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The evolution of insecticide resistance in mosquitoes is threatening the effectiveness and sustainability of malaria control programs in various parts of the world. Through their unique mode of action, entomopathogenic fungi provide promising alternatives to chemical control. However, potential interactions between fungal infection and insecticide resistance, such as cross-resistance, have not been investigated. We show that insecticide-resistant Anopheles mosquitoes remain susceptible to infection with the fungus Beauveria bassiana. Four different mosquito strains with high resistance levels against pyrethroids, organochlorines, or carbamates were equally susceptible to B. bassiana infection as their baseline counterparts, showing significantly reduced mosquito survival. Moreover, fungal infection reduced the expression of resistance to the key public health insecticides permethrin and dichlorodiphenyltrichloroethane. Mosquitoes preinfected with B. bassiana or Metarhizium anisopliae showed a significant increase in mortality after insecticide exposure compared with uninfected control mosquitoes. Our results show a high potential utility of fungal biopesticides for complementing existing vector control measures and provide products for use in resistance management strategies. biopesticide | DDT | pyrethoids | resistance management | vector control doi/ 10.1073/pnas.0908530106

Kofi Annan, then secretary-general of the United Nations, noted in 2002 that "[A] wide consensus has emerged on the potential of information and communications technologies (ICT) to promote economic growth, […]

Ecological and population biology issues constitute serious challenges to the application of genetically modified mosquitos (GMM) for disease control., Optimism that mosquito-borne diseases such as malaria, dengue, and filariasis can be effectively controlled or even eradicated with inexpensive drugs, vaccines, or insecticides has been sorely tested (1). The impact [...]

THE REPORTS BY S. BLANFORD ET AL. ('Fungal pathogen reduces potential for malaria transmission,' 10 June, p. 1638) and E.-J. Scholte et al. ('An entomopathogenic fungus for control of adult [...]

Biological control of malaria mosquitoes in Africa has rarely been used in vector control programs. Recent developments in this field show that certain fungi are virulent to adult Anopheles mosquitoes. Practical delivery of an entomopathogenic fungus that infected and killed adult Anopheles gambiae, Africa's main malaria vector, was achieved in rural African village houses. An entomological inoculation rate model suggests that implementation of this vector control method, even at the observed moderate coverage during a field study in Tanzania, would significantly reduce malaria transmission intensity., Mosquito vector control is an integral part of controlling malaria (1). In Africa, this is almost exclusively based on the use of chemical insecticides for indoor residual spraying and impregnation [...]

Background: Malaria still accounts for an estimated 207 million cases and 627,000 deaths worldwide each year. One proposed approach to complement existing malaria control methods is the release of genetically-modified (GM) and/or sterile male mosquitoes. As opposed to laboratory colonization, this requires realistic semi field systems to produce males that can compete for females in nature. This study investigated whether the establishment of a colony of the vector Anopheles arabiensis under more natural semi-field conditions can maintain higher levels of genetic diversity than achieved by laboratory colonization using traditional methods. Methods: Wild females of the African malaria vector An. arabiensis were collected from a village in southern Tanzania and used to establish new colonies under different conditions at the Ifakara Health Institute. Levels of genetic diversity and inbreeding were monitored in colonies of An. arabiensis that were simultaneously established in small cage colonies in the SFS and in a large semi-field (SFS) cage and compared with that observed in the original founder population. Phenotypic traits that determine their fitness (body size and energetic reserves) were measured at 10th generation and compared to founder wild population. Results: In contrast to small cage colonies, the SFS population of An. arabiensis exhibited a higher degree of similarity to the founding field population through time in several ways: (i) the SFS colony maintained a significantly higher level of genetic variation than small cage colonies, (ii) the SFS colony had a lower degree of inbreeding than small cage colonies, and (iii) the mean and range of mosquito body size in the SFS colony was closer to that of the founding wild population than that of small cage colonies. Small cage colonies had significantly lower lipids and higher glycogen abundances than SFS and wild population. Conclusions: Colonization of An. arabiensis under semi-field conditions was associated with the retention of a higher degree of genetic diversity, reduced inbreeding and greater phenotypic similarity to the founding wild population than observed in small cage colonies. Thus, mosquitoes from such semi-field populations are expected to provide more realistic representation of mosquito ecology and physiology than those from small cage colonies. [ABSTRACT FROM AUTHOR]

Objective: To estimate the effectiveness of live potted plants and thermal expulsion of plant materials in repelling African malaria vectors in traditional houses in western Kenya.Methods: Ocimum americanum, Lantana camara and Lippia ukambensis were tested in live, intact potted form whereas leaves of Corymbia citriodora, leaves and seeds of O. kilimandscharicum and O. suave were tested by thermal expulsion from modified traditional stoves. A latin square design was applied for randomly assigning the treatment and control plants to experimental houses over different nights.Results: All plant species showed significant repellency against Anopheles gambiae sensu lato Giles (Diptera: Culicidae) (81.5%An. arabiensis Patton and 18.5%An. gambiae sensu stricto Giles), the main vectors of malaria in Africa, with the highest repellency by C. citriodora (48.71%, P < 0.0001) followed by an equal level of repellency of O. kilimandscharicum and O. suave (44.54%, P = 0.001) during application of plant material by thermal expulsion. All three plant species also showed a residual effect against An. gambiae s.l. with 36-44% repellency post-application period (22.30-06.30 hours) after a period of thermal expulsion. Similarly, intact potted plants of O. americanum and L. camara repelled An. gambiae s.l. significantly (37.91%, P = 0.004; and 27.22%, P = 0.05, respectively). Thermal expulsion of leaves and seeds of O. kilimandscharicum significantly repelled An. funestus Giles, although none of the potted plants repelled this species.Conclusion: Both methods of application may offer cost-effective alternatives as additional means of household protection, and a useful complement to bed nets, particularly for the early part of the evening before bedtime. [ABSTRACT FROM AUTHOR]

Dutch approval policy for the application of transgenic crops builds on the precautionary principle, necessitating in-depth studies on potential ecological side effects of such plants. The principle dictates that the mere conception of a possible ecological hazard, even in the absence of scientific evidence, requires precautionary interim measures until research enables full risk management. However, exactly how much research is required remains open ended, and this is where different countries hold different views, which affects the speed at which legislation proceeds. Despite the global momentum of Bacillus thuringiensis (Bt)-engineered crops and extensive research and regulation by the U.S. Environmental Protection Agency, a Cogem-sponsored survey of nine prominent Dutch ecologists suggests that, in line with adherence to the precautionary principle, they still lack answers for issues too important to be ignored. Outcrossing of transgenes to related plant species and effects of transgenic plants on soil ecosystems and on multitrophic interactions are the three areas of concern, the last of which formed the focal point of the Cogem survey.