International Union for the Study of Social Insects (IUSSI2018), August 5-10, 2018 in Guarujá, Brazil.

only days left!
Find us: Ft

An alkaloid in toxic nectar alters olfactory learning differently between sympatric and introduced honey bees

Author(s):
Zhengwei Wang, Zhengwei Wang , Junjun Zhang , Yuan Li , Yufeng Qu , Ken Tan , James Nieh
Institution(s):
Chemical Ecology Group, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China; Chemical Ecology Group, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China ; University of Chinese Academy of Sciences, Beijing, China ; University of Chinese Academy of Sciences, Beijing, China ; Chemical Ecology Group, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China ; Chemical Ecology Group, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China ; Division of Biological Sciences Section of Ecology, Behavior, and Evolution University of California, San Diego La Jolla, California, USA
The nectar of the thunder god vine, Tripterygium hypoglaucum, contains a terpenoid, triptolide (TRP), that toxic to both sympatric Asian honey bee, Apis cerana, and introduced Western honey bee, Apis mellifera. However, these bees will forage on, recruit for, and pollinate this plant during a dearth season. To test two different hypotheses: firstly, the A. cerana was sympatric with T. hypoglaucum, which may lead a higher toxin tolerance than A. mellifera because of long co-evolution; alternatively, the A.mellifera may have a higher toxin tolerance than A.cerana simply because the larger size which can bear higher doses. Olfactory learning plays a key role in forager constancy and pollination, we therefore using proboscis extension reflex conditioning to test the effects of acute and chronic triptolide feeding on forager olfactory learning on these two honey bee species. Even though the A. mellifera was 1.17 fold larger in body mass, 1.69 fold in nectar consumption than A. cerana, at concentrations of 0.5-10 μg TRP/ml, there were no learning effects of acute exposure on A. cerana, while the high concentration of 5-10μg TRP/ml would reduce olfactory learning on A. mellifera. Chronic exposure did not alter learning and memory on A. cerana, except at high concentrations, and olfactory learning scores were dramatically reduced on A. mellifera even from lowest concentration of 0.5μg TRP/ml. The results may indicate TRP concentrations in nectar may therefore not significantly harm sympatric pollinators. More comparative studies between A. cerana and A. mellifera foraging on toxic nectar are needed to better understand the detoxification mechanisms and the co-evolution of the toxic plant and its reluctant visitors.
Back