Balcaen is a second-year student in the Master of Science in Bioscience, Technology and Public Policy program at the University of Winnipeg, and her approach is regarded as novel and something of great benefit to the local area.
Due to a seeming unpredictability with mosquito patterns, Balcaen embarked on a study mosquitoes with the aim of mapping spatial dispersal patterns, focusing on the direction mosquitoes taken when they are mature. Such information is essential in terms of pest control, such as targeting fogging using insecticides.
Every spring, the city uses ground crews and helicopters to apply larvicides to bodies of standing water both within city limits and just outside its borders. However, the targets selected are not always the right ones.
Hence current data on mosquito migration patterns is regarded as incomplete. According Balcaen: “The association of a trap count with a region doesn’t reflect anything about that region in terms of landscape characteristics.”
She adds: “In short, it is not telling us the reasons that trap counts may be high there. No analysis is done on these beyond ‘There are lots of mosquitoes here this year, we should fog or treat this region of the city first.’ When we treat an entire region based on point data from one location within that region, we may be wasting resources.”
Her methodology was based on using specially designed and pyramid-shaped breeding cages. These breeding sites were situated south of St. Norbert. Using these cages, Balcaen counted the number of insects and then she sprayed a fluorescent dust over the cage to mark each mosquito. The insects were then released.
Later on, the marked mosquitoes were re- captured and counted. The capture was through traps located within a four-kilometre radius of the original breeding site.
The data revealed that adult mosquitoes tend to remain within around five kilometres from the breeding site. This means that when an outbreak occurs, the point of origin will be relatively close by. Moreover, the data shows that from the breeding site, the migratory pattern is commonly towards to areas like wetlands, rivers, forests, and farms with livestock. This mapping model can help city authorities to tackle breeding sites and to reduce incidents.
The information provided to Ken Nawolsky, who is Winnipeg’s superintendent of insect control, has been of benefit, especially in understanding the movement of adult mosquitoes from rural areas, which are largely untreated with insecticides, to urban residential areas. This is especially important for disease control.
