Circumscription of the Ganaspis brasiliensis (Ihering, 1905) species complex (Hymenoptera, Figitidae), and the description of two new species parasitizing the spotted wing drosophila, Drosophila suzukii Matsumura, 1931 (Diptera, Drosophilidae)

Abstract

Based on host specificity and distribution data, it has been hypothesized that Ganaspis brasiliensis (Ihering, 1905), a natural enemy of the horticultural pest spotted-wing drosophila, Drosophila suzukii Matsumura, 1931 (SWD), was composed of multiple, cryptic species. Parasitoid wasps assigned to the species name Ganaspis brasiliensis and Ganaspis cf. brasiliensis were investigated using a molecular dataset of ultra-conserved elements (UCEs) and morphology. We report strong evidence for the presence of cryptic species based on the combination of UCE data (1,379 UCE loci), host specificity, ovipositor morphology, and distribution data. We describe these new cryptic species as: Ganaspis lupini sp. nov., and Ganaspis kimorum sp. nov. Ganaspis lupini was formerly recognized as Ganaspis brasiliensis G3, and Ganaspis kimorum as Ganaspis brasiliensis G1. These two new species appear to be restricted to the temperate climates, whereas Ganaspis brasiliensis (formerly recognized as Ganaspis brasiliensis G5) has a more pan-tropical distribution. We investigated the characterization of the ovipositor clip of these species, and hypothesize that G. kimorum, which has a reduced ovipositor clip, has an advantage in ovipositing into fresh fruit, still on the host plant, while attacking SWD; as a corollary, G. brasiliensis and G. lupini, which both have a larger ovipositor clip, are better adapted to attacking hosts in softer, rotting fruit on the ground. As Ganaspis kimorum was authorized for release as a biological control agent against SWD under the name Ganaspis brasiliensis G1, the results here have direct impact on the field of biological control.