A second species, Pseudacteon curvatus Borgmeier, was collected from black fire

ants in Las Flores, Argentina (Porter 2000). Pseudacteon curvatus is smaller than P.

tricuspis and studies on oviposition behavior have shown that female P. curvatus flies

attack fire ant workers that are significantly smaller than the colony mean (Morrison et al.

1997). Field releases of this species (summer 2000 and fall 2001) were successfully

established in Alabama and Mississippi on hybrid fire ants and black imported fire ants,

but failed in Florida on red imported fire ants (Graham et al. 2003, Vogt and Street 2003).

A new biotype ofP. curvatus was collected from S. invicta fire ants in Formosa,

Argentina (October 2001). A series of quarantine host-specificity tests demonstrated that

this new biotype was sufficiently host specific to be released in the field (Vazquez et al.

2004a). The obj ective of this study is to document the release, establishment, and

dispersal of P. curvatus around Gainesville, Florida.

 Materials and Methods

 The P. curvatus flies released in this study were collected by SDP and JAB in

October 2001 from a roadside site about 3 5 km NW of Formosa, Argentina on route 81

(km 1219; 250 56. 139' S, 58o 30.723' W). The collection procedures were similar to

those described by Porter (2000). These flies were then imported to quarantine facilities

in Gainesville, FL under a permit from USDA-APHIS. We released these flies in the field

after conducting host specificity evaluations on nontarget organisms in our quarantine

facility. The flies were released under a previous permit from the Florida Department of

Agriculture and the Finding of No Significant Impact (FONSI) issued by the USDA-

ARS .