Insect pests of wheat and their management

1. Course No. AENT – 5312
Course Title – Pests of crop and stored grain and their management

2. Aphid Armyworm Grasshopper
Pink borer
Termite
INSECTS PESTS OF WHEAT
Different insect pests attacking wheat are as follows:

3. Pink borer, Sesamia inferens
(Lepidoptera: Noctuidae)
• The pink borer is polyphagous insect.
• It feeds on wheat, finger millet, rice, sugarcane, maize,
sorghoum.
• The damage is caused by the caterpillars which are pinkish
brown and have a smooth cylindrical body, measuring about
25mm.
• The moth are straw coloured and have stout body.

5. Life cycle
• The pest breeds actively from March- April to November on rice and then
migrates to the wheat crop.
• The moth are nocturnal and lay eggs on leaves or on the ground.
• The egg hatch in 6-8 days and young caterpillar bore into the epidermal
layers of the leaf sheath.
• Later on, they bore into the stem as a result of which the growing shoot dries up
producing dead hearts.
• When the attacked plants die, the larva move onto adjoining plants.
• They are full fed in 3-4 weeks and pupate inside the stem or in
between the stem and leaves.
• The pupal stage last about a week and the life cycle is completed in 6-7 weeks.
• There are 4-5 generations of the pest in a year.

7. Damage:
• The attacked young plants shows dead hearts
and are killed together.
• The older plants are not killed, but they
produce a few grains only.

8. Management:
• The removal and destruction of stubble at the time of the first
ploughing after harvesting the crop.
• Ploughing and flooding the field is also effective in killing the
larvae
• Clipping of tips of seedling before transplanting can reduce the
carryover of eggs to the field
• Use trichocard with 50,000-1,00,000 trichogramma per ha
• The field showing more than 5% dead hearts should be
sprayed with 875 ml triazophos 40 EC or 2.5 liters of chlorpyriphos
20EC in 250 liter of water per ha.

9. THE WHITE ANT
Odontotermes obesus
,Rambur (Indian white
termite)

10. Distribution
Important pest of Wheat
throughout India
This termite is found in
western Asia, where it is a
pest of wood products and
crops like cereals,
sunflower or sugarcane
etc.

11. Marks of
Identification
Adult are yellow white in colour
Small and soft body
Social insect lives in
colonies
Chewing and cutting
type of mouth parts

12. Nature of
damage
Damage wheat crop
They feed on the
roots and stem below
the soil and plant
dried up
It cause 25%
destruction of
germinating grains

13. Life Cycle
Include 3 developmental stages ---Egg,
Nymph andAdult
Breeding takes place after the onset
of monsoon.they copulate during
nuptial flight.
After copulation king and queen shed their
wings and fall on the ground (serwaraki) and
form new colony and they become the queen
and king.
The queen lays upto 25000-35000 eggs per
day. Som kar e wrta wely ye.

14. Mounds
The termite forms
moundswhich may
reach 50 cm in
height and 100 cm
in circumference.

16. Eggs
Eggs are small
kidney shape.
Yellowish in
colour. 5 mm in
length.
The eggs
hatches in about
7-10 days to
produce tiny
nymphs.

17. White
Eggs

18. Nymph
Yellowish white in colour..
1mm in length.
First feed uponexcreta of parents
then on the roots and stem of wheat
crops.
After 6-12 months nymph
metamorphoses into adult undergoing
5-10 moults

19. Adults types
Adult of the colony is divided into 2 groups
1.The reproductive forms
2.The vegetative forms
Reproductive forms:-
They take part in reproduction and
responsible for continuation of the race.
Cast of reproductive forms are –Queen- king-
complementary form and colonizing forms.
Queen:-
Largest member of colony.
Mother of the colony and live in royal chamber
at 5 feet depth underground. Wingless female.
Abdomen is transversely marked.

20. King
Responsible for
copulation with the
queen
Smaller than queen
and live in
the royal chamber with
queen.

22. The vegetative forms
They are sterile forms.
They perform various activities of the
colony.
Different cast of vegetative from are is
Workers and soldiers.
Workers:-
80-90% of the colony population. smallest
members of the colony. Having strong MP
so that performing different function such as
->food collection Storage ,building of
termitorium and looking after young ones.

23. Soldiers
Their function is defence and
offence to protect colony.
Slightly larger in
size then workers.
They posses very strong
MP. Mandibles are very
strong for variety of function
but the main job is
protection of colony .
Act as scavenger b/c
remove dead and sickly
members of colony.

24. soldier

25. Control
We have 2 methods of control
A. Cultural method
B. Chemical method
A. Cultural method:-
1. Removal ofdead or stubbles from field b/c they attract the termites.
2. Deep ploughing and clean cultivation check the spread of this pest
3. Partially decompose manure should not be used b/c it attract this pest.
B.Chemical method:-
1. Dusting with 5% aldrine or 10% BHS 25kg/hc in furrows
at the time of effective
2. Wheat seed should be treated with insecticides before
sowing.