Dependence of Brood Cell Length on Nesting Cavity Width in Xylicolous Solitary Wasps of Genera Ancistrocerus and Symmorphus (Hymenoptera: Vespidae)

Abstract

The application of trap-nests for the studies of cavity-nesting Hymenoptera eventually implies a need for immediate nest identification using its structure. Possible nest characters that may be potentially useful for the separation of closely related species are body size-dependent metrical parameters of brood cells. We studied the dependence of brood cell length on nesting cavity width in ten cavity-nesting predatory wasp species. Five hypotheses were tested. We calculated the derived parameters of brood cells needed for testing the hypotheses and, applying correlation and linear regression, assessed the degree of fit of the actual data to the hypothesized dependences. In three studied wasp species, the dependences of cell length on nesting cavity width in the datasets of cells with the brood of different sex supported different hypotheses. The results of the study demonstrate that species-specific metrical differences between related species, if present, are likely to be found in the length and width of a cell, but not in its volume.