Sexual dimorphism in excess power index of four North American native bees (Hymenoptera, Andrenidae, Apidae, and Halictidae)

By

Vigueira, Patrick A.
Vigueira, Cynthia C.
Campbell, Joshua
Ladner, Samia
Hayes, Gabrielle
Riser, Elizabeth

Type

Article

Date of Publication

2023

Original Publication

Journal of Hymenoptera research

Volume

96

Pages

121--128

Subjects

excess power index , flight machinery , sexual dimorphism , wing loading

Contributed by

Pensoft Publishers

Language

English

Published by

Washington, D.C International Society of Hymenopterists

Identifiers

DOI: https://doi.org/10.3897/jhr.96.98652

 

Abstract

A multitude of hymenopteran species exhibit sexual dimorphism for simple traits, such as color, size, or antennal segment number. These differences can reflect selection for specialized biological roles, many of which have not been documented for the majority of bee and wasp species. The excess power index (EPI) is an estimate of insect flight performance that is inferred by the combination of several morphological characteristics. We compared the female and male EPIs in four species of native bees: Agapostemon virescens Fabricius, Andrena carlini Cockerell, Melissodes bimaculata Lepeletier and Xylocopa virginica L.. While females of each species had a significantly larger whole body mass, males had a significantly larger EPI. A larger body mass for females is associated with egg laying abilities and foraging behavior. Male fitness may be dependent on EPI; males that have greater flight capacity can travel further or remain in flight for longer time periods in search of mates.