The Role of Honey Bee Derived Aliphatic Esters in the Host-Finding Behavior of <i>Varroa destructor</i>
Jiamei Liu,
Ruonan Zhang,
Rui Tang,
Yi Zhang,
Rui Guo,
Guojun Xu,
Dafu Chen,
Zachary Y. Huang,
Yanping Chen,
Richou Han,
Wenfeng Li
Affiliations
Jiamei Liu
College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China
Ruonan Zhang
Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou 510260, China
Rui Tang
Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou 510260, China
Yi Zhang
School of Chinese Medicinal Resource, Guangdong Pharmaceutical University, Yunfu 527527, China
Rui Guo
College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China
Guojun Xu
College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China
Dafu Chen
College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China
Zachary Y. Huang
Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
Yanping Chen
USDA-ARS Bee Research Laboratory, Beltsville, MD 20705, USA
Richou Han
Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou 510260, China
Wenfeng Li
Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou 510260, China
Varroa destructor is an obligate ectoparasite of honey bees and shifted from its original host Apis cerana to the new host Apis mellifera in the first half of the twentieth century. The host shift has resulted in a great threat to the health and survival of A. mellifera colonies worldwide. Chemical signals play a crucial role in all aspects of the Varroa life cycle, including host finding. However, the chemical cues that affect the host finding behavior of Varroa mites are still not fully understood. In this study, we systematically profiled the headspace volatiles of both worker and drone larvae of the two honey bee species by using solid phase micro-extraction coupled to gas chromatography-mass spectrometry (SPME-GC-MS), and then used electrophysiological recording and Y-tube olfactometer bioassay to study the potential roles of the selected compounds. The chemical profiling showed that there were four aliphatic esters, ethyl myristate (EM), methyl palmitate (MP), ethyl palmitate (EP), and ethyl oleate (EO) commonly detected from all four types of larval hosts. Among them, EM was a new substance identified from honey bee headspace volatiles. Results from electrophysiological recordings indicated that all the aliphatic esters could elicit significant responses of Varroa pit organs on its forelegs. Moreover, behavioral analyses revealed that EM could significantly attract V. destructor at a medium dosage (10 µg), while MP had no observable effect on the mites and both EP and EO were able to repel the parasites. Our findings suggest an important role of host-derived aliphatic esters in Varroa host finding, and provide new chemicals for Varroa monitoring and control.
