Misetus obscurus Berthoumieu, 1897

Misetus obscurus Berthoumieu, 1897 View in CoL stat. rev.

Materials

Type status: Other material. Occurrence: recordedBy: S. Cantone, A. Di Giulio; individualCount: 4; sex: males; occurrenceID: 68D20C7A-8527-53E4-A2C5-DBB7EAF25FE8; Location: country: Italy; countryCode: IT; stateProvince: Sicily; municipality: Sortino, Siracusa; locality: Riserva Naturale di Pantalica ; Identification: identifiedBy: E. Diller; dateIdentified: 2024; Event: eventDate: 05/05/2023; year: 2023; month: 5; day: 5; Record Level: institutionCode: FDGC

Type status: Other material. Occurrence: recordedBy: S. Cantone, A. Di Giulio; individualCount: 2; sex: 1 female, 1 male; occurrenceID: A0AAA00E-9BEA-5FAF-8B24-F8C09E14E57C; Location: country: Italy; countryCode: IT; stateProvince: Sicily; municipality: Sortino, Siracusa; locality: Riserva Naturale di Pantalica ; Identification: identifiedBy: E. Diller; dateIdentified: 2024; Event: eventDate: 17/05/2023; year: 2023; month: 5; day: 17; Record Level: institutionCode: FDGC

Type status: Other material. Occurrence: recordedBy: S. Cantone, A. Di Giulio; individualCount: 1; sex: female; occurrenceID: 9B3ADB04-2D4B-5AEF-95A9-E91B6203414C; Location: country: Italy; countryCode: IT; stateProvince: Sicily; municipality: Sortino, Siracusa; locality: Riserva Naturale di Pantalica ; Identification: identifiedBy: E. Diller; dateIdentified: 2024; Event: eventDate: 09/07/2023; year: 2023; month: 7; day: 9; Record Level: institutionCode: FDGC

Distribution

Belgium, France (incl. Corsica), Romania, Sweden (but see Notes). This is the first record of the species for Italy.

Notes

According to Berthoumieu (1897), it is a colour form of Misetus oculatus Wesmael, 1845 , characterszed by scape brown to black, thorax entirely black, hind coxae and sometimes also fore coxae black, hind legs and abdomen black, the latter with reddish margins on metasomal segments II – III. This form was later reported from Romania by Constantineanu (1965) and from Corsica by Aubert (1969); Constantineanu also cited it from France, Germany, Sweden and Lapland, repeating Berthoumieu's account, although the latter did not differentiate between the distribution of the two forms. Compared to the original description ( Berthoumieu 1897), Aubert (1969) reports the scutellum as red and the hind legs as black, except for the yellow trochanters. In the specimens attributed to this form by Constantineanu (1965), the scutellum and postscutellum are black, whereas the hind femora are sometimes reddish-brown. According to Diller and Horstmann (1994), the obscurus form corresponds to var. 1 reported by Wesmael (1845) for Belgium and in Holmgren (1890) for Sweden.

In the key to females of the Palaearctic species of the genus Misetus ( Di Giovanni et al. 2018) , the female of M. obscurus runs to the couplet 2, resembling M. borealis Kusigemati, 1974 and M. nordicator Selfa, 1995 in having a distinctly concave metasomal tergite V ( Kusigemati 1974, Selfa and Diller 1995). However, it can be distinguished from both species by the number of flagellomeres (30), the occipital carina meeting the hypostomal carina at the base of the mandibles and the strigose-punctate postpetiole. Compared to the Mediterranean species (Figs 5 View Figure 5 , 6 View Figure 6 ), M. obscurus exhibits a moderately pronounced median tooth on the clypeus (much more prominent in M. oculatus , barely visible in M. strumiai Di Giovanni, Scaramozzino & Diller, 2018 ), a distinctive microsculpture of postpetiole and metasomal tergite II, a yellowish scutellum (black in M. hispanator Selfa, 1995 , red in M. strumiai ) and a typically brownish-black hind coxa and femora ( Selfa and Diller 1995, Di Giovanni et al. 2018).

Males are more difficult to distinguish and resemble M. strumiai males in colouration; they differ, however, by a more pronounced median tooth on the clypeus, antennae with a higher number of flagellomeres and tyloids (29-31 flagellomeres in M. obscurus vs. 24-25 in M. strumiai ), less marked punctation on face, clypeus and metasomal tergite II and by the colouration of scutellum (black in males of M. obscurus and red in M. strumiai ) ( Di Giovanni et al. 2020) (Figs 7 View Figure 7 , 8 View Figure 8 ).

Taxonomic identification was further supported by partial COX 1 sequencing (GenBank accession PX 272273). The closest matches in both the BOLD Systems v 5 species identification and NCBI BLASTn search corresponded to M. oculatus (BOLD: GMFIE 519-12; GenBank: MZ 607881 View Materials ), with a p-distance of 5.41–5.84 % (Table 1 View Table 1 ), indicating that the specimen cannot be confidently assigned to M. oculatus .

Diagnosis

Re-description, Female (Fig. 3 View Figure 3 ). Body length 7 mm. Fore wing length 4 mm.

Face about 0.5 × as high as wide (width between compound eyes at the level of clypeal suture; height from antennal sockets to clypeal suture), polished with few scattered punctures centrally. Frons and vertex polished with very fine punctures. Clypeus polished and shining, with just few inconspicuous punctures, its apical margin almost straight and with a small developed medial tooth. Mandible slightly down-twisted at apex, with upper tooth longer than the lower one. Occipital carina complete, joining hypostomal carina at base of mandible. Antenna with 30 flagellomeres. Mesoscutum with dense punctures, notaulus deeply impressed in the anterior half; scutellum with few inconspicuous punctures, without lateral carinae. Mesopleuron, except for smooth speculum, covered with fine longitudinal striae, with a few distinct punctures interspersed in between; sternaulus impressed in the anterior half of mesopleuron; epicnemial carina present and reaching anterior margin of mesopleuron; posterior transverse carina of mesosternum interrupted at level of middle coxa. Fore wing areolet pentagonal, with cu-a opposite Rs & M. Hind wing with distal abscissa of Cu 1 present. Coxa coriaceous and strongly punctate. Propodeum coriaceous, irregularly wrinkled, with propodeal carinae weakly marked, area superomedia slightly longer than wide; metapleuron smooth in the antero-dorsal half, with few scattered punctures, coriaceous and with irregular wrinkles on postero-ventral half. Metasoma covered with fine, short and sparse pubescence. Tergite I with dorsal longitudinal carinae weak, postpetiole strigose-punctate. Metasomal tergite II with thyridia weakly marked, slightly granulate basally, before thyridia, then slightly coriaceous medially and polished laterally and apically, with very few scattered punctures. Remaining metasomal tergites polished and without punctures; metasomal tergite V emarginate apically. Ovipositor short and upcurved.

Colour. Head black; antenna brownish-black with white markings on flagellomeres 5-9, scape and pedicel ventrally reddish; mandible, except for reddish teeth, yellowish-red; palps yellow. Mesosoma black; hind corner of pronotum, subtegular ridge, tegula and scutellum yellowish. Pterostigma yellowish-brown. Fore and mid-coxae and all trochanters yellow; fore and mid-femora and tibiae red; hind coxa black with yellow apex; trochanters yellow; hind femur black; hind tibia and tarsi reddish, tibia infuscate on apical third. Metasoma reddish-yellow; tergite I black, slightly reddish basally and apically; metasomal tergites II-III with a brownish median band. Ovipositor sheath red.

Male (Fig. 4 View Figure 4 ). As female, except for: antenna with 29-31 flagellomeres, tyloids on flagellar segments 7-15. Metasomal tergite II with thyridia more distinct, tergite roughly granulate basally, before thyridia, then slightly coriaceous medially and subpolished laterally and apically, with very few scattered punctures. In colour, similar to the female, except for mandible and scape brownish-black, scutellum black, hind trochanter black basally, yellow apically, hind tibia and tarsi darker, metasoma black with thyridia on metasomal tergite II and apical margin on tergites II-VI reddish.