|DAANE, KENT - University Of California|
|BIONDI, ANTONIO - University Of Catania|
Submitted to: Journal of Pest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/23/2021
Publication Date: 4/7/2021
Citation: Daane, K.M., Wang, X., Hogg, B.N., Biondi, A. 2021. Potential host ranges of three Asian larval parasitoids of Drosophila suzukii. Journal of Pest Science. https://doi.org/10.1007/s10340-021-01368-1.
Interpretive Summary: Spotted-wing drosophila has become a key invasive pest of soft, thin-skinned fruits in the Americas and Europe, where locally occurring natural enemies of fruit flies are largely absent or are not effective for the suppression of this pest. Three species of parasitic wasps that attack spotted-wing drosophila larvae in its native range in Asia are currently under consideration for release in North America to help control this pest. We evaluated these parasitic wasps in quarantine to assess their potential risk of attacking non-pest fruit flies in North America. Each of the three species of wasps was tested to see if it could attack and develop from 24 non-pest fruit fly species. One species appears to be safe and has been recommended for release in North America, while the other two species are capable of attacking some non-pest fruit fly flies and are not currently recommended for field release.
Technical Abstract: Asobara japonica (Hymenoptera: Braconidae), Ganaspis brasiliensis and Leptopilina japonica (Hymenoptera: Figitidae) are three major Asian larval parasitoids of spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae), an invasive pest of soft-skinned fruit. This study evaluated the capacity of these parasitoids to attack and develop from 24 non-target drosophilid species. Results showed that all three parasitoids were able to parasitize host larvae of multiple non-target species in artificial diet; A. japonica developed from 19 tested host species, regardless of the phylogenetic position of the host species, L. japonica developed from 11 tested species and G. brasiliensis developed from only four tested species. Success rate of parasitism (i.e., the probability that an adult wasp successfully emerged from a parasitized host) by the two figitid parasitoids was very low in hosts other than the three species in the melanogaster group (D. suzukii, D. melanogaster and D. simulans). The failure of the figitids to develop in most of the tested host species appears to correspond with more frequent encapsulation of the parasitoids by the hosts. The results indicate that G. brasiliensis is the most host-specific to D. suzukii, L. japonica attacks mainly species in the melanogaster group and A. japonica is a generalist, at least physiologically. Overall, the developmental time of the parasitoids increased with the host’s developmental time. The body size of female A. japonica (as a model species) was positively related to host size, and mature egg load of female wasps increased with female body size. We discuss the use of these parasitoids for classical biological control of D. suzukii.