Influence of Bloodmeal Source on Reproductive Output of the Potential West Nile Vector, Culex theileri (Diptera: Culicidae).

Culex theileri Theobald (Diptera: Culicidae) has a wide Afrotropical, southern Palaearctic, northern Oriental, and European distribution. It is mainly considered as a mammophilic mosquito and also feeds on birds and serves as a vector for various zoonotic diseases including West Nile virus. Despite its broad distribution and evidence indicating that Cx. theileri is a competent vector of human and domestic animal pathogens, basic biological and ecological features of this species have not been well investigated. We evaluated the impact of bloodmeal source (human, chicken, cow, and a double bloodmeal such as human and cow or chicken and cow and mixed bloodmeals [cow, chicken, and human] via artificial feeding) on fecundity, hatching rates, developmental times, and viability from egg to adult for laboratory colonized Cx. theileri. Fecundity in mosquitoes that took a chicken bloodmeal, a double bloodmeal and mixed bloodmeals was significantly higher than in females fed on a single cow or single human blood. This is the first study about the bloodmeal sources effect on laboratory-reared Cx. theileri populations and these findings contribute to our understanding of the impact of bloodmeal source on reproduction in Cx. theileri. As it is known that Cx. theileri is a vector for West Nile virus, the potential impacts of bloodmeal source on virus transmission are discussed.

Host Bloodmeal Source Has No Significant Effect on the Fecundity and Subsequent Larval Development Traits of the Progeny in Culicoides furens Poey (Diptera: Ceratopogonidae).

Culicoides Latreille species (Diptera: Ceratopogonidae) are insects of significant medical and veterinary importance worldwide because their bites can cause major annoyance, allergic reactions, and/or pathogen transmission to vertebrates, including humans. In this study, we examined the effect of host bloodmeal source on the fecundity and subsequent larval development traits of the progeny of Culicoides furens Poey, a nuisance species in coastal Florida. Field-collected females were fed on two different classes of hosts: birds (chicken) or mammals (human). Fecundity outcomes of the females and larval developmental traits of the progeny were recorded and compared between the two groups. The percentage of females that developed eggs, percentage of gravid females that deposited eggs, number of eggs produced per female, number of eggs deposited per female, egg hatch rates, larval survival rates, time to pupation, pupal sex-ratios, and adult eclosion rates were not significantly different between the two groups. Our results demonstrate that the host bloodmeal source has no significant effect on the fecundity and subsequent larval developmental life-history traits of the progeny in C. furens. Previous studies reported C. furens to be a generalist feeder that shows no host preference for birds or mammals. Collectively, these findings suggest that C. furens is well adapted, not just behaviorally, but also physiologically to efficiently utilize blood meals from avian and mammalian hosts, a quality that offers a major evolutionary advantage to the success of this midge species as a generalist feeder.

Characterization of an Indoor-Resting Population of Anopheles arabiensis (Diptera: Culicidae) and the Implications on Malaria Transmission in Tubu Village in Okavango Subdistrict, Botswana.

Comprehensive knowledge on vector dynamics is lacking in Botswana and yet essential for effective indoor residual spraying. This study assessed some of the entomological indices that contribute to malaria transmission by an indoor-resting population of Anopheles arabiensis Patton (Diptera: Culicidae) in Tubu village, Okavango subdistrict. The pyrethroid space-spray technique and hut searches were used to sample mosquitoes. Species and bloodmeal source identification were done using the polymerase chain reaction techniques. The infective status was determined by the enzyme-linked immuno-sorbent assay test. The human blood indices (HBI), human-biting rates (HBR), and vector densities were computed. Anopheles arabiensis was the sole vector and member of the Anopheles gambiae Giles complex identified. Significant changes in vector densities were observed over seasons, while nonsignificant differences were observed among the huts (P > 0.05). The main source of bloodmeal was cattle (46.8% [65]). There were no significant differences in HBI (P > 0.05) and HBR (P > 0.05) between the seasons. All the 271 mosquitoes tested for sporozoite infection were negative. The results showed that seasonal variations in vector densities corresponded to the traditional malaria and nonmalaria seasons. The vector population was relatively more zoophagic. The HBI and HBR were not influenced by the seasons. None of the endophilic mosquitoes tested (N = 271) was positive for sporozoites. Our study provided some relevant basic information to the local malaria control program that may be used to strategize their operations if malaria elimination has to be achieved by 2017.