Aleiodes modestus (Reinhard, 1863)

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 : 82-85

Aleiodes modestus (Reinhard, 1863) Figs 215-216, 217-229

Rogas modestus Reinhard, 1863: 271; Shenefelt 1975: 1177; Papp 1985a: 160 (lectotype designation); Tobias 1986: 83 (transl.: 138).

Aleiodes modestus ; Papp 1991: 99; Belokobylskij et al. 2003: 398.

Rhogas (Aleiodes) modestus var. piceus Fahringer, 1932: 302-303; Shenefelt 1975: 1177.

Type material.

Lectotype ♀ (ZMB) from Germany examined.

Additional material.

Widespread in western Europe: *Austria, British Isles (England: V.C.s 11, 17, 22, 28, 29, 31, 32, 38, 39, 52, 57, 58, 61, 62, 63, 64; Wales: V.C.s 48, 52: Scotland: V.C.s 88, 96, 97), Bulgaria, *Czech Republic, *Denmark, Finland, *France, Germany, Italy, Netherlands (DR: Borger; Wijster, GE: Heerde; Brummen (Voorstonden), FR: Terschelling (Midsland-Noord, dunes), LI: Epen, ZH: Asperen; Meijendel (dunes)), Poland, *Romania, Russia, Slovakia, Sweden, Switzerland. Specimens in NMS, MNHN, BMNH, RMNH, NRSM, BZL, MTMA, USNM, CNC, CMIM, M. Riedel coll., JLC, Delémont, ZSM, MCZ, SDEI, FRAH, WAE, UWIM, ZMC, ZMUO.

Molecular data.

MRS282 (Wales JF962850, CO1 + KU682267, 28S).

Biology.

A univoltine parasitoid of a wide range of Eupithecia species ( Geometridae : Larentiinae ), mummifying the host in its pupation chamber and overwintering in the mummy. Specimens reared from wild collected hosts determined as follows: Eupithecia absinthiata (Clerck) (2 NRS), Eupithecia exiguata ( Hübner) (1 ZMUH), Eupithecia gelidata hyperboreata Staudinger (2 SDEI), Eupithecia goossensiata Mabille (2 NMS, 1 OUM; T.H. Ford), Eupithecia innotata (Hufnagel) (2 ZMUH, 1 ZMUO); I. Itämes), Eupithecia lariciata (Freyer) (1 NMS, 2 Copenhagen, 2 Delémont, 10 FRAH), Eupithecia nanata ( Hübner) (22 NMS, 5 BMNH, 5 OUM]; T.H. Ford, G.T. Lyle), Eupithecia satyrata ( Hübner) (1 NRS), Eupithecia subfuscata (Haworth) (3 OUM; T.H. Ford), Eupithecia succenturiata (Linnaeus) (1 NMS, 1 OUM; T.H. Ford), Eupithecia vulgata (Haworth) (6 NMS, 2 OUM; T.H. Ford, M.R. Shaw) and 13 (NMS) from undetermined Eupithecia spp on various low plants (including Artemisia , Lotus and Pimpinella ). Experimental culture result in Eupithecia vulgata 2:16\16\\7+1. While it has been reared particularly from hosts feeding on field layer plants (as is the habit of the majority of European Eupithecia species), the rearing records also include a substantial number from Eupithecia lariciata on Larix ; however, it seems probable that many of the specimens seen were reared in a nursery context, in which young Larix would have presented as part of the field layer, and it is perhaps significant that Aleiodes modestus was not found to be a prominent parasitoid of Eupithecia lariciata on mature Larix sampled in the Alps (although it was indeed reared from it in small numbers at most sampling sites: Kenis et al. 2005). The host larva is usually fully grown and cocooned in the soil as a prepupa by the time mummification occurs, and the wide and sharp-rimmed clypeus of the adult probably reflects the need to chew its way through the host’s cocoon and soil. The winter is passed in the mummy, which is rather tough and dark, slightly dorso-ventrally flattened but not keeled (Fig. 216), and sometimes weakly upcurled. Typically the thoracic and first two abdominal segments are contracted, with the parasitoid occupying approximately abdominal segments 3-8 in a thin silken lining. The mummy is not stuck down, though probably the usual ventral opening for the expulsion of fluid occurs none the less (however, this is unconfirmed). The adult flight time in Britain is approximately from late June through August.

Diagnosis.

Antennal segments of both sexes 37 –(40–45)– 47 and third segment rather slender (Fig. 223); ventral margin of clypeus thin and protruding (Fig. 226); maximum width of hypoclypeal depression about 0.5 × minimum width of face (Fig. 225); length of malar space of female 0.2-0.3 × height of eye in lateral view (Fig. 226); OOL about equal to diameter of posterior ocellus (Fig. 227); area in front of anterior ocellus with a minute smooth tubercle (Fig. 227); vein r of fore wing 0.5-0.6 × vein 3-SR; vein 1-SR of fore wing short (Fig. 217); vein 1r-m of hind wing distinctly shorter than vein 1-M (Fig. 217); mesopleuron above precoxal area strongly shiny and superficially sculptured; third tergite without distinct striae; pterostigma largely yellow or yellowish brown; inner side of basal half of hind tibia yellowish; head and mesosoma largely blackish.

Description.

Figured ♀ (RMNH) from Wijster (Netherlands), length of fore wing 5.4 mm, of body 5.6 mm.

Head. Antennal segments of ♀ 43, moderately setose, length of antenna 1.2 × fore wing, its subapical segments distinctly longer than wide (Fig. 224); frons rather flat and granulate; OOL equal to diameter of posterior ocellus and finely granulate; vertex finely granulate, with satin sheen; clypeus rather large, micro-granulate; ventral margin of clypeus thin and rather protruding forwards (Fig. 226); width of hypoclypeal depression 0.5 × minimum width of face (Fig. 225); length of eye 1.9 × temple in dorsal view (Fig. 227); occiput behind stemmaticum mainly granulate with some rugulae; clypeus near lower level of eyes; length of malar space 0.25 × length of eye in lateral view; occipital carina complete; with a minute smooth tubercle in front of anterior ocellus.

Mesosoma. Mesoscutal lobes densely and finely granulate and with punctulation, matt; prepectal carina complete, distinct; precoxal area of mesopleuron with some rugulae medially; mesopleuron above precoxal area strongly shiny, sparsely punctate and with some superficial micro-granulation (Fig. 218); metapleuron largely granulate; scutellum flat, micro-granulate and without lateral carina; propodeum convex, finely rugose and interspaces micro-granulate (Fig. 219), without tubercles, median carina complete, weak and rather irregular.

Wings. Fore wing: r 0.6 × 3-SR (Fig. 217); 1-CU1 horizontal, slender, 0.35 × 2-CU1; r-m 0.5 × 3-SR; second submarginal cell rather long (Fig. 217); cu-a vertical, straight posteriorly; 1-M slightly curved posteriorly. Hind wing: marginal cell subparallel-sided but slightly constricted medially, its apical width equal to width at level of hamuli (Fig. 217); 2-SC+R subquadrate; m-cu faintly indicated; M+CU:1-M = 5:4; 1r-m 0.6 × as long as 1-M.

Legs. Tarsal claws yellowish setose; hind coxa granulate; hind trochantellus rather robust; length of fore femur, hind femur and basitarsus 5.7, 5.2 and 8.6 × their width, respectively (Figs 220-221); length of inner hind spur 0.25 × hind basitarsus.

Metasoma. First tergite rather robust (Fig. 219); first and second tergites densely and rather finely rugose, with rather weak median carina, reduced posteriorly; medio-basal area of second tergite absent; length of second tergite 0.9 × its basal width; second suture rather deep and distinctly crenulate; third tergite 0.8 × as long as second tergite, anterior two-thirds rugose and remainder of metasoma superficially granulate and punctate, somewhat compressed; fourth and apex of third tergite without sharp lateral crease; ovipositor sheath widened and setose.

Colour. Black; palpi, tegulae and pterostigma yellow; veins (except basally) dark brown; malar area ventrally, orbita dorsally and posteriorly, pronotum anteriorly and ventrally, mesopleuron antero-dorsally and postero-ventrally, hind coxa (but basally black), medio-posterior part of mesoscutum, first tergite latero-posteriorly, second and third tergites dark reddish brown; apical half of hind femur largely dark brown, except apically; antenna, telotarsi and clypeus dark brown; remainder of legs yellowish brown or blackish; wing membrane subhyaline.

Variation. Antennal segments of ♀ 38(1), 39(0), 40(0), 41(1), 42(18), 43(27), 44(12), 45(4) and of ♂ 40(1), 41(1), 42(2), 43(37), 44(18), 45(2); length of antenna of ♂ 1.3 × fore wing; length of eye of ♀ 1.2-1.9 × temple in dorsal view, of ♂ 1.6-2.5 times; dark specimens have mesosoma, metasoma and hind coxa nearly completely black; pale specimens have scapus, pedicellus, clypeus, entire orbita, notaulic area of mesoscutum, metapleuron posteriorly, first tergite apically and most of second–fourth tergites dark reddish brown; pterostigma sometimes slightly infuscate laterally, but remaining largely yellow; the infuscation of the hind femur is sometimes diffuse; vein cu-a of fore wing vertical or oblique; rugae of precoxal area may be entirely absent.

Note.

The number of antennal segments does not differ appreciably between the sexes. The specimens reported from Hungary by Papp (1983, 1985a, 2005) are misidentified Aleiodes fortipes (Reinhard).