Toxicity of Dimethoate and Chlorpyriphos on haemocyte count in male Platynotus belli Fairmaire (Coleoptera: Tenebrionidae)

Abstract

The toxicity of Dimethoate 30% EC and Chlorpyriphos 20% EC organophosphate insecticides in field concentration was observed against the haemocyte counts of Platynotus belli Fairmaire beetle. In these studies, seven types of haemocytes were identified viz., Prohaemocyte, Plasmatocyte, Granulocyte, Oenocytoid, Coagulocyte, Adipohaemocyte and Spherulocyte in the haemolymph of P. belli. The untreated specimen of control group P. belli beetle total haemocyte count (THC) were 26233.33 ± 251.66 cells/mm3. The Dimethoate and Chlorpyriphos treatment showed the differences cell number as compared to control group. The three concentrations 400ppp, 600ppm and 800ppm showed maximum increased in cell number which is inversely proportional to the concentration of insecticide i.e. 37150 ± 175.796; 34183.33 ± 175.599 and 27403.67 ± 352. 406 respectively in Dimethoate treated beetle. While, in Chlorpyriphos treatment also increased the cell number which is inversely proportional to the concentration of insecticide i.e. at 200ppm 35383.33 ±539. 289; 400pmm 26300 ± 100 and at 600ppm 11383.33 ± 534. 633. Both insecticides showed the decreased number of cells when concentration was increased.