Spider diversity in epiphytes

Spider diversity in epiphytes: Can shade coffee plantations promote the conservation of cloud forest assemblages? .
Francisco Emmanuel Méndez-Castro, Dinesh Rao
Abstract
Cloud forests (CF) are disappearing due to anthropogenic causes such as cultivation. A characteristic feature of the CF is that a high proportion of its biomass occurs in the form of epiphytes, which are vital microhabitats to canopy dwelling arthropods. Coffee plantations overlap with CF and replace them. Epiphytes are abundant in shade coffee (SC) plantations and therefore these plants are an appropriate background for comparing the diversity between these systems. Spiders are understudied in canopies, and since they are major predators and their communities are highly sensitive to environmental changes, they can be used to test the similarity between habitats. We conducted a diversity assay of spiders living in epiphytes in cloud forest fragments and SC plantations, to test the hypothesis that SC plantations function as refugia. We manually sampled epiphytes within the canopy of two coffee plantations and two fragments of cloud forest in central Veracruz, Mexico. Our results show that SC plantations account for higher spider abundance and species richness than cloud forest fragments, there is little overlap between the species found in both systems, and the range of distribution and the guild structure of the spider assemblages between both systems is similar. As there were no significant differences between cloud forest fragments and SC plantations in terms of spider species assemblages, species distribution and guild structure the epiphytes from the SC plantations can be consider a refuge for the spider fauna from the surrounding cloud forest fragments. Epiphyte load and tree height are important factors driving the differentiation at community level, between sites and habitats. Bromeliads harbored more spiders than the other types of epiphytes, and since these plants are frequently removed by farmers or extracted for commercial and religious purposes, we suggest that preserving epiphytes in coffee plantations and cloud forest fragments could aid in the conservation of spiders.

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PLOS ONE: Bat Predation by Spiders

In this paper more than 50 incidences of bats being captured by spiders are reviewed. Bat-catching spiders have been reported from virtually every continent with the exception of Antarctica (~90% of the incidences occurring in the warmer areas of the globe between latitude 30° N and 30° S). Most reports refer to the Neotropics (42% of observed incidences), Asia (28.8%), and Australia-Papua New Guinea (13.5%). Bat-catching spiders belong to the mygalomorph family Theraphosidae and the araneomorph families Nephilidae, Araneidae, and Sparassidae.

via PLOS ONE: Bat Predation by Spiders.

Why We Should All Celebrate Save a Spider Day

Babbitt’s personal favorite is the pinktoe tarantula, a South American spider with pink-tipped legs that give the impression of freshly-painted nails. Because the pinktoe spider comes from the rainforest, it’s one of the few tarantulas that can climb trees, survive falls and even swim. Where other tarantulas would be killed by a drop of just a few feet, these spiders “can essentially parachute down” from the treetops.

via Why We Should All Celebrate Save a Spider Day | Around The Mall.

New papers

After more than a year of paper ping pong, I am pleased to announce that the jumping spider paper, mostly based on the work I did here as a post-doc is out.

Characterisation of Predator-Directed Displays in Tephritid Flies

Abstract

Flies of the family Tephritidae are known to perform a display in front of their salticid spider predators. This display involves extending the wings while the fly moves from side to side. The wings of many of fly species are banded, and in some species, these bands are thought to deter their predators by mimicking the leg patterns of salticids. However, as this display is also seen in non-mimicking flies, there is some uncertainty over the functional significance of these displays. In this study, we explored the efficacy of displays by the lightly banded but non-mimicking Mexican fruit fly (Anastrepha ludens) in deterring attacks by the salticids Paraphidippus aurantius and Phidippus bidentatus. We tested the effect of band visibility and the fly’s physiological condition on the production of these displays and the probability of attack by salticids. We filmed the interactions of flies and spiders and analysed fly displays in the presence of the salticid. We show that the fly’s display deters salticids and promotes the fly’s chances of survival and that the presence or absence of bands does not alter the possibility of attack. Flies fed on different quality diets showed similar rates of display. Our results suggest that tephritid flies deter attacks because of their display and not their appearance.

 

Also the Anelosimus paper is out as well,

Notes on the ecology and behavior of a subsocial spider Anelosimus baeza (Araneae: Theridiidae) in Mexico 

Abstract. Subsocial spiders are located on the continuum between solitary species and social species and are characterized by extended maternal care, some cooperation in foraging and colony activities and dispersal in order to found new colonies. In the genus Anelosimus (Araneae: Theridiidae), up to nine species are thought to be subsocial. One of these spiders, A. baeza Agnarsson (2006), is distributed across a large geographical range from Mexico to southern Brazil, and potential differences in behavior in different populations are unknown. We studied the ecology and behavior of a population of A. baeza in a cloud forest habitat in Mexico. We tracked the population for ten months, analyzed the degree of cooperation and the presence of associated species, and explored the settling decisions made by dispersing spiders. We show that the breeding season for A. baeza in Mexico differs from other populations elsewhere in South America. Using a kinematic diagram, we recorded the sequence of behaviors involved in subduing and feeding on a model prey species. Larger colonies harbored more associated species. Anelosimus baeza prefers to settle in locations that already contain conspecifics or silk. Our study demonstrates that A. baeza is a viable candidate for research into sociality in spiders and its geographical correlates.