Evaluation of field augmentorium cages for Ganaspis kimorum
Drosophila suzukii (Diptera: Drosophilidae – EPPO A2 List) is a frugivorous fly native to East Asia. It has spread to many regions worldwide, including other parts of Asia, the Americas, Africa and the EPPO region. Portable augmentoria are insect cages with a selective mesh entrance that contain pest-infested fruit while allowing parasitoid escape. The effectiveness of these cages to increase the presence of the biological control agent Ganaspis kimorum (Hymenoptera: Figitidae) was tested in small fruit farms in western Oregon, USA, during 2024–2025. Augmentorium cages containing blueberries (Vaccinium corymbosum) infested with D. suzukii (approximately 400 eggs) were set out in treatment plots and were resupplied with infested fruit weekly. These treatment plots were compared with control plots that received no augmentorium cages. Fruit were sampled at 0, 5, and 10 m from augmentorium cages and then kept in the laboratory to assess insect emergence. In total, in 2024, 15 341 D. suzukii adults and 1 563 parasitoid wasps were collected from a total of 520 fruit. In 2025, 13 050 adult D. suzukii, but only 407 parasitoid wasps were collected from 469 fruits. For both years, the augmentorium cages were not associated with any increase in overall parasitism or in a decrease in pest infestation within the measured 10 m from the cages. A number of factors may have limited the effectiveness of the augmentorium cages, including an increased temperature within the cage and the attraction of ants.
Sources
McDonald NS, Lee JC (2026) Field evaluation of portable augmentorium cages for increasing parasitoid presence to manage Drosophila suzukii. Biological Control 219 https://doi.org/10.1016/j.biocontrol.2026.106076