coconut pest

edmurderrLEPIDOPTERAN PESTS OF COCONUT

Black headed caterpillar: Opisina arenosella, Symptoms of Damage
Dried up patches on leaflets of the lower leaves
Galleries of silk and frass on under side of leaflets.





















Burnt appearence
Identification of the pest
Larva
Caterpillar is greenish brown with dark brown head and prothorax, and a reddish mesothorax.
It has brown stripes on the body
Pupa
It pupates inside the web itself in a thin silken cocoon
Adult
Moth: Greyish white in colour
Female: with long antenna and three faint spots on the forewings
Male: with fringed hairs in hind wings in apical and anal margin.
Management
Among the larval parasitoids, the bethylid Goniozus nephantidis is the most effective in controlling the pest.
The optimum level of release is 1:8 of host-parasitoid ratio.
The parasitoid should be released @3000/ha under the coconut trees when the pest is in the 2nd or 3rd instar larval stage. Parasitoid release trap may be used to release the parasitoid at the site of feeding.
Parasitoids should not be released in the crown region since they will be killed by predators like spiders and reduviid bugs.
Remove and burn all affected leaves/leaflets.
Spray malathion 50 EC 0.05% (1mi/lit) to cover the undersurface of the leaves thoroughly in case of severe epidemic outbreak of the pest in young palms.
Root feeding for the control of coconut black headed caterpillar
Select a fresh and live root
Cut sharply at an angle and insert the root in the insecticidal solution containing monocrotophos 36 WSC 10 ml + water 10 ml in a 7 x 10 cm polythene bag.
Secure the bag tightly to the root with a cotton thread.
Twenty four hours later, check whether there is absorption.
If there is no absorption select another root.
These methods should not be resorted to as a routine practice and it is suggested only for cases of severe epidemic outbreak of the pest and when the survival of the tree is threatened.

Slug caterpillar: Parasa lepida and Contheyla rotunda, Symptoms of damage
Defoliation
Identification of the pest
i. Parasa lepida
Egg: Flat shiny eggs on the under surface of leaves
Larva: Greenish body with white lines and four rows of spiny scoli tipped red or black, which cause irritation and pain.
Pupa: It pupates in a compact elliptical chocolate brown shell like cocoon, which is convex above and flat ventrally as stems. Cocoons are covered with irritating spines and hairs
Adult: Adult moth has green wings with prominent dark patch at the base of each forewing.
ii. C. rotunda :
Larva- Black or grey dorsally and dorso laterally.
Adult - Small greyish brown moth. Forewings have slight dark in colour and series of black points. Hind wings are slightly darker.
ManagementSpray any one of the following
Dichorvos 76 WSC 2 ml/lit
Bacillus thuringiensis 2 g/lit,
Triazophos 40 EC 5 ml
Methyl demeton 25 EC 4 ml/lit
Root feeding with monocrotophos 15 ml + 15 ml of water

Coconut skipper: Gangara thyrsis ; Suastus gremiusSymptoms of damage
Tip of the leaflets rolled
Identification of the pesti. Gangara thyrsis
Larva: - Pale green with reddish markings. Body concealed in a covering of white waxy markings
Adult: Butterfly-brownish in colour. Chocolate brown wing with yellow spots
ii. Suastus gremiusSymptoms of damage
One half of the leaflets are cut and rolled into a case
Identification of the pest
Larva: Smooth, green, tapering at either end with a constriction between head and body
Adult: Chocolate brown with yellow spots on forewings
Management
Collect and destroy the immature stages of the insects by conducting study (or neem compaign) wherever possible and spray carbaryl 50 WP 2 gm/lit.
Root feeding with monocrotophos 36 WSC @ 10 ml + 10 ml water at 45 days interval for 3 times for control of leaf caterpillar.
Set up light traps to trap and collect adult moths
Spray dichlorvos 76 WSC 2 ml / lit.

Leaf caterpillars: Turnaca acutaSymptoms of damage
Feeds on leaflets leaving stick
Identification of the pest
Larva: -Brown with two pink stripes later turns greenish
Adult: Dull white
Management
Collect and destroy the immature stages of the insects by conducting study (or neem compaign) wherever possible and spray carbaryl 50 WP 2 gm/lit .
Root feeding with monocrotophos 36 WSC @ 10 ml + 10 ml water at 45 days interval for 3 times for control of leaf caterpillar.
Set up light traps to trap and collect adult moths
Spray dichlorvos 76 WSC 2 ml / lit.

Bag worm: Manatha albipes Symptoms of damage
Small and irregular hole on the leaves
Identification of the pestLarva: - Inside the conical bags constructed with silk and thread Management
Collect and destroy the immature stages of the wherever possible and spray carbary 50 WP 2 gm/lit.
Root feeding with monocrotophos 36 WSC @ 10 ml + 10 ml water at 45 days interval for 3 times for control of leaf caterpillar.
Set up light traps to trap and collect adult moths
Spray dichlorvas 76 WSC 2 ml / lit.
REFERENCES:
http://agritech.tnau.ac.in/crop_protection/crop_prot_crop_insect_oil_coconut.html