Gasteruption assectator (Linnaeus, 1758)

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 : 10-12

Gasteruption assectator (Linnaeus, 1758)

Figs. 1–12 .

For synonymy see Johansson & van Achterberg (2016).

Diagnosis: Smaller species, the body length of females (without ovipositor) 9–12 mm, ovipositor length 2.2–3.1 mm. Total length of males 8–12 mm. Head not elongated, with short gena and occipital carina narrow and developed only laterally. Head and mesonotum finely sculptured with coarser sculpture in subapical part, some specimens, usually from higher altitudes, have the mesonotum transversely rugulose. Ovipositor is short, ovipositor sheath 1.1–1.8× the length of the third tibia, and with black or dark brown apex. Gasteruption boreale and G. nigritarse are similar species, which were recently resurrected from the synonymy by Johansson & van Achterberg (2016). The main differences are in the sculpture and width of hypostomal bridge: G. nigritarse has a wider hypostomal bridge than the two other species, a satin greenish shine on the head and mesonotum, usually dark third tibia with only very small or missing whitish collar sub-apically, and the female’s ovipositor sheath carries elongated bristles. The sculpture of the head and mesonotum is very similar and much finer (especially on mesonotum) than at G. assectator . Gasteruption boreale has a similar sculpture to G. nigritarse but differs with no greenish shine on the body, a narrow hypostomal bridge and the female’s ovipositor sheath is with only short and irregular bristles ( Johansson & van Achterberg 2016).

Distribution ( Fig. 12 ): Holarctic species. Most of Europe, recorded from the following countries: Austria, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Finland, France + Corsica, Cyprus, Georgia, Germany, Greece, Hungary, Italy + Sardinia and Sicily, Montenegro, Netherlands, Norway, Poland, Romania, Russia, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine, and the United Kingdom, also in Middle East Asia: Jordan, Syria, and Iran, and in Morocco and Tunisia in North Africa ( Ferrière 1946; Šedivý 1958; Hedqvist 1973; Oehlke 1984; Madl 1989; Pagliano & Scaramozzino 2000; Broad & Livermore 2014; van Achterberg 2013; Strumia & Pagliano 2014; van Achterberg & Talebi 2014; Ceccolini 2016; Vas 2016; Madl & Mitroiu 2019, Özbek 2020, Wiśniowski 2020, and personal records). Orlovskyté et al. (2018) brings records from Lithuania, Žikić et al. (2014) from former Yugoslavian countries: Croatia, Macedonia, Montenegro, Serbia, and Slovenia. It is the most widespread species in nearly the whole of Europe and is also known from the USA and Canada ( Johansson & van Achterberg 2016).

Šedivý (1958; 1989) recorded this species from Czech Republic and Slovakia and from both Bohemia and Moravia in the Czech Republic. It is a widespread species with the largest distribution and number of records. It is recorded not only from lowlands and warmer parts of both countries but also from higher altitudes, where it is often the only species of the genus recorded. The number of records is 190 from the Czech Republic and 77 from Slovakia, and the number of localities where it occurs is 159 and 63. There are more new records, collected after the year 1990: 99 to 60 in the Czech Republic, and 34 to 29 in Slovakia ( Tab. 2).

Biology: Recorded from May to September. Predator-inquiline of bees and wasps nesting in cavities and loess walls. Bees of the genus Hylaeus (Colletidae) are reported as the main hosts: Hylaeus annularis (Kirby) , Hylaeus brevicornis Nylander , Hylaeus communis Nylander , Hylaeus confusus Nylander , Hylaeus pectoralis Förster , and Hylaeus rinki (Górski) ( Höppner 1904; Wagner 1907; Wolf 1953; Malyshev 1964; Danks 1971; Westrich 1979; Brechtel 1986; Wall 1994; Jakubzik & Cölln 1997; Tscharntke et al. 1998; Bürger 2004; Pereira-Peixoto et al. 2016; Orlovskyté et al. 2018); direct proof from the nest of Hylaeus punctatus (Brullé) was published by Šedivý (1958). Smaller species of Megachilidae were also reported: Chelostoma florisomne (Linnaeus) , Chelostoma rapunculi (Lepeletier) , Heriades truncorum (Linnaeus) , and Osmia caerulescens (Linnaeus) ( Lindemans 1921; Nicholson 1928; Jakubzik & Cölln 1997; Tscharntke et al. 1998; Petrischak 2014; van Achterberg & Talebi 2014; van Breugel 2014; Westrich 2018). Several authors have reported also crabronid wasps Passaloecus cuspidatus Smith , Pemphredon fabricii (Müller) , Pemphredon lethifer (Shuckard) , and Trypoxylon figulus (Linnaeus) ( Höppner 1904; Bradley 1908; Habermehl 1921; Fahringer 1922; Ferrière 1946; Gyorfi & Bajari 1962; Oehlke 1984; Bogusch et al. 2018) or solitary wasps ( Vespidae ): Odynerus spinipes (Linnaeus) ( Gyorfi & Bajari 1962; Oehlke 1984), although no host records of wasps for any Gasteruption have been directly confirmed ( Bogusch et al. 2018). Parslow et al. (2020b) have summarised all host records of this species. Like most species of this genus, G. assectator frequently visits flowers of multiple species of families Apiaceae and Asteraceae ( Wall 1994) .

Conservation: This species is not endangered in both countries and is very numerous, widespread and common. Red List Category: LC—least concern ( Tab. 2).

Figures

FIGURE 12. Distribution map of Gasteruption assectator in the Czech Republic and Slovakia. Full circles represent distribution after 1990 and empty circles distribution until 1990.

FIGURES 1–11. Gasteruption assectator (Linnaeus, 1758). 1—female, lateral habitus, 2—male, lateral habitus, 3—female, lateral head, 4—female, frontal head, 5—female, dorsal head, 6—female, lateral mesosoma, 7—female, dorsal mesosoma, 8—female, third leg, 9—female, ovipositor apex, 10—female, hypopygium, 11—female, hypostomal bridge. Scale bars represent 1 mm.