author(s)
KV Raghavendra, C Chinniah, GT Jayasimha and R Gowthami

abstract
An in-vitro study was conducted to screen certain plant derivatives and natural oils against Tetranychus urticae Koch based on percent mortality of mites and percent reduction in egg laying by mites. The study revealed that propargite 57 EC @ 2.00ml/l (standard check) was significantly superior than the botanical extracts and natural oils tested in terms of mortality of adults (84.63 percent) and reduction of eggs (81.82 percent) respectively. However among the different plant derivatives and natural oils evaluated, tulsi leaf extract @10 percent, neem oil @ 5 percent, neem oil @ 3 percent, nochi leaf extract @10 percent and nochi leaf extract @ 5 percent recorded the maximum mortality of mites (81.15, 80.72, 80.58, 80.29 and 79.98 percent) and the maximum reduction of eggs as well (74.93, 74.41, 73.99, 73.52 and 73.10 percent) respectively, which were statistically on par in their efficacy. From the present investigation it is evident that tulsi leaf extract @10 percent, neem oil @ 3 percent and nochi leaf extract @ 5 percent were found to be the best candidates which can be recommended as an alternative to synthetic chemical acaricides for the management of T. urticae Koch.