Afrotremex hyalinatus ( Mocsáry, 1891 )

Goulet, Henri, 2014, Revision of the African horntail genus Afrotremex (Hymenoptera: Siricidae), Zootaxa 3795 (3), pp. 201-254 : 229-233

3. Afrotremex hyalinatus ( Mocsáry, 1891)

Fig T3.1, T1.27 (female habitus); M4, M4a, M6, (morphology); K3, K8, K11, K13, K15, K18, K21, K35, K37, K39, K39a, K40, K40a, K41, K43 (keys); T1.1, T1.3, T1.5–T1.7, T1.12, T1.13, T1.17, T3.1–T3.8 (description). Map (T1.26), red square

Tremex hyalinatus Mocsáry, 1891: 158–159 . Holotype female (HNHM), not examined but photographs of eight characters and their states compared with the type by Dr. F. Koch. Type locality: Gabon. Name accepted by Dalla Torre 1894: 382 (catalog), Konow 1898: 84, 86, 90, Konow 1905a: 8, Konow 1905b: 115–117, Guiglia 1937: 433–437, Hedicke 1938:29, Benson 1943: 35, Maa 1949: 163 (incertis sedis), Pasteels 1951: 196–197.

Afrotremex hyalinatus ; Pasteels 1951: 196 (change of rank), Name accepted by Smith 1978: 90 (catalog), Taeger et al., 2010: 106, Taeger and Blank 2011.

Diagnosis. Among species with large and dense pits on gena ( A. xylophagus ), adults of A. hyalinatus are distinguished from those of A. xylophagus by a linear row of fused pits with striation at the bottom.

Comparative diagnosis. Afrotremex hyalinatus is a rather distinct species. It is unique in having the following four features: size of sculpticells on the dorsal surface of the pronotum between large shiny teeth; presence of sculpticells on the anterior 0.3 of the median and submedian bands; reduction in pits size and shiny teeth on axilla and distribution of pits of similar size to those of median band along anterior margin of axilla; and extent and position of the shiny surface on terga 4–8.

Afrotremex hyalinatus is distinguished from A. xylophagus by the unique characters mentioned above and the following eight features: density of pits with raised posterior edge in a row along a line between lower eye margin and occiput, and sculpture at the bottom of these pits; convergence of the lateral edge of the submedian band of mesoscutum; 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; pit size along anterior margin of axilla; extent and position of shiny surface on terga 6–8; and absence of a sharp ridge immediately ventral pit of annulus 10.

Afrotremex hyalinatus shares with A. xylophagus 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; level of expansion of the club at the apex of setae on clypeus, frons and postocellar area; degree of 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; pits extension laterally around the posterior end of the submedian band and anteriorly along the lateral margin of submedian band in posterior 0.5; 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 dorsal and lateral surfaces of tergum 10; presence of teeth on surface posterior to lateral tooth of tergum 10; and shape of pit on annuli 2 and 10 of the ovipositor.

Afrotremex hyalinatus is distinguished from A. pallipennis and A. violaceus , two similar species, by all unique features mentioned above and the following seven features: sharpness of the outline of the lateral edge of the submedian band of mesoscutum; lack of convergence of the lateral edge of the submedian band in anterior 0.5, and slight convergence of the lateral edge in posterior 0.5; width of median pits posterior to submedian band; size of teeth on axilla and the presence of pits of size similar to those of the median band of mesoscutum; fore wing color pattern; extent of the shiny surface on terga 5–8; and presence of large teeth on the lateral surface of tergum 10.

Afrotremex hyalinatus shares with A. violaceus and A. pallipennis the following ten features: row of fused pits in ventral 0.5 of gena; size of the sensory oval surface on the dorsal surface of flagellomere 2; relative width of the mesoscutal median band at its narrowest; lateral extension of pits of median band around posterior end of the submedian band on mesoscutum; presence of many pits anterolaterally on the lateral band of mesoscutum; presence of widespread sculpticells in the scutoscutellar furrow; absence or near absence of microsculpture around pits just above the lateral longitudinal furrow on tergum 9; absence of pitted sculpticells (meshes very lightly impressed along anterior margin only) in and around pits on median dorsal surface of tergum 10; distribution of pits on tergum 10; and shape of pit on annulus 2.

Afrotremex hyalinatus is distinguished from A. comatus and A. opacus , two similar species, by all unique features mentioned above and the following nine features: density of pits in a row along a line between lower eye margin and occiput, and the sculpture at the bottom of these pits; size of sensory oval on dorsal surface of flagellomere 2; the width of the mesoscutal median band at its narrowest; absence of the lateral extension of fine pits of the median band posterior to submedian band; number of pits on the anterolateral corner of the lateral band of mesoscutum; presence of microsculpture on the scutoscutellar furrow; extent of shiny surface on tergum 8; pitted sculpticells in and around pits on surface just above lateral longitudinal furrow of tergum 9; distribution of pits and pitted sculpticells along anterior surface of tergum 10, laterally on surface anterior lateral tooth; and the size and outline of pit on annulus 2 of the ovipositor.

Afrotremex hyalinatus shares with A. comatus and A. opacus the following feature: most of the fore wing color pattern (except the apex of 1Cu and 1A).

Description of female. COLOR. Fore wing darkly tinted with a purple hue (may be difficult to see) in following cells (cells codes as in Fig. M1): C, R, 1Cu (except for small apical clear spot posteroapically), 1A (except for clear spot in apical 0.5), 1M (spot in basal 0.3), 2Cu (small anterobasal spot), 1R1, Rs+1Rs2 (spot narrow along cell 1R1 and 3R1), 2R1, 3R1; remaining apical 0.2 of wing lightly but clearly tinted, the remaining cells clear (Fig. K43). Hind wing darkly tinted with a purple hue (may be difficult to see) in following cells (cells codes as in Fig. M1): C, R (spot in basal 0.4), 1Cu1 (spot in basal 0.4), C, and most of anal lobe (except for small clear spot anteriorly), the remaining cells clear (Fig. K43). Protrochanter and mesotrochanter ventrally in apical 0.3 black or somewhat paler.

HEAD. Gena with large pits forming a curved row between lowest eye edge to occiput, the pits fused completely and bottom of each pit consisting of irregular fine ridges (Fig. K35, insert); remaining surface with pits dense (usually polygonal in outline) in ventral 0.7 and scattered above, and in ventral two thirds 0.2–0.4 times and in dorsal third 0.2–0.3 times as large as diameter of lateral ocellus (Fig. K11). 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 (Fig K13 and T1.3, 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 (as in Fig. K1).

THORAX. Pronotum with vertical lateral surface very densely pitted in posterior 0.8 (Fig. T3.2); dorsal surface around large shiny teeth with few short ridges and mainly pits, the pits with irregularly defined edges (worm-like) and about 0.2 times as large as diameter of lateral ocellus (Fig. T3.3, insert); in lateral view, dorsal surface without long setae or with some very short setae (as in Fig. K46). Mesoscutum with median band generally finely sculptured, widest anteriorly, at its narrowest the band about 0.7 times as wide as diameter of lateral ocellus (Fig. K39); with pitted sculpticells in anterior 0.3, with pits gradually forming within microsculptured area, at first with pitted sculpticells at bottom of each pit then pit bottom becoming shiny in posterior 0.5 of band, and pits small (0.1–0.15 times as large as diameter of lateral ocellus) (Fig. T3.4, insert), pits extending laterally around posterior end of submedian band (as in Fig. K3a) and forward along lateral margin of submedian band in posterior 0.5 (Fig. K39a). Submedian band in anterior 0.1–0.3 with pitted sculpticells within pits (Fig. T3.4, insert); lateral edge not sharply outlined, in anterior 0.5 parallel (Fig. K37), and in posterior 0.5 slightly convergent and straight (Fig. K15). Lateral band shiny with many pits (>10) often fused on anterolateral corner (Fig. T3.4 and as in Fig. K4a). Scutoscutellar furrow with convex sculpticells (sculpticells area with metallic hue) over 0.7 central surface (Fig. T3.4 and as in Fig. 17a). Axilla with medium size pits without scallop-like pits as on submedian band, not connected along with small pits from submedian band along edge anteromedially, and with small pits (similar to those of median band) along anterior margin (Fig. K40a).

ABDOMEN. Terga 1–5 with deeply pitted sculpticells (surface matt). Terga 6–8 with shiny areas (microsculpture meshes absent or very lightly impressed). Tergum 6 shiny in posterior 0.2 medially; tergum 7 shiny in posterior 0.3 medially with a short anterior extension medially (Fig. T3.5); and tergum 8 matt in anterior 0.3 and medially in 0.7 otherwise shiny (Fig K5 and K21). Tergum 9 with median basin bearing about 20 tubercle (not shiny apically) on each side; each tubercle without a setae; longitudinal median ridge prominent, and without a small shiny central spot; maximum length slightly longer than wide (maximum width/ maximum median length: 0.79–0.84) (Fig M6 and T3.7). Tergum 9 in lateral view above longitudinal furrow in area with setae with pits in lower 0.75, pits deep clearly outlined by pitted sculpticells, and above this zone pits indistinctly outlined by pitted sculpticells (Fig. M4a). Tergum 10 in dorsal view widely pitted; each pit shiny at bottom (surface between pits shiny except along anterior margin); pits extending medially to but not reaching anterior edge (Fig M6 and K8); in lateral view surface posterior to lateral tooth shiny and with many large teeth (Fig. T3.6), and surface anterior to lateral tooth with distinctly outlined pits of moderate size and each pit with pitted sculpticells at bottom (Fig. T3.6). Ovipositor with annulus 2 wide, about 0.3 as long as annulus, and regularly tapered to edge of annulus 1 (Fig. T3.8, base); annulus 10 with large pit 0.3–0.4 as long as annulus; surface anterior to pit outlined by slightly convergent round fold forming a trough with shallow surface extending almost to anterior annulus; annulus without a long sharp ridge immediately ventral to pit (Fig. T3.8, middle).

Taxonomic notes. Afrotremex hyalinatus was the first species of Afrotremex to be discovered (originally described under Tremex ). I did not see the holotype specimen that was with F. Koch (Berlin). He kindly compared the type with color photographs showing eight significant characters and their states based on specimens of five species at hand (flagellomere 2 sensory oval; row of pits on gena; size and density of pits on gena; setae shape and size on clypeus, frons and postocellar area; number of pits on lateral band of mesoscutum; fore and hind wing color pattern; sculpture on tergum 8; pit and sculpture above lateral longitudinal furrow of tergum 9). He matched perfectly the holotype from Gabon with the specimen from the Republic of the Congo. A study of the excellent habitus illustration of the A. hyalinatus holotype by A. Baliani ( Guiglia 1937) (Fig. T1.26) shows six characters matching states of the specimen from the Republic of the Congo. Three of these characters were not compared with the type by F. Koch (parallel lateral edge of the mesoscutal submedian band in anterior 05; prominence of the median ridge in the median basin; and proportion of the length relative to the width of the median basin). All eleven characters match the specimen from the Republic of the Congo. Therefore, we consider the specimen from the Republic of Congo as A. hyalinatus .

Material examined. Republic of the Congo. Dept. Pool Iboubikro, Lesio-Louna Park 330 m 03̊16.196'S 015̊28.167'E, vii–ix 2008 Breat & Sharkey (1 female, USNM) .