Researching the
world’s only black
fly colony
Photos by Sean Montgomery
The University of Georgia Black Fly Rearing and Bioassay Laboratory is a one-of-a-kind public health resource that has been maintained at UGA since 1999.
From wriggling larvae to adult breeding pairs, thousands of generations of the same population have lived their lives inside UGA’s black fly colony, providing entomologists around the world with a reliable study population for a full range of research.
First founded in 1981 at Cornell University, the colony now housed at the UGA College of Agricultural and Environmental Sciences has been used for a variety of research projects through the years, including a wide range of vector transmission, environmental monitoring, vector control and larval feeding studies. The laboratory also serves as a preferred site for teaching and educational outreach visits for a wide range of students.
The black fly colony provides materials to researchers around the world covering all stages of the black fly life cycle, whether alive or preserved. The lab provides a unique opportunity for study on this important disease-carrying insect, as researchers can make unique biological comparisons with an organism that has been isolated in a colony for 40 years.
Black fly larvae attach to leaves and other substrates via a silkened pad and a circle of hooks at the base of their body, similar to Velcro.
Black flies — Simulium vittatum — require flowing water to complete their life cycle, and the colony simulates this environment with nine aquatic rearing units that create miniature rivers for the larval and pupal stages to develop.
Each unit can support approximately 300,000 larvae. Adult flies emerge within the rearing units and are captured, mated and provided moistened substrates to serve as egg-laying sites. At any given time there are more than 2 million of the tiny insects at the colony’s lab on Riverbend Road.
Black flies are one of the world’s most noxious pests, considered the third-most important arthropod vector and pest after mosquitoes and ticks due to their aggressive biting behavior. Black flies transmit the nematode that causes onchocerciasis, also known as river blindness, the second-most common cause of blindness due to infection.
Recently, Elmer Gray, UGA Cooperative Extension entomologist and director of the Black Fly Lab, led a team conducting field studies for Valent BioSciences to test the effectiveness of Vectobac 12AS, a naturally derived larvicide that uses Bacillus thuringiensis subsp. israelensis (Bti) to control black fly populations.
Each day, researchers measured the flow of the river — including its width, depth and speed — to determine how much water was moving through when treatments were applied.
After applying the larvicide at a set rate, researchers allowed the treated water to travel downstream for two hours before collecting black fly larvae samples. The larvae were then carefully transported back to the lab, kept cool and supplied with oxygen, and checked for survival 24 hours later.
The goal of the research is to help ensure that the larvicide continues to be a safe and effective tool for controlling black flies.
To learn more about research opportunities at UGA’s Black Fly Lab, visit caes.uga.edu/blackflylab.
