S. M. Mahboob Hassan*, Seema Kumari, Anju Kumari & Sunil Kumar
Department of Zoology, Patna Science College, Patna University, Patna, Bihar, India
Received : 22th October, 2017 ; Revised :27th December,2017
Abstract : The adult females of Dysdercus cingulatus pass the winter season lays eggs inside the soil near food plants. The females laid eggs either in one or two loose mass in the soil. At a time, one female Dysdercus cingulatus laid eggs 50 to 60 in numbers. Freshly laid eggs were spherical in shape and creamy white in colour. The eggs of Dysdercus cingulatus were measured bout 2.50 mm to 3.50 mm in diameter. The newly emerge females when kept with mature males laid eggs as early as 15 to 18 days after fledging. Before incubation, eggs changed from creamy white to dark brown in colour. The eggs were laid one after another and were glued together on the surface by means of some adhesive secretion. Five insectidies viz, Decamethrin, Cypermethrin, endosulfan quinalphos and phosphamidon were observed as ovicides against one day old eggs of Dysdercus cingulatus, when applied as 0.0025%, 0.005%, 0.0075% and 0.01% in the case of Decamethrin and 0.25%, 0.05%, 0.075% and 0.1% for the remaining four insecticides. The egg mortality of the insect varies from 9.85% in case of 0.0025% Decamethrin to 100.00% in 0.1% phosphamidon. However, 0.1% quinalphos caused 82.56% egg mortality followed by 58.75% mortality in 0.1% endosulfan. Non-Pyrethroids were applied as 0.05% emulsion, phosphamidon, quinalphos, endosulfan and cypermethrin caused 71.32%, 64.50%, 51.67% and 41.76% egg mortality respectively. Evidently, synthetic Pyrethroid Decamethrin is endowed with poor ovicidal activity. The Decamethrin did not posses ovicidal action as evidenced by low egg mortality.
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