In a study replicated across two states and two years, we tested the sublethal effects on honey bees of the miticides Apistan (tau fluvalinate) and Check Mite+ (coumaphos) and the wood preservative copper naphthenate applied at label rates in field conditions. A continuous covariate, a colony Varroa mite index, helped us disambiguate the effects of the chemicals on bees while adjusting for a presumed benefit of controlling mites. Mite levels in colonies treated with Apistan or Check Mite+ were not different from levels in non-treated controls. Experimental chemicals significantly decreased 3-day brood survivorship and increased construction of queen supercedure cells compared to non-treated controls. Bees exposed to Check Mite+ as immatures had higher legacy mortality as adults relative to non-treated controls, whereas bees exposed to Apistan had improved legacy mortality relative to non-treated controls. Relative to non-treated controls, Check Mite+ increased adult emergence weight. Although there was a treatment effect on a test of associative learning, it was not possible to statistically separate the treatment means, but bees treated with Apistan performed comparatively well. And finally, there were no detected effects of bee hive chemical on colony bee population, amount of brood, amount of honey, foraging rate, time required for marked released bees to return to their nest, percentage of released bees that return to the nest, and colony Nosema spore loads. To our knowledge, this is the first study to examine sublethal effects of bee hive chemicals applied at label rates under field conditions while disambiguating the results from mite control benefits realized from the chemicals. Given the poor performance of the miticides at reducing mites and their inconsistent effects on the host, these results defend the use of bee health management practices that minimize use of exotic hive chemicals.

No abstract

Interleukin-2 (IL-2) induces heterodimerization of the IL-2 receptor ␤ (IL-2R␤) and ␥ c chains of its receptor and activates the Janus family tyrosine kinases, Jak1 and Jak3. Whereas Jak1 associates with IL-2R␤, Jak3 associates primarily with ␥ c but also with IL-2R␤. We analyzed four IL-2R␤ mutations that diminish IL-2-induced proliferation and found that each also decreased IL-2-induced signal transducer and activator of transcription (STAT) activation. For this reason, and because the mutations were in the IL-2R␤ membrane-proximal region, we investigated and found that each mutation diminished IL-2R␤ association with both Jak1 and Jak3. This suggested that these Jaks might interact with the same region of IL-2R␤; however, certain IL-2R␤ internal deletions and C-terminal truncations differentially affected the association of Jak1 and Jak3. Interestingly, just as Jak1-IL-2R␤ association is Jak3-independent and functionally important, we show that Jak3-IL-2R␤ association is Jak1-independent and implicate this association as being important for IL-2-induced Stat5 activation. Moreover, Jak1 and Jak3 could associate only in the presence of IL-2R␤, suggesting that these kinases can simultaneously bind to IL-2R␤. Thus, our data not only demonstrate that somewhat more distal as well as membrane-proximal cytoplasmic regions of a type I cytokine receptor are important for Jak kinase association but also suggest that two IL-2R␤-Jak kinase interactions are important for IL-2 signaling.

No abstract

Managed honey bee ( Apis mellifera ) colonies are kept at much greater densities than naturally occurring feral or wild colonies, which may have detrimental effects on colony health and survival, disease spread, and drifting behavior (bee movement between natal and non-natal colonies). We assessed the effects of a straightforward apiary management intervention (altering the density and visual appearance of colonies) on colony health. Specifically, we established three “high density / high drift” (“HD”) and three “low density / low drift” (“LD”) apiary configurations, each consisting of eight bee colonies. Hives in the HD apiary configuration were of the same color and placed 1m apart in a single linear array, while hives in the LD apiary configuration were placed 10m apart at different heights, facing outwards in a circle, and made visually distinctive with colors and symbols to reduce accidental drift between colonies. We investigated disease transmission and dynamics between the apiary configurations by clearing all colonies of the parasitic mite Varroa destructor , and subsequently inoculating two randomly-chosen colonies per apiary with controlled mite doses. We monitored the colonies for two years and found that the LD apiary configuration had significantly greater honey production and reduced overwinter mortality. Inoculation and apiary management intervention interacted to affect brood mite levels, with the highest levels in the inoculated colonies in the HD configuration. Finally, foragers were more than three times more likely to drift in the HD apiary configurations. Our results suggest that a relatively straightforward management change–placing colonies in low-density visually complex circles rather than high-density visually similar linear arrays–can provide meaningful benefits to the health and productivity of managed honey bee colonies.