title: Notes on the biology of Trypoxylon (Trypargilum) opacum Brèthes (Hymenoptera; Crabronidae) in Southern Brazil.
abstract: The present study investigated the abundance, seasonality and various life-history traits of Trypoxylon (Trypargilum) opacum. Using trap-nests, 320 nests of T. opacum were collected in the Parque Municipal das Araucárias in Southern Brazil (25 degrees 23' 36" S and 51 degrees 27' 19" W) over a 3 year period. Nesting was more frequent during the warm season. Nests consisted of a linear series of 1 to 8 brood cells separated by mud partitions, usually followed by an empty vestibular cell and final-closure mud plug. Brood cells were most commonly provisioned with spiders of the family Araneidae. Sex-ratio was strongly female biased, 3.4:1 females:males. Natural enemies attacking nests T. opacum included chrysidids, ichneumonids, sarcophagids, bombyliids and ants.
authors.affiliation: Depto de Biologia, UNICENTRO, Guarapuava, PR, Brazil. isatunes@yahoo.com.br
authors.forename: M L T
authors.initials: ML
authors.lastname: Buschini
authors.forename: L L
authors.initials: LL
authors.lastname: Wolff
mesh_terms: D000818:Animals; D001938:Brazil; D017753:Ecosystem; D005260:Female; D008018:Life Cycle Stages / Q000502:physiology*; D008297:Male; D009425:Nesting Behavior / Q000502:physiology*; D011156:Population Density; D012621:Seasons; D012744:Sex Ratio; D014863:Wasps / Q000254:growth & development / Q000502:physiology*