Laboratory evaluation of chitin synthesis inhibitor Lufenuron in individuals mortality of subterranean termite Microcerotermes diversus (Silv.) (Isoptera: Termitidae) at different temperatures.

Abstract

The study was conducted by treatment of termite diet media with CSI (Lufenuron). The concentrations 8000 , 10000 and 12000 ppm were used to know the mortalities in workers and soldiers of termite Microcerotermes diversus (Silv.) at different temperature degrees (20 , 25 , 30 , 35 + 3 o C). Lufenuron at all concentrations and temperature degrees caused a gradual mortality and the results also showed no difference in susceptibility between workers and soldiers towards toxicity of Lufenuron. Temperate had a significant effect on the speed up of incidence of mortality. Therefore , the mortality percentage reached to 100% in workers and soldiers after 28 days from treatment at temperature of 25 and 30 + 3 o C , and after 49 days at temperature of 20 and 35 + 3 o C . The second reinfestation of the same treated diet after 60 days and the third reinfestation after 90 days of treatment had shown a gradual relative decline in the percentage mortalities of termite individuals depending on the duration of exposure. Mortality percentages reached to more than 50% at the highest concentration (12000 ppm) and less than 50% at the lowest concentration (8000 ppm) at temperatures at 25 and 30 + 3 o C after 90 days from treatment. The results showed that there is a positive correlation between concentrations and mortality percentages at all temperature degrees. It could be conducted that the effective duration and persistence of Lufenuron depend on concentration , temperature and exposure time.