Through the use of proboscis-extension reflex conditioning, we demonstrate that honey bees (Apis mellifera L.) bred for hygienic behavior (a behavioral mechanism of disease resistance) are able to discriminate between odors of healthy and diseased brood at a lower stimulus level than bees from a non-hygienic line. Electroantennogram recordings confirmed that hygienic bees exhibit increased olfactory sensitivity to low concentrations of the odor of chalkbrood infected pupae (a fungal disease caused by Ascosphaera apis). Three-week-old hygienic bees were able to discriminate between the brood odors significantly better than three-week old non-hygienic bees. However, the differential performance in brood odor discrimination was primarily genetically based, not a direct result of age, experience, or the temporary behavioral state of the bee. Lower stimulus thresholds for both the olfactory and behavioral responses of hygienic bees may facilitate their ability to detect, uncap and remove diseased brood rapidly from the nest. In contrast, non-hygienic bees, possessing higher response thresholds, may not be able to detect diseased brood as easily. Our results provide an example of how physiological and behavioral differences between the hygienic and non-hygienic honey bee lines, operating at the level of the individual, could produce colony-specific behavioral phenotypes.
|Original language||English (US)|
|Number of pages||12|
|Journal||Journal of Comparative Physiology - A Sensory, Neural, and Behavioral Physiology|
|State||Published - 2001|
Bibliographical noteFunding Information:
Acknowledgements The authors thank Gary Reuter for his expert technical assistance with the honey bee colonies, Jackie Gaustad and Jenny Warner for assistance with PER conditioning, and H.S. Arathi and the anonymous reviewers for their thoughtful review of the manuscript. The authors also thank David Tronrud, Jenny Warner, and John Hickey for assistance in the experiments and honey bee colony maintenance. This work is in partial fulfillment of the Ph.D. degree for R.M. at the University of Minnesota. We acknowledge the Louise T. Dosdall Fellowship, Alexander P. and Lydia Anderson Fellowship and University of Minnesota Department of Entomology Fellowships for support of R.M. This work was funded by grant number IBN 9722416 of the National Science Foundation awarded to M.S.
- Apis mellifera
- Hygienic behavior
- Proboscis-extension reflex
- Response thresholds