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Zayed A.,Cairo University | Zayed A.,Vector Biology Research Program | Soliman M.M.,Cairo University | El-Shazly M.M.,Cairo University
Journal of Medical Entomology | Year: 2013

Susceptibility of Phlebotomus papatasi Scopoli (Diptera: Psychodidae) larvae to the entomopathogenic fungus Metarhizium anisopliae (Metschinkoff) Sorokin (Ma79) (Hypocreales: Clavicipitaceae) was evaluated at two different temperatures. The ability of the fungus to reinfect healthy sand flies was followed up for ≈20 wk and the effect of in vivo repassage on the enhancement of its virulence was assessed. The fungus reduced the adult emergence at 26 ± 1°C when applied to larval diet. Six spore concentrations were used in the bioassays ranging from 1 × 106 to 5 × 10 8 spores/ml. Mortality decreased significantly when the temperature was raised to 31 ± 1°C at all tested concentrations. Fungus-treated vials were assayed against sand fly larvae at different time lapses without additional reapplication of the fungus in the media to determine whether the level of inocula persisting in the media was sufficient to reinfect healthy sand flies. Twenty weeks postapplication, there were still enough infectious propagules of Ma79 to infect 40% of P. papatasi larvae. A comparison between the infectivity of 10 subsequent in vitro cultures and the host-passed inocula of the fungus against sand fly larvae was conducted. Mortalities of P. papatasi larvae changed significantly when exposed to inocula passed through different insects. Presented data can provide vector control decision makers and end users with fundamental information for the introduction and application of M. anisopliae as an effective control agent against the main cutaneous leishmaniasis old-world vector P. papatasi. © 2013 Entomological Society of America.

Chabi J.,University of Ghana | Baidoo P.K.,Kwame Nkrumah University Of Science And Technology | Datsomor A.K.,University of Ghana | Okyere D.,University of Ghana | And 6 more authors.
Parasites and Vectors | Year: 2016

Background: The increasing spread of insecticide resistance in malaria vectors has been well documented across sub-Saharan Africa countries. The influence of irrigation on increasing vector resistance is poorly understood, and is critical to successful and ethical implementation of food security policies. This study investigated the insecticide resistance status of An. gambiae (s.l.) mosquitoes collected from the irrigated rice area of Okyereko, a village containing about 42 hectares of irrigated field within an irrigation project plan in the Central Region of Ghana. Large amounts of insecticides, herbicides and fertilizers are commonly used in the area to boost the annual production of the rice. Methods: Mosquito larvae were collected and adults were assayed from the F1 progeny. The resistance status, allele and genotype were characterized using WHO susceptibility testing and PCR methods respectively. Results: The An. gambiae (s.l.) populations from Okyereko are highly resistant to DDT and pyrethroid insecticides, with possible involvement of metabolic mechanisms including the elevation of P450 and GST enzyme as well as P-gp activity. The population was mostly composed of An. coluzzii specimens (more than 96 %) with kdr and ace-1 frequencies of 0.9 and 0.2 %, respectively. Conclusion: This study brings additional information on insecticide resistance and the characterization of An. gambiae (s.l.) mosquitoes from Okyereko, which can be helpful in decision making for vector control programmes in the region. © 2016 Chabi et al.

Krajacich B.J.,Colorado State University | Slade J.R.,Infoscitex Corporation | Mulligan R.F.,Infoscitex Corporation | La Brecque B.,Infoscitex Corporation | And 11 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2015

In this study, we characterize the ability of the previously described Infoscitex tent (IST) to capture mosquitoes in comparison to either the Centers for Disease Control Light Trap hung next to individuals under a bed net (LTC) or to human landing catches (HLC). In Senegal, the IST caught 6.14 times the number of Anopheles gambiae sensu lato (s.l.), and 8.78 times the Culex group V mosquitoes as LTC. In one of two locations in Burkina Faso, the IST caught An. gambiae at a rate not significantly different than HLC. Of importance, 9.1-36.1% of HLC caught An. gambiae were blood fed, mostly with fresh blood, suggesting they fed upon the collector, whereas only 0.5-5.0% from the IST had partial or old blood. The IST also caught outdoor biting species in proportions comparable to HLC. The results show this tent provides a safer and effective alternative to the skill-dependent, risky, and laborious HLC method. Copyright © 2015 by The American Society of Tropical Medicine and Hygiene.

Fawaz E.Y.,Vector Biology Research Program | Allan S.A.,Vector Biology Research Program | Bernier U.R.,Vector Biology Research Program | Obenauer P.J.,Vector Biology Research Program | Diclaro J.W.,Vector Biology Research Program
Journal of vector ecology : journal of the Society for Vector Ecology | Year: 2014

Mosquitoes of various species mate in swarms comprised of tens of thousands of flying males. In this study, we examined Aedes aegypti swarming behavior and identified associated chemical cues. Novel evidence is provided that Ae. aegypti females aggregate by means of olfactory cues, such as aggregation pheromones. Isolation of Ae. aegypti aggregation pheromones was achieved by aeration of confined mosquitoes and collection of associated volatiles by glass filters. The collected volatiles were identified through gas chromatography mass spectrometry (GCMS). Three aggregation pheromones were collected and identified as 2,6,6-trimethylcyclohex-2-ene-1,4-dione (ketoisophorone) (CAS# 1125-21-9, t(R) = 18.75), 2,2,6-trimethylcyclohexane-1,4-dione (the saturated analog of ketoisophorone) (CAS# 20547-99-3, t(R) = 20.05), and 1-(4-ethylphenyl) ethanone (CAS# 937-30-4, t(R) = 24.22). Our biological studies revealed that the identified compounds stimulated mosquito behavior under laboratory conditions. The mechanism of mosquito swarm formation is discussed in light of our behavioral study findings. A preliminary field trial demonstrated the potential application of the isolated aggregation pheromones in controlling Ae. aegypti. © 2014 The Society for Vector Ecology.

Ramalho-Ortigao M.,Kansas State University | Coutinho-Abreu I.V.,U.S. National Institutes of Health | Balbino V.Q.,Federal University of Pernambuco | Figueiredo C.A.S.,Federal University of Pernambuco | And 17 more authors.
Parasites and Vectors | Year: 2015

Background: The Phlebotomus papatasi salivary protein PpSP15 was shown to protect mice against Leishmania major, suggesting that incorporation of salivary molecules in multi-component vaccines may be a viable strategy for anti-Leishmania vaccines. Methods: Here, we investigated PpSP15 predicted amino acid sequence variability and mRNA profile of P. papatasi field populations from the Middle East. In addition, predicted MHC class II T-cell epitopes were obtained and compared to areas of amino acid sequence variability within the secreted protein. Results: The analysis of PpSP15 expression from field populations revealed significant intra- and interpopulation variation. In spite of the variability detected for P. papatasi populations, common epitopes for MHC class II binding are still present and may potentially be used to boost the response against Le. major infections. Conclusions: Conserved epitopes of PpSP15 could potentially be used in the development of a salivary gland antigen-based vaccine. © 2015 Ramalho-Ortigão et al.

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