Pactola Pascoe, 1876

Mazur, Miłosz A., 2014, Review of the New Caledonian species of the genus Pactola Pascoe, 1876 (Coleoptera: Curculionidae: Eugnomini), with description of two new species, Zootaxa 3814 (2), pp. 202-220 : 203-204

Genus Pactola Pascoe, 1876

Macropoda Montrouzier, 1861: 877 , non Macropoda Solier, 1835 (Tenebrionidae) ; Perroud & Montrouzier, 1865: 165. Type species not designated.

Pactola Pascoe, 1876a: 424 . Broun, 1880: 464 (redescription); Hudson, 1923: 394 (catalogue); Voss, 1936: 121 (transferred to Tachygoninae); Marshall, 1937: 333, figs. 3, 4 (transferred back to Eugnominae , key to species); Hudson, 1950: 51, pl. XIV (variation of P. variabilis ); Kuschel, 1964: 446 (synonymy between Macropoda and Pactola ); Cawthra, 1966: 171, 173–175, 177, figs. 7, 10, 15 (morphology); Kuschel, 1982: 279 (new synonymies, stat. n. for P. nigra ); Leschen et al., 2003: 26 (in checklist of tribe); Macfarlane et al., 2011: 433 (checklist of N.Z. species).

Type species: Pactola variabilis Pascoe, 1876a (by monotypy).

Diagnosis. Distinguished from other genera of Eugnomini by the following combination of characters: head not constricted near base, eyes distinctly convex without setae or scales between ommatidia; rostrum shorter or just slightly longer than head (figs. 14a–d); antennae inserted near apex of rostrum, funicles with seven segments (figs. 15a–d); elytra without large, sharp, conical spines, sometimes furnished with apically rounded tubercles; wings well developed; front coxae contiguous; hind femora strongly broadened, with distinct, enlarged tooth that is usually larger than half of maximum femoral width; hind tibiae strongly curved (figs. 17c, 18c, 19c, 20c).

Distribution. Fiji Archipelago, New Caledonia, New Zealand, ( Table 1).

Species Distribution

Pactola convexa (Montrouzier, 1860) New Caledonia Pactola demissa Pascoe, 1876b New Zealand

Pactola fairburni Marshall, 1938 New Zealand

Pactola fiji Mazur, 2012 Fiji Archipelago (Taveuni Is.) Pactola fuscicornis Broun, 1913 New Zealand

Pactola hudsoni Marshall, 1938 New Zealand

Pactola magna sp. n. New Caledonia Pactola nitidula Broun, 1913 New Zealand

Pactola proxima sp. n. New Caledonia Pactola posticalis Marshall, 1938 New Zealand

Pactola setacea ( Montrouzier, 1861) New Caledonia Pactola variabilis Pascoe, 1876a New Zealand

Cawthra (1966) mentioned P. variabilis as occurring also in New Caledonia, but this may have been meant to refer to the entire genus, not this particular species. Pactola variabilis has been recorded only from New Zealand, where it is common in many localities, and it has been listed as an endemic in this country by Kuschel (1990) and Macfarlane et al. (2011). My examination of numerous Pactola specimens from New Caledonia indicates that P. variabilis does not occur there.

Biology. No detailed biological information is known for the genus. Other members of Eugnomini have been reared from dead wood, subcortical tissues, live stems, galls, leaves or fruits of many species of plants in different families ( May, 1987). Larvae of Pactola demissa have been reared from the bark of dead branches of Hoheria populnea (Malvaceae) ( May, 1987) and adults are attracted to cut branches of Parsonsia heterophylla (Apocynaceae) ( Kuschel, 1990). Pactola variabilis has been reared from dying subcortical tissues of Pseudopanax lessonii (Araliaceae) ( May, 1987), Schefflera digitata (Araliaceae) ( Kuschel, 1990) and Hebe spp. ( Plantaginaceae ) ( Watt, 1956), and Styles (1973) reared P. variabilis and P. fuscicornis from Pseudopanax spp.

Remarks. The first species of Pactola described, from New Caledonia, namely P. convexa , P. s e t a ce a and P. kanalensis (Perroud) , were originally placed in Macropoda Montrouzier, 1861 ( Montrouzier, 1861; Perroud & Montrouzier 1865), but a genus with this name had already been established in Tenebrionidae by Solier (1835). The three New Caledonian species were later placed in Pactola , described by Pascoe (1876a) from New Zealand with only one included species, P. variabilis , when Kuschel (1964) synonymised Macropoda Montrouzier with Pactola . In 1876 Pascoe described one more species ( P. demissa ) but in a separate paper (1876b). Macropoda Solier, 1835 is presently treated as a subgenus of Adesmia Fischer de Waldheim, 1822, a tenebrionid genus occurring in sub-Saharan Africa.

Pactola is readily distinguishable from the other described genera of Eugnomini by its very short rostrum and the large tooth on the extremely extended hind legs ( Figs. 17 c, 18c, 19c, 20c). A relatively large tooth on the hind legs is found in many other genera as well, but their femora are usually more elongate and the rostrum is usually longer than the head or the head plus pronotum (e.g., Amylopterus Broun , Eugnomus Schoenherr , Gonoropterus Broun, Koghicola Mazur , Scolopterus White , Rhopalomerus Blanchard ). Some species of these genera also possess strongly protruding tubercles on the elytra (e.g., Amylopterus , Gonoropterus ) but these form sharp, conical spines usually furnished with a tuft of hair-like scales. Hoplocneme White is also similar to Pactola in having a similarly short rostrum and femoral tooth, but it differs in having the head strongly constricted near the base and 6- segmented antennal funicles. Pactolotypus Broun , with seven species described from New Zealand and the Chatham and Subantarctic Islands ( Kuschel, 1964), is also similar to Pactola , but it differs in having the metaventrite longer than abdominal ventrite 1 behind the coxae, 6- or 7-segmented antennal funicles, the humeral calli not developed (apterous) and the ommatidia convex with fine hairs or squamiform setae between them. The recently described genus Koghicola ( Mazur 2014) differs in having enlarged hind trohanters, and elytra strongly narrowed to apex, each elytra with prominent, divergent apical process.

Figures

FIGURES 17 – 20. Legs: 17 — Pactola setacea (Montr.): 17 a—front leg; 17 b—middle leg; 17 c—hind leg; 18 — P. proxima sp. n.: 18 a—front leg; 18 b—middle leg; 18 c—hind leg; 19 — P. c o nv e x a (Montr.): 19 a—front leg (minute tooth marked by arrow); 19 b—middle leg; 19 c—hind leg; 20 — P. magna sp. n.: 20 a—front leg; 20 b—middle leg; 20 c—hind leg.