Actinacantha globulata ( Walckenaer, 1841 )

Tan, Ji, Chan, Zi Yang, Ong, Ching Ang & Yong, Hoi Sen, 2019, Phylogenetic relationships of Actinacantha Simon, Gasteracantha Sundevall, Macracantha Hasselt and Thelacantha Simon spiny orbweavers (Araneae: Araneidae) in Peninsular Malaysia, Raffles Bulletin of Zoology 67, pp. 32-55 : 42-43

Actinacantha globulata ( Walckenaer, 1841)

( Figs. 1A , 5 A−C)

Plectana globulata Walckenaer, 1841: 151

Actinacantha globulata Simon, 1864: 286 .

Gasteracantha globulata van Hasselt, 1882: 12

Material examined. MALAYSIA. 1 sub-female (reg. UIR150116- AGLO1 ), Semenyih., Selangor, coll. Chan ZY, 15 Jan.2016 .

Diagnosis. Adult female A. globulata is differentiated from those of Gasteracantha hasselti and Macracantha arcuata based on the unique bulbous bases from which the middle spines originate.

Natural history. A sub-female was collected from a web in the understorey of a primary tropical forest. The species appears to be uncommon and very localised in the Malay Peninsula.

Distribution. Peninsular Malaysia, Borneo, and Indonesia (Sumatra and Java).

Remarks. The similarities in the morphological descriptions and geographical distribution of A. globulata and Gasteracantha crucigera suggest that they may likely be synonymous ( Walckenaer, 1841; Simon, 1864; Bradley, 1877; Chrysanthus, 1971; Dahl, 1914; Yong & Ono, 2009). However, a solid conclusion cannot be made based on the morphology and DNA sequence of only one A. globulata subadult female in its penultimate molt. This limited information may overlook cryptic or sibling species existing between Peninsular Malaysia, Borneo, and Papua New Guinea. The recent employment of molecular data has already revealed the existence of species complexes in spider and insect taxa which may well be possible among geographically isolated A. globulata and G. crucigera ( Franzini et al., 2013; Gregorič et al., 2015; Yong et al., 2015). Nevertheless, the morphological and molecular characterisation of more specimens of both species are expected to resolve this taxonomic uncertainty.

Figures

Fig. 1. General habitus. A, Actinacantha globulata (Walckenaer, 1841), sub-female; B, Gasteracantha diardi (Lucas, 1835), female; C, G. diardi yellow morph, female; D, G. diardi white morph, sub-female; E, G. kuhli, female; F, Gasteracantha hasselti C. L. Koch, 1837, female; G, Macracantha arcuata (Fabricius, 1793), female; H, Thelacantha brevispina (Doleschall, 1857), female; I, G. mengei Keyserling, 1864, female. Photos by Tan Ji.

Fig. 5. Sub-female Actinacantha globulata (Walckenaer, 1841). A, Dorsal habitus; B, Ventral habitus; C, Lateral habitus. Scale = 5 mm.