Cover Story

April 2014

Proceedings of the American Bee Research Conference

(excerpt)

Compiled and Edited by Drs. Juliana Rangel and Rose-Anne Meissner, Research Associate, Department of Entomology, Texas A&M University, College Station, TX 77843
 
The 2014 American Bee Research Conference was held January 10 & 11, 2014 in San Antonio, Texas in conjunction with the annual meeting of the American Honey Producers Association. The following are abstracts from the 2014 Conference.
 
1. Burand, J.a, S. Zhenga, E. Ramosb, N. Reichb & A. Dea - VIRUS INCIDENCE IN MASSACHUSETTS BEEHIVES aDepartment of Microbiology, University of Massachusetts Amherst, Amherst, MA 01003 (e-mail: jburand@microbio.umass.edu), bDepartment of Public Health, University of Massachusetts Amherst, Department of Public Health, Amherst, MA 01003
 
Individual honey bees (Apis mellifera), from hives in University of Massachusetts apiary were analyzed over a two year period for the presence of viral pathogens. Bees from these hives were found to be infected with one or more of the 3 honey bee viruses: Black Queen Cell Virus (BQCV), Deformed Wing Virus (DWV), and Sacbrood Virus (SBV). During this time period (August 2010 to August 2011) the prevalence of each of these viruses varied both within a hive and between hives throughout both seasons. In both years DWV was the most prevalent of the viruses being present in 37% and 44% of the bees in 2010 and 2011 respectively. BQCV and SBV levels were high in 2010 bees (23.6% and 32.4% respectively) with the levels of both these viruses dropping to ~11% in 2011. Throughout this study we found a significant number of bees that were infected with more than one virus. We are currently examining the rates at which bees are infected with single and multiple viruses to determine if virus infection can lead to immune activation or suppression in
individual bees.

2. Burand, J.P.a, S. Zhenga & K. Stonerb. - Epizootiology of Honey Bee Viruses in Bee Populations Pollinating Cucurbits aDepartment of Microbiology, University of Massachusetts Amherst, Amherst, MA 01003 (e-mail: jburand@microbio.umass.edu), and bConnecticut Agricultural Experiment Station, New Haven, CT 06504
 
Several honey bee viruses including Black Queen Cell Virus (BQCV), and Deformed Wing Virus (DWV) have been found to infect other bees including several species of bumble bees. These findings have led us to examine the possibility that these viruses move from honey bees to other bees during foraging on common floral resources. To investigate this possibility we used a molecular approach to detect the presence and prevalence of both of these viruses in bee pollinators found foraging on pumpkins (Cucurbita sp.) on four farms in Connecticut. The three main groups foraging on pumpkins, Apis mellifera, Bombus sp. and Peponapis pruinosa, were sampled 5 times at each site from early June to late September. Sampling included approximately 20 bees of each group when available. Our initial analysis has focused on BQCV which appears to be the most prevalent of the viruses in bees we have examined to date. Of the ~ 300 bees we have analyzed to date, 47% were found to be infected with BQCV. This virus was the most prevalent in Apis with 58% being infected, while the Bombus and Peponapis were infected at 39% and 3% respectively. The level of virus-positive bees from the different farms ranged between 4% and 58% and overall our results suggest a correlation between the level of this virus in honey bees and the level of infection of other bee species. On the two farm sites where we found honey bees infected with BQCV at 93% and 75%, Bombus bees were at 77% and 40% respectively. At the site where we found only 10% of Apis infected with BQCV we were able to detect only 5% BQCV infected Bombus, suggesting that the infection of Apis and Bombus is clustered and may be connected in some way.

3. Catalfamo, K.M., B.E. Traver, H.K. Feazel-Orr, N.G. Johnson, T.D. Anderson & R.D. Fell - VIRUS PREVALENCE IN HONEY BEES FOLLOWING COLONY TREATMENT WITH CHLOROTHALONIL, FUMAGILLIN, AND TAU-FLUVALINATE Virginia Tech University, Department of Entomology, Blacksburg, VA, 24061 (e-mail: kmcat92@vt.edu)
 
Increased colony loss has been a rising concern for European honey bee, Apis mellifera, populations. Although the causes of increased losses are unknown, researchers have hypothesized that various factors are to blame. Two factors believed to strongly correlate with colony losses are viral infections and exposure to pesticides. Viruses often lead to cell death and can cause the host to die. Pesticides are known to reduce immune system responses and make organisms more vulnerable to disease. This study focused on exposing honey bee colonies to three different pesticides to determine whether black queen cell virus (BQCV) and deformed wing virus (DWV) infection levels were impacted in honey bee colonies. The three pesticides used were the miticide tau-fluvalinate, the antibiotic fumagillin used for Nosema control, and chlorothalonil, a commonly encountered fungicide outside of the hive. The presence of DWV and/or BQCV in randomly sampled female workers was determined using RT-PCR. For samples positive for either virus, a semi-quantitative approach using band density was used to measure virus levels. All virus levels were normalized using each sample’s level of β-actin. For DWV, we did not see significant differences in levels across time or across treatments for fall, winter, and spring. There were no significant differences in levels of BQCV in the fall or winter, but there was a significant difference in the infection levels of BQCV across time during the spring (p<0.01). As a trend, the levels of BQCV decreased after the fall, persisted at low levels in the winter, and then increased in the spring. The levels of DWV decreased from fall through spring. We also saw a significant decrease in varroa mite levels in the fall with tau-fluvalinate treatment (p<0.01). The data from this study show low incidence of BQCV and DWV in colonies in both the absence and presence of pesticides. Our data suggest that chlorothalonil, fumagillin, and tau-fluvalinate do not have a direct impact on the prevalence of BQCV or DWV in honey bee colonies.
 
4. Coulson, R.N., M.D. Tchakerian, J. Rangel & W. Baxter – THE TEXAS APIARY INSPECTION SERVICE: INFORMATION MANAGEMENT SYSTEM (TAIS/IMS) Texas A&M University, Department of Entomology, College Station, TX 77843
 
The Texas Apiary Inspection Service Information Management System (TAIS/IMS) is an INTERNET-based application designed to standardize and automate apiary inspection in Texas. The Texas Apiary Inspection Service is charged with regulating the honey bee industry so that colonies with diseases and parasites are restricted from movement or are destroyed. The new program employs a mobile mapping/data collection system that captures, displays, and archives spatial and tabular information on the distribution, abundance, and location of honey bee diseases, parasites, and associated organisms. TAIS/IMS will expedite the apiary inspection process and facilitate timely reporting of results.

5. Eiri, D.M.a, G. Suwannapongb, M. Endlerc & J.C. Niehc – NOSEMA CERANAE CAN INFECT HONEY BEE LARVAE AND REDUCE SUBSEQUENT ADULT LONGEVITY aDepartment of Integrative Biology, University of Texas, Austin, TX 78712 (e-mail: eiri@utexas.edu), bDepartment of Biology, Burapha University, Chon Buri 20131, Thailand, cDivision of Biological Sciences, Section of Ecology, Behavior, and Evolution, University of California, San Diego, La Jolla, CA 92093
 
The microsporidian Nosema ceranae is a global problem that decreases honey bee fitness. It is thought to only infect adult honey bees and thus its potential to infect a key life stage, larvae, has been neglected. We reared honey bee (Apis mellifera) larvae in vitro and demonstrate that N. ceranae can infect larvae with subsequent detrimental effects. Three-day-old larvae were given a single dose 0 (0K), 10,000 (10K), or 40,000 (40K) spores. After larvae had defecated and become pre-pupae, we dissected out their midguts and counted the number of N. ceranae spores. Significantly more spores were present in pre-pupae from the 10K and 40K treatments as compared to the control. Separately, we reared larvae to adulthood and counted midgut spores at adult death. Larval infection significantly decreased 40K-treated adult longevity. However, the low dose (10K), unexpectedly led to significantly more infection than the high dose (40K). Adults infected as larvae contained an average of 16,021±3,085 spores (maximum of 215,000 spores), and 12,454±3,647 spores (maximum of 295,000 spores) for the 10K and 40K doses respectively. Control bees were minimally contaminated. Differential immune activation may account for these results if the higher dose triggered a stronger response. Immune defense can be costly and could result in 40K-treated bees having lower infection levels and longevity as compared to 10K-treated bees. Honey bee larvae can thus be a reservoir of N. ceranae infection whose effects may be masked by relatively low levels of adult infection but nonetheless decrease lifespan.