235 ENTOMON 42(3): 235-238 (2017) Short Communication No. ent. 42309 * Author for correspondence © 2017 Association for Advancement of Entomology Evaluation of ajwain and mustard seed extract on susceptibility of Anopheles stephensi Liston Neetu Kachhwaha * , Shashi Meena and Geeta Meena Department of Zoology, University of Rajasthan, Jaipur, 302004, Rajasthan, India Email: drneetu2011@gmail.com ABSTRACT: The most effective method to manage mosquito population is to kill aquatic stages (egg, larva and pupa) of mosquito than the aerial adult stage. The susceptibility test was evaluated against larvae of Anopheles stephensi in the laboratory conditions maintaining the temperature of 27±2ºC and 70±80% Relative Humidity. The combination of the seed extracts of Trachyspermum ammi (ajwain), mustard oil and naphthalene were taken in the ratio 1:2:1. Results of the larval susceptibility test after 25 hours of treatment revealed that the combination of the three components are significant in killing the larval population of Anopheles stephensi to some extent. It has also been noticed that the rise in dose from 1ml/199ml to 7ml/99ml of water increased the larval mortality. © 2017 Association for Advancement of Entomology KEY WORDS: Susceptibility test; Anopheles stephensi larvae; ajwain; mustard Mosquito and man relationship lies on earth from millions of year ago. Major focus is on killing adult stages of mosquito but larval stages are easy to manage as they are in known areas, do not fly, do not bite, do not spread diseases, safer, easy to kill by various integrated managements. The three stages of mosquito egg, larvae and pupae are aquatic while only the adult stage is aerial. So we can manage and control three stages at a time. Three strains of Aedes aegpti and a single species of Culex molestus were studied to determine susceptibility of larvae to various insecticides by George (1957). Anopheles stephensi is a well known urban vector found in tropic regions of India (Dash et al, 2007) breeds in man-made sites such as overhead tanks, wells, masonry tanks, water coolers, barrels, discarded tyres, tins, intradomestic containers, garden pots, curing water in construction sites etc (Kumar and Thavaselvam, 1992). There are many ways of larval control like application of tablet, pellet and granular formulation of larvicidal chemicals, introduction of larvivorous fishes like Gambusia affinis, Poecilia reticulate in large breeding sites (ponds and pools), use of insect growth regulators, use of mineral oils and other microbial control agents such as Bacillus thuringiensis israelensis (Bti), Bacillus sphaericus (Khyami-Horani, 1995). A combination of T rachyspermum ammi , mustard oil and naphthalene was tested on larval susceptibility Anopheles stephensi Liston in the laboratory. For conducting the test 250ml glassbeakers, dropper to transfer larvae, soxhlet apparatus for extraction of Trachyspermum ammi , mustard oil and naphthalene powder, third or fourth instar larvae, cooling incubator for maintain temperature were used. Larval susceptibility test was accomplished by taking the help of WHO guidelines (2005) and Khalil et al. (2015). Thirty larvae (basically third