Spiders associated with Psychotria carthagenensis Jacquin. (Rubiaceae): vegetative branches versus inflorescences, and the influence of Crematogaster sp. (Hymenoptera, Formicidae), in South-Pantanal, Brazil

Tn Lima,Rr Faria

doi:10.1590/s1519-69842008000200002

Abstract

The aim of this study was to analyze: i) the spider community in vegetative and reproductive branches of Psychotria carthagenensis concerning relative abundance, guild composition and body size distribution; ii) ant abundance in different types of branches and iii) the spider behavior when experimentally put in contact with inflorescences covered with ants. There was no difference between vegetative and reproductive branches in relation to spider abundance, composition of guilds and body size distribution of spiders. However, there was a significant difference in ant abundance. In the behavioral experiment, 90% of the spiders were expelled from inflorescences by ants; in control treatment, 100% remained in the inflorescences. The ant density in different parts of the plant may explain the spider distribution.

Highlights

Spiders are scattered over almost all terrestrial environments, being more abundant in areas of rich vegetation (Foelix, 1996)
The goal of this paper was to analyze: i) the spider community in vegetative and reproductive branches of P. carthagenensis concerning relative abundance, guild composition and body size distribution, ii) ant abundance in different types of branches, and iii) the spider behavior when put in contact with inflorescences covered with ants
There was no difference in the comparison between the average values of spider number in vegetative (Mean = 1.41; SD = 1.268) and reproductive (Mean = 1; SD = 1.462) branches of P. carthagenensis (t = –1.076; df = 28; p = 0.291)

Summary

Introduction

Spiders are scattered over almost all terrestrial environments, being more abundant in areas of rich vegetation (Foelix, 1996). carthagenensis concerning relative abundance, guild composition and body size distribution, ii) ant abundance in different types of branches, and iii) the spider behavior when put in contact with inflorescences covered with ants. The relative abundance of ants among vegetative and reproductive branches was estimated using similar methods to those which were previously carried out with the spiders.

Objectives

Results

Conclusion