Pests

Fruit flies (Bactocera cucurbitae)

Fruit fly maggots feed on the internal tissues of the fruit causing premature fruit drop and also yellowing and rotting of the affected fruits. This fly is difficult to control because its maggots feed inside the fruits, protected from direct contact with insecticides.

Control: Apply carbaryl 10 % DP in pits before sowing of seeds to destroy the pupae. Breaking of soil to expose pupae, and burning the soil in pit by dried leaves are also effective. Bury any infested fruits to prevent the build up of fruit fly population. Covering the fruits in polythene/paper covers helps to prevent flies from laying eggs inside the fruits. It can also be effectively controlled by the use of banana fruit traps prepared.

Epilachna beetle (Epilachna spp.)

The yellowish coloured grubs and adults of the beetle feed voraciously on leaves and tender plant parts, and the leaves are completely skeletonized leaving only a network of veins. When in large number, the pest causes serious defoliation and reduces yield.

Control: Remove and destroy egg masses, grubs and adults occurring on leaves. Spray carbaryl 0.2 %.

Pumpkin beetle (Aulacophora fevicolis, A. cincta and A. intermedia)

Adult beetles eat the leaves, makes hole on foliage and causes damage on roots and leaves. Grubs cause damage by feeding on root. It also feeds on flowers and bores into developing fruits that touch the soil.

Control: Incorporate carbaryl 10% DP in pits before sowing the seeds to destroy grubs and pupae..

Aphids (Aphis gossypi )

Aphids in large number congregate on tender parts of plant and suck sap resulting in curling and crinkling of leaves. Ants carry aphids from one plant to another.

Control: Apply 1.5% fish oil soap. First dissolve soap in hot water and then make up the volume. Alternatively apply dimethoate 0.05%.

Diseases

Downy mildew (Pseudoperonospora cubensis)

Cottony white mycelial growth is seen on the leaf surface. Chlorotic specks can be seen on the upper surface of the leaves. It is severe during rainy season.

Control: Complete removal and destruction of the affected leaves. Spraying 10 % solution of  neem or kiriyath preparation. If the disease incidence is severe spraying mancozeb 0.2% will be useful.

Powdery mildew (Erysiphe cichoracearum )

The disease appears as small, round, whitish spots on leaves and stems. The spots enlarge and coalesce rapidly and white powdery mass appears on the upper leaf surface. Heavily infected leaves become yellow, and later become dry and brown. Extensive premature defoliation of the older leaves resulting in yield reduction. High humidity and heavy dew increase the severity of the disease.

Control: Control the disease by spraying Dinocap 0.05%.

Mosaic

Mosaic disease is characterized by vein clearing and chlorosis of leaves. The yellow network of veins is very conspicuous and veins and veinlets are thickened. Plants infected in the early stages remain stunted and yield gets severely reduced. White fly (Bemisia tabaci) is the natural vector of this virus.

Control: Control the vectors by spraying dimethoate 0.05%. Uprooting and destruction of affected plants and collateral hosts should be done. Harvesting can be done only after 10 days (at least) of insecticide/fungicide application. The fruits should be washed thoroughly in water before cooking.