Submitted to: Imported Fire Ants Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/14/2007
Publication Date: 6/20/2007
Citation: Fink, T., Ramalingam, V., Du, S., Streett, D. A. Behavioral interactions of the black imported fire ant (solenopsis richteri forel) and its parasitoid fly (pseudacteon curvatus borgmeier) as revealed by high-speed video.. Imported Fire Ants Conference Proceedings. 2007
Interpretive Summary: Imported fire ants are serious pests that that have spread to over 300 million acres in the United States and Puerto Rico. Visual observations of phorid fly attack behavior are often inadequate for observing the extremely fast flight of phorid flies as they attack fire ants. Phorid fly attack behavior was studied with high speed video and it was found that flies cannot be easily detected by fire ants when the flies are nearby. Studies on the attack behavior of phorid flies will allow us to assess the effectiveness of these flies to control fire ants.
Technical Abstract: High-speed video recordings were used to study the interactions between the phorid fly (Pseudacteon curvatus), and the black imported fire ant (Solenopsis richteri) in the field. Phorid flies are extremely fast agile fliers that can hover and fly in all directions. Wingbeat frequency recorded with microphones and high-speed video was around 422 beats per second. Ants, unless attacked, did not seem to detect the flies or at least do not seem to react to the flies. Once attacked, fire ants will occasionally assume a defensive posture. Attacks can be extremely short in duration from about 0.03 seconds to 0.3 seconds. Phorid flies can hover in a very small area, at least up to 14.5 seconds for one recorded phorid female (recorded at 2000 fps). Previous accounts based on human visual observations and standard video (30-60 frames/second) suggest that fire ants can easily detect their relentless fly parasitoids and often display a particular posture when flies are nearby. However, our observations using high-speed video suggest that the ants cannot easily detect phorid flies in the vicinity.