Two new species of Aivalykus ( Hymenoptera : Braconidae : Doryctinae ) from China and Indonesia , with a key to species

The species and tribal position of the genus Aivalykus Nixon are discussed. Two new species of Aivalykus from China and Indonesia are described: A. nitidus sp. n. and A. bouceki sp. n. The genus Ecphyloides Marsh, 1993 is considered ajunior synonym of Aivalykus Nixon, 1938. A key to the species of Aivalykus is given.


INTRODUCTION
The genus Aivalykus was described by G.E.J. Nixon (1938) for two species from India -A.eclectes Nixon, 1938 (type species of the genus, which was also recorded in the Philippines) and A. sperches Nixon, 1938.Later additional species of this genus were described from Madagascar (A. niger Granger, 1949; but the status of this species must be verified) and the Southern Nearctic (A. nearcticus Marsh, 1965).Recently P. Marsh (1993) described a new genus from Brazil, Ecphyloides Marsh, 1993, with type species E.flavus Marsh, 1993.The main difference between Ecphyloides and Aivalykus is the number of the antennal segments (Marsh, 1993(Marsh, , 1997) (Ecphyloides has 14-segmented antennae).However, the known variation in the number of antennal segments in species of the most closely related genus Ecphylus Förster, 1862 range from 11 (E.schwarzii (Ashmead, 1900)) to 26 (E. hicoriae Rohwer, 1919), and within spe cies (for example) E. hypothenemi Ashmead, 1896 -from 13 to 16, or E. schwarzii -from 11 to 14 (Marsh, 1965).Additionally P. Marsh (1965) in the description of Aiva lykus nearcticus (p.677) noted that the number of antennal segments varied from 14 to 19.Because of this variation, and the study of the holotype of E.flavus in the Canadian National Collection (Ottawa) (female, "Brasil ien, Rio Caraguala, 21°48'B.52°27'L, 400 m, III-1953, Fritz Plaumann", "Holotype Ecphyloides flavus Marsh") by the first author, we propose to synonymize Ecphy loides Marsh, 1993with Aivalykus Nixon, 1938 (syn. n.).In addition, two new species of Aivalykus from China and Indonesia are described below.
The genus Aivalykus was placed originally in the tribe Hecabolini (Nixon, 1938;Marsh, 1965;Shenefelt & Marsh, 1976).But a recent reclassification of the infra generic taxa of the subfamily Doryctinae has indicated the apomorphic characters of the tribe Ecphylini Hellen, 1957, separating it from the tribe Hecabolini Förster, 1862 (Belokobylskij, 1992).On the basis of these charac ters, Aivalykus is considered a member of the tribe Ecphy lini (together with Ecphylus Förster, 1862 and Bohartiellus Marsh, 1983), because they both lack a nervellus and recurrent vein in the hind wing, and the brachial cell of fore wing is closed apically and the parallel vein has an interstitial position.The same tribe for Aivalykus was also proposed by J. Papp (1993).
Some species of Aivalykus are known to be parasites of larvae of Scolytidae (genera Sphaerotrypes Blandford, 1894, Phthorophloeus Rey, 1883, Phloeosinus Chapuis, 1873), which are the main hosts of all members of the tribe Ecphylini.It is very possible that, on the basis of the small size of the specimens examined in this study, the hosts of the new species might also be scolytid larvae.
Mesosoma.Length 1.8-1.9times its height.Neck of promesosoma very short.Pronotal carina distinct.Mesoscutum highly and almost perpendicularly raised above pronotum.Notauli deep in anterior half, very shallow or almost absent in posterior half, sparsely crenulate.Prescutellar depression deep, with distinct median carina, very finely rugulose, 0.3 times as long as scutellum.Subalar depression shallow, wide, very finely rugu lose.Sternauli distinct, smooth, connected with prepectal carina anteriorly, running along approximately half of lower part of mesopleura.Propodeum without lateral tubercles.
Wings.Fore wing 3.5-3.8times as long as its maximum width.Radial vein arising from or behind middle of pterostigma.Radial cell not shortened.First radial abscissa almost perpendicular to pterostigma, 0.8-1.0 times as long as maximum width of pterostigma, 0.6-0.7 times as long as first radiomedial vein.Second radial abscissa weakly curved, 6.8-7.8 times as long as first abscissa, about 4.5 times as long as first radiomedial vein.Discoidal cell 2.1-2.3 times as long as wide.Recur rent vein antefurcal, 1.6-2.0times as long as second abscissa of medial vein.Brachial cell narrow, gently closing apically distinctly before the recurrent vein.Dis tance from nervulus to basal vein 1.0-1.5 times nervulus length.In hind wing medial cell closed anteriorly.
Legs.Hind femur 3.8-4.4times as long as wide.Hind coxa without basoventral tooth.Hind tarsus 0.9 times as long as hind tibia.Basitarsus 0.7-0.75 times as long as second-fifth segments combined.Second tarsal segment 0.4-0.45times as long as basitarsus, about 1.3 times as long as fifth segment (without pretarsus).
Metasoma 0.85-1.1 times as long as head and meso soma combined.First tergite without spiracular tubercles, spiracles situated on basal 1/3, weakly and linearly wid ened from base to apex.Maximum width of first tergite 1.7 times its width at level of dorsope; length 1.1-1.2times its apical width.Second tergite without depressions, length of tergite 0.8 times its basal width, 1.4 times length of third tergite.Second suture shallow and straight.Ovi positor sheath 0.6-0.8times as long as body, 1.2-1.7 times as long as metasoma, 1.7-2.2times as long as mesosoma, 0.7-0.8times as long as fore wing.
Sculpture and pubescence.Vertex very densely and finely aciculate; frons almost entirely and temple smooth; face very finely and sparsely rugulose.Sides of pronotum almost entirely smooth.Mesoscutum granulate, finely and narrowly striate medioposteriorly.Scutellum almost smooth.Mesopleura and metapleura smooth.Propodeum smooth, with fine rugulosity along carinae, with median carina in basal half and with distinctly marginate, long, narrow and striate areola in apical half.Hind legs smooth.First metasomal tergite with distinct and complete dorsal carinae, densely striate, finely rugulose medially between dorsal carinae.Rest of tergites smooth.Hind tibia with rather sparse and semierect hairs dorsally, length of these hairs 0.7-0.8times maximum width ofhind tibia.
Colour.Head and anterior half of mesosoma reddish yellow, posterior half of mesosoma and entire metasoma reddish brown, sometimes darker or lighter.Two or three basal segments of antenna yellow, rest of segments red dish brown to dark reddish brown, 3 apical segments white.Palpi yellow.Legs entirely pale yellow or yellow.
Male.Body length 3.8 mm; fore wing length 1.9 mm.Recurrent vein of fore wing as long as second medial abscissa.Metasoma very long, strongly narrowed behind third tergite, then almost parallel-sided and depressed; 2.5 times as long as mesosoma and head combined.Length of first tergite 1.4 times its apical width.Metasoma behind third tergite ventrally with several sparse long hairs; dorsal hairs along border of tergites significantly shorter.Otherwise similar to female.
Discussion.This new species is similar to A. sperches from India, but differs in the shorter ovipositor, smooth second metasomal tergite, the 3 apical segments of antenna being white, the first flagellar segment being dis tinctly shorter than the second segment, and presence of sternauli.
Etymology.From Latin "nitidus" (shining), because most of the body of this species is shiny.
Description.Female.Body length 3.0 mm; fore wing length 2.5 mm.Head width 1.4 times its median length.Temple distinctly roundly narrowed behind eye; trans verse diameter of eye 1.6 times length of temple.Ocelli small, in triangle with base 1.3 times its sides.POL almost equal to Od, 0.4 times OOL.Eye glabrous, 1.4 times as high as broad.Malar space height 0.4 times height of eye, 0.8 times basal width of mandible.Face width 0.9 times height of eye and 1.1 times height of face and clypeus combined.Malar suture absent.Clypeus with narrow lower flange.Clypeal suture distinct.Hypoclypeal depression almost round, its width 0.7 times distance from edge of depression to eye.Occipital carina reduced below hence not fused with the hypostomal carina.Palpi long, length of maxillary palpi about 1.7 times head height.
Antennae filiform, 27-segmented, 1.3 times as long as body.Scapus about as long as its maximum width.First flagellar segment not flattened, weakly curved, almost 5 times as long as its apical width, 0.6 times as long as second segment.Penultimate segment 4.5 times as long as wide, 0.6 times as long as first flagellar segment, as long as apical segment, which is pointed apically.
Mesosoma.Length almost twice its height.Neck of promesosoma very short.Pronotal carina distinct.Mesoscutum highly and almost perpendicularly raised above pronotum.Notauli deep in anterior half, shallow in posterior half, sparsely crenulate.Prescutellar depression rather deep, with distinct median carina, very finely rugu lose, 0.3 times as long as scutellum.Subalar depression shallow, wide, partly finely rugulose.Sternauli deep, almost smooth, connected with prepectal carina anteriorly, running along approximately 2/3 of lower part of mesopleura.Propodeum without lateral tubercles.Figs 14-24.Aivalykus bouceki sp.n. 14 -head, frontal view; 15 -head, dorsal view; 16 -propodeum; 17 -basal and apical seg ments of antenna; 18 -fore wing; 19 -hind wing; 20 -mesosoma, lateral view; 21 -hind femur; 22 -hind coxa; 23 -metasoma, dorsal view; 24 -hind tibia.Wings.Fore wing 3.8 times as long as its maximum width.Radial vein arising behind middle of pterostigma.Radial cell not shortened.First radial abscissa almost per pendicular to pterostigma, almost equal to maximum width of pterostigma, 0.6 times as long as first radiome dial vein.Second radial abscissa weakly curved, 6.5 times as long as first abscissa, 4 times as long as first radiome dial vein.Discoidal cell almost twice as long as wide.Recurrent vein antefurcal, 4.2 times as long as second abscissa of medial vein.Brachial cell narrow, gently closing apically weakly before the recurrent vein.Dis tance from nervulus to basal vein almost twice length of nervulus.In hind wing medial cell closed anteriorly.
Legs.Hind femur 4.2 times as long as wide.Hind coxa without basoventral tooth.Hind tarsus 0.9 times as long as hind tibia.Basitarsus 0.65 times as long as second-fifth segments combined.Second tarsal segment 0.6 times as long as basitarsus, twice as long as fifth segment (with out pretarsus).
Metasoma 1.1 times as long as head and mesosoma combined.First tergite without spiracular tubercles, spira cles situated on basal third, distinctly and almost linearly widened from base to apex.Maximum width of first ter gite 1.8 times its minimum width; length 1.4 times its apical width.Second tergite with fine lateral furrows, which are parallel to tergite margins; length of tergite almost equal to its basal width, 1.7 times length of third tergite.Second suture shallow and regularly curved.Ovi positor sheath slightly longer than body, almost twice as long as metasoma, 3 times as long as mesosoma, 1.2 times as long as fore wing.
Colour.Head brownish yellow.Mesosoma and meta soma light reddish yellow, second tergite laterally and posteriorly, and apex of metasoma, yellow.Antenna red dish brown, 2 basal segments light reddish brown.Palpi yellow.Legs entirely yellow.Ovipositor sheath brown.Wings subhyaline.Pterostigma brown, paler in basal third and apically.
Male unknown.