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Revision of the World species of Xeris Costa (Hymenoptera: Siricidae)
CJAI 28 -- September 25, 2015
doi: 10.3752/cjai.2015.28
Henri Goulet1, Caroline Boudreault1 and Nathen M. Schiff2

8. Xeris malaisei Maa, new status

Fig. C8.1 (female habitus)

Fig. C8.2 (male habitus)

Xeris spectrum malaisei Maa, 1949: 88. Syntype females (TARI), examined by Henri Goulet. Though, Maa (1949) did not mention specifically a specimen as holotype, one of the two specimens from the same locality has a label identifying it as a holotype. The segregated specimen is labelled: [White] “TAIWAN TAIHEIZAN 9.v.1942 A. MUTUURA”; [White with black frame] “Xeris spectrum malaisei subsp. n. Holotype ♀ det. T. MAA 1949”; [red circle] “TARI”. Type locality, Taiwan, Taiheizan. Maa, 1950: 21; Cameron, 1965: 16; Chou & Naito, 1991: 91; Xiao et al., 1992: 42; Xiao, 2006: 200; Wei, et al,. 2006: 557; Schiff et al. 2012: 248..

Diagnostic combination

Among specimens with a light yellow cell C in the fore wing, with a white base of stigma on both sides of junction with vein 1r-rs, and with short setae (0.6–0.7 times as long as diameter of lateral ocellus) on the clypeus [malaisei, pallicoxae, spectrum, xanthoceros and xylocola], X. malaisei is recognized in both sexes by the wide smooth median area dorsally on the pronotum, in females by the reddish-brown color in apical 0.3 of antenna, and in males by the the dark brown or black metatarsomere 5.



Color. Head black except for white spot on gena dorsal to middle of eye; white spot basically oval, extending to genal ridge (Figs. B2.8 and as in B2.139); antenna black and reddish brown in apical 0.25–0.3 (B2.115); last maxillary palpomere black (Fig. B2.8). Thorax black except for white longitudinal band extending from posterolateral to anterolateral angles of pronotum including vertical portion of anterolateral angle, the band 0.4–0.7 times as wide as lateral 0.5 of pronotum and usually (at low elevation) extending to lateral margin of pronotum (as in B2.134). Coxae black and legs beyond coxae light reddish brown (Fig. C8.1) except in Taiwan where coxae, trochanters, diffused area in middle of metafemur, apical 0.5 of tarsomeres 1 and tarsomeres 2–5 brown (Fig. B2.108). Fore wing clear except for lightly tinted band in apical 0.25, and on posterior corner of cells 2CU and 3CU (Fig. B2.67); costal cell very light yellow (possibly bleached in old specimens) (as in Fig. B2.40); most of area ventral to anal cells yellowish brown; veins black (including veins C and R, but base of stigma on both sides of junction with vein 1r-rs white) (as in Fig. B2.40). Abdomen black (Fig. C8.1). Sheath with apical section black and basal section reddish brown.

Head. Distance between nearest eye edge and lateral ocellus edge about 1.1–1.5 times as long as distance between inner edges of lateral ocelli (as in Fig. C1.5). Setae on clypeus 0.6–0.7 as long as diameter of a lateral ocellus (Fig. B2.8). Eye in lateral view (N = 20) with its maximum height 1.2–1.6 times as long as its maximum length (Fig. B2.8), and maximum height of eye 0.44–0.53 times as long as maximum height of head (from transverse ridge on gena above mandible to top of head, measurements as in Fig. B2.8). Gena in dorsal view with maximum distance between outer edges clearly wider than maximum distance between outer edges of eyes (as in Fig. B2.41) (in frontal view outer edges of eyes clearly not intersecting genae) (as in Figs. B2.5), in lateral view with distance between outer edge of eye and genal ridge 0.32–0.54 times as long as maximum length of eye (Fig. B2.8, measurements as in Fig. B2.77), and with very small to moderate size pits (diameter of pit 0.05–0.2 times lateral ocellus diameter) between outer edge of eye and genal ridge (mainly near eye) (Figs. B2.8 and B2.131). Transverse ridge above mandible narrow, sharp and mainly smooth (as in Fig. B2.18), with few or no pits ventral to genal ridge. Vertex scarcely pitted and pits medium in size (diameter of pit 0.2–0.25 times lateral ocellus diameter), pits present from dorsoposterior edge of eye to occiput outside postocellar area, absent on most of postocellar area (as in Fig. B2.43); pits scattered and medium in size along all of shallowly outlined and gutter-like median furrow but a little more widespread near lateral ocelli (as in Fig. B2.43).

Thorax. Pronotum in lateral view with coarse polygonal pits on 0.3–0.7 of posterior surface (as in Fig. B2.97). Propleuron in lateral view basically with medium polygonal pits (as in Fig. C12.7); in ventral view generally with dense small teeth often in front of impressed pit with smooth surface in between (as in Fig. B2.22). Fore wing in middle 0.3 of vein 2A diverging very slightly away from wing edge (Fig. C8.3), and then more abruptly curved away from wing edge (Fig. C8.3); vein 3A absent (91%) or reduced to a stump (9%), not extending slightly as a short nebulous vein, and not extending along posterior margin of wing (N = 33).

Abdomen. Tergum 9 with meshes of microsculpture on ventral half above longitudinal furrow near center well impressed and sculpticells clearly scale-like (as in Fig. B2.92, insert); median basin with base (outlined by two lateral black longitudinal furrows; N = 6) 0.7–1.1 times as wide as its median length, with maximum width of basin 1.4–1.76 times as wide as its median length, and basin 0.43–0.47 times as long medially as median length of cornus (measurements as in Fig. A3.2). Cornus constricted in dorsal view, its minimum width (at constriction) about 0.8 times as wide as maximum width subapically (as in Fig. C1.15); with large teeth in apical 0.3 (as in Fig. B2.110). Sheath. Basal section 0.26–0.46 times as long as apical section (N = 32) (Fig. C8.1); lateral surface of apical section with well-defined ridge (as in Fig. B2.13, insert); length 1.2–1.4 times as long as fore wing length. Ovipositor. Lancet with 27–33 annuli (first 15 annuli hard to see, but still outlined; N = 15); junction of basal and apical sections of sheath aligned between 3rd–4th or 4th–5th annuli; major pits present on last 4–5 apical annuli before teeth annuli, and 8–20 preceding annuli with a with very small pit, on each the preceding annuli 2–14 (as in Fig. C1.18).


Color. Head with dorsal spot behind eye usually larger in size than in many females and extending between eye and genal ridge (Fig. B2.131). Pronotum with lateral longitudinal band narrower than in females (0.3 times as wide as pronotal half), the band becoming narrower posteriorly and not extending to lateral edge of pronotum (Fig. C8.2). Coxae black; trochanter generally black; pro- and mesofemur reddish brown to black, metafemur black; tibiae light reddish brown in basal 0.3 and sharply separated from black surfaces, protibia light reddish brown with a narrow to wide longitudinal band in apical 0.5 along outer 0.2–0.5 of dorsal surface and often with very narrow longitudinal inner band on dorsal surface with black in apical 0.5, mesotibia light reddish brown with black transverse band in apical 0.6, and metatibia black except for sharply outlined yellowish-white spot at base (Fig. C8.2 and for hind leg Fig. B2.123); pro- and mesotarsomeres 1 light reddish brown in basal 0.1–0.8 and black thereafter; tarsomeres 2, 3, 4 and 5 dark brown to black, metatarsomere 1 black (except reddish-brown base and extreme apex) (Figs. B2.119, B2.121 and C8.2).

Thorax. Fore wing in apical 0.3 of vein 2A not subparallel with wing edge and less abruptly curved away from wing edge and broadly curved in central section (as in Figs. C11.6). Metatibia with shallow notch on dorsal edge in basal 0.25 (Figs. B2.119).

Taxonomic notes

Until we studied the holotype and paratype females of X. malaisei, we did not associate them with the northern specimens from northern China, Korea, Japan and Russia. Maa (1949) stressed the color pattern of the femora. Maa (1950) reported a third female matching the first two. In Taiwan, the color pattern of the femora, trochanters, tarsi, and the marginal longitudinal band of the pronotum is darker than farther north in eastern Asia. The Taiwanese specimens are found at high elevation with a markedly increased precipitation which probably selects for dark specimens (Goulet 1986, see Geographical Variation under Dolerus yukonensis Norton). In Hokkaido, the northern major Japanese island, specimens at high elevation also have darker color patterns especially on the pronotum. For these reasons we do not put too much weight on color patterns.

Other structures were considered as more significant in studying both populations. The Taiwanese females share with those farther north the fore wing anal vein shape, the length of the apical section of the sheath relative to the basal section, the number of annuli with a small pits anterior to the apical annuli with large pits, the flagellum color pattern, and the sculpture of the lateral surface of the pronotum and of the propleuron. Therefore, we consider the populations of northern China, Korea, Japan, and adjacent Russia as conspecific with the Taiwanese population. We do not recognize them as subspecies.

Xeris malaisei females are distinguished from X. caudatus, X. melancholicus and X. pallicoxae by coxal and flagellum color, from X. caudatus and X. melancholicus by color at base of stigma at junction with vein 1r-rs and costal cell. Xeris malaisei females are distinguished from X. pallicoxae by a very small pit on many annuli preceding the typical apical annuli, by the macrosculpture on the longitudinal band and lateral surface of the pronotum and on the lateral surface of the propleuron, and in males by femur color. Xeris malaisei is also distinguished from X. spectrum by genal spot shape, in females by shape of fore wing vein 2A, and in males by the tarsi color pattern. X. malaisei is also quite similar to X. xanthoceros and X. xylocola. Females of both species have a flagellum that is more extensively light reddish brown than in X. malaisei. Both sexes of X. malaisei differ from these species by the shape of fore wing vein 2A.

Geographical variation

As noted under “Taxonomic Notes”, the females of Xeris malaisei from Taiwan are more darkly colored (e.g., black metafemur) than in the northern portion of the range. In the north at low elevations, the longitudinal marginal band may be very large (each band may be 0.5–0.7 as wide as the dorsal half of the pronotum) and in males tarsomere 1 is mainly pale in basal 0.3–0.8. However, in the mountains of Hokkaido, some specimens have narrow longitudinal bands on the pronotum that may not extend to the posterolateral angle (each band may be 0.2–0.4 as wide as the dorsal half of the pronotum) and in males tarsomere 1 is mostly black. It seems that the cooler the environment due to altitude and/or latitude the darker the specimens.

Hosts and phenology

Xeris malaisei probably has a wide host range. The reported hosts are Cryptomeria japonica (Cupressaceae) and Abies firma (Pinaceae) (Fukuda and Hijii, 1997).

Based on 53 field-collected specimens, the earliest and latest capture dates are May 30 and August 11. Fukuda and Hijii (1997) published their work under the name X. spectrum. Most likely their specimens refer this species, the most common species in Japan. In Japan, X. spectrum is very rare. Contrary to X. spectrum in Europe with only one major emergence period in late June, Fukuda et al. (1997) has shown that X. malaisei has two major and isolated emergence periods, in mid-May (late April to late June, N = about 225) and mid-August (August to late September, N = about 168) (C8.4).


CHINA (Jilin - Northeastern region). JAPAN (Hokkaido, Honshu). RUSSIA (Primorsky kray). SOUTH KOREA. TAIWAN (high elevation). Xeris malaisei has been intercepted at several ports. In United States, most intercepted specimens (6) originated from Japan and were recorded at ports on both coasts (California: Long Beach, Los Angeles, San Diego; Georgia: Savannah; Louisiana: Baton Rouge) and one specimen intercepted in New Orleans, Louisiana could have originated from China. In New Zealand all specimens (7) were intercepted from both islands (Dunedin, Napier and Wellington). The intercepted specimens came from crates pine cable drums, Cryptomeria japonica dunnage (a favorite host tree in Japan Fukuda and Hijii (1997)), and wood products.

Specimens studied: 44 females and 42 males from ANIC, CNC, FRNZ, NSMT, SDEI, and USNM.

Specimens for molecular studies: 8. See Fig. D1.2d. For each specimen the following is recorded: country, year, state/province, specimen code (in italics), and number of base pairs.

JAPAN: CBHR 1001, 658; CBHR 1002, 658; CBHR 1003 658; S79, 658; S10, 658; S92, 658; S218b, 658; S491, 658.

Table of contents Abstract Introduction Materials and Methods Biology Hosts Parasitoids Morphology Key DNA References Citation Appendices PDFs