Astymachus japonicus Howard

Noyes, John S. & Higashiura, Yoshimitsu, 2020, The species of Astymachus Howard (Hymenoptera: Encyrtidae) ı potentially important parasitoids of Aclerdidae (Hemiptera: Coccoidea) associated with grasses (Poaceae) ı with descriptions of three new species, Journal of Natural History 54 (9), pp. 665-679 : 676-677

8. Astymachus japonicus Howard

( Figures 3d – h )

Astymachus japonicus Howard, 1898: 239 . Syntypes ♂ ♀, Japan, USNM, examined .

Diagnosis. Female. Length, including ovipositor, 1.06 – 1.63 mm. Body generally yellow; antenna mostly pale yellow, scape, pedicel and F1 pale brown, clava slightly dusky in apical half; fore wing ( Figure 3h ) generally hyaline with only a small, weakly infuscate area at junction of marginal vein and stigmal veins that reaches level with apex of stigmal vein and an elongate streak parallel to posterior margin between linea calva and base of wing; head ( Figure 3d ) about 1.6 – 1.7× as long as eye; palp formula 4 – 3; antenna ( Figure 3e ) with F1 subquadrate, F2 – F5 clearly transverse, F6 transverse but larger, linear sensilla only on F6; clava 2-segmented; scutellum with about 4 – 6 setae; wings not shortened, fore wing ( Figure 3h ) about 3.0 – 3.2× as long as broad and 3.8 – 3.9× as long as mid tibia, reaching well past cercal plates; marginal vein not quite reaching anterior wing margin and about 0.8× as long as stigmal vein; stigmal vein ( Figure 3g ) only about 2.7× as long as depth of uncus; discal setae below apex of venation about one-half as long as distance between sockets or at least about 3× as long as diameter of socket; ovipositor about 2.2 – 2.4× as long as mid tibia or gonostylus. Male. Length 0.83 – 1.19 mm. Antenna ( Figure 3f ) with funicle segments subequal, subquadrate with F1 and F6 slightly larger; aedeagus equal in length to mid tibia.

Biology. Reared from a ‘ Lecanium-like coccid on Bambusa ’ ( Howard 1898: 239). Recorded below from Aclerda tokionis Cockerell ( Hemiptera : Aclerdidae ) and from a mealybug on sorghum, but the latter host is probably incorrect.

Distribution. Pakistan, Japan. Records from elsewhere require confirmation.

Material examined

Type material. JAPAN, 18♀, 17♂ syntypes plus 1 female of an unidentifed species of Metaphycus on slide under single coverslip: ‘ 1259 ’ [red ink] ‘ Coccid on Bambusa Gifu Japan Lecanium like form in manus behind leaves Koebele ’ [black ink]; ‘ Type No 5031 U.S.N.M. ’ [red label]; Q-code label ‘ USNMENT 01 – 25338 ’; ‘ Astymachus japonicus How. type ’.

Non type material. PAKISTAN: 1♀, 1♂, Rawalpindi, Com. Inst. Biol. Cont. , ex mealybug on Sorghum nitidum , 795, 24 January 1961, C.I.E. COLL. No. 17560, ‘ Xanthoencyrtus sp. R.D. Eady det. 1961 ’, ‘ Astymachus sp. E R.D. Eady det. 1965 ’, ‘ Astymachus japonicus Howard B. R. Subba Rao det. 1971; JAPAN, 4♀, 2 ┌, Honshu, Nara Pref., Ochi , Kashihara , ex Aclerda tokionis Cockerell on bamboo, em. June 1995 (Y. Higashiura) [determined to be Astymachus japonicus Howard by Y. Higashiura 1997].

Comments. All the syntypes are uncleared and most are in poor condition. For this reason, a lectotype is not designated here.

Females of Astymachus japonicus can be distinguished by the relatively short head, and the virtually naked and hyaline fore wing with a relatively short stigmal vein.

The named host species ( Aclerda tokionis ) is found on both sugarcane (Saccharum o ffi cinarum Linnaeus) and bamboo ( Poaceae ).

Figures

Figures 3. Astymachus phragmitis Trjapitzin: (a) antenna ♂; (b) fore wing; (c) apex of fore wing venation. Astymachus japonicus Howard: (d) head; (e) antenna ♀; (f) antenna ♂; (g) apex of fore wing venation; (h) fore wing. Astymachus srilankae sp. nov. (holotype):(i) head; (j) antenna ♀; (k) antenna ♂; (l) fore wing; (m) apex of fore wing venation.