Influence of the Rearing Host on Biological Parameters of Trichopria drosophilae, a Potential Biological Control Agent of Drosophila suzukii

Abstract

Trichopria drosophilae is a pupal parasitoid that can develop in a large number of drosophilid host species including the invasive pest Drosophila suzukii, and is considered a biological control agent. We investigated the influence of the rearing host on the preference and performance of the parasitoid, using two different strains of T. drosophilae, reared on D. melanogaster or D. suzukii for approximately 30 generations. Host switching was employed to assess the impact of host adaptation on T. drosophilae performance. In a no-choice experimental setup, T. drosophilae produced more and larger offspring on the D. suzukii host. When given a choice, T. drosophilae showed a preference towards D. suzukii, and an increased female ratio on this host compared to D. melanogaster and D. immigrans. The preference was independent from the rearing host and was confirmed in behavioral assays. However, the preference towards D. suzukii increased further after a host switch from D. melanogaster to D. suzukii in just one generation. Our data indicate that rearing T. drosophilae for several years on D. melanogaster does not compromise its performance on D. suzukii in the laboratory. However, producing a final generation on D. suzukii prior to release could increase its efficacy towards the pest.

Multiscale Determinants Drive Parasitization of Drosophilidae by Hymenopteran Parasitoids in Agricultural Landscapes

“…Most T. modesta emerged from D. subobscura, whereas in T. drosophilae no significant host preference was detected. While in our study we did not expose D. suzukii in the field due to non-native species regulations in Switzerland, in a laboratory study Boycheva Woltering et al [75] found that D. suzukii was preferred among D. melanogaster and D. immigrans by T. drosophilae.…”

“…The pupal parasitoids, which may use the exotic pest D. suzukii, have different preferences in terms of their microhabitat requirements. Due to its effective parasitization ability, Trichopria drosophilae has been preferred for augmentative control programs against D. suzukii [75]. However, the efficacy of the releases might be limited to pupae that are located on the ground.…”

The Pupal Ectoparasitoid Pachycrepoideus vindemmiae Regulates Cellular and Humoral Immunity of Host Drosophila melanogaster

“…One of the practical cases was that P. vindemmiae has prospects for control of olive fruit fly, Bactrocera oleae (Hoelmer et al, 2011). Additionally, a recent article reviewed that Trichopria drosophilae , a pupal parasitoid of D. suzukii , is desirable for high efficacy in biological control (Woltering et al, 2019). Similarly, as a well-known generalist pupal parasitoid of Diptera Cyclorrhapha, P. vindemmiae also possesses enormous potential on control of D. suzukii (Bonneau et al, 2019; Schlesener et al, 2019).…”

Host searching and host preference of resident pupal parasitoids of Drosophila suzukii in the invaded regions

“…The number of hosts and the length of the exposure period were chosen according to the egg-laying capacity of each parasitoid species to avoid host limitation. Female T. drosophilae emerge with a high number of mature eggs and can lay more than 30 eggs within 24 h. 23,24 In P. vindemmiae, eggs mature gradually, females need to host feed (i.e. they feed on host hemolymph and tissue) and lay fewer eggs per day.…”

“…14,31 For T. drosophilae, the preference for D. suzukii pupae over D. melanogaster pupae is in line with other studies. 23,24 According to Boycheva-Woltering et al, the preference for D. suzukii is irrespective of the rearing host and not related to host size as D. suzukii was preferred for oviposition over D. immigrans, which has much bigger pupae. 24 The females of T. drosophilae emerge with a large number of mature eggs and can start to oviposit soon after adult emergence.…”