Afrotremex xylophagus, ♀ H. Goulet, 2014

Goulet, Henri, 2014, Revision of the African horntail genus Afrotremex (Hymenoptera: Siricidae), Zootaxa 3795 (3), pp. 201-254 : 246-253

7. Afrotremex xylophagus n. sp.

Fig. T7.1 (female habitus); K6, K9, K17a, K19, K22, K36, K38, K39b, K40b, K42, K44 (keys); T7.3–T7.9 (description).

Fig. T7.2, (male habitus); T1.21, T7.10–21 (description).

Map T1.26, blue square

Type material. Holotype female ( ZMHB), perfect condition, labeled [ White , hand written] “N'kolbisson [Yaoudé] Éclos du bois Antricaryon Klaineamum [= Antrocaryon klaineanum Pierre : Anacardiaceae ]” 6-v-65; [ White ] “Muséum Paris CAMEROUN "; [ White ] "Lacourt"; [White, printed in blue] "Zool. Mus. Berlin" [Red] “ HOLOTYPE Afrotremex xylophagus ♀ H. Goulet, 2014 ”.

Paratype. 1 male. Cameroon: N'kolbisson, 29-vi-65 (1 M, ZMHB) .

Diagnosis. Among species with dense and large pits on gena and vertex ( A. hyalinatus ). Adults of A. xylophagus are distinguished from those of A. hyalinatus by the presence on the gena between the ventral edge of the eye and the occiput of a row of round pits with a raised posterior edge and a smooth bottom.

Comparative diagnosis. Afrotremex xylophagus is a rather distinct species. It is unique in the following four features: pedicel proportions; fore and hind wings color pattern; size and distribution of shiny surface on tergum 8; and presence of a sharp ridge immediately ventral to the pit on annulus 3–15.

Afrotremex xylophagus is distinguished from A. hyalinatus by all unique attributes mentioned above and the following six features: density of pits with raised posterior edge in a row along a line between lower eye margin and occiput, and the sculpture at the bottom of these pits; convergence of the lateral edge of the submedian band of mesoscutum in anterior 0.5; microsculpture distribution in anterior 0.3 of the median and submedian bands of mesoscutum; pit size on anterior 0.5 of the median band of mesoscutum; size of pits along the anterior margin of axilla; and size and distribution of shiny surface on terga 6–8.

Afrotremex xylophagus shares with A. hyalinatus the following eleven features: size of the sensory oval surface on the dorsal surface of flagellomere 2; pit size and density on gena, vertex and postocellar area; degree of expansion of the club at the apex of the setae on clypeus, frons and postocellar area; sharpness of the lateral edge of the submedian band of mesoscutum; curvature of the lateral edge in posterior 0.5 of the submedian band of mesoscutum; width of the pit surface of the median band extended laterally posterior to submedian band; posterior extension of pitted sculpticells medially in posterior 0.5 of tergum 8; median carina prominence in the median basin of tergum 9; large teeth extension on lateral surface of tergum 10 posterior to lateral tooth; pits distinctness on anterior surface of lateral tooth of tergum 10; and shape and length of pit on annuli 2 and 10 of the ovipositor.

Afrotremex xylophagus is distinguished from A. pallipennis and A. violaceus , two similar species, by all unique attributes mentioned above and the following six features: sharpness of the lateral edge of the submedian band of mesoscutum; curvature of the lateral edge in posterior in 0.5 of the submedian band of mesoscutum; width of the mesoscutellar median band of pits extended laterally posterior to submedian band; size of pits along the anterior margin of axilla; extent of the shiny surface on terga 5–8; and presence of large teeth on the lateral surface of tergum 10 posterior to lateral tooth.

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

Afrotremex xylophagus differs from A. comatus and A. opacus , two similar species, by all unique attributes mentioned above and the following eleven features: size of the sensory oval on the dorsal surface of flagellomere 2; width of the median band of mesoscutum at its narrowest; absence of extension of fine pits of the mesoscutal median band posterior to submedian band; number of pits on the anterolateral corner of the lateral band of mesoscutum; absence or restricted presence of microsculpture on the scutoscutellar furrow; size of pits along anterior margin of axilla; extent of pitted sculpticells on tergum 8; pitted sculpticells in and around pits on central surface above lateral longitudinal furrow on tergum 9; distribution of pits and pitted sculpticells along anterior surface of tergum 10; presence of pits on the surface anterior to lateral tooth on tergum 10; and size and outline of pit on annulus 2 of the ovipositor.

Afrotremex xylophagus shares with A. comatus and A. opacus the following feature: density of pits with raised posterior edge in a row between the lower eye margin and the occiput, and sculpture at the bottom of these pits.

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, 1A, 2A, 1M (in basal 0.5), 2Cu (in basal 0.5), 1R1, Rs+1Rs2 (broadly along apical, basal and anterior margins), 2R1, 3R1; 2Rs2, 3M, 3Cu (in apical 0.5), and 2M (in apical 0.25); remaining portion of cells (1M, 2Cu, Rs+1Rs2, 2M, and 3Cu) clear forming a small clear spot centrally (Fig. K44). Hind wing darkly tinted with a dark purple hue (may be difficult to see) in apical 0.3 and in the following cells in basal 0.5 (cells codes as in Fig. M1): C, R (in basal 0.25 and along apical margins), 1Cu1 (spot in basal 0.25), and most of anal lobe (with more or less clear spot anteriorly), R1, 1Rs (along apical, basal and anterior margins), 2Rs, 2M (in apical 0.5), 2Cu (extreme apex); remaining cells or part of cells (R. 1Cu, Anal lobe, 1M, 1Rs, 2M and 2Cu) clear (Fig. K44). Protrochanter and mesotrochanter ventrally in apical 0.3 reddish brown.

HEAD. Gena with large pits forming a curved row between lowest eye edge to occiput; pits 0.4–0.5 as long as diameter of lateral ocellus; each pit with raised posterior edge, isolated, and with shiny bottom (Fig. K36, insert); pits dense (usually polygonal in outline) in ventral 0.7, and less dense and round above; pits in ventral two thirds 0.3–0.5 times and in dorsal third 0.1–0.3 times as large as diameter of lateral ocellus (Fig K36, T7.3 and T7.4). Setae on clypeus, frons and postocellar area clearly clubbed at apex (about 2 times as wide as setal shaft), and on frons 0.5–0.7 as long as diameter of lateral ocellus (as in Fig K13 and T1.3, insert). Pedicel about 1.2 times as long as wide. Flagellomere 3 as long as wide and flagellomeres 4–11 clearly wider than long. Flagellomere 2 with sensory oval covering about 0.5 of dorsal surface (as in Fig. K1).

THORAX. Pronotum with vertical lateral surface densely pitted on all or almost all of surface (Fig. T7.6); dorsal surface sculpture around shiny teeth with ridges and with few deep pits, pits with irregularly defined edges (worm-like) of various heights and about 0.1 as large as diameter of lateral ocellus (Fig. T7.5, insert); in lateral view, dorsal surface without or with some very short setae (as in Fig. K46). Mesoscutum with median band generally with fine pits, widest anteriorly, at its narrowest the band about 0.7 times as wide as diameter of lateral ocellus; surface with pitted sculpticells only along anterior margin, with pits posterior to microsculpture area, pits small (at most 0.15 times as large as diameter of lateral ocellus), with shiny bottom, and quite narrowly extended laterally posterior to submedian band and very hardly extended anteriorly along lateral edge of submedian band (Fig K38, and K39b). Submedian band in anterior 0.1–0.3 without pitted sculpticells within pits; not sharply outlined along lateral edge (Fig. K38); lateral edge in anterior 0.5 slightly convergent, and in posterior 0.5 convergent and straight (Fig. K38). Lateral band shiny with many pits (>10) often partly fused on anterolateral corner (Fig. K38 and as in Fig. K4a). Scutoscutellar furrow with convex sculpticells (clearly with metallic hue) over 0.7 central surface (Fig. K17a). Axilla with large pits but without shiny teeth as those on submedian band, broadly connected with small pits from submedian band along edge anteromedially, and without small pits (similar to those of median band) along anterior margin (Fig. K40b).

ABDOMEN. Terga 1–7 with deeply pitted sculpticells (surface matt) at least at base. Tergum 8 generally matt but with shiny surface along lateral margin in posterior 0.5 (Fig. K6). Tergum 9 with median basin bearing about 20 shiny teeth on each side of median ridge; each tooth without a seta; median basin with longitudinal median ridge outlined and prominent, without a small shiny central spot, and slightly longer than wide (maximum width/ maximum median length: 0.85–0.97) (Fig. T7.8). Tergum 9 in lateral view above longitudinal furrow in (central surface with setae) with pits in lower 0.5, pits not deep but outlined by pitted sculpticells, in dorsal 0.5 pits not outlined but with numerous crescent-like shiny tubercles anterior to a seta surrounded by pitted sculpticells (Fig. T7.7). Tergum 10 in dorsal view widely pitted; each pit shiny at bottom (surface between pits shiny except along anterior margin); pits extended to anterior edge only medially (contact about 0.3 times as wide as posterior edge of median basin) (Fig. K9); lateral surface posterior to lateral tooth shiny and with many large teeth (Fig. K19); surface anterior to lateral tooth with indistinctly outlined pits partly bordered by shiny ridges, each pit moderate in size and covered with pitted sculpticells (Fig. K19). Ovipositor with annulus 2 wide, extended and tapered to edge of annulus 1 (Fig. T7.9, base); annulus 10 with large pit as long as most of annulus, pit sharply outlined ventrally along 0.3–0.4 of annulus length (Fig. T7.9, middle); surface anterior to pit outlined by slightly convergent with round fold forming a trough-like, shallow surface extended to anterior annulus (Fig T7.9, base and T7.9, middle); annulus with a long sharp ridge immediately ventral to pit (Fig. T7.9, insert).

Description of male. COLOR. Head. Capsule mainly reddish brown with occiput except posterior to margin adjacent to gena, vertex, postocellar area, and frons posterior to a line anterior to ocelli and top of eyes black with blue metallic reflections (Fig T7.10–T7.12). Antenna black with purple reflections (Fig. T1.21). Thorax. Pronotum generally reddish brown with median triangle and diffused spot submedially black with blue metallic reflections (Fig. T7.14). Propleuron black. Mesonotum with most of mesoscutum and central spot on axilla black with blue metallic reflections, with submedian area of mesoscutum (an anterior and posterior diffused spot), most of axilla, and all of mesoscutellum reddish brown (Fig. T7.14); mesepisternum with most of lateral surface reddish brown but black ventrally (Fig. T7.13). Metascutum with black with blue metallic reflections but metascutellum reddish brown (Fig. T7.14). Metapleuron reddish brown laterally but black ventrally (Fig. T7.13). Legs. Fore and middle legs with coxae black, with femur ventrally, apical 0.6–0.7 of tibia and tarsus reddish brown, and with basal 0.3–0.4 of tibia light reddish brown (Fig. T7.13). Hind leg with coxa, femur, apical 0.5 of tibia and tarsomeres 2–5 dark brown, with basal 0.3 of tibia, and on basal 0.3 and dorsal 0.7 of tarsomere 1 reddish brown (Fig. T7.21). Wings. Fore wing generally light brown tinted but clear in apical 0.8 of cells R and 1Cu, and a little darker in cells 1R1, 2 R1, and basal 0.3 of 3R1 (Fig. T7.20). Hind wing clear in basal 0.5 and light brown tinted in apical 0.5 and along margin of anal lobe (Fig. T7.2). Abdomen. Generally brown to dark brown; terga 2–8 with lateral triangular reddish brown spot becoming light reddish brown to white along lateral margin(Fig T7.15, T7.17 and T7.19); sternum 8 with posterior margin before median excision and apical 0.7 0f sternum 9 reddish brown (Fig. T7.16); sterna 4–8 along lateral margin in apical 0.5 light reddish brown (Fig. T7. 18).

HEAD. Head narrower than in female: flagellomere 1 0.9 as long as flagellomere 2, flagellomere 2 1.6 times as long as wide, and flagellomeres 3–10 longer than wide. Setae on clypeus, frons and postocellar area clearly clubbed at apex, and on frons 0.2–0.3 as long as diameter of lateral ocellus (Fig. T1.3, insert).

THORAX. Hind leg short and thick and in outline quite typical of siricid males; metatibia 4.7 times as long as wide and 1.3 times as long as metatarsomere 1; metatarsomere 1 3.6 times as long as wide and as long as metatarsomeres 2–5 combined (excluding claws); metatarsomere 5 as long as combined metatarsomeres 2 and 3.

ABDOMEN. Abdomen narrow and segments about equally long medially (segment 8 slightly longer) and in outlined quite typical of siricid males. Tergum 9 visible and with obvious teeth anterior each long seta. Harpes with a tooth anterior to long setae. Surface of terga with numerous medium-sized setae. The microsculpture varies between each tergum: tergum 1 and 2 completely matt with deeply pitted sculpticells; tergum 3 mainly matt but shiny (sculpticells either scale-like or flat) in posterior 0.1; tergum 4 and 5 matt and shiny in posterior 0.3–0.4; terga 6 and 7 matt in basal 0.5 and shiny in apical 0.5; and tergum 8 matt in basal 0.2 and shiny in apical 0.8. Sternum densely pitted and surface between pits with isodiametric meshes with flat sculpticells; pits with pitted sculpticells. Posterior edge of sternum 8 deeply excised, excision about 2 times as wide as long; and sternum about 0.5 as long as length of sternum 9.

Host. The two specimens were reared from Antrocaryon klaineanum (Anacardiaceae) a tree from central Africa.

Origin of specific epithet. From Greek meaning “wood eater” referring the emergence of the specimens from the wood of Antrocaryon klaineanum (Anacardiaceae) as noted on the label.