Acacesia tenella (L. Koch, 1871) L. Koch, 1871

Framenau, Volker W., Scharff, Nikolaj & Levi, Herbert W., 2009, Not from “ Down Under ”: new synonymies and combinations for orb-weaving spiders (Araneae: Araneidae) erroneously reported from Australia, Zootaxa 2073, pp. 22-30 : 23-25

Acacesia tenella (L. Koch, 1871) comb. nov.

Figs 1 A–D, 2A–E

Epeira tenella L. Koch, 1871: 76 –78, pl. 6, figs 5, 5a, 6, 6a; Butler 1876: 352. Aranea tenella (L. Koch) . Roewer 1942: 834.

Wixia tenella (L. Koch) . Archer, 1951: 15.

Araneus tenellus (L. Koch) . Rainbow 1911: 194; Bonnet 1955: 609.

Acacesia cornigera Petrunkevitch, 1925: 117 , figs 32–41; Glueck, 1994: 73 –75, figs 2–3, 9–16. New synonymy.

Types. Syntypes of Epeira tenella L. Koch, 1871: 1 male, 5 females, 1 penultimate female, 1 juvenile, listed in L. Koch (1871) from “Neuholland” (NHMW 1826. II.11) (examined).

Syntypes of Acacesia cornigera Petrunkevitch, 1925 : male, female, juvenile, San Lorenzo, Panama (PMY) (examined).

Remarks. Ludwig Koch (1871) listed 1 male and 9 females as syntypes in his original description of Epeira tenella (p. 78, “Neun entwickelte Weibchen und ein Männchen von Neuholland ohne nähere Angabe im k. k. Museum zu Wien.”), but the vial only contained the 8 specimens listed above. This also coincides with a copy of the NHMW register which lists 8 specimens. It appears that L. Koch (1871) erroneously listed 9 females and also misinterpreted the developmental stage of some of the spiders.

Acacesia cornigera was reported as widespread from central Mexico to southern Brazil and is found on both sides of the Andes ( Glueck 1994). The species has quite variable male pedipalps and the posterior view of the epigynum is generally heavily sclerotised and sometimes covered with debris and therefore difficult to examine; the female illustrated here has apparently recently moulted with less sclerotised epigyne ( Figs 1 D, 2B). All males from Mexico to Brazil have similar cone-shaped emboli, although it may be hidden in part by the conductor. The paracymbium is variable, Central American specimens have two distal prongs, the proximal short, the South American generally have only one ( Fig. 2 D). However, there is little doubt that the syntypes of Epeira tenella and those of Acacesia cornigera represent the same species and both are synonymised here as Acacesia tenella (L. Koch, 1871) comb. nov.

Based on the locality label “Neu-Holland” L. Koch (1871) erroneously assumed that the spiders were collected in Australia. It is possible that the spiders were collected in the Dutch colony of the same name in northeastern Brazil, although this colony had long seized to exist when the specimens were given to the MNHW in 1826.

Figures

FIGURE 1. Syntype male and female of Acacesia tenella (L. Koch, 1871) comb. nov. A, male, dorsal view; B, male right pedipalp, mesal view; C, female, dorsal view; D, epigyne, ventral view. Scale bar: A, C, 1 mm; B, D, 0.1 mm.

FIGURE 2. Syntype female and male of Acacesia tenella (L. Koch, 1871) comb. nov. A, female, dorsal view; B, epigyne, ventral view; C, epigyne, posterior view; D, paracymbium of left male pedipalp, dorsolateral view, E, male left pedipalp, mesal view. Scale bar: A, 1 mm; B – E, 0.1 mm.