Chrysis angustula Schenck, 1856

Paukkunen, Juho, Berg, Alexander, Soon, Villu, Odegaard, Frode & Rosa, Paolo, 2015, An illustrated key to the cuckoo wasps (Hymenoptera, Chrysididae) of the Nordic and Baltic countries, with description of a new species, ZooKeys 548, pp. 1-116 : 64-65

Taxon classification Animalia Hymenoptera Chrysididae

Chrysis angustula Schenck, 1856 Figs 86, 99, 119, 126

Chrysis angustula Schenck, 1856: 28.

Chrysis gracilis ? Schenck, 1856: 30.

Chrysis brevidens Tournier, 1879: 96.

Diagnosis.

Length 6-9 mm. The species can be confused with several other similarly coloured species of the Chrysis ignita group (e.g. Chrysis leptomandibularis , Chrysis schencki and Chrysis corusca ). Compared to Chrysis leptomandibularis and Chrysis schencki , the mandible is thicker, the punctation of T2 is finer, the black spots of S2 are more rectangular and the posterior margin of the propodeal tooth is directed more downward. Compared to Chrysis corusca , the mandible is thinner, the punctation of the tergites is finer and the colour of the sternites is more reddish (not green). The head and mesosoma are mainly dark blue, and usually have extensive green or golden reflections on the frons, pronotum, mesopleuron, mesoscutum and mesoscutellum, especially in the female. The metasomal tergites are golden red (Fig. 99) and the sternites golden or reddish (Figs 119, 126). The black spots of S2 are characteristically rectangular in shape (Figs 119, 126). The body is elongate and slender, with parallel sides (resembling Chrysis leptomandibularis ) (Fig. 99). The punctation of T2 is fine, and its surface is strongly shining posteriorly (Fig. 99). T3 is relatively long, and strongly shining, especially in the female (Fig. 99). The apical teeth are short, and the central interval is wide and shallow (Figs 86, 99). The ovipositor is narrow (as in Fig. 92) and the mandible relatively thick in both sexes.

Distribution.

Denmark, Estonia, Finland, Latvia, Lithuania, Norway, Sweden. Very common. - Trans-Palearctic. Europe, southwestern Asia, Siberia, China ( Linsenmaier 1997, Rosa et al. 2014).

Biology.

Habitat: forest margins, clearings and gardens with sun-exposed dead wood. Adults are often found on walls of wooden buildings, poles, log piles and dead tree trunks. Occasionally they also visit flowers of Apiaceae and Asteraceae ( Banaszak and Kochanowski 1994, our own obs.) and are attracted to honeydew of aphids. Flight period: late May to September. Host: primarily Symmorphus bifasciatus (Linnaeus) ( van Lith 1958, Niehuis 2000, Pärn et al. 2014, our own obs.), but occasionally also Ancistrocerus trifasciatus ( Müller), Symmorphus allobrogus (Saussure), Symmorphus connexus (Curtis) and Symmorphus debilitatus (Saussure) ( Vespidae ) ( van Lith 1958, Niehuis 2000, Pärn et al. 2014, our own obs.).