Stored product insect pest: Primary grain pests attack the whole grain. The eggs are laid inside the grain, before the larvae mature inside the grain and then chew their way out. Some of these pests include the Lesser grain borer, Granary weevil (Sitophilus granarius, the Wheat weevil) and Rice weevil (Sitophilus oryzae).

1. Stored Product Insect Pests
Presented by
Dr. S.KRISHNAMOORTHY
Assistant Professor,
PG and Research Centre in Zoology
Vivekananda College, Tiruvedakam West, Madurai

2. STORED PRODUCT INSECT PEST
• Cereal grain products and other foods stored in
kitchen cabinets, pantries or other areas in the
home may become infested with insects or other
organisms.
• These food invaders are commonly referred to as
"pantry pests."
• Nearly all dry, stored human food products as well
as dry pet food and birdseed are susceptible.
• Pantry pests eat and contaminate the products,
rendering them useless for consumption and can
leave infested foods to crawl or fly around the
house.
• When this happens, they become an annoyance for
many people.

3. • Control of stored product pests begins with
a careful examination of all susceptible
materials to find and identify the pests and
the extent of the infestation.
• This publication lists only the most
common arthropod pests of stored products
in Missouri and gives some brief
information about their biology, behavior
and treatment. Most of these pests are
beetles, moths, mites or psocids.

4. Types
• Grain insect pests may be divided into
primary and secondary pests.
• Primary grain insects have the ability to
attack whole, unbroken grains.
• while secondary pests attack only
damaged grain, dust and milled
products

5. Primary grain pests
• Primary grain pests attack the whole
grain.
• The eggs are laid inside the grain, before
the larvae mature inside the grain and
then chew their way out.
• Some of these pests include the Lesser
grain borer, Granary weevil (Sitophilus
granarius, the Wheat weevil) and Rice
weevil (Sitophilus oryzae).

6. secondary pests
• Flour beetles are secondary pests of all
grains and primary pests of flour and
other milled products.
• In grains, embryo or germ portion is
preferred.
• They construct tunnels as they move
through flour and other granular food
products.

8. Rice weevil: Sitophilus oryzae, S. zeamais, S. granarius
• Host range: Wheat, rice, maize, jowar, paddy.
Symptoms of damage
 Both grub and adults cause the damage.
 Grains are hollowed out; kernels are reduced to mere powder. S. oryzae and S.
zeamais starts its attack in field itself.
 Adults cut circular holes. Heating takes place during heavy infestation, which is
known as ‘dry heating’
• Identification of the pest
 Egg - Translucent white, plugs the egg hole with gelatinous secretion, laid singly
on grains.
 Grub - White with yellowish brown head, apodous, fleshy, curved, remains within
the grain
 Pupa - Pupates inside the grain.
 Adult - Small, reddish brown to chocolate coloured weevils has characteristic
snout, and the elytra have four yellow spot

9. Sitophilus oryzae

10. Khapra beetle:
Trogoderma granarium

11. Symptoms of damage
 Adults are harmless. Grub damages the grain starting with
germ portion, surface scratching and devouring the grain.
 It reduces the grain into frass.
 Excessive moulting results in loss of market value due to
insanitation caused by the cast skin, frass and hair.
 Crowding of larvae leads to unhygienic conditions in
warehouses.
• Damage is confined to peripheral layers of bags in bulk
storage.

12. Identification of the pest
 Egg - Eggs are laid on the grains or crevices.
 Grub - Grub is straw coloured with dark brown hairy
bands on each segment and typical posterior tuft
forming a tail of long hairs. It is active, move and feed
freely.
 Pupa - Pupation takes place on the surface of the grain
in bulk and overlapping edges of bags.
• Adult - Reddish brown, convex, oval in shape with
practically no distinct division of head, thorax and
abdomen. Abdomen size is comparatively larger.

13. Lesser grain borer/Hooded grain borer/paddy
borer beetle: Rhyzopertha dominica

14. • Host range: Paddy, rice, wheat, maize.
Symptoms of damage
 Grubs and adults cause damage and are voracious
feeders.
 Adults reduce the grain kernels to mere frass.
 Grubs eat their way into the grain or feed on the
grain dust and are capable of attacking grain
externally.

15. Identification of the pest
 Egg - Eggs are laid on the surface or on the interstices
of cereal grains singly or in clusters.
 Grub - White, apodous with brown head, free living
upto 3rd instar.
 Pupa - Grub enters the grain after 3rd instar for
pupation.
• Adult - Brown to blackish beetle, head is deflexed
down wards below prothorax to such an extent that it is
almost hidden in a dorsal view. Antenna clubbed with
large loose three segments

16. Pulse beetle:
Callosobruchus chinensis, C. maculatus
• Host range: All whole pulses, beans and
grams.
Symptoms of damage
 Grubs eat up the grain kernel and make a
cavity.
• Adults come out making exit holes.

17. Callosobruchus maculatus

18. Cigarette beetle: Lasioderma sericorne
• Host range: Wheat flour, cereal bran, peanuts, cocoa beans, cottonseed,
spices and even
insecticides containing pyrethrum, meat and fishmeal, ginger, turmeric and
chillies.
Symptoms of damage
 Grub causes the damage which made circular, pinhead sized bore holes on
processed tobacco.
• Identification of the pest
 Grub: White, fleshy and hairy grub.
 Adult: Small, robust, oval, light brown round beetle with its thorax and
head bent downward gives the insect a humped appearance. Elytra have
minute hairs on them and are not striated.

19. Lasioderma sericorne

20. Drug store beetle: Stegobium paniceum
• Host range: Turmeric, coriander, ginger, dry vegetable
and animal matter.
Symptoms of damage
 Circular pinhead sized bore holes, caused by grubs
• Identification of the pest
 Grub: Similar to cigarette beetle but not hairy.
 Adult: Reddish brown round beetle with striated elytra and
clubbed antenna.

21. Stegobium paniceum

22. Secondary storage pest

23. Rust red flour beetle: Tribolium castaneum
Confused flour beetle: Tribolium confusum,
• Host range:
• Broken grains/ mechanically damaged
grains, germ portion and milled
products.
• Heavy infestation causes stinking odour
in flour, adversely affecting the dough
quality. It is an important pest for mill
machinery.

25. Symptoms of damage
 Grubs feed on milled products.
 Flour beetles are secondary pests of all grains and
primary pests of flour and other milled products.
 In grains, embryo or germ portion is preferred.
 They construct tunnels as they move through flour and
other granular food products.
• In addition they release gaseous quinines to the
medium, which may produce a readily identifiable acid
odour in heavy infestations.

26. Identification of the pest
• Egg - White, translucent, sticky, slender and
cylindrical.
Grub - Worm like, whitish cream colour, faint stripes,
two spines like appendages at the end segment.
Pupa - Pupa remains loosely lying in the grain and is
naked.
Adult - Oblong, flat, brown in colour. In T. confusum,
the compound eyes are completely notched and
antennae are not gradually thickened whereas in
T.castaneum, the notch is not complete and antennae
have a clear 3-segmented club.

27. Long headed flour beetle: Latheticus oryzae
• Host range: Cereal flours, packaged food, rice
and rice products, grains with excessive dust,
dockage and broken grains with high moisture
contents preferred.

28. Identification of the pest:
• Egg - White, smooth, cylindrical eggs at
random in grain and seams of the bags.
Grub - Active grub feeds voraciously.
Pupa- Pupa is naked.
Adult- Light brown with elongated body,
resembles Tribolium sp. Antennae shorter
than head, 11 segmented with 5 clubbed
apical segments.
• Symptom of damage: Both grubs and
adults feed.

29. Saw toothed grain beetle:
Oryzaephilus surinamensis
• Host range: Rice, wheat, maize, cereal
products, oil seeds and dry fruits.

30. Identification of the pest
• Egg: Whitish eggs laid loosely in cracks of
storage receptacles or godowns.
Grub: Grub is slender, pale cream with two
slightly darker patches on each segment.
Pupa: Full grown grub makes protective
cocoon like covering with sticky secretion.
Adult:: Narrow, flattened, thorax having six
teeth like serrations on each side. Antenna
clubbed. Elytra cover abdomen completely.

31. Rice moth: Corcyra cephalonica
• Host range: Rice, jowar, other millets, whole
cereals, cereal products, pulses, processed
products of cereals, pulses, oil seeds, nuts, dry
fruits and milled spices.

33. Identification of the pest
 Egg: Small, oval, elliptical laid on wall, bags or
on grain.
 Larva: Creamy white has prothoracic shield.
 Pupa: It webs silken shelter before pupation. In
case of heavy infestation cocoons may be seen
sticking to the grain bags. Cocoon dense white
and tough.
• Adult: Pale buff brown colour, forewings pale
yellowish green and grey white hind wings.

34. THANK YOU