Pests
Fruit flies: Bactocera cucurbitae
Fruit fly is the most destructive insect pest of pumpkin. 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: Bury any infested fruits to prevent the build up of fruit fly population. In homestead gardens, covering the fruits in polythene/paper covers help to prevent flies from laying eggs inside the fruits. Breaking of soil to expose pupae, and burning the soil in pit by dried leaves are also effective. It can also be effectively controlled by the use of banana fruit traps.
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.
Control: Control the disease by spraying Dinocap 0.05%.
Mosaic(Cucumber Mosaic Virus)
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. Growths of plants infected in the early stages remain stunted and yield of the plant get 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.