Mealybug and its management

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Mealybug and its management

Mealybug insects are oval in shape and have a life cycle of four
stages in female —. egg, larva I, larva II and adult. Initially the
affected portion will be chlorotic, later changing to brown colour and
dry.

Black colour
The insect excretes honey dew, and as a result the infested portion
becomes shiny and moist and to this, secondary infection by sooty
mould fungus, capnodium occurs resulting in black colour covering the
affected parts.
Yellowing of leaves, malformation of affected portion due to toxin
injection, stunted leaf growth and fruit tip, presence of red/black
ants, honey dew excretion, are some of the symptoms to watch for.

Reproduction
Normally oviparous, eggs are laid just beneath the body or just at the
posterior end of the abdomen . Each female is capable of laying about
400 to 500 eggs. Nymphs become adults in a month. Adult lives for
about 30-60 days depending upon the environment and may move from one
area to another till it finds a suitable place for feeding and
reproduction. Normally they are seen beneath the stem, under surface
of the leaves, in the leaf axils, flower buds and fruits and
occasionally on the roots.
The insect is polyphagous. In addition they also attack a variety of
weeds which serve as alternate hosts when main crop is not available.

Management
— Remove alternate weed hosts and destroy the infested parts of the
plant,
— Take up the management at initial stage to get maximum control
— Wherever necessary, use botanical insecticides like neem derivatives
such as azadirachtin 0.03 percent neem oil 2 percent NSKE 5 percent
and fish oil rosin soap at 25g/litre of water.
— As a last resort use any recommended chemicals at the right dose for
maximum control.
After fortnight check for newly emerging crawlers; if necessary, go
for second spray.

S. Mohamed Jalaluddin
G. Ravi
& T. Jayaraj
Tamil Nadu Rice ResearchInstitute, Aduthurai