Aphidius silvaticus Starý

Jamhour, Aiman, Mitrović, Milana, Petrović, Andjeljko, Starý, Petr & Tomanović, Željko, 2016, Re-visiting the Aphidius urticae s. str. group: re-description of Aphidius rubi Starý and A. silvaticus Starý (Hymenoptera: Braconidae: Aphidiinae), Zootaxa 4178 (2), pp. 278-288 : 284

Aphidius silvaticus Starý

( Fig. 5 )

Diagnosis. For differentiation of A. silvaticus from A. rubi , see A. rubi diagnosis above. Aphidius silvaticus differs from A. urticae in having more longitudinal placodes on F2 (2–3 longitudinal placodes in A. silvaticus , one placode in A. urticae ) and a higher tentorial index ( A. silvaticus is 0.45–0.55, 0.35–0.40 in A. urticae ). It differs from A. urticae in its host range pattern, since A. urticae is a specialized parasitoid of the stinging nettle aphid ( Microlophium carnosum ), while A. silvaticus parasitizes Amphorophora aphid hosts.

Description. Female. Head: Head wider than mesoscutum (the ratio between head width and mesoscutum width is 1.30–1.39). Eyes oval, with sparse setae ( Fig. 5 a). Clypeus oval, with 10–16 long setae. Tentorial index (tentoriocular line/intertentorial line) equal to 0.45–0.55. Antennae (18) 19–20-segmented, filiform, reaching about half of metasoma with semierect and adpressed setae shorter than diameter of the segments. F1 ( Fig. 5 b) 3.30–3.80 × as long as median width, without longitudinal placodes. F2 ( Fig. 5 b) is 3.00–3.50 × as long as median width, with (2) 3 longitudinal placodes. F1 subequal to F2 (F1/F2 = 0.94–1.03) ( Fig. 5 b). Maxillary palp with four palpomeres, labial palp with three palpomeres.

Mesosoma: Mesonotum with notaulices distinct in the ascendent part, deep, crenulated, sparsely setaceous, with two rows of setae along the mesonotum. Notaulices effaced on the disc ( Fig. 5 c). Propodeum areolated with central pentagonal areola ( Fig. 5 d). Upper lateral areolae with 10–13 setae each, and lower lateral areolae with 4–5 setae. The ratio between hind leg tibia length and first tarsomere length is 3.35–3.42, while that between hind leg tibia length and second tarsomere length is 7.45–8.15. The ratio between lengths of the first and second tarsomeres of the hind leg is 2.18–2.45.

Fore wing: Stigma moderately elongate, 3.50–4.00 × as long as wide and 0.91–1.00 × as long as distal abscissa of R1 (= metacarpus). The ratio between length and width of the fore wing is 2.44–2.60.

Metasoma: Petiole elongate, slender, 3.30–3.60 × as long as wide at spiracles ( Fig. 5 f), with 10–12 costulae on its anterolateral area and with a short mediodorsal carina that is not clearly defined. Ovipositor sheath slightly concave on its dorsal margin ( Fig. 5 g).

Colour: Head black-brown with yellow face, frons, genae, clypeus and mouthparts. Scape yellow, pedicel brown. F1 yellow at the base, and sometimes F2 and F3 also yellow. Remaining part of antennae brown. Mesosoma and metasoma mostly yellow or light brown. Legs yellow with brown apices. Propodeum light brown. Ovipositor sheath black.

Body length: 2.9–3.6 mm.

Male: Antennae 21–22 segmented. F1 2.00–2.10 × as long as wide. F1 and F2 with 6–8 and 7–9 longitudinal placodes, respectively. Stigma about 3.50 × as long as wide, metacarpus subequal to stigma length. Petiole subsquare, about 2.80–2.90 × as long as wide at spiracle level. Body generally darker than female.

Examined material: We re-examined type specimens (for collection details, see Starý, 1962); Amphorophora ampullata Buckton on Dryopteris austriaca 2♀, Rusava, 20-VII-1963 (CZE); Amphorophora idaei (Börner) on Rubus idaeus 4♀ 5Ƌ, Sint–Truiden, 09-VII-2015 (BEL); on Rubus sp. 1♀ 1Ƌ, Sint–Truiden, 16-IX-2014 (BEL); Amphorophora rubi (Kaltenbach) on Rubus idaeus 1Ƌ, Kopaonik, 17-VII-2013 (SER); on Rubus sp. 1♀ 2Ƌ, Brestovik, 27-V-2011 (SRB); 2♀ 3Ƌ Helsinki 15-28-VII-1963 (FIN); 23♀ 15Ƌ, Plitvice–Kozjak, 21-VI-2015 (CRO); Amphorophora sp. on Dryopteris sp. 3♀ 1Ƌ, Divčibare, 05-VIII-1999 (SRB); on Rubus sp. 1♀ 1Ƌ Petnica, 18-V-1998 (SRB); 2Ƌ, Tara–Derventa, 31-V-1998 (SRB); 5♀ 2Ƌ, Tara–Derventa, 20-V-2000 (SRB); 4♀ 1Ƌ, Sint–Truiden, 16-IX-2014 (BEL), 1♀, Praha –Košíře, VI-1978 (CZE).

Figures

FIGURE 5. Aphidius silvaticus. female: a) head; b) flagellomere 1 and 2; c) mesonotum—dorsal view; d) propodeum—dorsal view; e) fore wing; f) petiole—dorsal view; g) ovipositor—lateral view.