A comparative study of the exocrine products of cleptoparasitic bees (Holcopasites) and their hosts (Calliopsis) (Hymenoptera: Anthophoridae, Andrenidae).

The cephalic secretion of females of the cleptoparasitic beeHolcopasites calliopsidis contains two main volatiles, 6-methyl-5-hepten-2-one and geranyl acetone. The mandibular gland secretion of its host,Calliopsis andreniformis, on the other hand, contains the two isomeric forms of citral (neral and geranial). Neral and geranial are also produced by mandibular glands of two other species ofCalliopsis and one species in the related genusNomadopsis. The Dufour's gland ofC. andreniformis contains an oily secretion composed of hydrocarbons that are deposited on the brood cell walls and pollen balls providing a waterproof lining for both.

Alkali bees: response of adults to pathogenic fungi in brood cells.

Female alkali bees (Nomia melanderi) opened sealed cells containing brood infested with Aspergillus flavus, A. tamarii, Fusarium solani, Rhizopus sp., or Mucor sp. and filled them with compact soil, thus reducing fungus sporulation. Such awareness of the condition of sealed brood is hitherto unknown among solitary bees.