Structure of Nests and Colony Sizes of the European Hornet (Vespa crabro) and Saxon wasp (Dolichovespula saxonica) (Hymenoptera: Vespinae) in Urban Conditions

Jerzy Nadolski

doi:10.13102/sociobiology.v59i4.486

Abstract

Studies of different groups of insects in urban areas sometimes show large populations, greater than in non-urban areas. The reason for this is a presence in the cities some of dominating species which often occur almost en masse.This group includes, inter alia, hymenopterans and especially social wasps (Vespinae). Colonies and nests of two wasp species, the European hornet (Vespa crabro) and Saxon wasp (Dolichovespula saxonica) in areas of the city of Łódź in Poland were studied. Whole colonies positioned both in buildings as well in natural places, size of societies, parameters their nests, differentiation of cells in combs and their location were investigated. We also studied the correlation between the size of the nest and societies of these insects. It was found that nests established in the buildings are much larger, produced more individuals of reproductive castes and thus obtained a better reproductivesuccess especially for the hornet colonies whose queens prefer the buildings as a place to nest.

Highlights

Due to the diversity of habitats and wealth of species as well their small size, there is often a lack of information regarding insects existing in urban areas
Studies were conducted on two species of social wasps – the European hornet - Vespa crabro (Linnaeus, 1758) and Saxon wasp - Dolichovespula saxonica (Fabricius, 1793)
The presented results of the analysis between the number of large cells and the number of workers in nests of Vespa crabro and Dolichovespula saxonica indicate no correlation of these variables in nests of V. crabro located in natural places and strong correlation in nests in buildings and for all colonies of D. saxonica

Summary

Introduction

Due to the diversity of habitats and wealth of species as well their small size, there is often a lack of information regarding insects existing in urban areas. Numerous and large-scale studies determined the species composition of this group of insects, their proportions as well as the dynamics of quantitative changes in the urbanized areas (Pawlikowski 1998; Nadolski 2000b; Nadolski 2001; Pawlikowski et al 2005; Hermes & Köhler 2006; Christie & Hochuli 2008; Langowska et al 2010) The study of this group of insects is important because wasps in the city can be hazardous for people. Studies were conducted on two species of social wasps – the European hornet - Vespa crabro (Linnaeus, 1758) and Saxon wasp - Dolichovespula saxonica (Fabricius, 1793) Both species differ in size of individuals, as well as colonies, and their nests are convenient for research because they are built in places relatively easy to locate. This fear, which is not always fully justified, causes that people massively inform municipal services about practically all of the observed colonies of wasps and a large part of the nests is removed

Methods

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Discussion