Insecticide Susceptibility of Aedes Aegypti Larvae to Bacillus Thuringiensis Israelensis and Juvenile Hormone in Dengue Epidemic Areas of Samutsongkhram, Thailand

Abstract

Dengue hemorrhagic fever (DHF) remains one of Thailand's main public health problems. Samutsongkhram is one of the areas undergoing an epidemic of this disease. To control this disease, public health officers focus on regulating the population of Aedes aegypti larvae. The aims of this research were to study the susceptibility of Ae. aegypti to Bacillus thuringiensis israelensis (Bti) and juvenile hormone, in order to end the spread of this disease in three epidemic DHF outbreak sub-districts of Ladyai, Suanluang and Jompuak. The results revealed that Ae. aegypti is susceptible to Bti and juvenile hormone in all areas, with a 100% death rate. Exposure to Bti eradicated the larvae in a very short time of less than 18 hours. In addition, juvenile hormone can completely hinder the growth of Ae. aegypti to adult stages. The results demonstrate the effectiveness of these agents for mosquito larvae eradication. Therefore, insecticidal bacterium and juvenile hormone may be an option to reduce the number of DHF patients in Samutsongkhram, Thailand.

Larvicidal and Adult Mosquito Attractant Activity of Auricularia auricula-judae Mushroom Extract on Aedes aegypti (L.) and Culex sitiens Wiedemann

“…aegypti at all concentrations. These findings are in line with previous research that found this concentration could best attract mosquitoes, especially Aedes mosquitoes (Cilek et al, 2011). However, a comparison of the number of mosquitoes attracted to A. auricula-judae extract and oetenol were different at all concentrations (p > 0.05) (Figure 2).…”

“…From all mentioned to this point, we selected Auricularia auricula-judae mushrooms as an edible and commercially available mushroom species grown in Thailand. The aim of this study was to assess larvicidal and adult mosquito attractant activity of this mushroom extract with respect to Aedes aegypti (L.) as a dengue vector and Culex sitiens Wiedemann as a filariasis and Japanese encephalitis vector (predominantly in costal habitats) (Chaiphongpachara and Sumruayphol, 2017). The results from this research revealed the ability of A. auricula-judae mushrooms to be utilized in controlling mosquitoes, leading to the creation of new additional new products.…”

“…Mosquitoes are small insects that are major vectors for the transmission of many diseases to humans, including malaria, dengue fever, yellow fever, lymphatic filariasis, and Japanese encephalitis (Service, 2008;Damapong et al, 2016). These diseases are significant public health problems worldwide, especially in tropical and sub-tropical countries (Chaiphongpachara et al, 2017). WHO estimates that every year, more than one million people die and nearly half of the world's population inhabit high-risk areas for mosquito-borne diseases (World Health Organization, 2014;World Health Organization, 2016).…”

“…There are two ways to control vectors reducing the number of larvae and compromising the adult stage of mosquitoes. Temephos is an organophosphate larvicide that is a popular and widely used chemical product which effectively controls larval stage especially Aedes aegypti, and it is not toxic to humans or animals (Chaiphongpachara et al, 2017). However, there are currently reports of resistance of mosquitoes to this chemical occurring in many areas around the globe, including Thailand, owing to the employment of this chemical for a long time (Jirakanjanakit et al, 2007).…”