author(s)
Santhana Bharathi N, Deepa A, Chithra P and Sujatha K

abstract
The Steinernema– Xenorhabdus symbionts were tested for its pathogenicity against 1^st to 4^th instar larvae and pupae of Aedes aegypti under laboratory conditions. The larval mortality study was carried out for treatments T₁ to T₁₀ with inoculum dosage of 100 to 1000 IJs/10 larvae and pupae of A. aegypti. After 24 and 48 h of application there was no mortality observed in 1^st and 2^nd instar larvae of A. aegypti. The maximum larval mortality of 63% and 60% were noted as 48 h of application in 4^th instar and pupae respectively. Further biochemical studies showed a highly significant reduction when compared to the control groups. This may be due to the utilization of these biochemical compounds for the metabolism of EPNs. The present work has shown the efficiency of Steinernema– Xenorhabdus symbionts against dengue viral vector A. aegypti. The study paves a way to identify novel nematodes and bacterial toxins against A. aegypti.