RESUMEN
Many mosquito species take bloodmeals predominantly from either birds or mammals. Other mosquito species are less host-specific and feed readily on both. Furthermore, some species tend to alter their feeding patterns over the course of the year; early in the mosquito season such species may feed primarily on a particular host type, and subsequently take an increasingly larger proportion of their bloodmeals from an alternative host type as the season progresses. We have examined the feeding patterns of the three mosquito species found in Bernalillo County, NM: Culex quinquefasciatus (Say), Culex tarsalis (Coquillett), and Aedes vexans (Meigen). Specifically, we seek to determine if any of these species displays a seasonal shift in terms of its host utilization pattern. Our analysis focuses on these three species because they are all considered to be competent vectors for the West Nile virus (WNV). Our current data for Cx. quinquefasciatus suggest that unlike elsewhere in its range, this species increases its proportion of avian bloodmeals as the season progresses. Alternatively, Ae. vexans feeds primarily on mammals, whereas Cx. tarsalis appears to feed on both mammals and birds throughout the mosquito season. A more complete understanding of the feeding habits of these three mosquito species may help to clarify the transmission dynamics of WNV in Bernalillo County.
Asunto(s)
Aedes/fisiología , Culex/fisiología , Preferencias Alimentarias , Insectos Vectores/fisiología , Fiebre del Nilo Occidental/transmisión , Animales , Aves , Mamíferos , New Mexico , Estaciones del Año , Virus del Nilo OccidentalRESUMEN
Female mammals typically become hyperphagic from mid- to late pregnancy and during lactation. Mexican free-tailed bats, Tadarida brasiliensis mexicana, double their nightly food intake from late pregnancy to peak lactation and consume an insect diet that is exceptionally high in fat. During late pregnancy and throughout lactation, fasting plasma levels of cholesterol in this insectivorous bat are high (215 +/- 8 mg/dl) and are nearly 10-fold higher than in three species of Old World frugivorous bats. Fasting triglycerides were unexpectedly low in T. brasiliensis (25 +/- 2 mg/dl), despite evidence of high fat intake during nightly feeding bouts (postprandial cholesterol and triglycerides, 268 +/- 18 and 122 +/- 20 mg/dl, respectively). High-density lipoprotein (HDL) cholesterol levels were extraordinarily high (124 +/- 5 mg/dl) and unaffected by feeding. Low-density lipoprotein cholesterol levels were correspondingly low (86 +/- 7 mg/dl). This unusual plasma lipid profile was not associated with coronary or aortic atherosclerosis, nor was there evidence of hyperglycemia or hyperinsulinemia. A high-fat diet and high levels of cholesterol in T. brasiliensis are not correlated with cardiovascular disease or (possibly) insulin resistance. Among several possible factors that might account for these observations, nightly bouts of powered flight (commuting and foraging for food) may contribute to elevated HDL cholesterol, which may protect this species from developing atherosclerosis.