Gasteruption boreale (Thomson, 1883)

Bogusch, Petr, 2021, The genus Gasteruption Latreille, 1796 (Hymenoptera: Gasteruptiidae) in the Czech Republic and Slovakia: distribution, checklist, ecology, and conservation status, Zootaxa 4935 (1), pp. 1-63 : 12-14

Gasteruption boreale (Thomson, 1883)

Figs. 13–22 .

For synonymy see Johansson & van Achterberg (2016).

Diagnosis: A smaller species, the body length of females (without ovipositor) 8–11 mm, ovipositor length 1.6–2.8 mm. Total length of males 8–10 mm. Head is not elongated, with short gena and occipital carina narrow and developed only laterally. Head and mesonotum finely sculptured. Ovipositor is short, with ovipositor sheath 0.9–1.5× as long as the third tibia, with a black or dark brown apex. This species was recently resurrected from the synonymy with G. assectator by Johansson & van Achterberg (2016). The main differences from G. assectator and G. nigritarse are in finer sculpture especially on the mesonotum, narrow hypostomal bridge and the female’s ovipositor sheath has only short and irregular bristles ( Johansson & van Achterberg 2016).

Distribution: ( Fig. 22 ): Probably widespread in Europe from south to the north but in older studies it is not distinguished from G. assectator . Recorded from the following countries: Austria, Bulgaria, Czech Republic, Finland, Germany, Hungary, Netherlands, Norway, Russia, Serbia, Slovakia, Slovenia, Sweden, Turkey and Ukraine ( Johansson & van Achterberg 2016, Özbek 2020, and personal records), Orlovskyté et al. (2018) bring records from Lithuania.

Previously was not distinguished from G. assectator . It is new for the Czech Republic (both Bohemia and Moravia) and also from Slovakia. This species is rarer than G. assectator . It was recorded in 48 localities in the Czech Republic and 15 in Slovakia, mostly in warmer regions of both countries (although recently it was collected near Orlické hory and Novohradské hory mountains in altitudes around 600–700 m n.m.). Recently, it is rarer than before the year 1990, there are 31 old and 17 recent localities of this species known from the Czech Republic and six recent and nine old from Slovakia ( Tab. 2).

Biology: Recorded from May to September. Host spectrum is probably a part of the species recorded as host of G. assectator ( Parslow et al. 2020b) . Orlovskyté et al. (2018) recorded Hylaeus communis (Colletidae) as a host of G. boreale . Like most species of this genus, G. assectator frequently visits flowers of multiple species of families Apiaceae and Asteraceae (personal records).

Conservation: G. boreale is the rarest from the three species of G. assectator s. l. and probably occurs mainly in warmer regions. Since the biology is not well-known, it is hard to state what the main reasons are for the loss of records in recent years. Red List Category: VU—vulnerable ( Tab. 2).

Figures

FIGURE 22. Distribution map of Gasteruption boreale in the Czech Republic and Slovakia. Full circles represent distribution after 1990 and empty circles distribution until 1990.

FIGURES 13–21. Gasteruption boreale (Thomson, 1883). 13—female, lateral habitus, 14—male, lateral habitus, 15—female, lateral head, 16—female, frontal head, 17—female, dorsal head, 18—female, lateral mesosoma, 19—female, dorsal mesosoma, 20—female, third leg, 21—female, ovipositor apex. Scale bars represent 1 mm.