In previous colloquia this semester, we’ve had the pleasure of learning about research focusing on a variety of different arthropods, ranging from potato leafhoppers to harvestmen. However, our most recent colloquium deviated slightly with a presentation focusing on entomopathogenic fungi and their potential to control the spread of deadly vector-borne illnesses. Dr. Raymond St. Leger started his presentation in the most well attended colloquium of the semester thus far with a video showcasing a diverse array of stunningly bizarre Cordyceps fungi. Many are known to have a profound and often grotesque effect on their infected insect hosts, with some well known for influencing insect behavior.
Metarhizium, which occurs frequently in nature as a plant symbiont, initially showed promise as a biological control agent against mosquitoes, but lacked the necessary virulence to kill them quickly enough to prevent the many bites that spread malaria. As St. Leger explained to us, it is not naturally in a pathogen’s interest to exterminate its host species. Mosquitoes infected with Metarhizium, in many cases, were able to feed and even mate before succumbing to their fungal parasite. By super-charging these fungi with proteases, the St. Leger lab was able to significantly decrease the amount of time required to kill mosquitoes and suppressed their appetites, in the interim, even in the presence of potential hosts.
Fang W, Vega-Rodriguez, J., Ghosh, A.K., Jacobs-Lorena, M., Khang, A and St. Leger, R.J., 2011. Development of transgenic fungi that kill human malaria parasites in mosquitoes Science 331: 1074-1077.
Rebecca Wilson is a 1st year master’s student in the lab of Dr. Bill Lamp. She is broadly interested in aquatic entomology and is currently studying larval black fly distribution in western Maryland.