Laboratory biology and host range ofHydrellia balciunasi [Diptera: Ephydridae]

Hydrellia balciunasi Bock, a native of Australia, was evaluated in quarantine in Florida, USA, for its potential as a biocontrol agent of the submersed aquatic weed,Hydrilla verticillata (L.f) Royle. Larvae are leafminers. Mean total development time at 27°C was 22.8 days. Mean duration of the egg stage was 3.0 days, larval was 11.5 days, and puparial was 8.3 days. Mean fecundity was 35.5 eggs. Mean female longevity was 19.7 days, and mean male longevity was 15.6 days. The sex ratio was 1.1∶1 (male: female). Fourteen plant species closely related to hydrilla in 4 families plus rice were tested in no-choice larval development tests and an additional 27 plant species in 16 families were tested in multi-choice tests. Larvae mined in 2 test plant species,Potamogeton pusillus L. andP. crispus L., but developed (1%) only on the introduced weedP. crispus L. Females oviposited on most test plants. Permission to release this fly in the United States was received from federal and state (Florida) officials, and it was released from quarantine on 24 May 1989.