EARLY SURVIVAL OF POLISTES APACHUS (HYMENOPTERA: VESPIDAE) COLONIES IN CALIFORNIA: A FIELD STUDY OF AN INTRODUCED SPECIES

Abstract

A local population of P. apachus in California was studied to determine population structure and colony survival during the first 3 months of colony development. Only 24.2% of the colonies survived to the end of July. Bird predation on colonies (60.6%) and loss of foundresses (12.1%) were the main causes of colony failure. Bird attacks occurred approximately 2 weeks prior to the emergence of workers and the scrub jay, Aphelocoma coerulescens, was identified as one of the avain predators. All colonies that survived this initial period persisted until observations were discontinued in late July.