Metaphycus nadius (Walker, 1838)

Wang, Ying, Li, Cheng-De & Zhang, Yan-Zhou, 2013, A taxonomic study of Chinese species of the alberti group of Metaphycus (Hymenoptera, Encyrtidae), ZooKeys 285, pp. 53-88 : 71-73

Metaphycus nadius (Walker, 1838) Figs 58-62

Encyrtus nadius Walker, 1838: 423. Lectotype ♀ (BMNH, examined), designated by Bouček and Graham (1978: 230), England.

Encyrtus syllaeus Walker, 1838b: 426. Lectotype ♂ (designated by Bouček and Graham 1978: 230), England, BMNH, examined. Synonymized by Guerrieri and Noyes 2000: 158.

Aphycus pinicola Mercet, 1917: 135. Lectotype ♀ (designated by Noyes 1981: 168), Spain, IEEM. Synonymized with nadius by Guerrieri and Noyes 2000: 158.

Aphycus (Euaphycus) pinicola Mercet; Mercet 1921: 205.

Euaphycus intermedius Mercet, 1925: 24. Synonymized with nadius by Guerrieri and Noyes 2000: 158.

Euaphycus callunae Alam, 1957: 433. Holotype ♀, England, BMNH. Synonymized with nadius by Guerrieri and Noyes 2000: 158.

Euaphycus duplus Chumakova, 1961: 324. Synonymized with nadius by Guerrieri and Noyes 2000: 158.

Metaphycus intermedius (Mercet): Trjapitzin 1975: 8.

Metaphycus callunae (Alam); Trjapitzin 1975: 13.

Metaphycus pinicola (Mercet); Trjapitzin 1975: 14.

Metaphycus duplus (Chumakova); Trjapitzin 1975: 14.

Metaphycus nadius ; 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.

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.

Relative measurements: HW 12, FV 3, FVL 4, POL 1.5, AOL 2, OOL 1, OCL 0.5, POD 1, AOD 1, EL 9, EW 5, MS 3, SL 6, SW 2, FWL 32, FWW 15, HWL 22, HWW 4, OL 11, GL 2.5, MT 10.

Male. Almost identical to female in general structure, habitus and coloration except for solid clava, genitalia.

Hosts.

Asterolecanium sp.; Asterolecanium minus ; Chionaspis pinifoliae ; Diaspidiotus bavaricus ; Metaphycus gigas ; Metaphycus zonatus ; Phenacaspis pinifoliae ; Quadraspidiotus bavaricus ; Quadraspidiotus gigas ; Quadraspidiotus perniciosus ; Quadraspidiotus zonatus ; Sphaerolecanium prunastri .

Distribution.

China (Heilongjiang, Inner Mongolia, Qinghai); Croatia, Czech Republic, England, Finland, France, Greece, Hungary, Italy, Netherlands, Poland, Portugal, Wales, Russia, Slovakia, Spain, United Kingdom.

Material examined.

China: 1♀, Inner Mongolia: Darhan Maomingan Allied county, 1979.VIII.1 (IZCAS); 7♀♀, 13♂♂, Qinghai Geermu, 2007.VII.4-5 (IZCAS), England: 1♀, 1985, Coll. S. M. Alam (BMNH); 1♀, Richmond Park, Surrey, 1996.VII.18, Coll. J. Noyes (BMNH).

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 Metaphycus 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 Metaphycus hubai , both with a small infuscate area below marginal and stigma veins.