Some Insects in the world are Harmful to the society. Some Harmful Insects explained in the slides

1. Harmful Insects
By
Dr. Narendra A. Manwar
Dept. of Zoology
Mahatma Phule Arts and Science College,
Patur, Dist-Akola (M.S.), India

2. Harmful Insects

3. Stored Food Grain Pests
(Injuries and Control)

4. Occurrence:
Throuhout the India, cosmopolitan
Identification:
The adult is a small beetle about 1/6th -1/8th of an inch in
length and radish brown, dark brown or almost black in
color with the head having shape of a long slender snout.
They are always found inside the kernels of grain.
The rice Weevil (Sitophilus oryzae):
Host complex:
In India it is commonly found in the stored cereals ssuch as rice wheat and millers like
maize, jowar, barley, bajara, etc.
Injuries:
Feeds on grains leaving behind only skin of the grains. Both adult and larvae feed
voraciously such that grain become unfit not only for consumption but also for seed
purposes.
Control:
Primary measures: Sun-drying of the storing grains. The broken grains must be
seperated. Godowns must be clean, damp-proof and with heating arrangement. Grains
must be mixed with dry neem leaves
Chemical measures: Grains can be mixed with 5% BHC at the rate of 0.15% by weight
of the grains. Empty godowns should be sprayed with 4% BHC or 0.02% malathion
before storage.
Fumigation of grains by HCN for 18 hrs in closed godown.

5. The Red Flour Beetle (Tribolium castaneum)
Occurrence:
Throuhout the India, cosmopolitan
Identification:
It is 4 mm in length and reddish brown in
color. Head and dorsal side of the thorax
are densely covered with minute puncture.
Host complex:
Common to powdered products granaries in India
Injuries:
Adult and larva both feeds on the germ of the cereals. It feeds on powdered products
produced by other pests after feeding the grains or the broken grains specially rice,
miller product like attam, maida and suji.
Control:
Primary measures: Sun-drying of the storing grains. The broken grains must be
seperated. Godowns must be clean, damp-proof and with heating arrangement. Grains
must be mixed with dry neem leaves
Chemical measures: Grains can be mixed with 5% BHC at the rate of 0.15% by weight
of the grains. Empty godowns should be sprayed with 4% BHC or 0.02% malathion
before storage.
Fumigation of grains by HCN for 18 hrs in closed godown.

6. Occurrence:
Throughout the India, cosmopolitan
Identification:
The adult beetle is brownish black,oval
and about 3-4 mm long, convex. The body
is covered with very fine hairs.
Host complex:
Common in stored wheat grain.
Injuries:
It is primary host of stored grain particularly wheat, rice, corn, barley, pulses, dried
fruits, nuts, dried milk, gresh meal, etc. only the larvae feed on grains right from
superficial layer to the internal embryo and the grains become useless for germination.
Larvae can tolerate as low as 2 degrees temp and high upto 44 degrees
Control:
Primary measures: Sun-drying of the storing grains. The broken grains must be
seperated. Godowns must be clean, damp-proof and with heating arrangement. Grains
must be mixed with dry neem leaves
Chemical measures: Grains can be mixed with 5% BHC at the rate of 0.15% by weight
of the grains. Empty godowns should be sprayed with 4% BHC or 0.02% malathion
before storage.
Fumigation of grains by HCN for 18 hrs in closed godown.
The khapra Beetle (Trogoderma granarium)

7. Occurrence:
Throughout the India, cosmopolitan. Severe
attach occur during the rainy season
Identification:
The adult mouth is small, 8-10 mm in length,
with narrow wings fringed with hairs. The head is
characterized by yellow brown color. While sitting
the wings zare completely floded over back in a
slopping manner.
Host complex:
Serioustore pest of wheat cereals (Wheat), millets like maize, sorghum, etc.
Injuries:
Catterpiller bore the cereal grains. The infected grains are hollowed out and filled by
excreta and webbing by the larvae. Grains become unfit for consumption.
Control:
Primary measures: Sun-drying of the storing grains. The broken grains must be
seperated. Godowns must be clean, damp-proof and with heating arrangement. Grains
must be mixed with dry neem leaves
Chemical measures: Grains can be mixed with 5% BHC at the rate of 0.15% by weight
of the grains. Empty godowns should be sprayed with 4% BHC or 0.02% malathion
before storage.
Fumigation of grains by HCN for 18 hrs in closed godown.
The Angoumois Grain Moth (Sitotrog acerealella)

8. Pests of Economically
Important Crops
A) Pests of cotton:

9. Spotted Bollworm (Earias vittela)
Host Plant: Cotton, Maize, Lady’s Finger, Hibiscus (Malvaceous Family).
Identifiction: It is a small moth measuring about 12 mm in length and 25 mm in
wing width. Fore wing have a broad green band which give it a banded
appearance. The body color is bright green and abdomen is silvery white.
Damage: The infective stage is caterpillar. The caterpillar bore the stem of
young seedlings and feed upon the buds, flowers and then bore the bolls
causing their heavy dropping. The infested shoot wither, dropped and die. A
number of holes are formed on the infested bolls plugged with excreta. One
caterpillar can destroy many bolls premature and produce poor lint which
fetches 50 -80% lower price.
Control Measures:
Primary: During June-July the attacked shoots and bolls should be collected along with
alternative host plant and destroyed or burned.
Chemical: Spray of Carbaryl 0.1% at 15 days interval during Aug-Sept, suppresses the
pest population. Dusting of 5% fenitrothion at the rate of 25 kg per hectare is also
effective.

10. Pink Bollworm (Pectinophora gossypiella)
Identifiction: It is a small grey, dark brown moth measuring 1 cm long and
wing span 1.5 cm. Forewings provided with blackish spots and hind wings
are deeply fringed. The antennae are filiform and they are nocturnal in habit.
Damage: The caterpillar bores flower buds, flowers and bolls of cotton. They
feed on seeds internally and seal the holes after entering the bolls. The
attacked seed cotton gives a poor ginning percentage, less oil extraction and
poor spinning quality of cotton.
Control Measures:
Primary:The seeds should be kept under ‘Sun heat Treatment’ before sowing. The
fallen leaves, bolls, cotton sticks should be collected and destroyed.
Chemical: cotton seeds fumigated by carbon di-sulphide or methyl bromide at 5 cc of
fumigant per 100 kg of seeds. Spraying with 0.2% Carbaryl, 0.05% endosulphan 4-5
times after 15 days during Aug-Sept.

11. Biological Control:
• Natural enemies like
larval parasites eg.
Mites,
Microbracongreeni,
Microbaconlefroyl
may be introduced.

12. Pests of Sugarcane:

13. Pyrilla purpusilla (Leaf hopper)
Adult is a straw colored
and is very active. Head with
long beak like proboscis and
prominent red eyes. It
measure about 20 mm long
• Both adult and nymph bugs suck plant
sap from leaves causing drying and
shedding of leaves.
• It discharges honey dew on leaves on
which the black fungus grows.
• Cane loses the percentage of sucrose,
about 50% during severe attack.Control:
1) Primary Measures:
Collection of egg masses and destruction.
Disposal of cane trash
Bagging of adults in nests.
Striping of dried leaves, leaf-sheaths at large scale.
2) Chemical Measures:
Spraying of dimecron, dimethoate, metasystox or carbaryl

14. Pests of Jowar
• More than 150 species of Insects reported to
damage Sorghum.
• Shoot fly, stem borers, shoots and ear head
gall and aphids are serious pests that reduces
the yield.

15. Jowar stem borer (Chilo partellus)
• Introduction: The adult moths
are straw colored with yellowish
grey forewings bearing fine dots
on apical margins. Females are
longer than male.
• Damage: Generally attacks older
plants. Larvae are the internal feeders
which leads to death of central shoot
and formation of dead hearts without
showing any external signs.
Control
1) Primary Measures:
 Removal and destruction of dead hearts
 Collection and destruction of caterpillars
 Collection and destruction of adults by light or pheromone traps
 Sowing of resistant varieties.
2) Chemical Measures:
No insecticide treatment is effective as larvae and adult develops under the stem.
3) Biological Measures:
Introduction of Trichograma, Telenomus as egg Parasites and Apantele
scolemany as the larval parasite are common.