Description and nesting biology of three new species of neotropical silk wasp (Hymenoptera: Apoidea: Pemphredoninae: Microstigmus)

The neotropical apoid wasp genus Microstigmus is of particular interest biologically because it represents an origin of eusociality independent of vespid wasps and bees, and is part of the only eusocial lineage among the approximately 10,000 solitary species of apoid wasps. Females construct nests made of silk and the species exhibit an unusual diversity of nesting strategies. However, research is hampered because many species remain undescribed and the basic nesting biology of only a few species is known. I describe three new species from north-west Ecuador related to M. bicolor Richards, including diagnostic morphological characters, altitudinal ranges and molecular data as well as descriptions of their nests and nesting biologies. M. rosae sp. nov. is a mass provisioner that preys on nymphal Thysanoptera, while M. lydiae sp. nov. and M. mirandae sp. nov. are progressive provisioners that prey on nymphal leafhoppers (Cicadellidae). Nests of all three species can contain multiple adult females but more than half of nests contain only a single female. http://www.zoobank.org/urn:lsid:zoobank.org:pub:E46768B9-FD13-4370-8E31-8D1819B724F4