SURVEILLANCE AND ECOLOGY OF MOSQUITO, BITING AND FILTH BREEDING INSECTS
Location: Mosquito and Fly Research Unit
Title: Amino acids in nectar enhance longevity of female Culex quinquefasciatus mosquitoes
Submitted to: Journal of Insect Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 28, 2010
Publication Date: July 1, 2010
Citation: Vrzal, E.M., Allan, S.A., Hahn, D.A. 2010. Amino acids in nectar enhance longevity of female Culex quinquefasciatus mosquitoes. Journal of Insect Physiology. 56(11):1659-1664.
Interpretive Summary: With the recent introduction and subsequent spread of West Nile across the United States, Culex mosquitoes have become the focus of many laboratory studies on ecology, control and disease transmission. Critical to these studies is a better understanding of the role of sugar feeding on life parameters of Culex. Sugar feeding is critical to survival of Culex mosquitoes but the potential role of amino acids from nectar sources is unclear. In this study conducted at USDA's Center for Medical, Agricultural and Veterinary Entomology (CMAVE) in Gainesville (Florida), longevity of male and female Culex quinquefasciatus reared on optimal and suboptimal larval diets was determined after feeding adults on sugar or sugar and amino acid diets. The addition of amino acids to sugar diets of adult females enhanced survival, however, this trend was not seen for males. Amino acids from nectar are important for increased survival, but are most important when larval nutrition is poor, as it is in many field habitats. These results contribute to our understanding of the role of plant nectar sources on mosquito survival which may be utilized for novel surveillance and control strategies.
Culex mosquitoes feed on a wide range of nectars consisting of mostly carbohydrates and amino acids, however, little is known about the utilization and effects of these different carbohydrates and their accompanying amino acids on longevity. Culex quinquefasciatus larvae were reared on high and low quantity food diets to produce adults that were nutritionally representative of laboratory-reared and wild-caught mosquitoes. Emerging adults reared on low or high quantity food diets as larvae were then provided Lantana camara nectar mimics containing mixtures of carbohydrates and amino acids to evaluate effects of nectar amino acids on longevity. Carbohydrates (with or without amino acids) were a critical component of the adult diet, and in their absence, adult mosquitoes died within 3-5 days. The nectar mimic that contained both carbohydrates and amino acids did not increase adult longevity of males originating from either poorly or well-fed larvae. However, females receiving adult diets containing both carbohydrates and amino acids lived 5% longer than females fed adult diets with only sugar. We hypothesize that nectar amino acids are important for increased survival, but are most important when larval nutrition is poor, as it is in many field habitats.