Journal of the Kansas Entomological Society
Colletes inaequalis Say, C. thoracicus Smith and C. validus Cresson usually occupy the same forest habitat in Mary-land, both sexes are interspecifically attracted to the same linaloolcitral mandibular gland pheromone, and two species share nest and mating aggregations. Nesting activity and food sources of all three overlap. The earliest, C. inaequalis, emerges as soon as the earth thaws in spring and uses primarily Acer pollen; C. validus pollinates mainly Vaccinium, and the latest, C. thoracicus, commonly visits Liriodendron. The subterranean nests of all three species are similar. Sexual behavior is described, including the in copula nuptial flight of C. thoracicus. An expanding aggregation of C. thoracicus in a suburban lawn included over 104,500 nests; other such outbreaks are known. Nest and cell construction were observed. The brood cells are lined with a polyester membrane derived from macrocyclic lactones secreted by the Dufour's gland, imbibed and applied by the glossa. Hylaeus constructs a morphologically similar membrane from silk secreted apparently by the thoracic salivary glands.
Batra, Suzanne W. T., "Ecology, Behavior, Pheromones, Parasites and Management of the Sympatric Vernal Bees Colletes Inaequalis, C. Thoracicus and C. Validus" (1980). Ba. Paper 94.
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