Aleiodes circumscriptus (Nees, 1834)

van Achterberg, Cornelis & Shaw, Mark R., 2016, Revision of the western Palaearctic species of Aleiodes Wesmael (Hymenoptera, Braconidae, Rogadinae). Part 1: Introduction, key to species groups, outlying distinctive species, and revisionary notes on some further species, ZooKeys 639, pp. 1-164 : 59-61

Aleiodes circumscriptus (Nees, 1834) Figs 125-126, 127-137

Rogas circumscriptus Nees, 1834: 216 (syntypes lost).

Aleiodes circumscriptus ; Shenefelt 1975: 1170-1171 (p.p.); Papp 1991: 113 (p.p.); Belokobylskij et al. 2003: 398.

Type material.

Neotype here designated, ♀ (NMS, Edinburgh), "[Scotland], Rowardennan, Stirlings., Hypena proboscidalis [on] Urtica , 2.ix.[19]89, mum. 17.iv.[19]90, em. 10.vi.[19]90, M.R. Shaw (♀ 2 in 1990 Expts)".

Additional material.

Widespread in western Europe: *Austria, Belgium, British Isles (England: V.C.s 1, 3, 4, 11, 12, 14, 17, 20, 22, 23, 25, 26, 27, 28, 30, 31, 32, 33, 58, 61, 62, 63, 64; Wales: V.C. 52; Scotland: V.C.s 72, 77, 84, 86, 87, 89, 99, 111; Ireland: Co. Cork), Bulgaria, Czech Republic, *Finland, Germany, Hungary, Italy, *Lichtenstein, Netherlands (FL: Lelystad (Oostvaardersplassen), FR: Ried, GE: Heerde; Tongeren; Brummen (Voorstonden), LI: Kerkrade; St. Pietersberg; Tegelen; Wrakelberg, NB: Bergen op Zoom, ZH: Asperen; Waarder; Lexmond), Norway, Spain, Slovakia, *Sweden. Specimens in NMS, BMNH, OUM, BZL, RMNH, MTMA, ZSSM, ZISP, World Museum Liverpool, CNC, USNM, UWIM, M. Riedel collection, H. Schnee collection, MSC, JLCWAE, and I. Kakko collection.

Molecular data.

MRS062 (England EU979579, CO1 + KU682264, 28S), MRS073 (England KU682256, CO1), MRS074 (England KU682220, CO1).

Biology.

Plurivoltine parasitoid of larvae of Hypena proboscidalis (Linnaeus, 1758) ( Erebidae : Hypeninae ), overwintering in the host larva. Mummy (Fig. 15) brown and moderately slender. Specimens (in NMS unless indicated) reared from Hypena proboscidalis (Linnaeus) (15 [1 BMNH, 1 OUM, 1 AAC, 3 H. Schnee collection]; A.A. Allen, G.M. Haggett, A. Hawkins, R.J. Heckford, S. Ratering, M.R. Shaw). It may be an absolute specialist on Hypena proboscidalis ; related species that similarly feed on Urtica ( Hypena obsitalis ( Hübner) and Hypena obesalis (Treitschke)) overwinter as adults and would not (by themselves) be capable of supporting the parasitoid’s annual life cycle: indeed, it has been absent from several large collections of Hypena obesalis made in various localities in the Alps (M.R. Shaw). The oviposition sequence (observations from two females, and Hypena proboscidalis ) is abnormal in that there is no separate pre-oviposition sting inducing temporary paralysis, nor is there a post-oviposition period of association. The host is scarcely antennated, but quickly recognised and pounced upon or snatched with the front two pairs of legs, and held aligned with the parasitoids’s body while the ovipositor is inserted for a prolonged period - sometimes there are several insertions, with self-superparasitism then often occurring. The egg is strongly attached to internal organs (gut and malpighian tubules both observed) at its narrow end. Because of subsequent disease in the stock, it is not possible to give quantitative results, but it appeared that enthusiastic attack on fourth instar hosts resulted in oviposition but no development, and that only earlier instar hosts were suitable. Mummification takes place on the host’s food plant, usually in a semi-concealed position.

Diagnosis.

Antennal segments of female 42-47, of male 42-46; fore femur of ♀ 5.4-5.7 × as long as wide (Fig. 131) and hardly sculptured, but of ♂ slenderer; scapus and pedicellus (yellowish) brown ventrally; temples directly narrowed behind eyes; precoxal area frequently with some rugae or rugulae; propodeum distinctly transversally rugose medially and median carina largely absent on posterior half of propodeum or irregular; posterior half of pterostigma of female largely dark brown; ivory part of malar space usually reaching clypeus (Fig. 134); mesosternum more or less blackish or dark brown, rarely completely reddish; hind femur of ♀ rather reddish brown, but may be largely infuscate in ♂; OOL about equal to diameter of posterior ocellus (Fig. 136); vein 1-CU1 of fore wing horizontal and vein cu-a short (Fig. 127); antenna dark brown or black (but scape below usually paler than face; Fig. 134), rarely completely yellowish brown; mesosoma black(ish) dorsally, especially mesoscutum and scutellum (but notaulic area may be brownish posteriorly); metasoma largely blackish with (pale) yellowish elliptical patch medially (Fig. 129). Similar to Aleiodes nigricornis Wesmael, 1838, which (like many Aleiodes circumscriptus ) has the mesoscutum usually without light markings, but Aleiodes nigricornis has the fore femur more slender (6.7-7.4 × as long as wide) and very finely sculptured, the scapus and the pedicellus more or less infuscate or black ventrally, the precoxal area usually without rugae, the propodeum largely coriaceous medially and the median carina at least anteriorly present on posterior half of propodeum and regular, the posterior half of the pterostigma of female more or less yellowish, but usually apical third laterally darkened, the pale yellowish part of the malar space usually not reaching the clypeus and the mesosternum usually reddish or brownish.

Description.

Neotype, ♀, length of fore wing 4.9 mm, of body 5.3 mm.

Head. Antennal segments 46, length of antenna 1.3 × fore wing, its subapical segments about 1.6 × as long as wide; frons coriaceous and posteriorly rugulose, weakly shiny; OOL equal to diameter of posterior ocellus and coriaceous; vertex coriaceous, with satin sheen; clypeus moderately convex, coriaceous; ventral margin of clypeus thick and depressed (Fig. 134); width of hypoclypeal depression 0.4 × minimum width of face (Fig. 134) and face mainly coriaceous with some rugae dorsally; length of eye 3.2 × temple in dorsal view and temple directly narrowed behind eye; occiput behind stemmaticum coriaceous and occipital carina nearly complete, interrupted dorsally by somewhat less than width of ocellus (Fig. 136); clypeus partly above lower level of eyes (Fig. 134); length of malar space 0.4 × height of eye in lateral view; eyes moderately protruding (Fig. 136).

Mesosoma. Mesoscutal lobes largely coriaceous, matt, but medio-posteriorly with a few longitudinal rugae; notauli narrow, shallow and crenulate, but posterior half absent; prepectal carina lamelliform medio-ventrally, reaching anterior border; precoxal area of mesopleuron coriaceous and with some rugae medially; mesopleuron above precoxal area (except large smooth and shiny speculum) coriaceous, but dorsally rugose; medially metapleuron coriaceous, matt; mesosternal sulcus narrow and rather deep, with carina posteriorly; mesosternum rather angulate posteriorly; scutellum nearly flat, coriaceous and largely non-carinate laterally; propodeum rather flat and coriaceous but posteriorly with some rugae, median carina present but absent on posterior half, without tubercles.

Wings. Fore wing: r 0.2 × 3-SR (Fig. 127); 1-CU1 horizontal, 0.5 × as long as 2-CU1; r-m 0.6 × 2-SR, and 0.4 × 3-SR; second submarginal cell medium-sized (Fig. 127); cu-a vertical, not parallel with CU1b, straight; 1-M nearly straight posteriorly. Hind wing: apical half of marginal cell parallel-sided or nearly so (Fig. 127); 2-SC+R short and longitudinal; short stub of m-cu present, unpigmented.

Legs. Tarsal claws setose; hind coxa superficially coriaceous, with satin sheen; hind trochantellus 2.3 × longer than wide; length of fore and hind femora 5.7 and 4.3 × their width, respectively (Figs 130-131); inner apex of hind tibia without comb; length of inner hind spur 0.3 × hind basitarsus.

Metasoma. First tergite as long as wide posteriorly, flattened and latero-posteriorly lamelliform; first tergite coriaceous and finely irregularly longitudinally rugose; second tergite robust (Fig. 129), without distinct median carina, with satin sheen and superficially rugulose; medio-basal area of second tergite absent; second suture shallow and largely crenulate; basal half of third tergite indistinctly rugulose, remainder of metasoma largely superficially coriaceous and rather shiny; fourth and apical third of third tergite without sharp lateral crease; ovipositor sheath largely densely setose.

Colour. Black or brownish black; antenna brown, but scapus dorsally and laterally dark brown; palpi, malar space up to eyes, mandible, tegulae, fore and middle coxae, trochanters and trochantelli, bases of fore and middle femora, medio-apical fifth of first tergite, medially second tergite and medio-basal patch of third tergite pale yellowish (Fig. 129); orbita (except latero-ventrally) brownish yellow (Figs 134-136) and remainder of head dark brown; mesopleuron ventrally yellowish brown with darker mesosternum; hind femur (except basally) fuzzy brown (Fig. 130), remainder of legs brownish yellow; veins and pterostigma (except yellow basal 0.4 and apex) dark brown; border between dark and pale part of pterostigma fairly sharp, contrasting with each other (Fig. 127); wing membrane subhyaline.

Variation. Length of fore wing 4.5-5.0 mm; antennal segments of ♀: 42(1), 43(1), 44(17), 45(46), 46(28), 47(4); of ♂: 42(13), 43(30), 44(38), 45(25), 46(1); notauli absent posteriorly or shallowly impressed; mesoscutum sometimes with weak diffuse reddish colouration posteriorly, along notaulic courses; orbita sometimes completely yellowish; mesosternum varying from (frequently) almost black, and then strongly contrasting with the reddish lower third of the mesopleuron, to reddish brown; median carina of propodeum sometimes traceable to posterior margin.

Note.

Males have on average about one fewer antennal segment than females.