Entering behavior of Gasteruption brachychaetum Schrottky (Hymenoptera, Gasteruptiidae) into a nest of Hylaeus Fabricius (Hymenoptera, Colletidae)

Nests of Hylaeus aff. guaraniticus (Schrottky, 1906) were parasited by females of Gasteruption brachychaetum Schrottky, 1906 in trap nests in Sao Paulo (Brazil). This is the first host record of a Gasteruptiidae in the Neotropical Region. The behavior of a G. brachychaetum female entering a host's nest is described as follows: an inquiline female hovered near the host's nest, landed and detected that a female of H. aff. guaraniticus was inside the nest, waited for the host female to fly out, entered backwards into the nest, remained there for almost six minutes, and then went out the nest. The development time of immature stages of G. brachychaetum varied between 16 and 299 days.Original Abstract: Ninhos de Hylaeus aff. guaraniticus (Schrottky, 1906) foram parasitados por femeas de Gasteruption brachychaetum Schrottky, 1906 em ninhos-armadilha em Sao Paulo (Brasil). Este e o primeiro registro de hospedeiro de um Gasteruptiidae na regiao Neotropical. O comportamento de uma femea entrando no ninho do hospedeiro e descrito: a femea inquilina pairou sobre o ninho do hospedeiro, pousou e detectou que a femea de H. aff. guaraniticus estava dentro do ninho, esperou a femea hospedeira voar para fora do ninho, entrou de costas no ninho, permanecendo no local por quase seis minutos, em seguida, partiu voando. O tempo de desenvolvimento dos imaturos de G. brachychaetum variou entre 16 e 229 dias.