Ormyridae

Abstract: Thirty-three species of Chalcidoidea (Hymenoptera) are newly recorded from the Maltese Islands, of which, 19 include host data. An updated checklist for the 181 chalcidoid species recorded from Malta is also included, which belong to 17 families as follows: Agaonidae (3), Aphelinidae (21, 1 as new record), Azotidae (1), Chalcididae (8 species, 5 as new records), Encyrtidae (24, 1 as new record), Eulophidae (51, 16 are new records), Eupelmidae (9, 2 as new records), Eurytomidae (6, 1 as new record), Leucospidae (4), Megastigmidae (1), Mymaridae (2), Ormyridae (1), Perilampidae (1 new record), Pteromalidae (39, 5 as new records), Signiphoridae (2), Tetracampidae (1) and Torymidae (7, 1 as new record).

Abstract: A quantitative catalogue of the regular members of the parasitoid and inquiline communities inhabiting cynipid galls of the tribes Aylacini, Diplolepidini and Pediaspidini in the western Palaearctic is presented. Quantitative and national data are included. There follows a checklist of the parasitoid (almost entirely Chalcidoidea) and inquiline species, with their cynipid hosts. The communities in galls of the three tribes are compared with those associated with Cynipini. Inquiline Cynipidae are well represented in Diplolepidini and Cynipini gall communities, but absent from galls of the other two tribes, although an inquiline eulophid (Dichatomus) develops in galls of Pediaspidini. The great majority of the parasitoids encountered belong to six families of Chalcidoidea that are all represented in Aylacini, Diplolepidini and Cynipini communities, except Ormyridae which have not been found in Pediaspidini galls. Representation of the chalcidoid families varies in the parasitoid faunas of different cynipid tribes, with species of Eurytomidae most abundant in Aylacini galls, Torymidae in Diplolepidini galls, Eupelmidae in Pediaspidini galls and Eulophidae in Cynipini galls. Pteromalidae are evenly represented in galls of all tribes. With the exception of Eupelmidae, which are mostly very polyphagous, few parasitoid species are regularly associated with more than a single tribe of Cynipidae. However, examples of parasitoid species attacking gall wasps in the ‘wrong’ tribes are not rare. While species diversities of the parasitoid communities of Cynipini are high, those of Aylacini are relatively low. The varied nature of galls of Cynipini, all on Quercus, creates a multiplicity of niches for the parasitoids, and these are mostly polyphagous attacking hosts in a range of galls. In contrast, galls of Aylacini present much less structural diversity, but they occur on several genera and families of host plant, and their parasitoids are, in general, less polyphagous and restricted to hosts on a more or less taxonomically limited host plant range.

Abstract: Research on recruitment of native parasitoids on the recently introduced invasive species Dryocosmus kuriphilus has been carried out on four sites in 2011 and 2012 in Croatia. In total 15 species of native parasitoids were reared which belong to 5 of 6 chalcid families attacking native oak cynipid gallwasps (Eupelmidae - 2, Eurytomidae - 4, Ormyridae - 1, Pteromalidae - 4 and Torymidae - 4 species). This research has shown that the time lag between introduction of new host and recruitment of native parasitoids is short. Sex ratios for the most abundant parasitoid species appeared to be female-biased and the parasitoid emergence rate for all sites was relatively low. Torymus flavipes was recorded from D. kuriphilus at all sites and in both years and was the most abundant species exploiting the new host. Among other species, especially T. flavipes and Megastigmus dorsalis, which have been reared from D. kuriphilus galls, could provide a good possibility for biological control but further research is needed.

Abstract: Dryocosmus kuriphilus (Hymenoptera: Cynipidae) is non-native to North America and induces formation of galls on petioles and leaves of all chestnut (Castanea spp., Fagales: Fagaceae). We investigated the interactions between the gall wasp D. kuriphilus, a native parasitoid, Ormyrus labotus (Hymenoptera: Ormyridae), and a non-native parasit- oid, Torymus sinensis (Hymenoptera: Torymidae). Galls were collected monthly from May to August and in January from four locations in the United States consisting of orchard-grown hybrid chestnuts (Hiram, OH and Meadowview, VA), suburban-grown orna- mental Chinese chestnuts (C. mollissima) (Broadview Heights, OH), or forest-grown American chestnuts (C. dentata) (Bowling Green, KY). Parasitoids were removed from galls and T. sinensis and O. labotus were identified using PCR-markers. The relative abundance of each parasitoid was compared in relation to collection date, habitat, presence of alternative hosts, and gall characteristics. T. sinensis was col- lected from each location and date, and was dominant in the orchard and suburban locations. However, relatively more O. labotus were collected within the forest, which had significant oak component and alternative cynipid hosts. O. labotus was only col- lected in spring and early summer, indicating the use of different summer and winter hosts. Observations suggest that in addition to parasitizing D. kuriphilus, O. labotus hyperparasitizes T. sinensis. T. sinensis has a longer ovipositor than O. labotus, and parasitized larger galls. This study improves our understanding of interactions between an invasive gall wasp, an intro- duced parasitoid, and native parasitoids, and illustrates novel relationships that may form as exotic species expand their geographic range.