Larvae of the elephant mosquitoes, Toxorhynchites spp. (Diptera: Culicidae) are predacious on larvae of other mosquito species and some small aquatic organisms; this predatory behavior can be applied in (mosquito) vector control. The present study examined the feeding behavior of Toxorhynchites splendens on Aedes albopictus in relation to search area [volume of water (X1)] and prey density (X2), prey instars, predatory preference and larvae's functional response on variable prey densities. Experiments were conducted to determine changes in the feeding activity of T. splendens with different search areas and showed that rate of prey consumption was inversely proportional to the search area as evidenced by a negative value of X1 in the regression equation and positively related to prey density. The non-linear polynomial logistic regression estimated a significant linear parameter (P1 < 0) for the functional response analysis suggesting a Type II functional response. Differences in feeding response related to the different combinations of prey instars were statistically not significant (p > 0.05), expressing that all the instars of prey were equally susceptible to the predator. Toxorhynchites splendens preferred to consume Ae. albopictus larvae rather than Tubifex when supplied together as a food source.

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In tropical and subtropical countries, mosquitoes play vital role as vectors of numerous dangerous diseases, such as dengue, yellow fever, filariasis, malaria, and zika, among others. Aedes albopictus, the Asian tiger mosquito can transmit the viruses of several life threatening diseases including, dengue, yellow fever, and zika. The present study aimed at assessment of the larvicidal activity of the crude extract of Diospyros montana leaves against Ae. Albopictus, and identification of the plant compound and functional groups responsible for larvicidal efficacy via FT-IR and different phytochemical analysis. Effect on the non-target organisms was also evaluated. However, more than 80% larval mortality is observed after 72 hours of exposure in all instars. After 72 hours of exposure, the LC50 caused moderate mortality of 12% and 8% against Chironomus circumdatus and Toxorhynchites splendens respectively. Numerous secondary metabolites, including terpenoids, saponins, flavonoids, and alkaloids, coumarins were present in the crude extract of D. Montana. This is the first study to examine the efficacy of D. Montana leaf extract as a larvicidal agent against Ae. albopictus through determination of its secondary metabolites.