Insect pests of wheat and their management

Insect pests of wheat and their management

1. Insect pests of wheat and their management Course N o . AENT – 5312 Course Title – Pests of crop and stored grain and their management Prepared by, Navneet Mahant Dept. of Agril . Entomology BHARTIYA COLLEGE OF AGRICULTURE, PULGAON, DURG (C.G) – 491001 Affiliated to Indira Gandhi Krishi Vishwavidyalaya , Raipur (C.G)

2. A p hid Armyworm G r ass h op pe r 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.

4. 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.

5. Dama g e: The attacked young plants shows dead hearts and are killed together. The older plants are not killed, but they produce a few grains only.

6. 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.

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

8. 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.

9. Marks of Id e ntif i cat i on Adult are yellow white in colour Small and soft body Social insect lives in colonies Chewing and cutting type of mouth parts

10. 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

11. Life Cycle Include 3 developmental stages --- Egg, Nymph and Adult 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.

12. Mounds The termite forms mounds which may reach 50 cm in height and 100 cm in circumference .

13. 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 .

14. White Eggs

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

16. Adults types Adult of the colony is divided into 2 groups 1.The reproductive forms 2.The vegetative forms Rep r odu c tive 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 cha m ber at 5 fe e t de p th undergroun d . Wingless female. Abdomen is transversely marked.

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

18. 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.

19. 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.

20. soldier

21. Co n trol We have 2 methods of control Cultural method Chemical method A. Cultural method:- 1. Removal of dead or stub b les from field b/c they attract the termites . 2. Deep plou g hing 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:- Dusting with 5% aldrine or 10% BHS 25kg/hc in furrows at the time of effective Wheat seed should be treated with insecticides before sowing. s o wing is quite