Afrotremex pallipennis, Goulet, 2014

Goulet, Henri, 2014, Revision of the African horntail genus Afrotremex (Hymenoptera: Siricidae), Zootaxa 3795 (3), pp. 201-254 : 237-239

5. Afrotremex pallipennis n. sp.

Fig. T5.1 (female habitus); M3a–M3e (morphology); K1, K3a, K4a, K5, K16, K17b, K24, K24b, K26, K28, K30, K32, K34 (keys); T1.2, T5.2–T5.7, T5.9 (description).

Map (T1.26), red triangle

Type material. Holotype female ( MRAC) in good condition but antennomeres missing beyond 4 on the left and 7 on the right, labeled [ White ] “Musée du Congo, [ Democratic Republic of the Congo] Bambesa 1-iv-1937 J. Vrydagh ”; [White] “ Afrotremex ♀ hyalinatus Mocs. J. Pasteels det., 1950; [Red] “ HOLOTYPE Afrotremex pallipennis ♀ H. Goulet, 2013 ”.

Paratype. 1 female. Democratic Republic of the Congo: Lulua : Kapanga ix-1932 F. G. Overlaet (1 F, MRAC) .

Diagnosis. Among species with concave outlined lateral edge of submedian band in posterior 0.5 ( A. violaceus ), adults of A. pallipennis are distinguished from those of A. violaceus by a longitudinal row of large pits (about 0.25 times as large as diameter of lateral ocellus) along the middle line in anterior 0.3 of median band, and in female, by a large and clear area at the centre of the fore and hind wings.

Comparative diagnosis. Afrotremex pallipennis is most similar A. violaceus . It is unique in the following 2 features: extent of the clear pattern of the fore and hind wings; and position and wide extent of the shiny surfaces on terga 4–8.

Afrotremex pallipennis shares with A. violaceus the following ten features: a row of fused pits in lower 0.5 of gena; size of the sensory oval on the dorsal surface of flagellomere 11; relative size of the median band at its narrowest; presence of many pits anterolaterally on the lateral band of mesoscutum; width of the lateral extension of small pits of the median band of the mesoscutum posterior to submedian band; presence of widespread sculpticells in the scutoscutellar furrow; size of the shiny surface on tergum 8; absence of microsculpture around most pits on most of surface above the lateral longitudinal furrow of tergum 9; absence of pitted sculpticells between pits on the dorsal surface of tergum 10; distribution of teeth posterior to lateral tooth on lateral surface of tergum 10; and width and length of the pit on annulus 2.

Afrotremex pallipennis is distinguished from A. violaceus by all the unique attributes mentioned above and the four following features: extent of dense pits on the vertical lateral surface of pronotum; presence of large median row of large pits in the anterior 0.5 of the median band of mesoscutum; color pattern of the pro- and mesotrochanters in apical 0.3; extent of the clear pattern on the fore and hind wings; and position and extent of shiny surfaces on terga 4–8.

Afrotremex pallipennis is distinguished from A. hyalinatus by all the unique attributes mentioned above and the eleven following features: density and size of pits on gena; shape of setae at their apex and their relative length on clypeus, frons and postocellar area; size of sculpticells on the dorsal surface of pronotum between shiny teeth; sculpticells distribution on the anterior 0.3 of the median and submedian bands of mesoscutum; sharpness of the lateral edge of the submedian band, convergence of its edge in anterior and posterior 0.5, the curvature of its edge in posterior 0.5; size and number of shiny teeth centrally and size of pits along the anterior margin of axilla; position and extent of shiny surfaces on terga 5–8; extent of the shiny surface along the median area anteriorly on tergum 8; median ridge prominence in the median basin of tergum 9; density and size of pits on sterna 2–6; and length and width of pits on at least annulus 2 and 10 of the ovipositor.

Afrotremex pallipennis shares with A. hyalinatus the following nine features: size of the sensory oval surface on the dorsal surface of flagellomere 2; a row of fused pits in lower 0.5 of gena; size of the sensory oval on the dorsal surface of flagellomere 2; relative width of the median band at its narrowest; width and extent of the pitted surface of the median band of the mesoscutum posterior to submedian band; abundance of pits on anterolateral corner of the lateral band of mesoscutum; extent of sculpticells in the scutoscutellar furrow; absence of pitted sculpticells in pits on the median dorsal surface of tergum 10; distribution of pits on dorsal surface of tergum 10; and shape of the pit on annulus 2.

Afrotremex pallipennis is distinguished from A. xylophagus by all the unique attributes mentioned above and the six following features: organization of pits in a row along a line between the lower eye margin and the occiput, and of sculpture at the bottom of these pits; sharpness of the outline of the lateral edge of the submedian band of mesoscutum; curvature of the lateral edge of submedian band of mesoscutum in ventral 0.5; lateral extent of pitted surface of the median band of the mesoscutum posterior submedian band; extent and position of the shiny surface on terga 4–8; extent of shiny surface along the median area anteriorly on tergum 8; and median ridge prominence in the median basin of tergum 9.

Afrotremex pallipennis shares with A. xylophagus the following nine features: size of the sensory oval surface on the dorsal surface of flagellomere 2; relative width of the median band at its narrowest; lateral extension of the median band pits posterior to submedian band; presence of many pits on anterolateral corner of the lateral band of mesoscutum; presence of widespread sculpticells in the scutoscutellar furrow; absence of microsculpture laterally on tergum 8; absence of pitted sculpticells in and around pits on the median dorsal surface of tergum 10; distribution of pits anteriorly on tergum 10; and size of the pit on annulus 2 of the ovipositor.

Afrotremex pallipennis is distinguished from A. comatus and A. opacus by all the unique attributes mentioned above and the twelve following features: organization of pits in a row along a line between lower eye margin and occiput, and presence of sculpture at the bottom of these pits; size of sensory oval on the dorsal side of flagellomere 2; sharpness of the outline of the lateral edge of the submedian band of mesoscutum; curvature of the lateral edge of submedian band of mesoscutum in ventral 0.5; width of the median band of the mesoscutum at its narrowest; lateral extension of fine pits of the median band posterior to the submedian band of mesoscutum; number of pits on the anterolateral corner of the lateral band of the mesoscutum; extent of microsculpture on the scutoscutellar furrow; extent and position of the shiny surface on terga 5–8; pitted sculpticells in and around pits on most of surface of tergum 9 above the lateral longitudinal furrow; distribution of pits along the anterior surface of tergum 10; extent of pitted sculpticells on the dorsal surface of tergum 10; and length and width of the pit on annulus 2 of the ovipositor.

Description of female. COLOR. Fore wing darkly tinted with a dark purple hue (may be difficult to see) in the following cells (cells codes as in Fig. M1): C, R, 1Cu (except for a small clear spot posteroapically), 1A (except for clear spot in apical 0.5), 1M (small spot anterobasally), 2Cu (small spot anterobasally), 1R1, 2R1 (small basal spot), 3R1 (anterior 0.5 lightly tinted); apical 0.2 of wing lightly tinted, the remaining cells clear (Fig. K34). Hind wing darkly tinted with a dark purple hue (may be difficult to see) in the following cells (cells codes as in Fig. M1): C, R (spot in basal 0.4), 1Cu (spot in basal 0.4), most of anal lobe (except for clear central spot); the remaining cells clear (Fig. K34). Protrochanter and mesotrochanter ventrally in apical 0.3 light reddish brown (Fig. T5.6).

HEAD. Gena with large pits forming a curved broad furrow between lowest eye edge to occiput, the pits fused completely and bottom of each pit consisting of irregular fine ridges (Fig. T5.4); the remaining surface with pits less dense near mandible and scattered in dorsal 0.5, pits in ventral half 0.2–0.3 times and in dorsal half at most 0.2 times as large as lateral ocellus (Fig. T5.4). Setae on clypeus, frons and postocellar area truncate or very slightly enlarged apically (about 1.5 times as wide as setal shaft or truncate), and on frons 1.5–2.0 times as long as diameter of lateral ocellus (as in Fig K14, insert). Pedicel about 0.9 times as long as wide (as in Fig. T1.4). Flagellomere 2 with sensory oval covering about 0.5 of dorsal surface (Fig. K1).

THORAX. Pronotum with vertical lateral surface very densely pitted in posterior 0.3 (Fig. T5.3); dorsal surface around major shiny teeth with short ridges followed by deep and dense pits, the pits with irregularly defined edges (worm-like) of various heights and about 0.1 as large as diameter of lateral ocellus (Fig. T5.2); in lateral view, dorsal surface without long setae or with some very short setae (as in Fig. K46). Mesoscutum with median band generally with fine microsculpture, widest anteriorly, and at its narrowest the band about 0.7 times as wide as diameter of lateral ocellus (Fig. K16); pits without microsculpture at bottom, very deep, their edges irregularly defined (worm-like), and 0.1–0.15 times as large as diameter of lateral ocellus; with large pits (about 0.25 times as large as diameter of lateral ocellus) on anterior margin and extending along middle line in anterior 0.3 (Fig. K24b), and with pits becoming slightly smaller (at most 0.1 times as large as diameter of lateral ocellus) in posterior 0.5 and extending laterally posterior to submedian band (Fig. K3a). Submedian band in anterior 0.1–0.3 without pitted sculpticells inside pits; band sharply outlined along lateral edge, edge convergent in anterior and posterior halves and clearly concave in posterior 0.5 (Fig. K16). Lateral band shiny with many pits (>10) fused on anterolateral corner (Fig. K4a). Scutoscutellar furrow with convex sculpticells (sculpticells clearly with metallic hue) over all of surface (Fig. K17b). Axilla with large scallop-like pits similar to those on submedian band but somewhat smaller, not connected with small pits from submedian band along edge anteromedially (at most with some wrinkles) (Fig. K3a), and without small pits (similar to those of median band) along anterior margin (Fig. K17b).

ABDOMEN. Terga 1–3 with deeply pitted sculpticells (surface matt). Terga 4–8 with shiny areas (microsculpture meshes absent or very lightly impressed). Tergum 5 shiny in anterior 0.25 medially; tergum 5 shiny in anterior 0.5 medially; tergum 6 shiny in anterior 0.8 medially; tergum 7 shiny in anterior 0.9 medially (Fig. K26); and tergum 8 shiny in posterior 0.85 with a short anterior extension medially(Fig K5 and K28). Tergum 9 with median basin of bearing about 20 crescent-shape teeth on each side on central portion, each tubercle with or without seta posteriorly; seta when present as small as size of shiny tubercle; longitudinal median ridge of median outlined but not prominent, suggested posteriorly, or absent; median basin with a small shiny central spot; median basin slightly longer than wide (maximum width/ maximum median length: 0.90–1.00) (Fig. T5.5). Tergum 9 in lateral view above longitudinal furrow (only surface with setae centrally) with clearly outlined pits smooth at bottom in ventral 0.3 and with some pitted sculpticells at bottom in dorsal 0.7 (Fig. T5.9). Tergum 10 in dorsal view widely pitted (about 0.75 times as wide as posterior width of median basin of tergum 9); each pit shiny at bottom (surface between pits with microsculpture except centrally); pitted surface extended medially to but reaching anterior edge (Fig. K30); lateral surface posterior to lateral tooth shiny and without large teeth (Fig. K32); surface anterior to lateral tooth with distinctly outlined pits bordered by shiny ridges, each pit small and with pitted sculpticells except at center of pit (Fig. K32). Ovipositor annulus 2 (Fig. T5.7, base) and probably annulus 10 [ovipositor missing after annulus 7, probably as in Fig. T6.8] each with one wide pit as long as annulus; each pit clearly folded dorsally and sharply ventrally, and hardly tapering anteriorly.

Taxonomic notes. Despite being very similar females of A. violaceus and of A. pallipennis show marked differences in wing color pattern. The wings of A. pallipennis have the largest extent of clear areas in the species studied whereas those of A. violaceus are darkly tinted throughout. Guiglia (1937) studied the specimen from Kapanga and noticed marked differences in the sculpture on the head and the abdominal terga between it and the holotype of A. hyalinatus . She chose to retain this specimen under the name A. hyalinatus . Pasteels (1951) saw this specimen and one more from Bambesa and accepted Guiglia’s conclusion, without additional comments.

Origin of specific epithet. From Latin meaning “pale wing” referring to the large clear portion of the fore wing.