Location: Chemistry Research Unit
Title: Examining the role of foraging and malvolio in host-finding behavior in the honey bee parasite, Varroa destructor (Anderson & Trueman) Authors
Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 26, 2013
Publication Date: December 24, 2013
Citation: Cabrera, A.R., Shirk, P.D., Grozinger, C.M., Evans, J.D., Teal, P.E. 2013. Examining the role of foraging and malvolio in host-finding behavior in the honey bee parasite, Varroa destructor (Anderson & Trueman). Archives of Insect Biochemistry and Physiology. 85(2):61-75. Interpretive Summary: The varroa mite is the major ectoparasite pest of the honey bee in North America and weakens the infested colonies not only by feed but vectoring pathogens. Scientists at the USDA ARS, Center for Medical, Agricultural and Veterinary Entomology identified the genes for 2 proteins that can influence feeding behaviors in the varroa mite. The foraging gene that regulates intra-cellular communication and the malvolio gene that regulates heavy metal transport were DNA sequenced and the transcripts characterized. The levels of transcript for both genes remained constant when the female mite transitioned between a feeding stage and a reproductive stage. These genes provide significant targets for disruption using molecular techniques to control or disrupt the physiology of the pest varroa mites.
Technical Abstract: When a female varroa mite, Varroa destructor (Anderson & Trueman), invades a honey bee brood cell, the physiology rapidly changes from the feeding phoretic to reproductive. Changes in the foraging and malvolio transcript levels in the brain have been associated with modulated intra-specific food searching behaviors in insects and other invertebrates. We examined the regulation of these two genes as potential control elements for brood cell invasion by determining transcript profiles for the foraging (Vdfor) and malvolio (Vdmvl) genes in varroa mites immediately following invasion. The complete transcripts from Vdfor and Vdmvl were sequenced and the genomic organization of each gene was identified and characterized. The foraging gene codes for a cGMP-dependent protein kinase (PKG) while the malvolio gene codes for a manganese, iron and copper transporter. Vdfor and Vdmvl transcripts were found in all organs of the varroa mites. Changes in transcript levels of Vdfor and Vdmvl in synganglion preparations were not associated with the cell invasion process, remaining comparable between early reproductive mites (collected from the pre-capping brood cells) and phoretic mites. The varroa mite is a critical component for the decline of honey bee populations and finding varroa mite genes associated with the brood cell invasion will facilitate the search of novel control avenues for this honey bee parasite.