Abstract

CAMILLO, Evandro. A solitary mud-daubing wasp, Brachymenes dysmenes (Hymenoptera: Vespidae) fron Brazil with evidence of a life-cycle polyphenism . Rev. biol. trop [online]. 1999, vol.47, n.4, pp.949-958. ISSN 0034-7744.

Nests (n=60) of a solitary mud-daubing wasp, Brachymenes dyscherus were collected at Fazenda Santa Carlota, Cajuru, São Paulo, Brazil in 1995 and 1996. The multi-celled mud nests were constructed on the interior walls of abandoned houses in dry and shaded places. Nests were composed of 1 to 4 layers with cells constructed in two parallel series. The number of cells per nest ranged from 3 to 62. Cells containing prey (larvae of Lepidoptera) numbered from 4 to 29. B. dyscherus is a univoltine species. Adults emerge from September to December, and nesting takes place at the beginning of the following year; however, the developmental period for some immatures with prolonged diapause lasted up to 596 days. The total duration of immature stages in nests collected in 1996 was less for males than for females. The sex ratio for the total population was 1.5 males : 1 female with males emerging earlier than females. A life table was constructed, and details of the life cycle of the wasps and parasitoids are presented. The most common mortality factors were either endogenous or due to Melittobia sp. (Eulophidae).

Keywords : Insecta; Eumeninae; wasps; nest structure; natural enemies; polyphenism.