The Chilean Recluse Spider (Araneae: Sicariidae) Displays Behavioral Responses to Conspecific Odors, but Not to Several General Odorants

Abstract

Spiders of the family Sicariidae pose a serious threat to affected populations, and Loxosceles laeta (Nicolet) is considered the most venomous species. Development of nontoxic olfaction-based spider repellents or traps is hindered by a current lack of knowledge regarding olfactory system function in arachnids. In the present study, general plant odorants and conspecific odors were tested for behavioral responses in L. laeta. Although general odorants triggered neither attraction nor aversion, conspecific odor of the opposite sex caused aversion in females, and attraction in males. These results support the presence of a specific olfactory system for the detection of conspecifics in L. laeta, but suggest the absence of a broadly tuned system for general odorant detection in this species.

The visual spectral sensitivity of the Chilean recluse spider Loxosceles laeta

“…The visual pigment template described by Stavenga (2010) was fitted to the green sensitivity peak using the least squares method via the curve_fit function from the open source SciPy 1.3.1 package. The video recordings were analyzed offline with a modified version of a custom-programmed tracking algorithm previously used by the laboratory (Calbiague et al, 2017), which is available online at https://sourceforge.net/projects/spider-tracking/.…”

“…Being a group of highly venomous species common in Latin America, with closely related albeit slightly less poisonous species inhabiting the southern USA, the Mediterranean and other temperate parts of the world, it seems relevant to better understand what sensory stimuli attract or repel species of the genus Loxosceles, and by what criteria they choose their habitat. However, to the best of our knowledge, there are no data available regarding the visual capabilities of any of the species of the genus Loxosceles, and only a handful of reports have shed light on its biology (Calbiague et al, 2017;Canals and Solís, 2014;Canals et al, 2015a,b,c).…”