An unusually dense population of Sphodros rufipes (Mygalomorphae: Atypidae) at the edge of its range on Tuckernuck Island, Massachusetts

Abstract

We counted and measured Sphodros rufipes (Latreille 1829) pursewebs in two survey plots on Tuckernuck Island, Massachusetts. Our objectives were to quantify web density, record physical web characteristics and determine the main components of 5. rufipes' diet. We counted 479 webs in the two plots and report web densities between 0.058 and 0.18 webs/m^, denser than previously reported populations. Webs were not distributed evenly, and densities ranged from 0 to 0.38 webs/m". Aggregation indices suggest that webs are aggregated on a landscape level, but are more evenly distributed at a local level. Contrary to most previously published literature on S. rufipes, we noted the predominance of the grass-like sedge, Carex pensylvanica, rather than trees, as a web support. Coleopterans and isopods made up 79 percent of the prey parts collected from 56 pursewebs.

Aggregations of Sphodros rufipes (Araneae: Atypidae) in an urban forest

“…Five species are confined to the United States (Gertsch & Platnick 1980), with Sphodros rufipes (Latreille 1829) being the most widespread and known from scattered locations throughout the eastern United States (Hoffman 1992). The species has been described as uncommon throughout most of its range (Hardy 2003), but occasionally may be locally abundant (Poteat 1889;Morrow 1986;Mckenna-Foster et al 2011). As the widest-ranging Sphodros spider, S. rufipes is also the best studied.…”

“…Previous studies have reported population densities (Poteat 1889;■ Coyle & Shear 1981), but only one has described spatial patterns (Mckenna-Foster et al 2011).…”

Do disturbed environments affect density of the tunnel-web spider Acanthogonatus centralis (Mygalomorphae: Nemesiidae) from native grasslands in Argentina?

“…Unfortunately, we were not able to carry out a more extensive analysis due to the low numbers of spiders found for the other sampling dates and sites. Aggregation is usually found in mygalomorph spiders, as has been reported for 2 different populations of the atypid Sphodros rufipes (Latreille, 1829) (Mackena-Foster et al, 2011;Reichling et al, 2011), and for the nemesiid spider Prorachias bristowei Mello-Leitão 1924(Souza-Silva et al, 2014. Moreover, the trapdoor species Calathotarsus simoni Schiapelli & Gerschman 1975 (Migidae), from the same area as A. centralis, also showed a clumped distribution (Ferretti et al, 2014b).…”

Atypus karschiDönitz, 1887 (Araneae: Atypidae): an Asian purse-web spider established in Pennsylvania, USA

“…While vertical tubes are characteristic of North American Sphodros species, Sphodros niger Hentz, 1842 may preferentially build horizontal tubes, at least in some settings (59,60). Mckenna-Foster et al (61) found that Sphodros rufipes Latreille, 1829 in New England will use whatever support is available and many webs were close to the ground. The suggestion that horizontal webs are an adaptation to prey capture under the snow (7) may ignore the function of vertical webs at ground level.…”

“…Mckenna-Foster et al (61) found that Sphodros rufipes Latreille, 1829 in New England will use whatever support is available and many webs were close to the ground. The suggestion that horizontal webs are an adaptation to prey capture under the snow (7) may ignore the function of vertical webs at ground level.…”