E x t e nsio n Folder No. 14

COCONUT LEAF EATING CATERPILLAR

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~ CENTRAL PLANTATION CROPS RESEARCH INSTITUTE ~ (INDIAN COUNCIL OF AGRICULTURAL RESEARCH)

CPCRI Kasaragod . 670124, Kerala, India

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The leaf eating caterpillar Opisina arenosella is

one of the mqjor caterpillar pests of the coconut

palm. The caterpillar devours t~ green

parenchymatous tissue of the leaves. The pest

inhabits the lower surface of the leaflets inside

galleries made of silken webs reinforced with

excreta and the scraps of leafbits. As the

c at e rpilla r s f eed on the func tiona l c hlorophyll

containing tissues, the photosynthetic e'ffedency

of the palm is reduced drastically and this results

in pOor nut production. The leaves which are put to

thatching, fencing and such other purposes are also

rendered unsuitable. The pest also infests paJmyrah,

talipot, wild date and certain ornamental palms.

In India . the p es t infestation w a s recorded

mostly from the coastal and backwater areas. But.

it also occurs in coconut gardens near rivers, tanks

and paddy fields in some of the interior tracts.

The pest occurs throughout the year; but the

peak period of infestation is in summer; particularly . ------.

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r;;, • during February-March. But, when the South-West

monsoon is delayed the pest population can be

noticed upto June. Among the weather factors,

high relative humidity prevailing in the coastal and

backwater areas favours the pest build up.

O. arenoseJ/a completes its egg to adult stages

in about two months. Eggs are laid on the lower side

of the leaflets on or near the old larval gelleries and

the emerging larvaelpupaeJadults spend their life on

the palm itse lf.

Control

Infested leaveslJeaflets can be dipped off and

burnt in cases of mild infestation. This prevents

further spread of the pest.

When the infestation occurs at a medium level,

biological pest suppression using the indigenous

parasitoids is quite effective. The bethylid parasitoid

Goniozus nephantidis @ 20%. the elasmid Elasmu s

nephantidis @ 5 0% and the c h a lcidid B rachyme ria

nephantidis @ 30% may be relelased depending on

the stage of the pest present in the field. The

dose for release of the parasitoid is fixed on the . --------. 3

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• I .--- . ...... he leaf eating caterpillar Opisina arenosella is

f the mcijor caterpillar pests of the coconut

The caterpillar devours t~ green

:hymatous tissue of the leaves. The pest

t:s the lower surface of the leaflets inside

es made of silken webs reinforced with

t:a and the scraps of leafbits. As the

)illars feed on t he functional c hlorophyll

ning tissues. the photosynthetic effeciency

, palm is reduced drastically and this results

r nut production. The leaves which are put to

ling, fenting and such other purposes are also

'ad unsuitable. The pest also infests palmyrah,

:, wild date and certain ornamental palms.

India, the pest infestation w as recorded

, from the coastal and backwater areas. But,

occurs in coconut gardens near rivers, tanks

lddy fields in ~ome of the interior tracts.

1e pest occurs throughout the year. but the

eriod of infestation is in summer. particularly

• 2

during February~March. But, when the South-West

monsoon is delayed the pest population can be

noticed upto June. Among the weather factors,

high relative humidity prevailing in the coastal and

backwater areas favours the pest build up.

O. arenosella completes its egg to adult stages

in about two months. Eggs are laid on the lower side

of the leaflets on or near the old larval gelleries and

the emerging larvaeJpupaeladults spend their life on

the palm itself.

Control

Infested leaveslleaflets can be clipped off and

burnt in cases of mild infestation. This prevents

further spread of the pest.

When the infestation occurs at a medium level,

biological pest suppression using the indigenous

parasitoids is quite effective. The bethylid parasitoid

Goniozus nephantidis @ 20%, t he elasmid Elasmus

nephantidis @ 50% and the chalcidid Brachymeria

nephantidis @ 30% may be relelased depending on

the stage of the pest present in the field. The

dose for release of the parasitoid is fixed on the

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population of the target stage of the pest. When

it occurs in a multistage condition, release all the

parasitoids @ 40%. The release has to be done, at

fortnightly intervals, and continued till the

population subsides below the economic irtjury level.

The parasitoids are multiplied in the Zonal

Parasite Breeding Laboratories and in the Biological

Control Laboratory at Central Plantation Crops

Research Institute, Kayangulam. The latter supplies

the nucleus cultures of parasitoids to the Zonal

Parasite Breeding Stations in the coconut growing,

states, where O. arenoseJ/a is a problem. The

parasitoids are made available to the farmers, on

request, from the Zonal Parasite Breeding Stations

maintained by the Department of Agriculture,

KeraJa State.

In cases of severe outbreaks following

integrated approach is more feasible.

1. Cut and burn the badly infested leaves!

leaflets and then spray the palms with 0.02%

dichJorvos, which is less toxic to the beneficial

parasitoids.

2 . Mix 2 m l of dichlorvos 100 E. C. in 10 I of

water and this suspension is suffident for spraying

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.---. four palms at a time . The insecticide suspension is

t o b e spray ed on the lo w er surface of the leaves.

so as to drench the la r v al galle ries.

3. Release of parasitoids can be done three

weeks after spraying. Suitable species of parasitoids

at the specified doses are to be released till the pest

popula tion is suppressed.

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Publ~ed by:

M. K. NAIR

Director

Central P la n tation Crops Research Institute

Kasa ragod · 6 7012 4. Kerala.

Text prepared and edited by

G. B. Pillai

B . Sathiamm a

August 1989

Printed at: Sharada Press. Mangalore.

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