ARS | Publication request: A PHYLOGENETIC ANALYSIS OF NESTING BEHAVIOR IN THE GENUS OSMIA (HYMENOPTERA:MEGACHILIDAE)

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 19, 2001
Publication Date: July 1, 2001
Citation: Bosch Gras, J., Maeta, Y., Rust, R.W. 2001. A phylogenetic analysis of nesting behavior in the genus osmia (hymenoptera:megachilidae). Annals of the Entomological Society of America.

Interpretive Summary: Most phylogenetic studies use morphological or molecular characters to establish the evolutionary history of organisms. Behavioral characters are seldom used because they are traditionally considered to be more subject to evolutionary change than morphological or molecular characters. In this study we use behavioral characters and molecular characters to establish the phylogenetic relationship of 11 species of solitary bees in three subgenera of the genus Osmia. The comparison of both phylogenetic hypotheses (one based on behavioral characters and the other based on molecular characters) indicates that behavioral characters are consistent at the subgeneric level and useful to establish phylogenies in this bee group.

Technical Abstract: Cladistic analysis is used to study the evolution of 29 biological characters related to nesting behavior, nest provisioning, oviposition, cocoon spinning, defecation and life cycle ("nest characters") in 11 species of Osmia bees (Insecta: Hymenoptera: Megachilidae) and two outgroup genera. A molecular phylogeny based on 38 allozyme loci-as- characters and a combined character phylogeny are produced to compare to the nest character phylogeny. All phylogenetic trees support the monophily of the genus Osmia and the subgenus Osmia (Osmia) with Osmia ribifloris basal to the other species in this subgenus. The subgenus Chalcosmia is resolved as a sister clade to O. (Osmia) in the molecular tree and as sister to Cephalosmia in the nest character and combined trees. Levels of homoplasy are lower for nest characters than for molecular characters, indicating the strength of behavioral and physiological characters in phylogenetic analysis. Incomplete biological information from additional species of all three subgenera is provided to support the consistency of nest characters at the subgeneric level, and their use in the establishment of subgeneric phylogenies in the family Megachilidae.