Aleiodes rugulosus (Nees, 1811)

van Achterberg, Cornelis, Shaw, Mark R. & Quicke, Donald L. J., 2020, Revision of the western Palaearctic species of Aleiodes Wesmael (Hymenoptera, Braconidae, Rogadinae). Part 2: Revision of the A. apicalis group, ZooKeys 919, pp. 1-259 : 1

Aleiodes rugulosus (Nees, 1811) Figs 701-703 , 704-716 , 717, 718 , 719 , 720-727

Bracon rugulosus Nees, 1811: 32; Papp 1985a: 162 (neotype designation).

Rogas rugulosus ; Shenefelt 1975: 1247-1248.

Rogas (Rogas) rugulosus ; Tobias 1976: 84, 1986: 78 (transl.: 128).

Aleiodes ( Neorhogas ) rugulosus ; Papp 1987b: 36, 1991a: 79; Riedel et al. 2002: 106.

Aleiodes (Chelonorhogas) rugulosus ; Belokobylskij et al. 2003: 398.

Aleiodes rugulosus ; Bergamasco et al. 1995: 5; Zaldívar-Riverón et al. 2004: 234; Papp 2005: 177.

Rhogas rugulosus var. pictus Kokujev, 1898: 296; Shenefelt 1975: 1247-1248 (not Herrich-Schäffer 1838).

Type material.

Neotype, ♀ (KBIN), " A. rugulosus ", “dét. C. Wesmael", "Coll. Wesmael", "Belgique, Bruxelles"/ teste Papp J., 1983", "Neotypus, Bracon rugulosus Nees, 1812 [sic!], ♀, Papp 1983 ", " Aleiodes rugulosus Ns. ♀, det. Papp J., 1983".

Additional material.

Albania, Austria, Belgium, Bulgaria, Czech Republic, British Isles (England: V.C.s 1, 3, 4, 11, 17, 25, 27, 29, 69; Wales: V.C.s 41, 48; Scotland: V.C.s 78, 81, 88, 98; Ireland: V.C. H30), Finland, France, Germany, Hungary, Moldova, Netherlands (DR: Borger; GE: 't Harde; Heerde; Otterlo, NB: Kampina; NH: Crailo; OV: Buurserzand), North Macedonia, Norway, Poland, Romania, Russia, Slovakia, Spain, Sweden. Specimens in ALC, ZJUH, BZL, HHC, IKC, MMUM, MRC, MSC, MSNV, MTMA, NMS, NRS, OUM, RMNH, SDEI, UWIM, ZSSM.

Molecular data.

MRS191 (Hungary), MRS217 (UK), MRS398 (France), MRS884 (Poland).

Biology.

Collected in (May)July-August(September), usually in open habitats such as mosses, heaths, herb-rich grasslands and fens. Partly plurivoltine, at least in the southern part of its range, but largely univoltine in the north (in a UK culture only one female out of 20 reared, and two males out of 69, emerged in the same year as mummy formation). Reared from Noctuidae , Acronictinae : Acronicta auricoma (Denis & Schiffermüller) (7 [1 BZL, 1 MSC, 1 ZMUO]; J. Voogd/Netherlands, M & J. Schwarz/Austria, Finland), Acronicta euphorbiae (Dennis & Schiffermüller)/ cinerea (Hufnagel) (5 [2 IKC, 1 BZL, 1 FMNH]; M.J. Pellinen, D. & J. Steedan), Acronicta menyanthidis (11; R.P. Knill-Jones, W.A. Watson), Acronicta rumicis (Linnaeus) (5 [1 ZJUH, 1 IKC, 1 MTMA]; R.J. Heckford, M.J. Pellinen, M.R. Shaw), Oxicestra geographica (Fabricius) (17 [12 BZL, 5 MTMA]; Hungary), Acronicta sp. on low plants (3), Simyra albovenosa (Goeze) (14 [5 ZJUH, 4 FMNH, 2 UMZC, 1 NRS]; M.R. Shaw); A. Lozan, Romania), Acronicta euphorbiae (Dennis & Schiffermüller) on Euphorbia sanguinea Hochst (5 [2 RMNH, 3 ALC]). These species all feed on low plants. The mummy is moderately arched, very strongly glued down (usually to a narrow twig or stem low in the vegetation), and persists through the winter. The pupation chamber, occupying approximately abdominal segments 3-7 of the host, is rather densely lined with silk which is laid down after the mummy has hardened suggesting that the larva within can turn easily. Rearing experiments, undertaken using stock originally reared from A. menyanthidis , suggested that this host and A. rumicis were equally suitable, but most experiments were not conducted in a way to provide clear data in this respect. The behaviour of the adult females towards these hosts indicated some adaptation to use of highly aggregated species (i.e., that lay large batches of eggs) as, firstly there was a habituation process whereby repeated contacts with hosts generally preceded oviposition, and secondly there was only weak displacement following oviposition (resulting in rather frequent super-parasitism). The antennae were used to locate hosts with wide sweeping motions, and usually the host curled up and was manipulated backwards against the hind tarsi before the ovipositor was inserted and the egg was laid. Generally, there was no pre-oviposition sting and post-oviposition association with the only slightly subdued host was minimal, but the oviposition process was variable and occasionally there was a brief jab, but no subsequent waiting period, before oviposition. Less enthusiasm for sub-active hosts, such as those oviposited into a few seconds or minutes earlier, provided a short-lived impediment to super-parasitism, although sometimes two (on one occasion four, confirmed by dissection) eggs were laid into a single host in separate consecutive bouts without the parasitoid really relinquishing the host. First instar hosts were less easy than 2nd or 3rd instars for the parasitoid to deal with, and although oviposition into 2nd instar hosts was somewhat more successful than into 3rd instars, occasionally successful oviposition into early 4th instar hosts occurred. Mean development times from oviposition to mummification in different instar hosts ( A. rumicis ) under the same ambient conditions (Reading, S. England, July) varied as might be expected given that mummification was always at essentially the same (penultimate instar) stage of the host’s larval life: for 1st (N = 23), 2nd (N = 40) and 3rd (N = 7) instars, 27.0, 25.5 and 20.7 days, respectively. There is no venom effect to influence successful host development. Opportunities to offer other hosts were limited but it was clear that, although oviposition into larvae of the closely related arboreal species Subacronicta megacephala (Dennis & Schiffermüller) was fairly readily obtained (N = 15), though slightly inhibited by the host’s adherence to its silken pad rather than curling up, the parasitoid was always encapsulated (as a 1st instar larva in observed cases) and no progeny resulted. No rearings of A. rugulosus from arboreal Acronictinae have been seen, although these conspicuous larvae are often collected and reared.

Diagnosis.

Maximum width of hypoclypeal depression 0.3-0.4 × minimum width of face (Fig. 711 ); OOL approx. equal to diameter of posterior ocellus and coarsely punctate (Fig. 712 ); vertex flattened behind ocelli; ventral margin of clypeus thick and not protruding in lateral view (Fig. 713 ); mesoscutal lobes coriaceous; mesopleuron (including precoxal sulcus area) nearly or completely smooth; propodeum with pair of crest-like protuberances laterally; vein 1-CU1 of fore wing much shorter than vein 2-CU1; basal half of marginal cell of hind wing parallel-sided and subapically widened (Fig. 704 ); tarsal claws with large dark brown pecten up to apical tooth of claw (Fig. 716 ); hind spurs (dark) reddish brown; hind tibial spurs of ♂ acute apically (Fig. 722 ); head black; dorsal 0.4 of mesopleuron, mesosternum and scutellum black; metasoma entirely black (typical) or 1st and 2nd tergites orange or yellowish brown; apex of hind femur yellowish or reddish; basal half of hind tibia pale yellowish.

Description.

Redescribed ♀ (RMNH) from Netherlands (Buurserzand). Length of fore wing 6.3 mm, of body 7.7 mm.

Head. Antennal segments of ♀ 65, length of antenna 1.3 × fore wing, its subapical segments rather slender (Fig. 716 ); frons largely smooth except few striae; OOL equal to diameter of posterior ocellus, coarsely punctate and shiny; vertex coarsely punctate with some rugae, shiny; clypeus coarsely punctate; ventral margin of clypeus thick and not protruding forwards (Fig. 713 ); width of hypoclypeal depression 0.4 × minimum width of face (Fig. 711 ); length of eye twice temple in dorsal view (Fig. 712 ); vertex behind stemmaticum flattened and punctate-rugose; clypeus between eyes; length of malar space 0.3 × length of eye in lateral view.

Mesosoma. Mesoscutal lobes finely punctate with very finely granulate interspaces, rather matt; precoxal area of mesopleuron smooth, mesopleuron densely punctate posteriorly; scutellum coarsely punctate and rather flat; propodeum rather flattened medially, very coarsely reticulate-rugose, medio-longitudinal carina nearly complete, and with small crest-like protuberances laterally.

Wings. Fore wing: r 0.6 × 3-SR (Fig. 704 ); 1-CU1 horizontal, 0.4 × 2-CU1; r-m 0.9 × 3-SR; 2nd submarginal cell short (Fig. 704 ); cu-a inclivous, straight; 1-M nearly straight posteriorly; 1-SR wide; surroundings of M+CU1, 1-M and 1-CU1 largely setose. Hind wing: basal 0.6 of marginal cell subparallel-sided and remainder linearly widened, its apical width 1.8 × width at level of hamuli (Fig. 704 ); 2-SC+R subquadrate; m-cu absent; M+CU:1-M = 37:28; 1r-m 0.8 × 1-M.

Legs. Tarsal claws with conspicuous and robust blackish pecten (Fig. 716 ); hind coxa largely densely and coarsely punctate; hind trochantellus rather robust; length of hind femur and basitarsus 3.9 and 5.0 × their width, respectively; length of inner hind spur 0.5 × hind basitarsus.

Metasoma. First tergite moderately convex, 0.9 × longer than wide apically; 1st and 2nd tergites with coarse medio-longitudinal carina and very coarsely and irregularly longitudinally rugose; medio-basal area of 2nd tergite large and distinct (Fig. 707 ); 2nd suture deep, rather wide and coarsely crenulate; basal half of 3rd tergite punctate-rugose, remainder of metasoma finely punctate; 4th and apical half of 3rd tergite without sharp lateral crease; ovipositor sheath wide, with rather long setae and apically narrowed and rounded (Fig. 702 ).

Colour. Black (including fore and middle telotarsi, apical half of hind tibia and hind tarsus); basal half of hind tibia pale yellowish; palpi (but basally somewhat infuscate) and remainder of legs reddish brown; tegulae yellowish brown; hind tibial spurs and pterostigma dark brown; veins brown; mesopleuron with broad dark reddish longitudinal band; wing membrane slightly infuscate.

Variation. Micro-sculpture of lateral lobes of mesoscutum very finely granulate or absent and resulting in a largely smooth surface; maximum width of marginal cell of hind wing 1.5-2.3 × its width near hamuli; body entirely black (both sexes) or 1st and 2nd metasomal tergites and mesosoma partly dark reddish (both sexes, but 2nd and 3rd tergites of males more or less darkened); hind tibial spurs dark brown or reddish brown. Antennal segments: ♀ 60(4), 61(7), 62(10), 63(18), 64(14), 65(2), 66(8), 67(4), 68(3), 69(1); ♂ 53(1), 56(2), 57(1), 58(7), 59(6), 60(15), 61(15), 62(19), 63(28), 64(12), 65(10), 66(4), 67(2), 68(1). Females have on average ca one more antennal segment than males. Male is similar to the dark female form, with acute hind tibial spurs (Fig. 722 ), 3rd tergite convex in lateral view (Fig. 720 ), with dense and long setosity and apical tergites type 1 and no fringe observed (Figs 721 , 724 ).

Aleiodes rugulosus is a very colour-variable species; the 1st and 2nd metasomal tergites are quite frequently mostly or entirely dark red or orange brown (Fig. 701 ) in populations in which entirely black females (Fig. 717 ) also often occur. The variation is not geographical, since most populations definitely have both forms. In rearing experiments, a strong genetic basis for this feature became evident: from a virgin female with completely black metasoma, all five males reared were black, and a cross between one of them and a (wild-reared) black female produced eleven female progeny, all black. In contrast, a lineage from a pairing between a weakly red male and a red female comprised three red males and eight red females, separate individuals of which produced a single red and a single black male as progeny. When sufficient material from single sites is available it is usual to see a clear predominance of one form or the other. Sometimes the lower part of mesopleuron is pale (often looking unpigmented there, but narrowly), and in extreme reddish specimens the scutellum, much of the mesopleuron (but usually the mesosternum remains darkish), the metanotum dorsally, the metapleuron in part and much of the propodeum are also reddish.

Distribution.

Albania, Austria, Belgium, Bulgaria, Czech Republic, British Isles (England, Wales, Scotland, Ireland), Finland, France, Germany, Hungary, *Netherlands, *North Macedonia, *Moldova. Norway, Poland, *Romania, Russia, *Slovakia, *Spain, Sweden.

Figures

Figure 719. Aleiodes rugulosus (Nees), Netherlands, Ede, mummy of Acronicta auricoma (Denis & Schiffermueller). Photograph: J. Voogd.

Figures 701 - 703. Aleiodes rugulosus (Nees), ♀, U. K., culture 701 habitus lateral 702 ovipositor sheath lateral 703 mummy of Acronicta rumicis (Linnaeus).

Figures 704 - 716. Aleiodes rugulosus (Nees), ♀, U. K., culture 704 wings 705 mesosoma lateral 706 mesosoma dorsal 707 propodeum and 1 st- 3 rd metasomal tergites dorsal 708 fore femur lateral 709 hind femur lateral 710 antenna 711 head anterior 712 head dorsal 713 head lateral 714 base of antenna 715 apex of antenna 716 outer hind tarsal claw.

Figures 717, 718. Aleiodes rugulosus (Nees), dark form, ♀, U. K., Meathop Moss 717 habitus lateral 718 mummy of Acronicta menyanthidis (Esper).

Figures 720 - 727. Aleiodes rugulosus (Nees), ♂, Hungary (Halasto) 720 habitus lateral 721 metasoma lateral 722 hind tibial spurs and basitarsus lateral 723 base of antenna 724 metasoma dorsal 725 fore femur lateral 726 head dorsal 727 hind femur lateral.