Cavity-nesters
Guides
Hylaeus
Masked Bees, Yellow-faced Bees
Hylaeus is a large, diverse genus of solitary bees in the family Colletidae, commonly known as masked bees or yellow-faced bees. The genus contains over 500 species with cosmopolitan distribution, reaching peak diversity in subtropical Australia and the Hawaiian Islands. These bees are distinguished by their nearly hairless, wasp-like appearance and unique method of transporting nectar and pollen internally in a crop rather than externally on body hairs. Many species nest in pre-existing cavities such as hollow stems, beetle borings in wood, or abandoned galls.
Pachodynerus
potter wasps
Pachodynerus is a genus of approximately 50 species of solitary potter wasps in the subfamily Eumeninae. The genus exhibits highest diversity in central South America, with species distributed across the Neotropical and Nearctic regions. These wasps are cavity-nesters that construct mud cells in pre-existing holes, including abandoned insect burrows, plant stems, and human-made structures. Several species have been introduced beyond their native ranges, including P. nasidens which has established populations on oceanic islands and caused aviation safety incidents in Australia by nesting in aircraft pitot probes.
Potter and Mason Wasps
Potter Wasps, Mason Wasps
Eumeninae is a cosmopolitan subfamily of solitary wasps within Vespidae, commonly known as potter and mason wasps. The group includes approximately 3,579 described species worldwide, making it the most diverse group within Vespidae. Adults are primarily nectar-feeders, while larvae are predatory, developing on paralyzed caterpillars or beetle larvae provided by females. Nesting strategies are diverse: many species use pre-existing cavities in hollow stems, wood, or abandoned insect burrows, while others construct free-form mud nests or excavate burrows in soil. Females typically lay a single egg suspended by a silken thread before provisioning cells with prey, a distinctive trait among solitary wasps.
Pseudoanthidium
Small Carder Bees, African Carder Bee (for P. repetitum)
Pseudoanthidium is a genus of small carder bees in the family Megachilidae, first described by Friese in 1898. The genus occurs across Eurasia, Africa, and Australia, with nine species recorded in Europe. Some species are cavity-nesters that utilize plant fibers and foreign materials for nest construction. The introduced African carder bee (P. repetitum) has established populations in eastern and Western Australia since 2000 and shows potential for continued range expansion.