White Grub the most dangerous plant pest and its effective Control

White Grub the most dangerous plant pest and its effective Control

General characteristics:

Ø   Grubs belong to family Scarabaeidae.

Ø  Grubs are larvae of May beetle also called  June beetle or Japanese beetle

Ø  200 species exists.

Ø  Larvae live underground attack mostly on roots of corn, potato, tomato, wheat ,beans and turnip

Life Cycle :

The Phyllophaga life cycles vary somewhat because some species complete their growth in one year, some require as much as four years. 

The adults mate in the evening and, at dawn, females return to the ground to deposit 15 to 20 eggs, 1 to 8 inches deep in the soil.

 hatch about three weeks later into young larvae that feed upon roots and decaying vegetation throughout the summer and, in autumn, migrate downward (to a depth of up to 1.5 meters) and remain inactive until the following spring. for more click here

 The greatest amount of damage occurs as the larvae move near the soil surface to feed on the roots of the plants. The next autumn the larvae again migrate deep into the soil to overwinter, returning near the soil surface the following spring to feed on plant roots until they are fully grown in late spring

     These grubs then form oval earthen cells and pupate. The adult beetles emerge from the pupal stage a few weeks later, The beetles overwinter in the soil, emerging the following year in May or June when feeding, mating, and egg-laying take place.

   

CONTROL MANAGEMENT:

 Cultural Control

·         The greatest damage to crops occurs the year after the appearance of the adults.

·         The year following heavy flights of May beetles, planting corn or potatoes should be avoided in fields that were previously   under sod or grass.

·         During the years of heavy May beetle infestation, deep-rooted legumes, such as alfalfa or clovers, should be planted.

·         Farmers should apply only well decomposed farmyard manure in fields.

Biological control:

 A pelecinid wasp, a natural enemy of white grubs.

·         A pyrgotid fly, a natural enemy of white grubs,

Mechanical Control:

Use of different traps like Light traps are most effective for control of adult in the May-July is helpful in reducing the population of grubs for the next season.

Chemical Control

Ø  Maize crop can be protected through pre-sowing soil application of Agrotox/Phorate 10G @1.5Kg/Kanal.

Ø  In standing crops Biomax / Chloropyriphos 20ec may be applied with irrigation

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