Seasonal foraging characteristics during mid-day of successful underground colonies of Vespula vulgaris (Hymenoptera, Vespidae) in England

Summary:

The hourly transit rates and the number of forager types during the middle of the day are presented for successful colonies of V. vulgaris. Outgoing foragers are divided into earth carriers and non-earth outgoers. Incoming foragers are divided into pulp, flesh and fluid carriers, and empty incomers. Fluid carriers also are divided into full and partial fluid carriers. The transit rates of different colonies are expressed as a percentage of their highest transit rates so that data from different colonies can be considered together. The percentage values of each type of outgoing and incoming forager are calculated from the daily counts so that again, data from different colonies can be considered together. The total hourly number of foragers and forager types during the middle of the day is used to generate a model for a hypothetical larger and smaller colony, during the whole of the colony's existence. During a colony's existence, 27.5 % of the outgoers are earth carriers, and of the incomers, 12.2 % are pulp carriers, 12.0 % flesh carriers, 72.2 % fluid carriers, and 3.7 % empty incomers. The relative lack of earth carriers during the large-cell colony phase can be related to the use of the nocturnal resting space in which some of the large-cell combs are built. This space, at the bottom of the nest, was excavated and used by the workers during the small-cell colony phase. Empty incomers are considered to be new foragers and/or colony guards.