Odor learning and odor discrimination of bees selected for enhanced hygienic behavior.

Chakroborty, Neloy; Bienefeld, Kaspar; Menzel, Randolf

Odor learning and odor discrimination were tested in a line of honeybees selected for increased hygienic behavior (HB) against the Varroa mite and compared with control bees (CB). Olfactory proboscis extension conditioning was used to quantify learning, discrimination, and generalization. Retention tests were performed after 1 h and after 1 day to probe the stability of memory. HB and CB did not differ in their learning, discriminating, generalizing, and remembering behavior when pairs of floral odors and pairs of sting pheromone and floral odor were tested. Colony odor used as a background odor during learning and discrimination reduced the performance in both groups, possibly due to an adaptation effect. This effect was found to be particularly strong in CB. In both groups of test bees, no learning was found if wax caps of Varroa-infected and Varroa-uninfected cells were used as test stimuli, possibly because of the common odors. Volatile odors from Varroa-infected and noninfected pupae, however, were learned and discriminated indicating that the volatile signals are strong enough to override the similar cues of pupae. HB performed somewhat better than CB when infected pupae were used as the rewarded stimulus, but the difference between the two groups of test bees was small. Taken together, we conclude that odor learning and discrimination do not differ between HB and CB as long as general odors are involved, but when specific odor profiles from infected pupae are used as the reinforced signal, then a slightly better performance is seen in HB.

COGNITIVE structures; LEARNING curve; BIOLOGICAL control of mites; COLONY collapse disorder of honeybees; BEHAVIOR

Apidologie, 2015, Vol 46, Issue 4, p499

0044-8435

Academic Journal

10.1007/s13592-014-0342-x