A taxonomic study of Chinese species of the alberti group of Metaphycus (Hymenoptera, Encyrtidae)

Abstract Ten alberti-group species of the genus Metaphycus Mercet from China are reviewed. Six species Metaphycus dorsalis sp. n., Metaphycus chinensis sp. n., Metaphycus wui sp. n., Metaphycus stylatus sp. n., Metaphycus fusiscapus sp. n. and Metaphycus fusiformis sp. n. are described as new to science. Four known species from China are redescribed. A key to the females of the Chinese species is given and photomicrographs are provided to illustrate morphological characters of these species. All specimens unless otherwise specified are deposited in the National Zoological Museum of China Institute of Zoology Chinese Academy of Sciences Beijing.


Introduction
Metaphycus is a large genus of the family Encyrtidae, including 455 species worldwide (Noyes 2012). All species of Metaphycus with known biology are primary endoparasitoids of scale insects, mainly species of Coccidae, Diaspididae, Eriococcidae and Mar-garodidae (Guerrieri and Noyes 2000;DeBach and Rosen 1991). Metaphycus play a role in the control of agricultural and forestry pests, and probably contribute to the population control of potential pests of forest and fruit trees, ornamentals and agricultural crops. In China, M. parasaissetiae controls their host Parasaissetia nigra at the earlier stage of the egg-laying season (Zhang et al. 2010). It is one of the most successful groups of insects to have been used in the biological control of scale insects (such as Coccus and Saissetia) (Guerrieri and Noyes 2000;Noyes 2004;Lotfalizadeh 2010).
Due to the economical and particularly the extraordinary diversification of Metaphycus, many taxonomic works have been published and a few good keys have been presented for the regional species of Metaphycus (Compere 1940;Annecke and Mynhardt 1971, 1972, 1981Myartseva 1987;Viggiani and Guerrieri 1988;Guerrieri and Noyes 2000;Trjapitzin 1989;Zeya and Hayat 1993). Most of them are based on the distinction of species groups using the palpal formula as suggested by Compere and Annecke (1960). Based on the palpal formula, Compere and Annecke (1960) suggested dividing the genus Metaphycus into three species groups: alberti-group (Plate I-A) (with 2-segmented maxillary palpi), insidiosus-group (Plate I-B) (with 3-segmented maxillary palpi) and zebratus-group (Plate I-C) (with 4-segmented maxillary palpi). The alberti-group is interpreted here as having 2-segmented maxillary and 2-segmented labial palpi (Anneck and Mynhardt 1971; Guerrieri and Noyes 2000). Graham (1959) used hederaceus as the group name, but later he proposed asterolecanii for the same group, since hederaceus belongs to Aphycus rather than Metaphycus (Graham, 1969). Tachikawa (1963) was the first author to use alberti as the name of this group, and this is widely accepted (Guerrieri and Noyes 2000;Noyes 2004;Zeya and Hayat 1993). Guerrieri and Noyes (2000) described M. babas as a new species, with a palpal formula of 2-3. Therefore, they prefer to define these species on the number of segments in the maxillary palpi alone. Noyes (2004) broke with this framework and introduced several other characters (e.g. presence or absence of subapical setae on the 2 nd valvifer). These characters are very difficult to observe unless high quality slide-mounted specimens are prepared. In the course of this work, the framework of Compere and Annecke (1960) was followed.
The Chinese fauna of Metaphycus is poorly known, though some taxonomic contributions (Jiang 1982;Shi 1986;Xu and Jing 1990) have been made in the later years of past century. But some synonyms and homonyms can be found easily, such as Metaphycus ericeri Xu & Jiang, 1990(renamed M. xujiangi by Özdikmen 2011. Recently, several new species and new records have been reported from China (Dang and Wang 2002;Li and Xu 2006;Li and Li 2008;Zhang and Huang 2006;Zhang and Wu 2008;Tan 2008). So far, more than twenty species of Metaphycus species have been recorded from China, including four alberti group species. To facilitate the accurate identification of this large group of Encyrtidae, systematic study of all species known in China is necessary (Zhang and Wu 2008). The present work is part of this effort.
Accurate identification of Metaphycus species is very difficult because of their small size and general appearance (Annecke and Mynhardt 1971;Guerrieri and Noyes 2000). Thus high quality slide preparation is needed, and it is necessary to dissect the mouthparts and ovipositor parts. The characters (e.g. body coloration, width of frontovertex) used in the keys to species are disputable (Guerrieri and Noyes 2000); however our recent studies using molecular markers show these characters are arguable and can help us to disentangle these species complexes (unpublished data).
Morphological terminology and abbreviations follow those of Noyes (2004). Absolute measurements were used for body length. Relative measurements were used for other dimensions and measured with a Motic SMZ-168 stereomicroscope, under 50x magnification, and the absolute measurement of each unit is 0.02 mm. The following abbreviations are used in the text:

F1, F2, … Fn Funicle segment number AOD
Largest diameter of anterior ocellus HW Head width measured in facial view FV Minimum width of the frontovertex FVL Length of frontovertex from occipital margin to top of antennal scrobes as seen in dorsal view MS Malar space or the minimum distance between eye and mouth margin POL The minimum distance between the posterior ocelli OCL The minimum distance between the posterior ocellus and the occipital margin AOL The minimum distance between posterior ocellus and anterior ocellus OOL The minimum distance between the eye margin and the adjacent posterior ocellus POD Largest diameter of posterior ocellus EL The maximum diameter of eye EW The minimum diameter of eye SL The length of the scape SW The maximum width of the scape FWL Length of fore wing excluding the marginal fringe FWW The maximum width of the fore wing excluding the marginal fringe Female: Body length, including ovipositor about 1mm. Frontovertex orange; orange in ocellar area, pale orange between occipital margin and posterior ocelli; immaculate with yellow from occiput to base of mandible; mouth margin medially yellow below torulus; rest of head, except occiput, white; antenna ( Fig. 1) with radicle dark brown; scape with both faces dark brown, blackish, only base and apex white; pedicel dark brown in proximal one third, otherwise white; F1-F3 dark brown, F4 very pale brown, F5-F6 white, clava dark brown, becoming slightly paler towards apex, apex very pale brown; occiput with a brown area above foramen, rest white; neck of pronotum dark brown, posterior margin white, lateral spots relatively large and distinct; dorsum of thorax orange; sides and posterior margin of mesoscutum and axillae conspicuously bordered brown, mesoscutum and scutellum (Plate I-D) with brown line from front edge of mesoscutum to apex of scutellum; setae translucent pale brown, silvery in most lights; tegula white with apex pale brown; metanotum orange; mesopleuron yellow; prosternum and mesosternum pale yellow; legs (Figs 5-7) pale yellow; fore wing ( Fig. 4) hyaline and with linea calva interrupted; venation yellowbrown; hind wing hyaline; propodeum medially orange-brown, laterally pale yellow; gaster orange and ovipositor sheath orange.
Head with polygonally reticulate sculpture and mesh size slightly less than that of one eye facet; frontovertex about one-fourth head width; ocelli forming an acute angle about 30°; eye not quite reaching occipital margin, separated by much less than diameter of a facet; frontovertex subparallel and from anterior ocellus slightly wider anteriorly; scrobes shallow and U-shaped; antenna with scape about 3-3.1× as long as broad; funicle with F1-F4 smallest, F5 a little larger than F4 but transverse, F6 largest and slightly wider than long; linear sensilla only on F5 and F6; clava 3-segmented, its apex more or less rounded but with a short slightly oblique truncation; mandible relatively broad with three subequal, apical teeth; palpal formula 2-2 ( Fig. 3), notaular lines reaching about 0.4× across mesoscutum; fore wing venation and setation as in Fig. 4; ovipositor ( Fig. 2) slightly exserted, about 5.6× as long as ovipositor sheath.
Male. Unknown. Host. Unknown. Distribution. China (Sichuan, Yunnan). Etymology. The specific epithet of this new species refers to the medial longitudinal dark brown strip on the mesoscutum and scutellum.
Diagnosis. Antenna with scape about 3-3.1× as long as broad; mesoscutum and scutellum with brown line running from front edge of mesoscutum to apex of scutellum; legs pale yellow; fore wing hyaline and with linea calva interrupted. Using the keys of Trjapitzin (1989) and Guerrieri and Noyes (2000), this species runs to M. dispar (keys couplet 11 and 15). It can be separated from dispar as follows: mesoscutum and scutellum with a longitudinal dark brown strip in the middle (in dispar, mesoscutum and scutellum without a longtitudinal dark brown strip). Scape about 3× as long as broad (in dispar, scape about 3.3× as long as broad). Ovipositor about 5× as long as ovipositor sheath (in dispar, ovipositor about 4.3× as long as ovipositor sheath). The colour of the radicle is dark brown, and the metanotum is orange (in dispar, radicle with yellow, and metanotum is brown). ( Female. Body length, including ovipositor, 0.72-1.1 mm. Frontovertex pale orange; orange in ocellar area, pale orange between occipital margin and posterior ocelli; immaculate from occiput to base of mandible; occiput with a large dark brown area above foramen, rest white; antenna ( Fig. 8) with radicle very pale brown; scape mostly pale yellow and with a dark brown mark in middle, dorsal margin pale yellow; pedicel dark brown in proximal half, otherwise white, F1-F3 brown, F4-F6 white, clava dark brown, becoming slightly paler towards apex, apex pale brown; neck of pronotum brown, posterior margin translucent white, lateral spots relatively small and faint, rest white; dorsum of thorax orange; sides and posterior margin of mesoscutum and axillae inconspicuously bordered brown; setae translucent yellow, silvery in most lights; tegula white with apex pale grey-brown; metanotum orange; mesopleuron pale yellow; prosternum and mesosternum pale yellow; legs (Figs 12-14) mainly pale yellow; fore wing ( Fig. 11) hyaline and with linea calva interrupted, stigmal vein about 2.3× as long as marginal vein, venation yellow-brown; hind wing hyaline; propodeum medially orange, laterally dark brown, sides white; gaster mostly yellow, sometimes pale brown dorsally from cercal plates to near apex, ovipositor sheath yellow. Head with polygonally reticulate sculpture and mesh size slightly less than that of one eye facet; ocelli forming an acute angle less than 35°; eye not quite reaching occipital margin, separated by much less than diameter of a facet; frontovertex parallel-sided; scrobes shallow and U-shaped; antenna with scape about 2.7-3.5× as long as broad; funicle with F1-F4 smallest, subequal and transverse, F5 a little larger, F6 largest and slightly wider than long; linear sensilla only on F5 and F6; clava 3-segmented, its apex more or less rounded but with a short slightly oblique truncation; mandible relatively broad with three subequal, apical teeth; palpal formula 2-2 ( Fig. 10), notaular lines reaching about 0.4× across mesoscutum; fore wing venation and setae as in Fig. 11; ovipositor ( Fig. 9) slightly exserted, about 5.2× as long as ovipositor sheath.
Male. Length 0.7 mm. Generally similar to female but for coloration, structure of clava and genitalia. Frontovertex with ocellar area dark brown; dorsum of thorax and gaster dark brown. Antenna similar to that of female but clava solid and relatively slender; aedeagus about half as long as mid tibia.
Hosts. Coccus hesperidum (Annecke & Mynhardt, 1981), Coccus elongates, Coccus longulus and Ceroplastes sp.  Diagnosis. Antenna with radicle very pale brown; scape mostly pale yellow and with a dark brown mark in middle, dorsal margin pale yellow; legs mainly pale yellow, scape about 2.7-3.5× as long as broad, ovipositor slightly exserted, about 5.2× as long as ovipositor sheath. Metaphycus alberti is very similar to M. dispar in general coloration and habitus. The female of alberti can be identified reliably by the pale yellow dorsal margin of the scape (in dispar dorsal margin of the scape medially interrupted by dark brown mark), and the ovipositor about 5.2× as long as ovipositor sheath (in dispar ovipositor about 4.3× as long as ovipositor sheath). (Mercet, 1925 (Mercet); Babaev 1971: 70-75. Trjapitzin 1978: 314;Trjapitzin 1989: 384;Guerrieri and Noyes 2000: 168. Female. Body length, including ovipositor, about 0.67mm. Frontovertex orange; orange in ocellar area, pale yellow between occipital margin and posterior ocelli; immaculate from occiput to base of mandible; mouth margin pale yellow below torulus; rest of head, except occiput, white; antenna ( Fig. 15) with radicle yellow; scape mostly pale yellow and with a dark brown mark in middle, dorsal margin in middle brown; pedicel in proximal two thirds dark brown and distal one third white, dark brown area extending slightly towards apex externally and internally; F1-F3 dark brown, F4 pale brown, F5-F6 yellow-white, clava dark brown, becoming slightly paler towards apex, apex yellow; occiput with a large dark brown area above foramen, rest white; neck of pronotum black, posterior margin white, lateral spots relatively large and distinct, rest white; dorsum of thorax orange; sides and posterior margin of mesoscutum and axillae inconspicuously bordered brown; setae translucent pale orange, silvery in most lights; tegula white with apex pale brown; metanotum brown; mesopleuron white; prosternum and mesosternum white; legs (Figs 19-21) pale yellow; fore wing ( Fig. 18) hyaline and with linea calva interrupted, venation yellow-brown; hind wing hyaline; propodeum medially pale brown, brown laterally, sides white; gaster dorsally mainly very pale brown, but basal tergite dark brown, sides and venter white; ovipositor sheath yellow. Head with polygonally reticulate sculpture and mesh size slightly less than that of one eye facet; ocelli forming an acute angle less than 35°; eye not quite reaching occipital margin, separated by much less than diameter of a facet; eye margins subparal- lel with frontovertex slightly wider anteriorly; scrobes shallow and U-shaped; antenna ( Fig. 15) with scape about 3.1-3.3× as long as broad; funicle with F1-F4 smallest, subequal and transverse, F5 a little larger and F6 largest, linear sensilla only on F5 and F6; clava 3-segmented, its apex more or less rounded but with a short slightly oblique truncation; mandible relatively broad with three subequal, apical teeth (Fig. 17); palpal formula 2-2 ( Fig. 16), notaular lines virtually absent; fore wing venation and setation as in Fig. 18; ovipositor (Fig. 22) slightly exserted, about 4.3× as long as ovipositor sheath.
Male. Length 0.7-0.8 mm. Very similar to female except for antenna, genitalia and darker coloration; torulus with several pores inside the lower margin. (Guerrieri and Noyes 2000).
Hosts  (Trjapitzin 1989;Guerrieri and Noyes 2000). Diagnosis. Scape mostly pale yellow and with a dark brown mark in middle, dorsal margin in middle brown, and about 3.1-3.3× as long as broad; ovipositor slightly exserted, about 4.3× as long as ovipositor sheath. See diagnosis under the M. alberti. According to Guerrieri and Noyes (2000), M. dispar is very close to M. kozari Sugonjaev (1975).  dark brown in proximal half, otherwise white; F1-F3 dark brown, F4 pale brown, F5-F6 white, clava dark brown, becoming paler towards apex, apex paler brown; occiput with a large dark brown area above foramen, rest white; neck of pronotum black, posterior margin translucent brown, lateral spots relatively large and distinct, rest white; dorsum of thorax orange; sides and posterior margin of mesoscutum and axillae inconspicuously bordered pale brown; setae translucent orange, silvery in most lights; tegula white with apex pale grey-brown; metanotum pale brown; mesopleuron pale yellow; prosternum and mesosternum white; legs (Figs 26-28) mainly pale yellow, occasionally mid and hind tibiae with faint brown marking; fore wing ( Fig. 25) hyaline and with linea calva interrupted, venation yellow-brown; hind wing hyaline; propodeum medially dark brown, laterally white; dorsum of gaster brown but T8 white, sides and venter white; ovipositor sheath yellow.

Metaphycus chinensis
Head with polygonally reticulate sculpture and mesh size slightly less than that of one eye facet; ocelli forming an angle of about 40°; eye not quite reaching occipital margin, separated by much less than diameter of a facet; frontovertex subparallelsided; scrobes shallow and U-shaped; lateral antennal groove absent; antenna (Fig. 23) with scape about 2.3× as long as broad; funicle with F1-F4 smallest, subequal and transverse, F5 larger but transverse, F6 largest, linear sensilla only on F5 and F6; clava 3-segmented, its apex more or less rounded but with a short slightly oblique truncation; mandible relatively broad with three subequal, apical teeth; palpal formula 2-2 ( Fig. 24), notaular lines virtually absent; fore wing venation and setation as in Fig. 25; ovipositor (Fig. 29) hardly exserted, about 4.8× as long as ovipositor sheath.

Distribution. China (Jiangsu).
Etymology. The specific epither of this new species is derived from the type locality "China".
Diagnosis. Antenna with radicle brown; scape with both faces blackish, extreme base and apex yellow; scape about 2.3× as long as broad; dorsum of gaster brown but T8 white, sides and venter white; ovipositor sheath yellow; ovipositor hardly exserted, about 4.8× as long as ovipositor sheath. This species is close to M. ericeri in appearance. It can be separated from the latter as follows: fore wing 2.7× as long as broad (Fig. 25), ocelli forming an angle of about 40°; ovipositor (Fig. 29) about 4.8× as long as ovipositor sheath (in ericeri, fore wing 2.4× as long as broad (Fig. 53), ocelli forming an angle of about 50°; ovipositor (Fig. 57) about 5.4× as long as ovipositor sheath). Paratypes. 2♀♀, same as holotype (IZCAS). Female: Body length, including ovipositor, 0.7-0.8mm. Frontovertex orange; orange in ocellar area, orange between occipital margin and posterior ocelli; gena with brown-yellow from occiput to base of mandible; mouth margin yellow below torulus; rest of head, except occiput, white; antenna (Fig. 30) with radicle very pale brown; scape mostly black only extreme base and apex white; pedicel dark brown in proximal half otherwise white, F1-F4 dark brown, F5-F6 white, clava dark brown, becoming slightly paler towards apex, apex paler brown; occiput with a large black area above foramen, rest white; neck of pronotum black, posterior margin brown, lateral spots relatively large and distinct, rest brown; dorsum of thorax brown-yellow; sides and posterior margin of mesoscutum and axillae inconspicuously bordered yellow-brown (Fig. 34); setae translucent yellow, silvery in most lights; tegula white only apex pale brown; metanotum dark brown; mesopleuron pale yellow; prosternum and mesosternum white; legs (Figs 35-37) mainly pale brown-yellow; fore wing ( Fig. 32) hyaline, venation yellow-brown; hind wing hyaline and with linea calva interrupted; propodeum medially dark brown; gaster dorsally brown, side and venter white; ovipositor sheath pale yellow.

Distribution. China (Guangxi).
Etymology. The species is named after Professor Sanan Wu, who helped to identify many hosts of Encyrtidae.
Diagnosis. Antenna with radicle very pale brown; scape mostly black, only extreme base and apex white, about 2.3× as long as broad; legs mainly pale brown-yellow; ovipositor slightly exserted, about 4.7× as long as ovipositor sheath. This species is similar to M. fusiscapus in colour and size. It can be separated from the latter as follows: scape about 2.3× as long as broad (in fusiscapus, scape about 2× as long as broad); mid and hind tibiae immaculate (Fig. 36), at most with a fuscus spot near base of mid tibiae (in fusiscapus mid and hind tibiae with distinct dark brown marking). Paratypes. 2♀♀, same as holotype (IZCAS). Female: Body length, including ovipositor about 0.8mm. Frontovertex orange; orange in ocellar area, orange between occipital margin and posterior ocelli; gena with a fairly broad, oblique, pale brown-yellow from occiput to base of mandible; mouth margin narrowly pale brown below torulus; rest of head, except occiput, white; antenna ( Fig. 39) with radicle yellow; scape mostly dark brown and base white; pedicel dark brown in proximal half, otherwise white, F1-F4 dark brown, F5-F6 pale browngrey, clava dark brown, becoming slightly paler towards apex, apex paler brown; occiput with a large dark brown area above foramen, rest white; neck of pronotum pale black, posterior margin brown, lateral spots relatively large and distinct, rest white; dorsum of thorax yellow-brown; sides and posterior margin of mesoscutum and axillae inconspicuously bordered brown; setae translucent yellow, silvery in most lights; tegula white and apex grey-brown; metanotum dark brown; mesopleuron pale yellow; prosternum and mesosternum white; legs (Figs 43-45) mainly pale yellow but tibiae at knees narrowly dark brown, mid and hind tibiae with a pair of dark brown rings at about 0.2× and 0.5×; fore wing ( Fig. 42) hyaline and with linea calva interrupted, venation yellow-brown; hind wing hyaline; propodeum medially brown, laterally yellow; gaster dorsally brown, sides and venter white; ovipositor sheath yellow.

Distribution. China (Beijing).
Etymology. The specific epithet is derived from the latin word "stylatus" referring to the long ovipositor sheath of the new species.
Diagnosis. Scape mostly dark brown and base white and about 5.5× as long as broad; legs mainly pale yellow but tibiae at knees narrowly dark brown, mid and hind tibiae with a pair of dark brown rings at about 0.2× and 0.5×; gaster dorsally brown, sides and venter white; ovipositor sheath strongly exserted, the exserted part about two thirds gaster length; ovipositor length about 2.8× as long as ovipositor sheath.
Metaphycus stylatus differs from other species studied here by the strongly exserted ovipositor sheath, which is about two thirds gaster length. In other species, the ovipositor sheath is less than one fifth the gaster length. Using the key of Guerrieri and Noyes (2000), this species runs to M. asterolecanii (key couplet 12). It can be separated from asterolecanii as follows: scape about 5.5× as long as broad; head about 3× as broad as frontovertex, and ocelli forming an angle of about 60°; ovipositor (Fig. 47) strongly exserted, about 1.7× as long as mid tibia (in asterolecanii, scape about 3× as long as broad; head about 4× as broad as frontovertex, and ocelli forming an angle of clearly less than 60°; ovipositor hidden and nearly as long a mid tibia).
Head with polygonally reticulate sculpture and mesh size slightly less than that of one eye facet; ocelli forming an angle of about 50°; eye not quite reaching occipital margin, separated by much less than diameter of a facet; frontovertex not parallel-sided, becoming slightly broader anteriorly from the narrowest point which is slightly in front of posterior ocelli; scrobes shallow and U-shaped; antenna with scape about 2.3× as long as broad; funicle with F1-F4 smallest, subequal and transverse, F5 a little larger but transverse, F6 largest, linear sensilla only on F5 and F6; clava 3-segmented, its apex more or less rounded but with a short slightly oblique truncation; mandible relatively broad with three subequal, apical teeth (Fig. 49); palpal formula 2-2 (Fig. 50), thorax dorsally with notaular lines present only anteriorly; fore wing venation and setation as in Fig. 53; ovipositor (Fig. 57) hardly exserted, about 5.4× as long as ovipositor sheath.
This species is similar to M. helvolus in appearance. It can be separated from M. helvolus as follows: dorsal margin of scape pale black; linear sensilla on F5 and F6 (in helvolus dorsal margin of scape yellowish, linear sensilla absent on F5), head is about 3.5× as broad as frontovertex, the ovipositor about 0.6× as long as mid tibia (in helvolus head about 3× as broad as frontovertex, and the ovipositor about as long as mid tibia). ( Bouček and Graham 1978: 230;Trjapitzin 1989: 246;Li and Xu 2006: 112-113. Metaphycus syllaeus (Walker); Bouček and Graham 1978: 230. Female. Body length, including ovipositor, 0.7-0.8mm. Frontovertex dark orange; brown in ocellar area, brown between occipital margin and posterior ocelli; dark brown from occiput to base of mandible; mouth margin narrowly dark brown below torulus; rest of head, except occiput, brown; antenna ( Fig. 58) with radicle dark brown; scape with both faces dark brown and base of scape white; pedicel in proximal half dark brown, distal half white, dark brown area extending slightly towards apex externally and internally; F1-F4 pale brown, F5-F6 white, clava dark brown, becoming slightly paler towards apex, apex paler brown; occiput with a large dark brown area above foramen; neck of pronotum black, posterior margin translucent brown; dorsum of thorax dark brown; sides and posterior margin of mesoscutum and axillae inconspicuously bordered brown; setae translucent pale brown, silvery in most lights; tegula pale brown with apex pale darker; metanotum dark brown; mesopleuron pale brown; prosternum and mesosternum brown; legs (Fig. 59) mainly pale yellow but tibiae at knees narrowly dark brown and each with a pair of dark brown rings at about 0.2× and 0.5× (fore tibia at about 0.5×); fore wing ( Fig. 62) hyaline with a small infuscate area beneath stigmal vein, and with linea calva interrupted; venation yellow-brown; hind wing hyaline; propodeum dark brown; gaster dorsally and venter dark brown, sides very pale brown to white; ovipositor sheath pale brown.

Metaphycus nadius
Head with polygonally reticulate sculpture and mesh size slightly less than that of one eye facet; ocelli forming an angle of about 45°; eye not quite reaching occipital margin, separated by much less than diameter of a facet; eye margins subparallel; scrobes shallow and U-shaped; antenna with scape about 4.5× as long as broad; funicle with F1-F4 smallest, subequal and transverse, F5 a little larger but transverse, F6 largest and quadrate; linear sensilla only on F6; clava 3-segmented, its apex more or less rounded but with a short slightly oblique truncation; mandible relatively broad, with three subequal, apical teeth; palpal formula 2-2 (Fig. 60), gaster with ovipositor slightly exserted, notaular lines reaching about 0.7× across mesoscutum; fore wing venation and setation as in Fig. 62; ovipositor (Fig. 61) clearly exserted, about 4.3× as long as ovipositor sheath.

Male.
Almost identical to female in general structure, habitus and coloration except for solid clava, genitalia.
Hosts  Diagnosis. Antenna with radicle dark brown; scape with both faces dark brown and base of scape white; scape about 4.5× as long as broad; legs mainly pale yellow but tibiae at knees narrowly dark brown and each with a pair of dark brown rings at about 0.2× and 0.5× (fore tibia at about 0.5×); fore wing hyaline with a small infuscate area beneath stigmal vein. The female of M. nadius can be identified reliably from other Chinese species in this group by the brown mark under the stigmal vein and the two rings on the mid tibia, antenna with linear sensilla on F6 and clava only. According to Guerrieri and Noyes (2000), it is also similar to M. hubai, both with a small infuscate area below marginal and stigma veins. Female: Body length, including ovipositor, 0.9-1mm. Frontovertex orange; very pale brown in ocellar area, pale brown between occipital margin and posterior ocelli; gena with brown-grey; mouth margin narrowly pale brown below torulus; rest of head, except occiput, white; antenna ( Fig. 63) with radicle dark brown; scape with both faces black, dorsal margin black, extreme apex white; pedicel in proximal four fifths dark brown, distal one fifth white, dark brown area extending slightly towards apex externally and internally; F1-F3 dark brown, F4 pale brown to pale yellow, F5-F6 white, clava proximal half dark brown, becoming white towards apex; neck of pronotum dark brown, posterior margin translucent brown, lateral spots relatively large and distinct, rest white; dorsum of thorax dark orange; sides and posterior margin of mesoscutum and axillae inconspicuously bordered brown; scutellum slightly darker in center; setae translucent pale brown, silvery in most lights; tegula white with apex brown; metanotum black; mesopleuron white; prosternum and mesosternum pale brown; legs (Figs 66-68) with insides white, and outsides very pale brown, coxae white, but tibiae at knees narrowly dark brown and fore tibia with faint brown rings, mid and hind tibiae with a pair of dark brown rings at about 0.2× and 0.5×; fore wing ( Fig. 65) hyaline and venation brown; hind wing hyaline, and with linea calva interrupted; propodeum medially black, laterally white; gaster dorsally black, sides and venter white; ovipositor sheath pale brown.
Etymology. This specific epither of this new species is referring to the dark brown scape.
Diagnosis. Scape with both faces black, dorsal margin black, extreme apex white, and about 2× as long as broad; legs (Figs 66-68) with inner sides white, and outer sides very pale brown, coxae white, but tibiae at knees narrowly dark brown and fore tibia with faint brown rings, mid and hind tibiae with a pair of dark brown rings at about 0.2× and 0.5×; ovipositor hardly exserted, about 4.1× as long as ovipositor sheath.
Using the key of Guerrieri and Noyes (2000), M. fusiscapus runs to M. pretiosus (key couplet 8), but can be separated from the latter by scape about 2× as long as broad and head 4.1× as broad as frontovertx (in pretiosus, scape about 4× as long as broad, head 3× as broad as frontovertex). Using the key of Zeya and Hayat (1993) Female: Body length, including ovipositor about 0.8-0.9mm. Frontovertex orange; orange in ocellar area, very pale brown to orange between occipital margin and posterior ocelli; gena with a fairly broad, oblique, brown mark from occiput to base of mandible; mouth margin narrowly pale brown below torulus; rest of head, except occiput, white; antenna ( Fig. 70) with radicle dark brown; scape with both faces dark brown, blackish, dorsal margin narrowly pale yellow, extreme apex white; pedicel base at most two thirds dark brown, white distally, dark brown area extending slightly towards apex externally and internally; F1-F3 dark brown, F4 brown, F5-F6 whiteyellow, clava in proximal 2/3 dark brown, becoming slightly paler towards apex, apex yellow; occiput with a large dark brown area above foramen, rest pale yellow; neck of pronotum dark brown, posterior margin translucent yellow, lateral spots relatively large and distinct, rest orange; dorsum of thorax orange; sides and posterior margin of mesoscutum and axillae conspicuously bordered brown; setae translucent pale brown, silvery in most lights; tegula white with apex pale grey-brown; metanotum brown; mesopleuron pale yellow; prosternum yellow and mesosternum white; legs (Fig. 73-75) mainly white but tibiae at knees narrowly dark brown and mid and hind tibiae with a pair of dark brown rings at about 0.2× and 0.5×; fore wing ( Fig. 72) hyaline, a faintly infuscate area below marginal and stigmal veins, and with linea calva interrupted, venation yellow-brown; hind wing hyaline; propodeum medially brown, laterally white; gaster mostly brown but dark brown dorsally from cercal plates to near apex, sides and venter white; ovipositor sheath yellow.
Head with polygonally reticulate sculpture and mesh size slightly less than that of one eye facet; ocelli forming an angle of about 35°; eye not quite reaching occipital margin, separated by much less than diameter of a facet; frontovertex subparallelsided; scrobes shallow and U-shaped; antenna ( Fig. 70) with scape about 2.4× as long as broad; funicle with F1-F4 smallest, subequal and transverse, F5 a little larger but transverse, F6 largest and quadrate, linear sensilla only on F6, clava 3-segmented, its apex more or less rounded but with a short slightly oblique truncation; mandible relatively broad with three subequal, apical teeth; palpal formula 2-2 (Fig. 71); notaular lines reaching about 0.6× across mesoscutum; fore wing venation and setation as in Fig. 72; ovipositor (Fig. 76) slightly exserted, about 5.2× as long as ovipositor sheath, second valvifer without subapical setae.
Male. Unknown. Host. Unknown. Distribution. China (Beijing, Hainan, Shanxi). Etymology. The species name 'fusiformis' is derived from the infuscate area of the fore wing.
Diagnosis. Scape with both faces dark brown, blackish, dorsal margin narrowly pale yellow, extreme apex white and about 2.4× as long as broad; fore wing ( Fig. 72) hyaline, a faintly infuscate area below marginal and stigmal veins. Using the key of Guerrieri and Noyes (2000), this species runs to couplet 10 and is similar to M. ibericus in having a uniformly weakly infuscate fore wing. It can be separated from the latter as follows: dorsal margin of scape pale orange, not marked brown medially and 2.4× as long as broad (in ibericus, dorsal margin of scpae marked brown medially and 3× as long as broad); ovipositor about as long as mid tibia (in ibericus with ovipositor about 0.8× as long as mid tibia).   Xu & Jiang nec Trjapitzin (1967).
Female. Body length, including ovipositor about 1.1mm. Frontovertex orange to dark orange; orange in ocellar area, orange between occipital margin and posterior ocelli; immaculate from occiput to base of mandible; rest of head, except occiput, yellow-white; antenna ( Fig. 77) with radicle yellow; scape with both faces blackish, only extreme apex and extreme distal yellow, dorsal margin black; pedicel dark brown in proximal half and apex white; F1-F4 brown, F5-F6 white, clava dark brown, becoming paler towards apex, apex white; occiput with dark brown area above occipital foramen, rest white; neck of pronotum dark brown, posterior margin translucent white, lateral spots relatively small and undistinct, rest white; dorsum of thorax orange; sides and posterior margin of mesoscutum and axillae bordered brown; setae translucent yellow, silvery in most lights; tegula white; metanotum pale brown; mesopleuron yellow; prosternum and mesosternum pale yellow; legs (Figs 80-82) mainly pale yellow; fore wing ( Fig.  79) hyaline, and with linea calva interrupted, venation dark yellow; hind wing hyaline; propodeum medially dark orange; gaster dorsally pale brown, becoming paler towards apex, side and venter white; ovipositor sheath yellow.
Ocelli forming an angle of about 50°; eye not quite reaching occipital margin, separated by much less than diameter of one facet; frontovertex subparallel-sided, becoming slightly broader anteriorly from the narrowest point which is slightly in front of posterior ocelli; scrobes shallow and U-shaped; antenna with scape about 2-2.5× as long as broad; funicle with F1-F4 smallest, subequal, F4 transverse, F5 a little larger but transverse, F6 largest; clava 3-segmented, its apex more or less rounded and with a short slightly oblique truncation; mandible relatively broad with three subequal, apical teeth; palpal formula 2-2 (Fig. 78), notaular lines reaching about 0.6× across mesoscutum; fore wing venation and setation as in Fig. 79; ovipositor (Fig. 83) hardly exserted, length about 5.4× as long as ovipositor sheath.
Male. (length 0.8-1.33mm). Thorax black-brown, ocellar area black-brown, antenna yellow-brown, clava solid and as long as F3 to F6. Digitus of genitalia apically with two hooks; aedeagus robust, length about 3× as long as broad. (Xu and Jiang 1990).  Diagnosis. Antenna with radicle yellow; scape with both faces blackish, only extreme apex and extreme distal yellow, dorsal margin black, scape about 2-2.5× as long as broad; ovipositor hardly exserted, length about 5.4× as long as ovipositor sheath. Jiang (1982) misidentified this species as M. tamakatakaigara, and Xu and Jiang 1990 described it as a new species. Metaphycus xujiangi is very similar to M. ericeri. It can be separated from M. ericeri as follows: head is about 5× as broad as frontovertex, POD=POL and the ovipositor about 0.7× as long as mid tibia (in M. ericeri, the head is about 3.5× as broad as frontovertex, 2POD=POL and the ovipositor about 0.6× as long as mid tibia).