Leptopilina australis (Belizin, 1966)

Vogel, Jonathan, Martin, Jakob, Forshage, Mattias, Salden, Tobias, Staverløkk, Arnstein, Verheyde, Fons, Nordlander, Göran, Herz, Annette & Peters, Ralph S., 2025, The Leptopilina Förster, 1869 of the Western Palearctic, and an updated list of the world species (Hymenoptera, Figitidae, Eucoilinae), Journal of Hymenoptera Research 98, pp. 915-969 : 915-969

Leptopilina australis (Belizin, 1966)

Rhoptromeris australis Belizin, 1966: 87 .

Diagnosis.

Leptopilina australis is a relatively small species ( 1.3–1.4 mm ♀ body length in a small number of measured females) with somewhat slender appearance and a relatively short antenna (Fig. 2 A ).

The species is unique in the combination of the mesoscutum having rows of setae mediolaterally (Fig. 11 A , susceptible to damage), a state shared with L. clavipes (mesoscutum glabrous in other species), and the short metapleural ridge 1 (Fig. 2 D , see Fig. 9 A for an overview on the metapleural ridges 1–3). The short ridge is shared with L. fimbriata , but in other species it is either absent ( L. boulardi ) or at least half the length of the metapleuron.

The metapleural ridge 2 is shorter than half the length of the metapleuron, albeit longer than ridge 1 (Fig. 2 D ). The ridge 2 is equally long in L. boulardi , L. clavipes and L. fimbriata but at least half the length of the metapleuron in the other species.

A setal patch on the base of the hind coxa is present (Fig. 2 D ), in contrast to L. japonica and L. boulardi , where there are at most a few singular setae that are not arranged in a patch.

Biology.

Habitat. Occurs in parks and forests, mainly in nemoral deciduous forest, with decaying plant material and fungal fruiting bodies. In one study, the species emerged from Drosophila spp. developing in the petioles of Heracleum mantegazzianum Sommier & Levier (giant hogweed). Additionally, it shows attraction to Phallus impudicus L. (common stinkhorn), but was never recovered from it in situ. Not attracted to fermenting fruit. Rarely collected in Malaise traps or by sweep netting.

Flight period. July to September.

Host. Mainly Drosophila limbata Roser, 1840 and other species within the Drosophila quinaria species group ( van Alphen et al. 1991; Eijs and van Alphen 1999).

Ex situ reared from Drosophila kuntzei Duda, 1924 and Scaptomyza pallida (Zetterstedt, 1847) , and to a lesser degree from Drosophila transversa Fallén, 1823 ( van Alphen et al. 1991). Not reared from D. busckii Coquillett, 1901 , D. immigrans Sturtevant, 1921 , D. phalerata Meigen, 1830 , D. subobscura Collin, 1936 , and Lordiphosa fenestrarum Fallén, 1823 , despite sharing the ecological niche with the suitable hosts ( van Alphen et al. 1991).

Population parameters. Primarily thelytokous with occasional development of males, observed after ex situ diapause by van Alphen et al. (1991).

Distribution.

Western Palearctic but sparsely distributed, possibly spreading towards northwest but slowly and still uncommon. Armenia (locus typicus of Rhoptromeris australis ), Belgium (new record), Denmark, the Netherlands and Slovenia.

Remarks.

Originally described in the genus Rhoptromeris Förster, 1869 but moved to Leptopilina Förster, 1869 by Nordlander and Grijpma (1991).

We did not successfully sequence any specimen of L. australis . At present, barcode sequence information is available neither on BOLD nor on DROP.

Figures

Figure 2. Female specimen of L. australis (ZFMK - TIS- 2637706) A lateral habitus B left antenna C dorsal view on mesoscutellum D lateral view on metapleuron and base of metacoxa E posterior view on mesoscutellum and propodeum.

Figure 9. Lateral view on the metapleuron and base of metacoxa, highlighting shape and position of the metapleural ridges (note that their extent is described from posterior to anterior throughout the manuscript) and the metacoxal setae A female specimen of L. heterotoma (ZFMK - TIS- 2629375, facing left) with highlighted metapleural ridges 1–3 and the setal patch on the metacoxa B female specimen of L. boulardi (ZFMK - HYM- 00039733) with highlighted short ridge 2 and a seta that might be mistaken as a ridge.

Figure 11. Dorsal view on the mesoscutum showing present or absent rows of setae (the whiteish rings on the mesuscutum are reflections of the ring light used for imaging) A female specimen of L. clavipes (ZFMK - TIS- 2637705) with distinct rows of setae mediolaterally B female specimen of L. heterotoma (ZFMK - TIS- 2629375) without distinct rows of setae mediolaterally.