Comparison of Flight Periods of Solitary and Primitively Eusocial Bees in Urban Environments and Nature Conservation Areas: a Preliminary Report

Abstract

Solitary and primitively eusocial bees, an important group of pollinators, have declined in the past few decades. In view of the recent focus on safeguarding pollinating insects, it is vital to understand the basic ecology of species for their conservation, for example their phenologies. We observed the flight periods of solitary and primitively eusocial bees in both the urban core of a large British town and nearby nature conservation areas. The bee surveys were conducted with standardised methods, on warm sunny days from the first appearance of bees in March 2012 and continued until October 2012. This study confirmed that a high number of species are active in the spring season. The emergence dates of species in urban areas and nature sites varied; about 26 of the 35 species were recorded at least one week earlier in urban areas; in contrast, only four species were seen earlier in nature conservation sites. When comparing this with the expected flight periods recorded (largely in nature sites) in the literature, many species were recorded at their expected time. However, a few individuals were recorded after their usual flight activity time, suggesting that the populations were possibly affected by the microclimate in urban areas. More urban phenological data are needed to understand the phenological trends in bees in urban habitats.