Abstract:

 In 2009 and 2010, the nest and cell structures and behavior of the Colletes gigas were studied in Guangdong province, China. We excavated some nests of the species aggregating in one place, and had a detailed description of two nests’ structure. We also observed and described the external morphology of the egg, larva and pupa of the species using scanning electron microscopy and light microscope. In addition, through using molecular and morphology methods, we identified another species of the genus Colletes, whose nest are found beside the nests of C. gigas. We found that C. gigas likes to construct nests in soil mixed with sand, and the nests often distribute in an aggregation. The nests consist of a main burrow and some lateral ones, each of which ends with a single cell. The abandoned nests of C. gigas can be reused by the female of the next generation, which constructs its new lateral burrows or expands the old ones. C. gigas feeds obligately on some species of the family Theaceae in Southern China, especially Camellia oleifera. The food mass of C. gigas contains a high proportion of nectar, liquid and even water. In addition, both the COI and 28S D2 data confirmed that the C. gigas can share nest habitat with another Colletes species.

Key words: Colletidae, Colletes gigas, nesting biology, DNA taxonomy, morphology