Pushing the limits – two new species of Pteromalus (Hymenoptera, Chalcidoidea, Pteromalidae) from Central Europe with remarkable morphology

Abstract

Two new species, Pteromalus briani sp. n. and Pteromalus janstai sp. n., with unusual characters are described from the Central Plateau and the Alps in Switzerland, respectively. Pteromalus briani sp. n. is remarkable in that it has the metatibia quite abruptly expanded before the middle. This type of modification of the hind tibia is unique within the Pteromalidae and probably also the entire Chalcidoidea. It is also very rare in other parasitic wasps, where it is suspected to be associated with pheromone glands. The species is a gregarious endoparasitoid of pupae of Vanessa atalanta (Linnaeus) and Aglais urticae (Linnaeus), two common butterflies (Lepidoptera: Nymphalidae) in Europe. It is furthermore a koinobiont parasitoid ovipositing in an early larval stage of the host. The other species, Pteromalus janstai sp. n., shows a flattened mesosoma. A dorsoventrally depressed body is a unique feature within the genus Pteromalus, but known from a number species in unrelated genera and subfamilies. The two records demonstrate that it is possible to discover entirely new species with extraordinary characters even in one of the taxonomically most thoroughly explored parts of the world.

An interactive key to Central European species of the Pteromalus albipennis species group and other species of the genus (Hymenoptera: Chalcidoidea: Pteromalidae), with the description of a new species

“…Characters were selected and measured according to the procedure described in Baur (2015) (Table 2). The distances were measured using ImageJ, version 1.51j8 (Schneider et al 2012).…”

“…With our interactive key, we want to create a basic descriptive dataset on which other taxonomists and interested laymen can build. Despite the range of species that is covered by Graham’s work and more recent discoveries (Gijswijt 1999, Graham and Gijswijt 1991, Janzon 1984, Gijswijt 1972), there are still new species to be found even in relatively well studied areas like Central Europe (Baur 2015). In this context, a new species from Switzerland and Northern Italy is described here and also included in the key.…”

Systematics, biology and distribution of Microdontomerus iridis (Picard, 1930), comb. n. (Hymenoptera, Torymidae, Toryminae, Microdontomerini), a parasitoid of Mantodea oothecae

“…Verification of host records is required and many biological features still need to be understood before we will fully appreciate the evolution of host associations in Microdontomerus and related groups. Metafemur breadth Greatest breadth of metafemur, outer aspect (Baur 2015) fm3.l Metafemur length Length of metafemur, from distal end of trochanter to tip of metafemur, measured along midline, outer aspect (Baur 2015) frv.b Frontovertex breadth Minimal distance between compound eyes at level level of median ocellus…”

“…1. They mostly follow Graham (1969), Gibson et al (1997), Graham and Gijswijt (1998), Krogmann and Vilhelmsen (2006) and Baur (2015) or are newly defined. Some additional abbreviations which are not mentioned in Appendix 1 are: F1-F6 = funicle segments 1-6; Gt 1 -Gt 5 = gastral terga 1-5; MPS = multiporous plate sensilla; OI (ovipositor index) = ratio of ovipositor length to length of metatibia.…”

“…Character definition fwi.b Fore wing breadth Greatest breadth of fore wing, measured at about right angle to marginal and postmarginal veins (Baur 2015) fwi.l Fore wing length Greatest length of fore wing, measured from end of humeral plate to tip of wing (Baur 2015) hea.b Head breadth Greatest breadth of head, dorsal view (Baur 2015) hea.h Head height Distance between anterior margin of clypeus and anterior edge of anterior ocellus, frontal view (Baur 2015 …”