Aleiodes esenbeckii (Hartig, 1838)

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 : 69-73

Aleiodes esenbeckii (Hartig, 1838) Figs 165-166, 167-177, 178-179, 180-189

Rogas esenbeckii Hartig, 1838: 255; Tobias 1986: 81 (transl.: 135) (examined).

Rhogas esenbeckii ; Kokujev (in Serebryanikova), 1901: 100.

Aleiodes esenbecki ; Papp 1991: 93 (as synonym of Aleiodes procerus ).

Aleiodes esenbeckii ; Belokobylskij et al. 2003: 398.

Rhogas corsicus Szépligeti, 1906: 616 (examined).

Aleiodes corsicus ; Papp 1991: 93 (as synonym of Aleiodes procerus ), 2004: 215 (holotype).

Rogas gastropachae Kokujev (in Serebryanikova), 1901: 100-101.

Aleiodes gastropachae ; Papp 1991: 93 (as synonym of Aleiodes procerus ).

Phanomeris dendrolimi Matsumura, 1926: 41; Chen and He 1997: 50 (as synonym of Aleiodes esenbeckii ).

Aleiodes dendrolimi ; Shenefelt 1975: 1172-1173.

Phanomeris dendrolimusi Matsumura, 1926: 32 (invalid emendation).

Phanomeris spectabilis Matsumura, 1926: 33; Chen and He 1997: 50 (as synonym of Aleiodes esenbeckii ).

Rhogas metanastriae Rohwer, 1934: 47; Chen and He 1997: 50 (as synonym of Aleiodes esenbeckii ).

Type material.

Holotype of Rogas esenbeckii , ♂ (ZSSM), "715, [Germany, Charlottenburg]", " esenbeckii n.", together with mummy of Dendrolimus pini (L.); holotype of Rhogas corsicus , ♀ (MTMA), "[France, Corsica,] Ajaccio", " praetor Reinh.? (Corsica)".

Additional material.

f. esenbeckii : Austria, *Croatia, Czech Republic, France (*mainland and Corsica) *Netherlands (Muiderberg), Germany, Spain (*Mallorca); f. dendrolimi : China, *Finland, Russia, Switzerland. Specimens in NMS, ZSSM, RMNH, BZL, MTMA, BMNH, SDEI, ZISP

Molecular data.

MRS180 (Finland EU979581,CO1 + EU854329, short 28S), MRS500 (Mallorca JF962845/KU682240, CO1).

Biology.

Apart from the examined holotype (see above) all the reared specimens we have seen (of form dendrolimi ) were from Siberian populations of Dendrolimus superans sibericus (Rozhkov) ( Lepidoptera : Lasiocampidae ) (7). Aleiodes esenbeckii is a well-known parasitoid of Dendrolimus species. In the central part of its range the host species Dendrolimus pini (Linnaeus) is normally univoltine, but in southern European (Mediterranean) popula tions it is at least bivoltine (Vadim V. Zolotuhin, pers. comm.), while in northern Siberia the host Dendrolimus superans sibericus Tchetverikov usually has a 2-year life cycle. The parasitoid overwinters inside the diapausing host larva, and adapts its seasonality according to that of the host: Boldaruev (1958) reports that in Siberia Aleiodes dendrolimi spends over 20 months inside its host larva, which is mummified in late May to June following the second winter of the 2-year cycle, but in captivity (and also ocassionally in the wild) the host, and similarly the parasitoid, can be induced to develop within a year or even less. He also found that the adult parasitoid is long-lived and that females develop eggs only after a prolonged period of feeding on honeydew. Specimens seen from Europe have been collected from late May–October, no doubt reflecting local seasonality of the host.

Diagnosis.

Antennal segments of ♀ 56-62; head entirely brownish yellow apart from stemmaticum (Figs 173-175): f. esenbeckii ) or blackish (Figs 185-187: part of f. dendrolimi ); scapus in lateral view ratherly oblique apically; OOL 0.3 × diameter of posterior ocellus; occipital carina complete ventrally (Fig. 174); length of malar space 0.25 × height of eye in lateral view; vein 2-CU1 of fore wing 0.7-1.2 × vein 1-CU1 (Fig. 167); vein 1-SR angled to vein 1-M and vein 1-M distinctly curved (Fig. 167); vein r of fore wing gradually merging into vein 3-SR; tarsal claws small (Fig. 170); fourth metasomal tergite superficially coriaceous; length of fore wing 6-10 mm. Often confused with Aleiodes varius (as Aleiodes procerus ), but differs by the relative lengths of veins 1- and 2-CU1 and by the number of antennal segments.

Description.

Redescribed ♀ (NMS) from Mallorca (Spain), length of fore wing 7.6 mm, of body 9.5 mm.

Head. Antennal segments 59, length of antenna 1.3 × fore wing, its subapical segments about 1.9 × as long as wide and scapus in lateral view rather oblique apically; frons superficially granulate, rather shiny; OOL 0.3 × diameter of posterior ocellus and granulate; vertex superficially coriaceous, with satin sheen; clypeus rather high, convex dorsally and flattened ventrally, coriaceous and with long setae; ventral margin of clypeus thick and gradually depressed (Figs 173, 185); width of hypoclypeal depression 0.4 × minimum width of face (Figs 173, 185) and face mainly rugose with interspaces coriaceous; length of eye 4.7 × temple in dorsal view and temple directly narrowed behind eye; occiput behind stemmaticum finely rugose and occipital carina curved and interrupted medio-dorsally and complete ventrally (Figs 174, 186); clypeus entirely above lower level of eyes (Figs 173, 185); length of malar space 0.25 × height of eye in lateral view; eyes strongly protruding (Figs 173-175, 185-187).

Mesosoma. Mesoscutal lobes very finely coriaceous, with satin sheen; notauli narrow, shallow and mainly coriaceous; prepectal carina rather lamelliform medio-ventrally, almost reaching anterior border of mesopleuron and latero-ventrally curved; precoxal area of mesopleuron coriaceous, without fine rugae medially; mesopleuron above precoxal area (including shiny and granulate speculum) coriaceous, but dorsally finely rugose (cf. Fig. 181); medially metapleuron superficially granulate and shiny; mesosternal sulcus narrow and deep, without carina posteriorly; mesosternum angulate posteriorly; scutellum superficially coriaceous and carinate antero-laterally; dorsal face of propodeum rather long and coriaceous, posterior face short, hardly differentiated, with some short carinae and smooth in between, median carina complete and with weak tubercles postero-laterally.

Wings. Fore wing: r 0.3 × 3-SR (Fig. 167); 1-CU1 horizontal, 1.1 × as long as 2-CU1; r-m 0.9 × 2-SR, and 0.45 × 3-SR; second submarginal cell stout (Fig. 167); 1 -SR rather angled to 1-M; cu-a somewhat reclivous and curved; 1-M slightly curved. Hind wing: marginal cell parallel-sided submedially and slightly widened apically (Fig. 167); 2-SC+R short and subquadrate; m-cu present as slightly pigmented vein; M+CU:1-M = 6:5; 1r-m 0.7 × 1-M.

Legs. Tarsal claws with fine brownish pecten basally; hind coxa finely coriaceous, with satin sheen; hind trochantellus 2.2 × longer ventrally than wide; length of fore and hind femora 5.7 and 4.5 × their width, respectively; inner apex of hind tibia without comb; length of inner hind spur 0.35 × hind basitarsus; hind basitarsus wider than following segments.

Metasoma. First tergite 1.3 × as long as wide posteriorly, flattened and latero-anteriorly widely lamelliform; first–second tergites densely finely irregularly rugulose and with fine median carina; second tergite as long as wide basally and 1.4 × as long as third tergite (Fig. 169); minute medio-basal area of second tergite present; second suture rather deep, widened medially and distinctly crenulate; third and following tergites superficially coriaceous and shiny; fourth tergite largely without sharp lateral crease; ovipositor sheath largely densely setose and apically truncate.

Colour. Yellowish brown; antenna (except yellow scapus and pedicellus) dark brown; stemmaticum black; hypopygium, middle and hind tarsi more or less infuscate; pterostigma and veins of middle third of wings dark brown (Fig. 167); other veins brownish yellow; wing membrane subhyaline.

Variation. Length of fore wing 6-10 mm, of body 7.5-11.5 mm; antennal segments of ♀ 58(1), 59(2), 60(3), (and of f. dendrolimi : 60(2), 61(2), 62(1), 63(1)), of ♂ 55(1), 56(2), 57(1), 58(2), 59(2), 61(1) (of f. dendrolimi : 54(1), 61(1)); latero-anterior lamella of first tergite rather wide or narrow; marginal cell of hind wing parallel-sided or slightly narrowed submedially; f. dendrolimi has head partly, palpi, mesosoma ventrally and posteriorly, metasoma and legs more or less dark brown or blackish; rarely nearly entire head black.

Notes.

Aleiodes esenbeckii f. dendrolimi differs morphologically only in colouration and occurs in the East Palaearctic region and in boreal Europe, perhaps reflecting a 2-year life cycle. The CO1 sequences (between Mallorcan f. esenbeckii and Finnish f. dendrolimi ) are, however, divergent, differing by at least 32 base pairs in the barcode region (around 5%) (D.L.J. Quicke, pers. comm.), suggesting effective genetic isolation of at least these populations. For mediterranean specimens the name Aleiodes corsicus Szépligeti, 1906, is available. From limited data males appear to average about 3 fewer antennal segments than females, in both forms.