APPLYING TRANSGENIC FUNGI IN A MOSQUITOSPHERE

Here we report on a semi field trial testing the efficacy of a mosquitocidal Metarhizium strain (Met-hybrid) engineered to express an insect-specific spider neurotoxin (hybrid) and GFP. The experiments are being conducted in a multi-chambered MosquitoSphere (a contained, near-natural environment) constructed for this purpose in a region of Burkina Faso where malaria is endemic. We used the sphere to test a variety of low technology treatment protocols that could be used routinely by householders and found that suspending Metarhizium in locally produced sesame oil and spreading that on netting or black sheets achieves a long term effect in the sphere. Compared to a strain of wild-type virulence expressing RFP (Met-RFP), Met-Hybrid killed anopheline mosquitoes in half the time and at much lower spore doses, which increased the percent of lethally infected mosquitoes and the effective persistence of the pathogen. We also demonstrated that Met-hybrid had important pre-lethal effects that included reduced feeding by infected mosquitoes and improved control of insecticide resistant mosquitoes. This NIH funded, international effort represents an important step in the progression of transgenic mosquito control technologies into field application. We are currently working on community engagement and policy for an eventual open field release to test epidemiological and clinical impacts of transgenic Metarhizium. Our results will have broad implications for any project proposing to scale up new, complex, and potentially controversial technologies for malaria eradication.