Studies On The Biology, Morphology And Host Range Of The Melon Bug Coridius Viduatus (Fabricius) (Hemiptera, Dinidoridae) In The Northern State .

Abstract

The melon bug Coridius viduatus(Fabricus),(Hemiptera, Dinidoridae) recently became a serious pest attacking cucurbits in the Northern State. The present study covered the insect biology, ecology and morphology as well as the host plant range. The average of incubation period was 10.50±0.05 days, hatchability was 100%. The durations of nymphal instars (from 1st till 5th) were 6.04±0.09,6.00±0.24, 5.27±0.21,7.04±0.12and 17.77±0.33 days respectively. Mean of the total developmental period from egg to adult was 53.64±3.23 days. Life span for adults was 57.36±1.58 and 78.48±1.22 days for male and female respectively. The female fecundity was 214.28±20.48 eggs. The maximum number of eggs produced by a single mated female was 319 eggs, and the peak of egg laying was in the 3rd week from first mating. The field survey confirmed that both adults and nymphs attack cucurbits . They feed on stem, leaves and developing fruits which resulted in the plant wilting, shedding of leaves and finally plant death. Host range included watermelon Citrullus lanatus, snake melon Cucumis melo var. flexuosus and Tasali (Jurum) Citrullus sp. Also cucumber Cucumis sativus and musk melon Cucumis melo were attacked by the bug. The noncrop plant bitter apple Citrullus colocynthis was observed as host for feeding and sheltering. Some plants and trees were used as a shelter for aestivation. The main shelter tree is the date palm Phoenix dactylifera which is widely dispersed in the area and its growing nature secured good place for hiding. Other shelter plants were Soddom apple Calotropis procera , Neem, Azadirachta indica and some forest trees like Acacia spp.