Taxonomy

Menemerus is a genus with many species found throughout the world.  Australia has a single, cosmotropical species, Menemerus bivittatus. Further information on the species can be found in Richardson and Żabka (2017) and Whyte and Anderson (2017). A second Australian species known as Menemerus bracteatus was transferred to Apricia by Richardson (2016).

Description

Menemerus bivittatus is a medium-sized spider, body length 5 mm, with an ovate abdomen. The head, viewed from above, is pear-shaped and widest behind the posterior lateral eyes. The carapace is low and flat, with a white band along the edges. The pattern on the abdomen varies between the sexes and the width of the brown stripes on the sides of the females can be narrow, consisting of a simple lateral edge, or extending, as a pattern, almost to the dorsal midline. Each chelicera has a single (unident) retromarginal tooth and two promarginal teeth. The fourth pair of legs are longest.

The male’s palpal tibia has a single, sharp retro-lateral tibial apophysis. The tegulum is longer than wide, without any marked proximal lobe. The short, thick embolus forms a clockwise, partial curve on the distal edge of the tegulum and is accompanied by a membranous filament.

Females have a single epigynal atrium, partly divided in two. Copulatory openings, with sclerotised guides, open medially. The convoluted insemination ducts are anterior to the spermathecae. The spermathecae are rounded and are located within the margins of the atrium.  

Biology

It is unclear whether this widespread species arrived in Australia with European settlement or whether it has been present for a much longer period. It is a synanthropic tramp species and often seen on sunny walls, retreating to cracks when disturbed.

Distribution

The species has a widespread cosmotropical distribution. In Australia it is known from subtropical coastal regions of eastern and western Australia.

References

Davies, V.T. & Żabka, M. 1989. Illustrated keys to the genera of jumping spiders (Araneae: Salticidae) in Australia. Memoirs of the Queensland Museum 27, 189-266.

Richardson, B.J. 2016. New genera, new species and redescriptions of Australian jumping spiders (Araneae: Salticidae). Zootaxa 4114, 501-560.

Richardson, B.J. & Żabka , M. 2016. Salticidae. Arachnida: Araneomorphae. Canberra, Australian Faunal Directory. Australian Biological Resources Study, at https://biodiversity.org.au/afd/taxa/SALTICIDAE.

Whyte, R. & Anderson, G. 2017. A Field Guide to Spiders of Australia. CSIRO Publishing: Clayton.

* The information sheet should be interpreted in the context of the associated diagrams and photographs. Diagrams explaining anatomical terms can be found in the ‘Salticidae’ pictures at the beginning of the list of genera.