Toxeuma Walker, 1833.

Tselikh, Ekaterina V. & Dale-Skey, Natalie, 2021, Review of the genus Toxeuma Walker, 1833 (Hymenoptera, Pteromalidae) from Russia, with a key to Palaearctic species, Journal of Hymenoptera Research 84, pp. 391-403 : 391

Toxeuma Walker, 1833.

Toxeuma fuscicornis Type species: Toxeuma fuscicornis Walker, 1833, by subsequent designation of Westwood (1839: 68).

Cirdania Hedqvist, 1974: 145. Type species: Cirdania styliclava Hedqvist, 1974, by original designation. Synonymy by Bouček (1991: 205).

Diagnosis.

Clypeal margin entire, truncate or slightly arched; antennal clava with or without short or long spicula; antennal formula 11263; pronotum with collar margin carinate; notauli complete; prepectus reticulate, without carinae; sculpture of propodeum at least partly irregular, petiole from transverse to slightly elongate; fore wing with slender M, metasoma ovate or lanceolate ( Graham 1959; Hedqvist 1974; Heydon and Grissell 1988; Bouček and Rasplus 1991).

Distribution.

Palaearctic, Nearctic and Neotropics.

Comments.

Unfortunately, the biology of most Toxeuma species is unknown. The only biological records exist for T. fuscicorne , which was reared from the primary host Agromyza schineri Giraud, 1861 ( Diptera , Agromyzidae ) ( Bouček 1977), and for T. paludum , reared from the primary host Coleophora sp. ( Lepidoptera , Coleophoridae ) ( Askew 1968).

The genus can be distinguished from other Pteromalidae genera using the keys of Graham (1969) and Bouček and Rasplus (1991).

In this genus, the antennal clava can have three variations: acute (Fig. 24 ), with a spicula (e.g., Figs 4 , 17 , 27 , 30 ) or without spicula and rounded apically (e.g., Figs 13 , 35 ). This is an important feature to identify species of this genus. Unfortunately, in the original descriptions of T. acilius (Walker, 1848) and T. paludum (Graham, 1959) as well as in previously published keys ( Graham 1959, 1969) this feature was neither mentioned nor shown on the figures. However, after studying the types and additional material, the presence of a spicula was found in almost all individuals of these species. Interestingly, T. paludum Graham is characterized by variation of antennal clava from acute (Fig. 24 ) to that with very short and straight spicula (e.g., Figs 23 , 27 ).

The discovery of a previously undescribed spicula in some Palaearctic species suggests that some members of Toxeuma from Nearctic Region described by Heydon and Grissell (1988) might be synonyms of the Palaearctic species, but additional research is needed to confirm this assumption.

Figures

Figures 22 - 32. Toxeuma paludum holotype female (23) paratype female (24) non-type female (22, 25, 26) 22 body, lateral view 23 antenna (dry material) 24 antenna (dry material) 25 metasoma, dorsal view 26 scutellum, propodeum and petiole, dorsal view 27 F 6 and antennal clava (slide) Toxeuma styliclava paratype female (28, 29) non-type female (30 - 32) 28 antenna (dry material) 29 body, lateral view 30 F 6 and antennal clava (slide) 31 metasoma, dorsal view 32 propodeum and petiole, dorsal view Scale bars: 1.0 mm.

Figures 1 - 9. Toxeuma acilius holotype male (1) non-type female (2 - 6) 1 body, dorsal view 2 body, dorso-lateral view 3 antenna (dry material) 4 F 6 and antennal clava (slide) 5 antenna (slide) 6 propodeum and petiole, dorsal view Toxeuma discretum holotype female (7 - 9) 7 metasoma, dorsal view 8 body, dorsal view 9 body, lateral view Scale bars: 1.0 mm.

Figures 10 - 21. Toxeuma fuscicorne non-type female (10 - 14) 10 body, lateral view 11 metasoma, dorsal view 12 scutellum, propodeum and petiole, dorsal view 13 F 6 and antennal clava (slide) 14 antenna (slide) Toxeuma leleji sp. nov. holotype female (15, 16, 18 - 20) paratype female (17, 21) 15 body, lateral view 16 fore and hind wings 17 antennal clava (slide) 18 metasoma, dorsal view 19 propodeum and petiole, dorsal view 20 head, frontal view 21 antenna (slide) Scale bars: 1.0 mm.

Figures 33 - 38. Toxeuma subtruncatum paratype female (33, 34) paratype male (36) non-type female (35, 37, 38) 33 body, lateral view 34 antenna (dry material) 35 antennal clava (slide) 36 body, lateral view 37 metasoma, dorsal view 38 propodeum and petiole, dorsal view Scale bars: 1.0 mm.