Aphidius rubi 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 : 282-283

Aphidius rubi Starý

( Fig. 4 )

Diagnosis. In its host range pattern, long R1 vein and light body colour, Aphidius rubi belongs to the A. urticae s. str. group, from which it differs with respect to a combination of several characters [wing venation pattern, shape and carination of the dorsal side of petiole, number of longitudinal placodes on flagellomere 1 (F1) and the tentorial index]. Aphidius rubi differs from the sibling species A. silvaticus in having a prominent carina on petiole ( Fig. 4 f), which is not clearly defined in A. silvaticus ( Fig. 5 f). Moreover, the R1 vein (= metacarpus) is shorter than the stigma in A. rubi (the ratio between the stigma and the metacarpus is 1.11–1.34 in A. rubi ), in contrast to A. silvaticus , where the metacarpus is equal to or longer than the stigma (the ratio between the stigma and the metacarpus is 0.91–1.00 in A. silvaticus ). Also, A. rubi is a parasitoid of the blackberry aphid ( Macrosiphum funestum ) and probably some other Macrosiphum species, as well as Aulacorthum spp., while A. silvaticus parasitizes different Amphorophora aphid hosts. Aphidius rubi differs from A. urticae in having more longitudinal placodes on F2 (2–3 longitudinal placodes in A. rubi instead of one placode in A. urticae ) and a higher value of the tentorial index (the tentorial index in A. rubi is 0.48–0.55, instead of 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 ).

Description. Female. Head: Head wider than mesoscutum (the ratio between head width and mesoscutum width is 1.25–1.41). Eyes oval, with sparse setae ( Fig. 4 a). Clypeus oval, with 10–17 long setae. Tentorial index (tentoriocular line/intertentorial line) equal to 0.48–0.55. Antennae 18–19 (20)-segmented, filiform, reaching about half of the metasoma, with semi-erect and adpressed setae shorter than diameter of the segments. Flagellomere 1 (F1) ( Fig. 4 b) 3.40–3.70 × as long as median width, usually without longitudinal placodes. Flagellomere 2 (F2) ( Fig. 4 b) is 2.70–3.30 × as long as median width, with 3 (2) longitudinal placodes. F1 subequal to F2 (F1/F2 = 0.93–1.06) ( Fig. 4 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 setae positioned in two rows along the mesonotum. Notaulices effaced on the disc ( Fig. 4 c). Propodeum areolated with narrow central pentagonal areola ( Fig. 4 d). Upper lateral areolae with 8–13 setae each, lower lateral areolae with 4–6 setae. The ratio between hind leg tibia length and first tarsomere length is 3.10–3.35, while that between hind leg tibia length and second tarsomere length is 7.20–8.45. The ratio between lengths of the first and second tarsomere of the hind leg is 2.30–2.60.

Fore wing: Stigma moderately elongated, 3.60–4.10 × as long as wide and 1.11–1.34 × as long as distal abscissa of R1 (= metacarpus) ( Fig. 4 e). The ratio between length and width of the fore wing is 2.50–2.66.

Metasoma: Petiole elongate, slender, 3.30–3.60 × as long as wide at spiracles ( Fig. 4 f), with 10–12 costulae on its anterolateral area ( Fig. 4 g) and with prominent central mediodorsal carina ( Fig. 4 f). Ovipositor sheath slightly concave on its dorsal margin ( Fig. 4 h).

Colour: Head yellow with occiput and frons brown to light brown. Mouthparts yellow. Scape light brown to yellow, pedicel brown. F1 with yellow ring at the base, remaining part of the antennae brown. Mesosoma and metasoma yellow to light brown. Legs yellow with brown apices. Propodeum brown to light brown. Ovipositor sheath black.

Body length: 2.4–4.0 mm.

Male: Antennae 22-segmented. F1 short, 1.60–1.90 × as long as wide. F1 and F2 with 9–10 and 11–12 longitudinal placodes, respectively. Stigma about 3.30–3.50 × as long as wide, metacarpus about a quarter shorter than stigma length (the ratio between stigma length and metacarpus length is 1.15–1.30). Petiole 3.10–3.30 × as long as wide at spiracle level. Body generally darker than female, with brown and black body parts.

Examined material: We re-examined type specimens (for collection details see Starý, 1962); Aulacorthum solani Kaltenbach on Filipendula ulmaria 1Ƌ, Plitvice–Okrugljak, 20-VI-2015 (CRO); on Fuchsia magellanica 2♀, Wellen, 15-V-2015 (BEL); 1♀, Wellen, 15-VI-2015 (BEL); on Lathyrus tuberosus 3♀ 3Ƌ, Prokuplje – Bresničić, 16-VI-2014 (SRB); on Myosotis aquatica 3Ƌ , Sremska Mitrovica, 24-V-1998 (SER), on Raphanus sativus 3♀, Tivat, 25-V-2011 ( MNE) ; on Sanguisorba minor 1♀ 1Ƌ, Durmitor–Crno jezero lake, 01-VII-1998 (MNE); Aulacorthum vaccinii Hille Ris Lambers on Vaccinium uliginosum 3♀, Obergurgl, 28-VII-2015 (AUT); Macrosiphum funestum (Macchiati) on Rubus armeniacus 3♀ 1Ƌ, Tara–Mitrovac, 03-VII-2012 (SRB); on Rubus fruticosus 12Ƌ, Rudolfov, 26-VI-2004 (CZE); on Rubus hirsutum 4♀ 8Ƌ, Komovi, 07-X-2013 (MNE); on Rubus idaeus 1Ƌ, Vlasina, 10-VI-2010 (SRB); on Rubus sp. 1♀, Roskoff, 02-V-1974 (FRA); 1Ƌ, Roskoff, 26-V-1974 (FRA); 1Ƌ, Gérardmer, 19-VI-1974 (FRA); 6♀ 2Ƌ Soto de Sajambre, 09-VII-1982 (ESP); 1Ƌ 5♀, Šara, 17-VII- 1995 (SRB); 1♀, Užice – Sredići, 10-VI-2011 (SRB) ; 12♀ 9Ƌ, Golija–Bele vode, 21-VII-2011 (SRB); 1♀ 4Ƌ, Vasojevća Komovi, 22-VII-2012 (MNE); 11♀ 13Ƌ Prokletije–Pepići, 24-VII-2012 (MNE); 17♀ 7Ƌ, Andrijevica– Komovi, 10-VII-2013 (MNE); 29♀ 10Ƌ, Murino, 11-VII-2013 (MNE); 3♀ 1Ƌ Plitvice–Vidikovci, 20- VI-2013 (CRO); 1♀ 5Ƌ Plitvice–Kozjak, 22- VI-2013 (CRO).

Figures

FIGURE 4. Aphidius rubi. female: a) head; b) flagellomere 1 and 2; c) mesonotum—dorsal view; d) propodeum—dorsal view; e) fore wing; f) petiole—dorsal view; g) petiole—lateral view; h) ovipositor—lateral view.

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.