Mediation of oviposition responses in the malaria mosquito Anopheles stephensi Liston by certain fatty acid esters

Abstract

The chemical factors involved in oviposition site selection by mosquitoes have become the focus of interest in recent years, and considerable attention is paid to the chemical cues influencing mosquito oviposition. Studies on synthetic oviposition attractants/repellents of long-chain fatty acid esters against Anopheles stephensi are limited. Screening and identification of chemicals which potentially attract/repel the gravid females to/or from oviposition site could be exploited for eco-friendly mosquito management strategies. The ester compounds demonstrated their ability to repel and attract the gravid A. stephensi females in the treated substrates. Significant level of concentration-dependent negative oviposition response of mosquitoes to octadecyl propanoate, heptadecyl butanoate, hexadecyl pentanoate, and tetradecyl heptanoate were observed. In contrast, decyl undecanoate, nonyl dodecanoate, pentyl hexadecanoate, and propyl octadecanoate elicited concentration-dependent positive oviposition responses from the gravid mosquitoes. Forcing a female to retain her eggs due to unavailability of a suitable oviposition site and attracting them to lay the eggs in a baited ovitraps shall ensure effective control of mosquito breeding and population buildup because the oviposition bioassay target the most susceptible stage of an insect life cycle. Treating relatively smaller natural breeding sites with an effective repellent and placing ovitraps containing an attractant in combination with insect-growth regulator (IGR)/insecticide would be a promising method of mosquito management.

Attraction of Culex pipiens to House Sparrows Is Influenced by Host Age but Not Uropygial Gland Secretions

“…Despite our negative results, the role of these esters in host-seeking may be worthy of further study in light of the suggestions of Bernier et al and Allen et al, that microbial degradation of the secretions, or synergistic interactions with other chemical cues emitted by house sparrows could contribute to mosquito feeding choice. Moreover, while gravid female mosquitoes seeking oviposition sites are reported to be both attracted to and repelled by esters [29,30], to our knowledge the role of esters in female blood-seeking behavior has not been studied.…”

Gravid females of the mosquito Aedes aegypti avoid oviposition on m-cresol in the presence of the deterrent isomer p-cresol

“…This effect is also reported for the oviposition pheromone erythro-6-Acetoxy-5-hexadecanolide on Cx. quinquefasciatus oviposition [34] and for undecyl decanoate on the oviposition of Anopheles stephensi [35]. Plant infusions also have a dose dependent effect in which the mass of plant material and fermentation period play a major role in determining the effect of the infusion on oviposition [6,20,36].…”

Development of Metarhizium anisopliae and Beauveria bassiana formulations for control of malaria mosquito larvae

“…Frequency of re-application has to be determined based on the residual effect of formulated spores in the field. The feasibility of applying formulated spores at artificial breeding sites, baited to attract ovipositing females, is also worth testing [52]. A good delivery system will reduce the chances of non-target organisms coming into contact with fungal spores.…”