Reversed cannibalism, foraging, and surface activities of Allocosa alticeps and Allocosa brasiliensis: two wolf spiders from coastal sand dunes

Habitat Preference and Effects of Coastal Fragmentation in the Sand-Dwelling Spider <i>Allocosa brasiliensis</i> (Lycosidae, Allocosinae)

“…Along with this, and although the dispersal mechanisms of A. brasiliensis are not well known, the species could be influenced by the fragmentation habitat reducing ballooning but increasing the cursorial dispersion. This species presents the reproductive period and its higher surface activity in warmer months [16] [18]. As was expected, we found that for most beaches A. brasiliensis density increased with temperature (Figure 7).…”

“…This is in agreement with the sex-role reversal reported for this species [30] [31], and consequent higher mobility in this sex. Also, females of A. brasiliensis need to forage intensively before mating because after that they will remain buried in male burrows, ovipositing there and exiting for spiderling dispersal, approximately one month later [18] [29] [31]. Intense foraging activity will also be reflected by high surface activity during the summer of the Southern hemisphere.…”

“…This nocturnal species constructs burrows in the sand [26]- [29], and shows sex-role reversal: males are bigger than females and females are the mobile sex that initiates courtship [30]. Copulation take place inside male burrows [30] [31] and males show reversed sexual cannibalism (they prey on rejected females) [18] [32]. A. brasiliensis shows morphological and behavioral features strongly associated to inhabiting the dune lines of natural sandy coasts and it has been catalogued as a good bio-indicator for coastal environments in Southern Uruguay [33].…”

Spatial distribution, burrow depth and temperature: implications for the sexual strategies in twoAllocosawolf spiders

“…High levels of intraguild predation have been Downloaded by [Florida Institute of Technology] at 17:09 25 August 2014 reported for wolf spiders in general (Fernández-Montraveta & Ortega 1990;Wagner & Wise 1996;Moya-Laraño et al 2002;Wise 2006), and seem to be common between the two Allocosa species (Aisenberg et al 2009). The larger size and consequently higher predator capacity of A. brasiliensis adults seems to be driving the spatial exclusion of A. alticeps females and males from the former species' burrowing areas.…”

“…Oviposition will take place inside male burrows (Aisenberg et al 2007;Aisenberg & Costa 2008). The preference of A. brasiliensis adults for the base of the sand dune could be associated with better protection from the southwest winds that frequently blow in these areas (Costa et al 2006;Aisenberg et al 2009) and, possibly, higher prey abundance (Aisenberg, unpublished data). Individuals of both Allocosa species are drastically constrained by humidity levels in the air and in the ground for constructing more stable burrows and for their physiological requirements (Aisenberg, unpublished data).…”