Pristiphora caraganae Vikberg & Prous

Prous, Marko, Kramp, Katja & Liston 1, Veli VikbergAndrew, 2017, North-Western Palaearctic species of Pristiphora (Hymenoptera, Tenthredinidae), Journal of Hymenoptera Research 59, pp. 1-190 : 65-68

Pristiphora caraganae Vikberg & Prous sp. n. Figs 194, 311-319

Description.

Female (holotype DEI-GISHym80209 and one paratype), Figs 194, 311-313, 315. Body 6.1-6.3 mm. Colour mostly black. Labrum brown; labial and maxillary palps pale; mandibles reddish-brown at apex; flagellum ventrally slightly paler than dorsally or extensively pale; tibia and tarsi of fore and middle legs more or less entirely pale; apex of profemur pale; metatibia and metatarsomere 1 pale with small black area at apex; trochanters and trochantelli mainly pale; pterostigma bicoloured, basally darker than apically; pronotum and tegula extensively pale. Labrum more or less symmetrical; clypeus truncate; postocellar area about 1.4 times as long as diameter of lateral ocellus; flagellum length 3.9-4.0 mm, 2.3-2.4 times as long as width of head. Mesopostnotum matt; mesepisternum smooth; claws with large subapical tooth clearly separated from apical one; anterior protibial spur with velum. Hypopygium posteriorly not excised. Sawsheath (valvula 3 + valvifer 2) with distinct scopa directed posteriorly and with short medial projection. Lancet with numerous setae on annuli; serrulae protruding, more or less triangular, and with numerous denticles on ventro-apical surface; small spiny pectines on the inner surface (dentes semicirculares) that reach sclerora weak; tangium without lobe, campaniform sensilla present.

Male (31 paratypes), Figs 314, 316-319. Body 5.0-5.6 mm (n=6). Colour mostly black, similar to female. Flagellum ventrally distinctly paler than dorsally; labial and maxillary palps pale; mandibles reddish-brown at apex; tibia and tarsi of fore and middle legs more or less entirely pale; apex of pro- and mesofemur pale; metatibia pale with small black area at apex, trochanters and trochantelli slightly pale; pterostigma bicoloured, basally darker than apically; pronotum black or apically slightly brownish, tegula black to extensively pale. Labrum more or less symmetrical; clypeus truncate; postocellar area about 1.5 times as long as diameter of lateral ocellus; flagellomeres with numerous stout black setae among finer paler ones; flagellum length 4.0-4.3 mm, 2.6 -3.1 times as long as width of head. Mesopostnotum matt; mesepisternum smooth; claws with long subapical tooth close to or clearly separated from the apical one; anterior protibial spur with velum. Tergum 8 without apical projection; sternum 9 without notch. Penis valve with large valvispina that nearly entirely replaces paravalva. Valvispina strongly bent in dorsal direction, narrow and with posterior and anterior margin of similar shape, apex sharp; pseudoceps relatively short and broad, apex distinctly narrowed and ventroapical part only slightly extending beyond dorsalmost margin, dorsally without depression, distinct spines, hair, and membranous regions or folds.

Etymology.

The species name refers to the host plant Caragana .

Similar species.

Externally, females of this species (only the holotype and one paratype known so far) are not distinguishable from many specimens of P. confusa , as well as from P. armata and P. leucopus that have completely black metafemora. However, the lancet has small spiny pectines on its inner surface (Fig. 194) as in other species of albitibia subgroup. Unfortunately, these spiny pectines might easily be overlooked, because they are rather weakly developed (at least in the holotype) compared to other species in the group. In the albitibia subgroup, the female as well as the male of P. caraganae differ from the other species by having the antenna ventrally pale. The female differs additionally from astragali and sootryeni by having a smooth mesepisternum and different lancet (see the Key). Males seem externally most similar to P. bifida , but the penis valves of P. caraganae (Fig. 317) clearly indicate a close relationship with the albitibia subgroup. Compared to other species in the group (although males of P. astragali are unknown), the penis valves seem to be sufficiently distinct (see the Key). There appears to be one more species belonging to the albitibia subgroup that has ventrally pale antennae. Pristiphora nigromongolica Haris, 2002 (http://dx.doi.org/10.6084/m9.figshare.5057791), which is so far known only from the holotype male, differs from P. caraganae by having a smaller subapical tooth of the claw, possibly darker pterostigma (uniformly dark) and a different penis valve that is most similar to P. sootryeni (http://dx.doi.org/10.6084/m9.figshare.4690174).

Genetic data.

Based on two identical COI barcode sequences, P. caraganae possibly forms its own cluster (no BIN number has been assigned yet) (Fig. 4). Based on nuclear data (two specimens and both genes combined), within species divergence is 0.0% and the nearest neighbour is 0.6% different ( P. astragali ).

Host plants.

Caragana arborescens Lam.

Rearing notes.

The type specimens were collected from Caragana arborescens that grew intermixed with Populus tremula . One larva swept on 18.VI.2017 from the same spot as the adults was offered leaves of Caragana , Populus , and Vicia cracca L., but fed only on Caragana . The larvae made a cocoon on 22.VI.2017 and a female emerged on 2.VII.2017. The reared female laid 44 eggs in leaflets of Caragana and one egg in a leaflet of Vicia . The first larvae emerged on 7.VII.2017. The larva emerged from Vicia was also feeding on Vicia , but died the following day (8.VII.2017). The larvae feeding on Caragana had four instars and possibly a few (3?) had five instars and their development was rapid. On 17-19.VII.2017, 41 prepupae were counted (three larvae had died earlier as rather young) and they made brown cocoons in filter paper in petri dishes, except four prepupae which were stored in alcohol. On 31.VII.-5.VIII.2017, 30 males emerged.

Distribution and material examined.

West Palaearctic. Finland.

Holotype. Female. Finland, Hame, Janakkala, Kuumola [ETRS-TM35FIN 67558:[8]3721], 60.91707°N 24.64196°E, 28.VIII.2016, leg. V. Vikberg (MZH). Paratypes. 1♂ (DEI-GISHym80356), same data as the holotype, except 30.V.2017 (MZH), 1♀, same data as the holotype, except reared ex larva from Caragana arborescens found on 18.VI.2017, emerged 2.VII.2017 (CVV), 30 ♂♂, same data as the holotype, except reared ex ovo from the reared female, emerged 31.VII.-5.VIII.2017 (15 in CVV, 5 in MZH, 8 in SDEI, 2 in UEF), 4 prepupae (♂), same data as the holotype, except reared ex ovo from the reared female (SDEI).