred as structural pests.
The termites (i.e. white ants) are colonial and social insects, feed on cellulose, mean while
damage wooden material in variable form. Silver fishes food on starch material and ghee,
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thus damaging book bindings, wall papers, photographs and all kinds of adhesive labels.
Cloth moths and carpet beetles can also be damage cloths, carpets as structural pests.
2. Medical and Veterinary Entomology
Medical entomology or human health entomology is the branch of entomology that deals
with arthropods that affect human health; veterinary entomology is that branch of entomology
that deals with arthropods affecting the health of nonhuman animals, particularly
domesticated species. These two disciplines are often combined into a single field known as
"medical and veterinary entomology". Medical and veterinary entomology involves the study
of insects and other arthropods, especially arachnids, and is a broad science that includes
studies on biology, ecology, morphology, taxonomy and many aspects related to disease
transmission. Medical and veterinary entomology also includes pest control, parasitology,
and the study of vector-borne and zoonotic diseases.
Forensic entomology is a specialist branch of medical and veterinary entomology in which
insects are used as evidence in criminal investigations. Insects may be particularly important
in establishing the post-mortem interval (time since death) in a homicide investigation.
Insects develop at predictable rates. Since many of the insects that feed on human cadavers
arrive soon after death, information about the developmental stage of these insects can be
used to estimate when death actually occurred. Some types of problems caused to humans
and other animals by insects and other arthropods include annoyance, envenomation, allergic
reactions, invasion of host tissues, arthropod-borne diseases, food contamination, phobia for
arthropods and delusory parasitosis. Envenomation occurs by the injection of venom by
arthropods through bites and stings.
In Japan, the giant Asian hornet, Vespa mandarinia, a species native to temperate and tropical
Eastern Asia, is the world's largest hornet with a body length of approximately 5 cm, a
wingspan of about 7.5 cm, and a 1 cm long sting that can inject large amounts of a potent
venom which has a high content of acetylcholine. Each year as many as 40 people die
because of allergic reactions caused by the sting of this species.
Other problems may result when poisonous arthropods are touched or ingested; for example,
the larvae of some moths can cause allergic reactions to the skin when touched, as in the case
of the stinging rose caterpillar Parasa indetermina.
Delusory parasitosis refers to the psychosis that occurs when a person has a strong delusional
belief that they are infested with parasites, when they are actually not infested with any. Each
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year arthropod-borne diseases and new strains of known pathogens are being discovered
making the study of medical and veterinary entomology an essential field in human and
animal health.
3. Arthropod-borne Diseases
Numerous human diseases are transmitted by insects and other arthropods that carry
pathogens, such as bacteria, flukes, protozoa, viruses, roundworms and tapeworms, between
vertebrate hosts. Insects that carry pathogens between hosts are called "vectors". Here are
listed just a few of the many known vectors of human pathogens. Mosquitoes of the genus
Anopheles are vectors of protozoans of the genus Plasmodium, the causal agents of malaria,
which is the most deadly arthropod-borne disease, affecting about 250 million people
worldwide, with about 2 million deaths accredited to this disease annually. Viruses that are
transmitted through the bite of mosquitoes are commonly known as "arboviruses" (a
shortening of `arthropod-borne viruses'). The most commonly known arboviruses are those
that cause dengue, yellow fever and several kinds of encephalitis (e.g., Venezuelan equine
encephalitis, Western equine encephalitis, others). The yellow fever mosquito, Aedes aegypti
is the main vector of dengue virus, yellow fever virus, and other diseases.
Fleas are capable of transmitting the bacterium, Yersinia pestis, the causal agent of plague.
Three forms of plague (bubonic, pneumonic, and septicemic) are known to occur in humans.
Plague has killed millions of people, especially in the 14th and 17th centuries and is still a
problem in society, with some 5,000 cases annually.
House flies are vectors of bacteria that cause enteric diseases. For example, typhoid fever
caused by Salmonella typhi, cholera caused by Vibrio cholera and shigellosis caused by
Shigella spp. cause dysentery and diarrhea, and Escherichia coli causes urogenital and
intestinal infections. Triatomine bugs are capable of transmitting the protozoan Trypanosoma
cruzi, the causative agent of Chagas disease . Deer ticks may act as vectors of the bacterium,
Borrelia burgdorferi, which causes Lyme disease in the northern hemisphere. In some parts
of Africa, the tsetse flies, Glossina spp., are vectors of two forms of the protozoan
Trypanosoma brucei, the causative agent of sleeping sickness or African trypanosomiasis.
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4. Chagas Disease
Chagas disease, also known as American trypanosomiasis, is a potentially life-threatening
illness caused by a flagellate protozoan parasite, Trypanosoma cruzi. The disease was named
after the Brazilian physician Carlos R.J. Chagas who first described T. cruzi and its infection
in humans in 1909. The protozoans invade the muscle cells of the digestive tract, heart, and
sometimes the skeletal muscle of their hosts. The life cycle of T. cruzi is complex, consisting
of three main developmental forms. The disease is found from the southern USA to Central
America and South America and is generally transmitted to humans by the infested feces of
triatomine bugs, although there are other ways of transmission (e.g., via contact of mucosal
surfaces, blood transfusion, congenitally, or through organ transplant).
Triatomine bugs feeds on blood using their sucking mouthparts. As the bug feeds, it defecates
in order to expel excess liquid from its gut. The feces of a bug infected with T. cruzi will
contain the infectious parasites. The saliva of triatomine bugs contains anesthetics,
anticoagulants and vasodilators that permit the insect to feed without disturbing its host. Once
satiated, the insect leaves its human host and the effect of the anesthetic wears off. The bite
begins to itch and the sleeping human will scratch the bug bite. The act of scratching disrupts
the protective layers of the skin, allowing the protozoans found in the infected feces to
penetrate the skin. Chagas disease is typical of poor rural communities, especially among
people who live in houses with thatch roofs in areas where the protozoans and their
triatomine bug vectors are endemic. Chagas disease affects about 18 million people in Latin
America.
5. Forestry entomology
Forest entomology concerns the study of insects and other arthropods associated with forest
ecosystems. It deals mostly with insect pest management, seeking to control insects that
cause crown dieback or death of trees, degradation and destruction of wood, defoliation, and
other problems related to the health of a forest and wood products.
Forest entomology may include studies on biodiversity, biology and ecology of insects in
natural or cultivated forest ecosystems, and damage assessment to tree structures, forest
stands and wood products. Insects (and other arthropods) may affect the health of a tree by
interrupting its normal growth and causing stunted growth and ruining tree form.
Damage caused by insects may include perforation of tree bark, leaves and roots, which often
become an entry route for pathogens (fungi, virus, others); crown dieback which consists of a
substantial progressive decline in crown health, often resulting in tree death; degradation of
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wood quality through tunneling caused by insect feeding; staining of the wood either by
feeding or by fungi carried by the tunneling insect; destruction of flowers and seeds; and
decrease in photosynthetic activity and other physiological processes due to defoliation or
injection of toxins, etc. On the other hand, in general, insect populations in forest ecosystems
are in balance. But insects are also essential in maintaining healthy forests. Some services
provided by insects in a forest include the aeration of soil through tunneling activity
improving gas exchange in the root system; decomposition of organic matter of the forest
floor; pollination; biological control; food source for other invertebrates and vertebrates that
live in the forest; and production of food products such as honey.
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II. SOME COMMON AGRICULTURAL PESTS WITH RESPECT TO THEIR
BIOLOGICAL NAME, IDENTIFICATION MARKS, LIFE HISTORY, NATURE OF
DAMAGE AND CONTROL MEASURES
1. RED COTTON BUG
Fig. 1: Dysdercus male and female copulating
Source: https://upload.wikimedia.org/wikipedia/commons/a/ab/Dysdercus_cingulatus,_mating.jpg
Class Insecta
Order Hemiptera
Family Pyrrhocoridae
Genus Dysdercus
Species cingulatus / koenigii (Feb)
The red cotton bug has wide distribution, it is a minor pest in cotton growing region of
northern India particularly Punjab and Uttar Pradesh. This pest also occurs throughout the
Maharashtra state but is minor importance. It is commonly known as a "cotton stainer". (Fig.
1)
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Host Plants
Cotton, bhendi, ambadi, hollyhock and several other malvaceous plants.
Identification Marks
The adult bug measures about 12-15 mm in length. The females are Longer (15 mm) than the
males (12 mm). It is blood red in colour except eyes, scutellum, anal style, and antennae
which are black colored. Besides, there is a black spot on each of the membranous forewings.
A series of white transverse bands are present on the ventral side of the abdomen. Mouthparts
are adapted for piercing and sucking. They form a straight beak or rostrum. The nymphs are
smaller than adults and are wingless.
Fig. 2: Dysdercus nymph (larval form)
Source: https://upload.wikimedia.org/wikipedia/commons/0/0b/Red_cotton_bug_%28Dysdercus_koenigii%29
_nymph_on_Hibiscus_lobatus_W_IMG_4064.jpg
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Life Cycle
The mature female lays eggs during spring in clusters of 70-80 eggs each under the moist soil
surface; fallen leaves and in crevices. The eggs are spherical, yellowish-white about 1.2 mm
in length. After 7 days of incubation period and moist weather, eggs are hatched into active 1
mm long red colored nymphs which are resemble the adult except size and absence of wings
(Fig. 2). The nymphs feed gregariously on the cotton bolls. The nymphs undergo 5-moults
within 49-89-days to reach adult stage (Fig. 3). In winter the life of the adult is about 3-
months but in summer it is varied. Pest breeds on cotton from August- November; takes
shelter under leaves or debris from December-middle of March and feeds on bhendi from
April-July. The life cycle of bug is completed within six to eight weeks.
Fig. 3: Dysdercus (identification marks)
source: https://upload.wikimedia.org/wikipedia/commons/c/c6/Dysdercus_Cingulatus-Fabricius_-
_Red_cotton_stainer_bug_%282%29.jpg
Nature of Damage
Both nymphs and adults suck the cell sap from the leaves and tender shoots and impair the
vitality of the plant. If the attack is severe, bolls open badly and the lint is of poor quality. In
addition they also feed on the seeds and lower their oil content and low percentage of
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germination; such seeds are unfit for sowing. The lint is stained by the excreta of bugs or by
their body juice as they are crushed in the ginning factories, so named cotton stainer.
Control Measures
1. Cotton field should be ploughed to expose eggs to sunlight.
2. Insects should be hand picked and killed in kerosene water.
3. The crops of bhendi should be sown as trap crop and pests collected there, should be
destroyed.
4. Moistened cotton seeds should be hanged up at different places in the field where bugs
congregate, they may get killed in the kerosene water.
5. Spraying of Malathion O.O5% is effective to control the pest.
6. Spraying of 1 liter endosulfan 35% EC, 0.25 liter phosphamidon = 100% EC or 1 liter
Fenitrothion 100% EC per hectare is very effective or reduce pest population.
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2. JOWAR STEM BORER
Class Insecta
Order Lepidoptera
Family Pyralidae
Genus Chilo
Species zonellus = partellus (Swinhoe)
Jowar is the most important stable food crop of the Maharashtra state. Besides being stable
food crop of the people, it also supplies very good fodder for the cattle. It is cultivated in
Kharif, Rabi and also in hot weather. Jowar stem borer is one of the major pests of jowar.
This pest is generally observed in the early growth of the crop and even after the ear-head
formation. This pest is active throughout the year but the infestation is more noticed on rabbi
and hot weather crops. The hybrid varieties are more susceptible to this pest.
Distribution
It occurs throughout India. The jowar stem borer is commonly called as spotted stalk borer or
pink borer. Identification Marks The adult moth is a medium sized insect with 3 cm wing
span. Its forewings are straw or light brown in colour with numerous shining brown spots on
the margin and hind wings are white and papery. The caterpillars (Larvae) are dirty white in
color with dark brown head with mandibulate type of mouthparts. Many dark spots are
appeared on the body.
Mature caterpillars are measured about 12-20 mm in length and shows four broad and patchy
strips on the body.
Fig. 4: Jowar Stem Borer
Source: https://upload.wikimedia.org/wikipedia/commons/thumb/7/79/Chilo_phragmitella.jpg/220px-
Chilo_phragmitella.jpg
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Fig. 5: Chilo partellus damage ('dead heart')
Source: own, chetan Jawale ©
Host Plants
This is the major pest of jowar and maize but also recorded on bajra, ragi and other grasses.
Fig. 6: Host plant (Jowar / Sorghum)
Source: own, chetan Jawale ©
Life Cycle
A female lays about 50-300 eggs in clusters arranged in two rows on the under surface of the
leaves during April-May. Eggs are creamy white in color They hatch into the young
caterpillar in about six days of incubation period. The young caterpillar feeds on tender
leaves for a day or two and bores into the central shoot. The larval stage last for about 3-4
weeks and have normally five molts. Pupation takes place inside the stem and it last for about
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7-10 days. The adult lives for 2-4 days. The pest is generally active from June to November
and about four generations are completed in a year. The pest hibernates in the larval stage in
stubbles during unfavorable period.
Fig. 7: Chilo partellus Life cycle
Source: own, chetan Jawale ©
Nature of Damage
Newly hatched caterpillars initially feed on the leaves causing numerous small holes in the
leaf lamina and attack all parts of jowar plant except the roots. The larvae on entering the
leaf, whorl and cut the leaves, which on emergence manifest characteristic pin holes, shoot
holes and longitudinal streaks. At times the growing point is cut which results in drying of the
central shoot and subsequently formation of dead-heart. The larvae after entering the stem,
feed on the tissues (pith) and tunnels or galleries are formed.
Fig. 8: Symptoms of Damage
Source: own, chetan Jawale ©
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Control Measures
Cultural Method
1. Hand picking or light trapping of adult moths and collection of their eggs for destruction.
2. Burning of stubbles and trash which harbor borers and act as source of infestation for the
next crop.
3. Changing the sowing and harvesting timing reduces infestation.
4. Crop rotation is another cultural practice that does not allow the pest of one crop to survive
next year for lack of its host.
5. Growing resistant varieties of jowar like CHS-7, CHS-8, Indian sorghum types IS-5566,
5285 and 5613.
Chemical Method
1. For the Chilo on jowar a spray of 0.05% lindane or 0.1% endosulfan on 15 days old plants
has been found effective. This may be followed after another fortnight with a second
application of 1.0% lindane or 4% endosulfan granules. A third application with 0.2%
carbaryl spray may be carried out, if found necessary.
2. If the crop infestation is noticed, dusting of crop in the early stage with 10% BHC at the
rate of 25 kg per hectare or spraying the crop with 350-400 ml of aldrin or dieldrin in 200
liter of water helps to control the pest.
Biological Method
1. The hymenopteran, Trichogramma minutum is employed as egg parasite.
2. Apanteles flavipes and Bracon brevicornis as larval parasites.
3. The lady beetles, Coccinella septempunctata and Menochilus.
Sexmaculata have been recorded predating on early stages of the larvae of this pest.
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3. BRINJAL FRUIT BORER
Class Insecta
Order Lepidoptera
Family Pyralidae
Genus Leucinodes
Species orbonalis (Guenee)
Common Name: Brinjal shoot and fruit borer.
Host Plants
Brinjal (main) and other Solanaceae plants and peas (alternative). L. orbonalis is the most
important and destructive pest of brinjal and has a countrywide distribution.
Identification Marks
The moths are medium sized of about 20 mm across the spread wings. The head and thorax
are blackish brown. The wings are white and provided with small hairs along the apical and
anal margins. A number of black, pale and light brown spots are found on the fore and hind
wings of the moth. The caterpillars are pale white and about 12 mm long when fully grown.
Fig. 9: Brinjal fruit borer Leucinodes orbonalis
Source: https://upload.wikimedia.org/wikipedia/commons/9/9c/Leucinodes_orbonalis.jpg
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Fig: 10: Brinjal fruit borer larva
Source: https://upload.wikimedia.org/wikipedia/commons/9/9c/Leucinodes_orbonalis_larva_late_instar.jpg
Life Cycle
The moth lays elongated eggs singly or in small batches, on the leaf surface, shoots and
fruits. They hatch in 3-5 days. On hatching the caterpillars start boring into the shoot, leaf
midrib, petiole and fruits and feeds on the internal tissues. The larva undergoes 5-moults in
10-15 days. The fifth instar larva is stout pink and measures about 1.6 cm in length. Pupation
takes place in a cocoon on the plant and lasts for 6-8 days. Moth lives 2-5 days and the
female lays up to 250 eggs. The larva is parasitized by Pristomerus testaceus Morl, Cremastus
flauoorbitalis and Bracon species.
Nature of Damage
The larval stage is the only destructive stage. In the early stages the larvae bore into tender
shoot as a result the infested shoots droop down and ultimately dry up. The larvae also bore
into flower buds and developing fruits under the calyx, leaving no visible signs of infestation.
The attacked fruits show holes on them plugged with excreta. In case of severe infestation in
the initial stages, there may be no fruiting at all. The pinkish larvae make zigzag tunnels in
the fruits and fruits are holed; such infested fruits are rendered totally unfit for human
consumption. Up to 70% loss of crop is caused by this pest.
23
Fig. 11: Symptoms of shoot attack
Source: own, chetan Jawale ©
Fig. 12: Symptoms of fruit attack
Source: own, chetan Jawale ©
Control Measures
1. The affected fruits and drooping shoots, containing caterpillars inside, should be clipped
off and destroyed.
2. The crop should be sprayed with suspension / emulsion of any of the following
insecticides.
3. The biological agencies like, Braconid wasps (Bracois chinensis, Shirakia schoenobi) and
Ichneumonid wasps (Trathela flauoorbitais) parasitize the larvae of this pest.
Details
- Pages
- Type of Edition
- Erstausgabe
- Publication Year
- 2016
- ISBN (PDF)
- 9783960675457
- ISBN (Softcover)
- 9783960670452
- File size
- 7.4 MB
- Language
- English
- Institution / College
- Savitribai Phule Pune University, formerly University of Pune – Department of Zoology
- Publication date
- 2016 (May)
- Keywords
- Pesticide Agricultural pest Non-insect pest Pest control Plant protection Insect pest India
- Product Safety
- Anchor Academic Publishing
