Khamul, Gates, 2008

Gates, M. W., 2008, Description of Khamul, gen. n. (Hymenoptera: Chalcidoidea: Eurytomidae), with a hypothesis of its phylogenetic placement, Zootaxa 1898 (1), pp. 1-33 : 25-26

Khamul n. gen.

Type species: Khamul erwini Gates , by present designation.

Etymology: Named for the only Nazgl specifically named by J. R. R. Tolkein, Khaml, the Shadow of the East (aka Black Easterling) ( Tolkein 1980). Gender masculine.

Diagnosis: Four apomorphies support the monophyly of Khamul as defined herein: flagellomeres cylindrical and tightly appressed, parallel-sided, with decumbent setation (female only; Figs. 6, 7), apex of clava with elongate sensillar region ( Figs. 18, 45); deep notauli ( Fig. 22); reticulate scutellar boss present ( Figs. 22, 26). These are also shared with a taxon ( Eurytoma San Alberto) coded by Lotfalizadeh et al. (2007). Globally, all but one of these characters is homoplastic (i.e., scutellar boss), a common occurrence in Eurytominae due to its mosaic evolutionary trends ( Lotfalizadeh et al. 2007). The aforementioned characters may be used in combination with the following as a suite of characters for identifying Khamul : clypeus produced ventrally with apex broadly notched ( Fig. 15), prepectus ~3/4 size of tegula ( Figs. 36, 37), preorbital carinae continuous across vertex posterad anterior ocellus, pedicel roughly wedgelike in lateral view ( Fig. 13) (also seen in Eurytoma San Alberto ( Lotfalizadeh et al. 2007)), and infuscate wing ( Figs. 33, 55, 57). Khamul may be confused with the Philolema genus group ( Lotfalizadeh et al. 2007) with which it shares a depressed postgena at the oral fossa ( Fig. 39), the postgenal lamella (PGL) smoothly joining the posterior margin of the gena ( Fig. 39), and the supraclypeal area bound by two submedian carinae ( Fig. 38), but it can be reliably separated by the aforementioned diagnostics. It may also be confused with Aximopsis s.l. given that Aximopsis s.l. shares many characters with Philolema s.l. ( Lotfalizadeh et al. 2007): deep sublateral prepectal pit ( Fig. 68), mesopleuron with a long sloping ventral shelf (horizontal in Aximopsis s.l.) ( Fig. 80), ventral shelf medially projecting ( Fig. 23), subalar pit deep ( Fig. 36), procoxa with oblique carina delimiting basal reticulate depression (receives venter of head) ( Figs. 40, 47), and lateral and anteroapical surface umbilicate punctate. Khamul possesses a small sublateral prepectal pit, but it is usually not visible in lateral view due to the closely approximated pronotum and mesopleuron. This close approximation is typically not observed in other taxa sharing the pit (e.g., Philolema s.l., Axima , Chryseida , Aximopsis s.l.) because the prepectus is longer. The other characters seen in Philolema s.l. (ITS not dorsally produced and flat LFP, both homoplastic; see character descriptions), more useful for separating it from Aximopsis s.l., are absent in Khamul . Khamul has the ITS not produced, the LFP convex, and a simple change of sculpture and a slight angulation along the track on which the procoxal carina occurs in Philolema s.l., Axima , Chryseida , and Aximopsis s.l.

In the key to eurytomid genera of Burks (1971), Khamul runs to couplet 25 whereupon it splits the diagnostic characters. In the first half of the couplet, Khamul possesses a reduced prepectus, smaller than the tegula, and has the epicnemium impressed to receive the procoxae; however, the antennae are sexually dimorphic and have only 10 segments in the female (if the fused clava is counted as one, 12 if not) and 11 in the male. Proceeding through the second half of the couplet, ignoring the prepectal character, couplet 43 is ultimately reached where Bephratelloides and the Eurytoma complex key. Khamul has six funiculars, a solid clava, and infuscate fore wing much like Bephratelloides , but differs in that Khamul has a smaller prepectus, black coloration, preorbital carina, scutellar boss, and cylindrical antenna. Bephratelloides has a large, triangular prepectus, largely golden/orange coloration, no preorbital carina or scutellar boss, and non-cylindrical antenna.

Description. Female. Length 3.3–5.3 mm. Head, body, and coxae black, non-metallic. Scape black; pedicel mostly black, especially basally, often dark brown apically; flagellum dark brown to blackish. Tegula pale brown or black. Pronotum brown on anterolateral panel. Legs and pretarsus brown, except extreme apices of femora, tibiae, and tarsomeres whitish, generally darker basally and lightening apically ( Fig. 1). Sculpture generally umbilicate with interstices alveolate ( Figs. 1, 22, 26, 37).

Head ( Figs. 1, 15, 16, 19, 20, 38, 39, 41, 43, 44, 48, 54, 60, 65). Umbilicately punctate dorsally, laterally, and anteriorly, 1.40–1.43X as broad as high. Lower tentorial pits small; two submedian carinae extending ventrally from toruli and connecting with smooth supraclypeal area ( Fig. 38); genal carina present, eye 1.8–3.4X as high as malar space ( Figs. 38, 54); scrobal depression carinate laterally, carina usually distinct dorsally ( Fig. 41), depression minutely elevated medially in dorsal half ( Fig. 41); mandible with lower and middle teeth acute, upper tooth rounded; clypeus produced ventrally, apical margin broadly emarginate ( Figs. 15, 16); preorbital carinae present, extending medially between anterior and lateral ocellus to meet posterad anterior ocellus ( Figs. 38, 65). Posterior surface of head with postgenal lamina, postgenal grooves evidently ridged, divergent ventrally, extending beyond upper margin of hypostomal bridge; dorsal margin of lateral foraminal plate visible, convex; postgenal sulci vestigial; postgenal depression present ventrally between hypostomal fossa and genal carina; postgenal bridge ornamented with digitiform expansions ( Fig. 48). Antenna ( Figs. 6, 7). Scape reaching dorsal margin of anterior ocellus. Pedicel wedge-shaped in lateral view, with strong basal bottle-neck, narrowed ventrally; anellus very thin, closely appressed to F1 ( Fig. 13); F1–6 cylindrical, tightly appressed, parallel-sided, each F with multiple rows of multiporous plate sensilla and dense, decumbent setation; claval segments fused, apex with elongate sensillar area ( Figs. 18, 45).

Mesosoma ( Figs. 1, 22, 23, 26, 36, 37, 46, 56, 66, 67). Pronotum 1.74–2.0X as broad as long. Mesoscutal midlobe 0.75–1.27X as broad as long; notauli complete, narrow and deep ( Fig. 22) (except not deeply impressed in K. lanceolatus ). Lateral lobe of mesoscutum finely reticulate in anterior half, separated by steplike ridge from umbilicately punctate posterior half ( Fig. 37). Scutellum 0.67–0.72X as broad as long at its widest; broadly convex dorsally, with scutellar boss dorsomedially ( Figs. 22, 66). Dorsellum glabrous except for anterolateral row of setae ( Figs. 3, 4, 56). Lateral panel of propodeum and callus umbilicately punctate, separated from median area by carinae ( Fig. 3, 4, 46), carinae bordered medially by row of umbilicate punctae, median channel formed by irregular foveae bordered by smaller, shallower punctae ( Fig. 3, 4, 46), propodeal angle relative to longitudinal axis mesosoma>90 but <130; lateral prepectus triangular, broadly rounded apically, smooth; sublateral prepectal concavity present, obscured by appressed mesopleuron and pronotum; ventral prepectus with median flange ( Fig. 58), depressed along posterior margin ( Fig. 23); epicnemium flattened, with superficial submedial, shallow depressions to receive procoxae ( Fig. 23), discrimen visible as anteromedial ovate depression, in anteroventral view with ventral shelf bearing a projection inserted between apices of procoxae ( Fig. 23); mesopleural shelf horizontal. Procoxa slightly depressed anteriorly, anterobasally and posteriorly reticulate ( Figs. 40, 47), anteroventrally and laterally umbilicately punctate ( Fig. 47). Mesocoxa glabrate to finely reticulate; mesocoxal foramina narrowly open posteriorly ( Fig. 23). Forewing ( Figs. 33, 53, 55) usually infuscate at least along anterior margin ( Figs. 33, 55, 57), venation brown, setae on disk dark, absent in basal 1/3 except for basal setal line and cubital setal line, basal cell with 2–3 setae near apex ( Figs. 30, 31, 33); postmarginal vein ranging from 1.4–2.7X length marginal vein and stigmal 0.70–2.4X length of marginal vein.

Metasoma ( Figs. 1, 42). Petiole 3.0–4.0X as broad as long in dorsal view, some fine sculpturing laterally and ventrally, glabrous; anterior transverse carina protruberant laterally, paired submedian carinae ventrally define triangular fovea (except see K. lanceolatus description) ( Figs. 49, 59). Gaster ovate in lateral view, slightly acuminate posteriorly; all terga with some effaced reticulation, increasingly defined posteriorly, asetose along midline; Gt1 with paired depressions dorsad petiole, line of three+ setae dorsolaterally in posterior half ( Figs. 42, 49); Gt3–4 setose dorsolaterally in posterior half; Gt5 nearly entirely setose; syntergum completely setose.

Male. Similar to female in coloration and structure except as follows: five funicular segments and a twosegmented clava ( Figs. 50, 61); funiculars pedicellate with whorls of setae on dorsal surface basally and apically, except F5 with strong basal whorl only; and apex of each funicular body angled ( Figs. 63, 69). Petiole roughly as broad as long in dorsal view, with anterodorsal margin carinate ( Fig. 53) dorsolateral margin finely carinate.