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Cocoa


Mealy bugs


Symptoms of damage

It colonizes on the tender parts of the plant such as growing tips of the shoots, the terminal buds, the flower cushions, the young cherelles and mature pods. Feeding of mealy bugs induces cherelle wilt. Following control measures are recommended.

Identification of pest

When the infestation is lesser: Spraying of Neem Oil 3% or fish oil rosin soap 25g/litre

Adult : Grayish beetle with two pink dots and lateral spine

Management

When the infestation is lesser: Spraying of Neem Oil 3% or fish oil rosin soap 25g/litre
In case of severe incidence, spraying of any one of the following chemicals is recommended : Dimethoate (2 ml/litre) , Profenophos (2 ml/litre), Chlorpyriphos (5 ml/litre), Buprofezin (2 ml/litre), Imidacloprid (0.6 ml/lit), Thiamethoxam (0.6g/litre)
In the area where P. marginatus alone occurs, field release of Acerophagus papayae, the encyrtid parasitoid @ 100 per hamlet is recommended as the best management strategy.

Tea mosquitoe bugs


Symptoms of damage

Infested pods develop circular water soaked spots around the feeding punctures. These punctures subsequently turn pitch black in color. Deformation of pods occurs because of multiple feeding injuries.

Identification of pest

When the infestation is lesser: Spraying of Neem Oil 3% is recommended.

In case of severe incidence, spraying of any one of the following chemicals is recommended: Imidacloprid (0.6 ml/lit) , Thiamethoxam (0.6g/litre), Profenophos (2 ml/litre), Carbaryl (2g/lit)

Management

Remove and destroy dead and severely affected branches of the tree
Remove alternate host, silk cotton and other hosts
Grow tolerant mango varieties viz., Neelam, Humayudin.
Padding with monocrotophos 36 WSC 10 ml in 2.5 cm /tree soaked in absorbent cotton
If infestations are severe then apply the copper oxychloride paste on the trunk of the tree.
Hook out the grub from the bore hole - apply monocrotophos 36 WSC 10 to 20 ml/ hole
One celphos tablet (3 g aluminum phosphide) per hole
Apply carbofuran 3G 5 g per hole and plug with mud.

Flatid Plant hoppers


Symptoms of damage

Nymphs and adults suck the sap from flowers, tender shoots and pods. They excrete honey dew resulting in the development of sooty mould fungus on the leaves and pods.

Management

Foliar application of a newer molecule Thiacloprid @ 2 ml/litre twice at 5 days interval is recommended for the management of these flatid plant hoppers.

Aphids


Symptoms of damage

They colonize on the underside of tender leaves, succulent stem, flower buds and small cherelles. Heavy infestation may occur during hot summer and after rainy season which brings about premature shedding of flowers and curling of leaves.

Management

Spraying of dimethoate @ 2 ml per litre

Hairy caterpillars


Symptoms of damage

They cause serious leaf damage on seedlings and young trees.

Management

Foliar spray of acephate @ 2g/litre of water

Stem Girdler


Symptoms of damage

Damage was done by female beetle which girdles the branches and inserts whitish spindle shaped eggs singly into the tissue in a slanting manner. Due to mechanical injury caused by girdling and oviposition, the branches above the girdle wither and dry.

Management

Swab Coal tar + Kerosene @ 1:2 or carbaryl 50 WP 20 g / litre (basal portion of the trunk - 3 feet height) after scraping the loose bark to prevent oviposition by adults.
Hook out the grub from the bore hole and apply monocrotophos 36 WSC 5 to 10 ml/ bore hole (or) apply carbofuran 3G 5 g/bore hole and plug with mud.
Injection of dichlorvas (DDVP) + monocrotophos solution into bore holes after removing the webs and subsequently sealing of the holes with clay gives satisfactory control of the pest.

Non- Insect pests


Symptoms of damage

Rats (Rattus rattus) and squirrels (Funambulus trisriatus and F. palmarum) are the major rodent pests of cocoa. They cause serious damage to the pods. The rats usually gnaw the pods near the stalk portion whereas squirrels gnaw the pods in the center

Management

The rats can be controlled by placing 10 g bromadiolone (0.005%) wax cakes or ripe banana stuffed with carbofuran on the branches of cocoa trees twice at an interval of 10-12 days.
Squirrels are best controlled by trapping with wooden or wire mesh single catch ‘live’ trap with ripe coconut kernel as the bait.