Host Feeding by Jaliscoa hunteri Crawford (Hymenoptera: Pteromalidae) Suppresses Populations of Anthonomus testaceosquamosus Linell (Coleoptera: Curculionidae)

The hibiscus bud weevil (Anthonomus testaceosquamosus, HBW) is an economically important pest of tropical hibiscus, Hibiscus rosa-sinensis. Although Jaliscoa hunteri parasitizes other Anthonomus species, its suitability as a biocontrol agent for HBW remains unknown. This study evaluated its potential under laboratory and greenhouse conditions. In laboratory assays, a couple of parasitoids were exposed to HBW at different developmental stages. Parasitism was rarely observed, but host feeding was evident, and eggs, first instar larvae, and pupae showed high mortality in comparison to controls with no parasitoids. Cage experiments compared three release rates (one, two, or three parasitoid pairs) on infested flower buds. Mortality was lowest in controls, but increasing parasitoid numbers did not enhance pest suppression. In greenhouse trials, hibiscus plants were infested and exposed to the same release rates. Mortality was higher in the one-pair treatment than in controls, whereas higher release rates produced intermediate mortality, suggesting possible disruption of female reproductive activity or other unknown limiting factors. Overall, J. hunteri showed promising potential as a natural enemy of HBW, functioning like a predator rather than a parasitoid. Additional research on its reproductive biology, host interactions, and release strategies is needed to improve its effectiveness for biological control in hibiscus nurseries.