Nesting Biology of a Quasisocial Sphecid Wasp Trypoxylon fabricator : I. Nests and Inhabitants

The Neotropical spider hunting wasp Trypoxylon fabricator SMITH builds mud nests mainly on vertical walls. Nests are combed, consisting of cells made in parallel but cells not sharing walls with each other. Cells are reused and some nests contain up to 207 cells ; nests are inhabited by up to 20 adult wasps (more females than males). Cohabiting females are similar in size, age and reproductive condition, and some cases of cell sharing are recorded. Hence the colonies are considered to be quasisocial (MICHENER, 1974). However, cell sharing is evidenced by the presence of some anomalous contents suggesting negative interference. Possibly quasisociality is kept unstable in part by such behavioral noise.