Evaluation of non-toxic visible dyes as markers for microtermes obesi and odontotermes lokanandi (blattodea: Termitidae)

Workers and soldiers of microtermes obesi holmgren and odontotermes lokanandi chatarjee and thakur (blattodea: termitidae) were force-fed on different concentrations of nile blue-a and sudan red-7b. results showed that 0.5% nile blue-a caused 100 % mortality in m. obesi on 15th day in m. obesi and on 9th day,whereas 0.5% sudan red caused 100% mortality in m. obesi on 9th day in o. lokanandi,on 5th day m. obesi and o. lokanandi were released on baits containing different concentrations of nile blue-a. m. obesi got colour at 100% relative humidity after day 10 at all concentrations,while at 92 and 76% relative humidity they got colour at high concentration only. however,o. lokanandi was found sensitive to nile blue. m. obesi and o. lokanandi released on baits of sudan red-7b,did not get any colour under all tested relative humidities. nile blue-a and sudan red at medium and low concentrations remained in bodies of more than 90% m. obesi for 25 and 10 days,respectively. after 60 days,maximum of 59.33% termites were blue with low concentration of nile blue. all m. obesi stained with sudan red were dead by day 60.