Host recognition in a pollen-specialist bee: evidence for a genetic basisChristophe J. Praz, Andreas Müller and Silvia Dorn
ETH Zurich, Applied Entomology, Schmelzbergstrasse 9/LFO, 8092 Zurich, Switzerland
Received 25 January 2008 – Revised 15 May 2008 – Accepted 16 May 2008 - Published online 28 October 2008
Abstract - To investigate the effect of larval pollen diet on floral choice in a specialized bee species, we compared the floral preferences of individuals of Heriades truncorum (Megachilidae) reared on host pollen with those of individuals reared on two different types of non-host pollen. Females were allowed to nest in cages where both host and non-host flowers were available. All females, regardless of larval diet, restricted pollen collection to their host, although they visited the flowers of both host and non-host plants for nectar. When offered only the non-host pollen source, females ceased nesting activities. Males reared on non-host pollen exclusively restricted their patrolling flights to flowers of their normal host. This study provides the first empirical investigation of the imprinting theory in oligolectic bees, and unambiguously suggests that host recognition has a genetic basis in H. truncorum. We discuss the implication of this finding for the understanding of bee-flower relationships.
Key words: oligolecty / imprinting / Hopkin's host selection / Heriades truncorum / host recognition
© INRA, DIB-AGIB, EDP Sciences 2008