Euxiphydria Semenov & Gussakovskij

Smith, David R. & Shinohara, Akihiko, 2011, Review of the Asian wood-boring genus Euxiphydria (Hymenoptera, Symphyta, Xiphydriidae), Journal of Hymenoptera Research 23, pp. 1-22 : 2-3

Euxiphydria Semenov & Gussakovskij

Euxiphydria Semenov & Gussakovskij, 1935: 117. Type species: Xiphydria potanini Jakovlev 1891, by original designation.

Diagnosis.

Species are typically black with a contrastingly orange or mostly orange head ( Figs 1 , 13 , 23 , 30 , 37 ). Antenna with 13-19 antennomeres, middle antennomeres dilated and compressed ( Fig. 29 ). Head polished and shiny on upper genae and vertex to about level of lateral ocelli, variously sculptured on frons below lateral ocelli; in front view, inner margins of eyes parallel to slightly diverging below, lower interocular distance 1.4-1.7 × eye height ( Figs 4 , 18 , 28 , 34 , 41 ); head from above with distance behind eyes about equal to ( Figs 3 , 40 ) or longer than eye length ( Figs 17 , 27 , 33 ); area posterior to upper orbits in profile usually longer than eye length; both mandibles 4-dentate; maxillary palpus ( Figs 20 , 35 ) slender, with four palpomeres; labial palpus ( Figs 20 , 35 ) with three palpomeres, first two palpomeres slender and third palpomere dilated, oval, with sensory pit. Forewing ( Figs 1 , 23 , 36 ) with cell R closed, vein 2A+3A complete. Hind wing ( Figs 1 , 23 , 36 ) with cell R closed, cells Rs and M present; anal cell present, petiole subequal to width of cell. Tarsal claws with long inner tooth near center of claw, about half length of outer tooth; claw of hind legs larger than those of fore- and midlegs. Tergite 10 posteriorly tubuliform, strongly protruding caudad.

Discussion.

The above combination of characters will separate Euxiphydria from other xiphydriid genera. The only other genus with four maxillary palpomeres and three labial palpomeres is Carinoxiphia Wei (in Wei and Xiao 1999). In Carinoxiphia , the third labial palpomere is slender, the same width as the first two palpomeres, the radial cell of the forewing is open at its apex, the tarsal claws have a minute inner tooth, and the wings are hyaline. Other xiphydriid genera have a different palpomere formula, commonly with three or five maxillary palpomeres, have a slender third labial palpomere, are usually black with various white, yellow, or orange markings, the eyes are larger, commonly converging with the lower interocular distance equal to or shorter than the eye height, the head behind the eye in dorsal view is commonly strongly narrowing with the distance behind the eyes shorter than the eye length, the antennae various but commonly filiform, and the tarsal claws may be simple or with the inner tooth nearly as long as the outer tooth and close to the outer tooth.

Four species were described prior to 1938, Xiphydria potanini Jakovlev, 1891, Xiphydria ruficeps Mocsáry, 1909, Xiphydria ruficeps Matsumura, 1912, and Xiphydria maidli Zirngiebl, 1937. When describing the genus, Semenov and Gussakovskij recognized and separated two species, Euxiphydria potanini and Euxiphydria ruficeps (= ruficeps Matsumura), and Gussakovskij (1935) recognized and separated the same two species. Takeuchi (1938) treated two species from Japan, Euxiphydria ruficeps ( = potanini, ruficeps Matsumura, akazui Matsumura, and maidli Zirngiebl) and Euxiphydria leucopoda , a second species described from Japan with a new form, which he called Euxiphydria leucopoda var. nakanishii. Maa (1944) keyed four species, his newly described Euxiphydria atriceps and Euxiphydria subtrifida , as well as Euxiphydria potanini and Euxiphydria ruficeps . Later, Maa (1949) transferred Euxiphydria leucopoda , Euxiphydria nakanshii , and Euxiphydria atriceps to Hyperxiphia Maa, and recognized Euxiphydria potanini , Euxiphydria ruficeps , Euxiphydria subtrifida , and Euxiphydria maidli . He also proposed a new subfamily, Euxiphydriinae , including only Euxiphydria . The only subsequent species described was Euxiphydria pseudoruficeps Okutani, 1966, from Taiwan. The catalogs by Smith (1978) and Taeger et al. (2010) have followed Takeuchi (1938) and Stroganova (1968) by regarding Euxiphydria potanini as a variable species and including Xiphydria ruficeps Mocsáry, Xiphydria ruficeps Matsumura, Xiphydria akazui , and Xiphydria maidli as synonyms, and listing two other species, Euxiphydria subtrifida Maa and Euxiphydria pseudoruficeps as distinct species. Here, we recognize five species, the more common Euxiphydria potanini with synonymy as given by Smith (1978) and Taeger et al. (2010), but also proposing Euxiphydria subtrifida as a new synonym, placing Euxiphydria leucopoda back into Euxiphydria , recognizing Euxiphydria pseudoruficeps as a distinct species, and describing two new species, one from China and one from Vietnam.

Key to species

1	Legs entirely black; abdomen black ( Figs 13 , 24 , 37 )	2
-	Legs entirely white or black with basal third of hind tibia and hind basitarsomere white; abdomen with white spot laterally on eighth tergite ( Figs 2 , 30 )	4
2	Head orange with frons from about level of lateral ocelli to clypeus black ( Figs 17, 18 ); frons densely rugose ( Fig. 18 ); axilla and mesoscutellum reticulate ( Fig. 15 ); wings black, paler toward apex ( Fig. 16 )	Euxiphydria potanini (Jakovlev)
-	Head entirely orange ( Figs 27, 28 , 40, 41 ); frons with irregular carinae at least close to antennal toruli ( Figs 28 , 41 ); axilla and mesoscutellum with irregular longitudinal carinae ( Figs 26 , 39 ); wings almost hyaline to very slightly, uniformly infuscate ( Figs 23 , 36 )	3
3	Head from above narrowing behind eyes, distance behind eyes equal to eye length ( Fig. 40 ); sculpture on frons reticulate in front of ocelli with carinae close to antennal toruli ( Fig. 41 ); carinae on mesepimeron short, irregular ( Fig. 38 )	Euxiphydria shaanxiana , sp. n.
-	Head from above gently curved behind eyes; distance behind eye much longer than eye length ( Fig. 27 ); sculpture on frons consisting of more or less parallel carinae, without reticulations ( Fig. 28 ); carinae on mesepimeron long, straight, almost parallel ( Fig. 25 )	Euxiphydria pseudoruficeps Okutani
4	Legs white, apical tarsomeres brownish ( Fig. 2 ); frons reticulate ( Fig. 4 ); head from above strongly narrowing behind eyes, distance behind eye less than eye length ( Fig. 3 ); axilla and mesoscutellum with irregular, longitudinal carinae, smooth and shiny laterally and posteriorly ( Fig. 5 )	Euxiphydria leucopoda Takeuchi
-	Legs black with basal third of hind tibia and hind basitarsomere white ( Fig. 30 ); frons with almost parallel carinae ( Fig. 34 ); head from above straight behind eyes, distance behind eye much longer than eye length ( Fig. 33 ); axilla and mesoscutellum entirely sculptured, reticulate ( Fig. 32 )	Euxiphydria vietnamensis , sp. n.

Figures

Figures 1 - 6. Euxiphydria leucopoda, holotype 1 Dorsal view 2 Lateral view 3 Head, dorsal view 4 Head, front view 5 Thorax, dorsal view 6 Thorax, lateral view.

Figures 13 - 15. Euxiphydria potanini 13 Lateral view 14 Thorax, lateral view 15 Thorax, dorsal view.

Figures 23 - 24. Euxiphydria pseudoruficeps, holotype 23 Dorsal view 24 Lateral view.

Figures 30 - 35. Euxiphydria vietnamensis, holotype 30 Lateral view 31 Thorax, lateral view 32 Thorax, dorsal view 33 Head, dorsal view 34 Head, front view 35 Mouthparts (labial palpus on right, maxillary palpus on left).

Figures 36 - 37. Euxiphydria shaanxiana, holotype 36 Dorsal view 37 Lateral view.

Figures 25 - 29. Euxiphydria pseudoruficeps, holotype 25 Thorax, lateral view 26 Thorax, dorsal view 27 Head, dorsal view 28 Head, front fiew 29 Antenna.

Figures 7 - 12. Hyperxiphia nakanishii, holotype 7 Dorsal view 8 Lateral view 9 Head, dorsal view 10 Head, front view 11 Thorax, dorsal view 12 Thorax, lateral ivew.

Figures 16 - 20. Euxiphydria potanini 16 Dorsal view 17 Head, dorsal view 18 Head, front view 19 Head, lateral view 20 Mouthparts (labial palpi above, maxillary palpi below).

Figures 38 - 41. Euxiphydria shaanxiana ,, holotype 38 Thorax, lateral view 39 Thorax, dorsal view 40 Head, dorsal view 41 Head, front view.