Light traps to capture caterpillar moths in coconut

Among different caterpillars that feed on coconut leaves, the slug
caterpillar can cause sporadic outbreak under favourable conditions
especially in summer months. Grown up caterpillars eat the entire
laminar portion of the leaf leaving the mid ribs.
Some times, balls of excreta will be seen as a layer on the ground
around the coconut palm basin.
In severe outbreak, the pest invades nuts and even leaf stalks. Drying
of entire foliage, drooping of leaves and bunches, falling of buttons
and nuts are ultimate symptoms of pest attack.

Damage to intercrops
The pest was observed causing damage even to intercrops such as banana/
cocoa and surrounding hedge plants like agave after drying of coconut
crop. In such cases, falling of buttons and nuts, drying of total
foliage leads to severe yield loses and spathe emergence will be
delayed till the palm recovers.
The total life cycle of the pest is completed in about two months.
Caterpillar is yellowish green in colour, a series of tubercles are
present on the dorsal and lateral sides of the caterpillar. After
completion of larval period all the caterpillars congregate together
and pupate in the corners of the leaflets or crown region.

Light trap studies
There is a natural phenomenon of getting attracted to light source to
certain types of lepidopteran insects (moths), which can be exploited
for pest monitoring, mass trapping and destruction.
To test this phenomenon in the caterpillar, studies were conducted at
infested coconut gardens of Sakinetipalli village with electric bulbs,
gas lights and emergency lights.
Observations were recorded throughout the night (5 pm to 5 am). A
large number of moths (about 100 to 1,200 per light) were being
attracted in a night. These attracted moths were trapped and killed by
placing a big pan with water and sticky paper under the bulb.
Major breakthrough
This is a major break through in the slug caterpillar management and
it can be used as tool for monitoring and also for mass trapping and
destruction of the pests.

Dr. A.Sujatha
Dr. N.Emmanuel
&. Dr. B.Gautham
Andhra Pradesh
Horticultural University
Ambajipeta
Andhra Pradesh