header image
Siricidae (Hymenoptera: Symphyta: Siricoidea) of the Western Hemisphere
CJAI 21, July, 2012
doi: 10.3752/cjai.2012.21
Nathan M. Schiff, Henri Goulet, David R. Smith, Caroline Boudreault, A. Dan Wilson, and Brian E. Scheffler

Xeris tropicalis Goulet, n. sp.

Fig. C46.1 (female habitus)
Fig. C41.3 (map)

Xeris tarsalis; Smith, 1978: 89; Smith, 1988: 243 (not Cresson, 1880: 52).

Diagnostic Combination

Both sexes of X. tropicalis are easily recognized by the broad rounded and coarsely pitted transverse ridge dorsal to the mandible, the widespread and dense pits on the head dorsally, and the pits on the gena ventral to the genal ridge continuous with pits on the occiput.



Color. Head and thorax black except for white spot extending from dorsal edge of eye to surface between genal ridge and outer edge of eye (Fig. C46.1); antenna black but 7 apical antennomeres reddish brown. Pronotum in dorsal view with small white spot on anterolateral corner. Legs black except yellow at extreme apex of femora, basal 0.2 of tibiae, and base of tarsomere 1 (Fig. C46.1). Wings very darkly tinted except for clear base of hind wing, veins black (including veins C and R, and vein 1r-rs near junction with stigma). Abdomen segment 1, lateral surface of tergum 2 and sternum 2 black; segments 2–10 reddish brown except for black apical section of sheath.

Head. Eye in lateral view (one specimen measured) with maximum height 1.23 times as long as maximum length, and maximum height of eye 0.51 times as long as maximum height of head (from transverse ridge on gena above mandible to top of head) (Fig. B5.6). Gena in dorsal view with maximum distance between outer edges hardly wider than maximum width between outer edges of eyes (in frontal view, outer edges of eyes not intersecting genae, but very close to them), and in lateral view distance between outer edge of eye and genal ridge 0.42 times as long as maximum length of eye (Fig. B5.6). Transverse ridge above mandible broad, rounded and coarsely pitted (Fig. B5.20). Head in dorsal view with pits dense and widespread, but absent along weakly outlined furrow behind lateral ocelli, in lateral view pits numerous on gena ventral to level of eye and genal ridge, and pitted area of gena broadly connected to pitted area of occiput.

Thorax. Fore wing vein 3A reduced to a stump or absent.

Abdomen. Median basin of tergum 9 with base (outlined by two lateral black longitudinal furrows) 0.8 times as wide as median length of basin, with maximum width of basin 1.7 times as wide as median length, and basin 0.45 times as long medially as median length of cornus. Cornus constricted in dorsal view, its minimum width (at constriction) 0.85 times as wide as maximum width subapically. Sheath. Length 0.9 times as long as length of fore wing; basal section 0.4 times as long as apical section (Fig. B5.12); lateral surface of apical section with well defined ridge (as in Fig. B5.13, see insert). Ovipositor. Lancet with 31 annuli (first 14 annuli outlined but difficult to see); junction of basal and apical sections of sheath aligned between 4th and 5th annuli; major pits present on last 6 annuli before teeth annuli, and two preceding annuli with very small pits.



Type material

Holotype female (CNC), in perfect condition except left antenna broken and glued on label; labeled: [White] “6 mi.N.E. San Cristobal L. C., Chis. Mex. V.19 1969 H. E. Howden”, [White & black frame] “Xeris tarsalis (Cr.) D. R. Smith 75”, [Red] “HOLOTYPE Xeris tropicalis Goulet CNC No. 23908”. Type locality: Mexico, Chiapas, San Cristobal de las Casas.

Origin of specific epithet

Xeris tropicalis is the southernmost record of Xeris and the specimen is clearly in a tropical region. The name tropicalis stress this aspect. The name is an adjective.

Host and Phenology

The host of X. tropicalis is unknown but conifers are suspected. The single female was captured in mid May.


Xeris tropicalis is only known from the type locality in southernmost Mexico (Fig. C41.3).