Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2005
Publication Date: 4/1/2006
Citation: Thead, L.G., Streett, D.A. 2006. Duration of Pseudacteon curvatus Borgmeier (Diptera: Phoridae) pupal stage at reduced temperatures. Journal of Entomological Science. 41: 120-125.
Interpretive Summary: Imported fire ants are serious pests that infest 300 million acres in the United States. The phorid flies or decapitating flies are biological control agents that only attack imported fire ants. These flies are currently being released in the United States to control imported fire ants. Studies showed that phorid flies can be stored over the short term so that more flies are available for mass release on a desired date. This will make the release program more efficient and enhance the success of mass release efforts.
Technical Abstract: The ability to slow development time of phorid pupae would prove beneficial in mass rearing programs and in pupal mass storage for use in large-scale release programs. Developmental rates were determined for phorid fly (Pseudacteon curvatus Borgmeier) pupae subjected to varying temperature regimes. Pupae that had initially developed 12-15d in parasitized fire ant workers held at approximately 27oC were collected and subsequently held at different temperature regimes. A 26.7oC treatment had the shortest development time with a peak fly emergence 15d later. Pupae exposed to a lower temperature of 18.3oC for 12 or 19d and then exposed to a temperature of 26.7oC required an additional developmental time to peak fly emergence of 7 and 11d, respectively. Exposure at 18.3oC until emergence resulted in a 20d increase before peak fly emergence. At 10oC for 12 or 19d followed by 26.7oC, peak fly emergence was delayed an additional 11.5 and 18d, respectively. Holding pupae at 10oC for 54d followed by 26.7oC delayed peak fly emergence by an additional 51d with a correspondingly high mortality. Fly survival rates tended to decrease as peak emergence was delayed. Models that predict fly emergence when pupae are held at reduced temperatures will prove useful in mass rearing programs where extended storage of phorid fly pupae is necessary for optimizing mass releases.