Host Specificity of a Biotype of the Fire Ant Decapitating Fly Pseudacteon curvatus (Diptera: Phoridae) from Northern Argentina

• Published in: Environmental entomology Vol. 33; no. 5; pp. 1436 - 1441
• Main Authors: Vazquez, Ricardo J, Porter, Sanford D, Briano, Juan A
• Format: Journal Article
• Language: English
• Published: 01-10-2004
• Subjects: Diptera; Formicidae; Phoridae; Pseudacteon; Solenopsis geminata; Solenopsis invicta; Solenopsis xyloni
• ISSN: 0046-225X
• DOI: 10.1603/0046-225X(2004)033[1436:HSOABO]2.0.CO;2

We tested the host specificity of Pseudacteon curvatus Borgmeier from Formosa, Argentina, on North American colonies of the red imported fire ant, Solenopsis invicta Buren, and the native fire ants Solenopsis geminata (F.) and Solenopsis xyloni McCook. No-choice tests showed that P. curvatus hovered over and attacked all three species of fire ants. The number of pupae successfully completing development to adult flies in the trials was 5.03 plus or minus 1.55 (mean plus or minus SE) per female fly in S. invicta, 0.66 plus or minus 0.24 per female fly in S. xyloni, and 0 per female fly in S. geminata. Paired preference tests showed that P. curvatus preferred to hover over S. invicta instead of S. xyloni 77 plus or minus 3% (mean plus or minus SE) of the time and preferred S. invicta over S. geminata 87 plus or minus 4% of the time. The oviposition attempts of active female P. curvatus were 2.8 times higher on S. invicta than on S. xyloni and 16 times higher on S. invicta than on S. geminata. These results demonstrate that this new biotype of P. curvatus is more host specific to North American red imported fire ants than a previous biotype collected from black imported fire ants.