FIRST RECORD OF Brachymeria podagrica (HYMENOPTERA: CHALCIDIDAE) AS PARASITOID OF Peckia collusor (DIPTERA: SARCOPHAGIDAE)

In this work, the wasp Brachymeria podagrica is recorded for the first time for Colombia, a solitary parasitoid of larvae of the Peckia collusor fly. Third instar larvae of P. collusor were exposed to outdoor ambient conditions for 6 hours in the garden of the Tecnológico de Antioquia (Medellín, Colombia). 29 B. podagrica adults were obtained from the host pupae. Prevalence of parasitism was 14.5 %.

Asymmetries affecting aggressive contests between solitary parasitoids: the effect of host species

Conflicts in animals are usually resolved based on asymmetries, where contest winners are often those that value a resource the most and/or those who have the greatest potential to retain it. In parasitoid wasps, contests between females determine which individual exploits hosts for offspring production. Previous studies on solitary parasitoids rarely considered the role of biotic factors generating phenotypic variation that could influence the strength of asymmetries. Some parasitoid species parasitize host species of various sizes, producing offspring that vary considerably in size and potentially fighting ability. In this study, we reared the egg endoparasitoid Telenomus podisi (Hymenoptera: Scelionidae) on two host species to measure the effect of body size on contest resolution and how it interacts with ownership and resource value (RV) asymmetries. Our results showed that ownership status best predicts the final contest outcome when similar-sized wasps fight over hosts. The frequency and outcomes of individual fights structuring contests were better explained by the difference in the number of eggs laid in the hosts by each female at a given time. When contestants varied in body size, larger intruders frequently dislodged small owners regardless of ownership and RV asymmetries. These results imply that body size is an important factor to consider in solitary parasitoid contests and that it can overshadow the effects of other asymmetries. Our study suggests that host community diversity could have a direct effect on parasitoid contests and that biotic communities, through their effects on animal phenotypes, may play an underrated role in contest resolution.

Redescriptions of two parasitoids, Metapelma beijingense Yang (Hymenoptera, Eupelmidae) and Spathius ochus Nixon (Hymenoptera, Braconidae), parasitizing Coraebus cavifrons Descarpentries & Villiers (Coleoptera, Buprestidae) in China with keys to genera or species groups

Two parasitoids, Metapelma beijingense Yang (Hymenoptera, Eupelmidae) and Spathius ochus Nixon (Hymenoptera, Braconidae) are redescribed and illustrated. Both were reared from Coraebus cavifrons Descarpentries & Villiers (Coleoptera, Buprestidae) boring in Symplocos stellaris Brand (Symplocaceae). Metapelma beijingense is a solitary parasitoid with a parasitism rate of about 13.5% and S. ochus is a gregarious parasitoid with a parasitism rate of about 21.2%. A revised key to Oriental and Palaearctic species of Metapelma Westwood and a key to the species of the Spathius labdacus-group are provided.

Discovery of the genus Venanides Mason 1981 (Hymenoptera: Braconidae, Microgastrinae) in Europe, with description of a new species parasitizing Carcina quercana (Fabricius) (Lepidoptera: Peleopodidae)

The small Microgastrinae genus Venanides is recorded from Europe (Netherlands, Germany and Czech Republic) for the first time, where one species, Venanides carcinae sp. nov., described here, proves to be a regular solitary parasitoid of Carcina quercana. Outline notes on its biology, phenology and abundance are given.

Parasitism of diamondback moth Plutella xylostella by the solitary parasitoid wasp Cotesia vestalis in Samoa

Plutella xylostella is a major pest of crucifier crops in Samoa and other Pacific islands. This pest has developed resistance to most insecticides available in the island nations so the objective of this study was to examine potential biological control options for P. xylostella in Samoa. Existing parasitism of P. xylostella on Chinese cabbage (Brassica rapa subspp.) was investigated at a farm in Alesia and at the USP farm in Alafua, and established populations of Cotesia vestalis were found at both locations. Plutella xylostella larvae turn light yellow and show sluggish behaviour after parasitism, and they could be easily differentiated from unparasitised ones. Developing C. vestalis larvae emerge from their hosts and spin white cocoon around their body. After 5–6 days, a single adult emerges from the C. vestalis cocoon. The average parasitism rate between April 2015 and March 2016 was 10–18% but was significantly higher at the USP farm than the Alesia farm. This result could be because no insecticides were applied to the crops at USP. Parasitism was highest between June and August when the lowest average daily temperatures occur.