Spiders Used as Prey by the Hunting Wasp Trypoxylon (Trypargilum)agamemnon Richards (Hymenoptera: Crabronidae)

ABSTRACT

Spiders used as prey by the hunting wasp Trypoxylon (Trypargilum) agamemnon Richards(Hymenoptera Crabronidae). Zoological Studies 49(2) 169-175. The purpose of this study was to monitor thespider fauna in Trypoxylon agamemnon nests. The study was carried out from Dec. 2001 to Dec. 2006 in theParque Municipal das Araucárias, in the municipality of Guarapuava, state of Paraná, southern Brazil. Nests ofT. agamemnon were obtained using trap-nests made of wooden blocks. To investigate the similarity betweenspider species in T. agamemnon’s diet, spiders species were grouped according to their abundances, using theBray-Curtis coefficient as a metric method and the unweighted pair group method average (UPGMA) as theclustering method. Spider species dominance was calculated, and Chi-square tests were used to test the nullhypothesis that there was no significant difference among the proportions of collected juvenile, male, and femalespiders. In contrast to what was recorded for other species of spider-hunting wasps, T. agamemnon exclusively captures spiders (of the Anyphaenidae) that forage on the vegetation. This probably maintains niche partitioning between Trypoxylon species that occur in the Parque Municipal das Araucárias, reducing competition for prey.