@article{iwasa_motoyama_ambrose_roe_2004, title={Mechanism for the differential toxicity of neonicotinoid insecticides in the honey bee, Apis mellifera}, volume={23}, ISSN={["1873-6904"]}, DOI={10.1016/j.cropro.2003.08.018}, abstractNote={Laboratory bioassays were conducted to determine the contact honey bee toxicity of commercial and candidate neonicotinoid insecticides. The nitro-substituted compounds were the most toxic to the honey bee in our laboratory studies with LD50 values of 18 ng/bee for imidacloprid, 22 ng for clothianidin, 30 ng for thiamethoxam, 75 ng for dinotefuran and 138 ng for nitenpyram. The cyano-substituted neonicotinoids exhibited a much lower toxicity with LD50 values for acetamiprid and thiacloprid of 7.1 and 14.6 μg/bee, respectively. Piperonyl butoxide, triflumizole and propiconazole increased honey bee toxicity of acetamiprid 6.0-, 244- and 105-fold and thiacloprid 154-, 1,141- and 559-fold, respectively, but had a minimal effect on imidacloprid (1.70, 1.85 and 1.52-fold, respectively). The acetamiprid metabolites, N-demethyl acetamiprid, 6-chloro-3-pyridylmethanol and 6-chloro-nicotinic acid when applied topically, produced no mortality at 50 μg/bee. These results suggest that P450s are an important mechanism for acetamiprid and thiacloprid detoxification and their low toxicity to honey bees. When honey bees were placed in cages in forced contact with alfalfa treated with acetamiprid and the synergist, triflumizole, in combination at their maximum recommended application rates, no mortality was detected above that of the control.}, number={5}, journal={CROP PROTECTION}, author={Iwasa, T and Motoyama, N and Ambrose, JT and Roe, RM}, year={2004}, month={May}, pages={371–378} }
 @article{stanghellini_ambrose_schultheis_2002, title={Diurnal activity, floral visitation and pollen deposition by honey bees and bumble bees on field-grown cucumber and watermelon}, volume={41}, ISSN={["2078-6913"]}, DOI={10.1080/00218839.2002.11101065}, abstractNote={SUMMARY Honey bees (Apis mellifera) and bumble bees (Bombus impatiens) were compared for three aspects of pollinating behaviour on field-grown cucumber (Cucumis sativus) and watermelon (Citrullus lanatus). We measured: (1), diurnal foraging activity periods (as related to anthesis); (2), floral visitation rates (number of flowers visited per min by individual foragers); and (3), stigmatic pollen deposition (number of pollen grains deposited on stigmas after single bee visits to female flowers). B. impatiens was more effective than A. mellifera for all three parameters on both crops. B. impatiens initiated foraging activity 15–40 min before A. mellifera; both species continued foraging until flowers closed in early afternoon. B. impatiens consistently visited more flowers per min (P < 0.001) and deposited equal or greater amounts of pollen (P < 0.001) than A. mellifera, particularly during the initial hours of floral anthesis which is when these crops are most receptive to pollination. The data additionally suggest that researchers evaluating different pollinator candidates should consider time-of-day effects when comparing pollen deposition rates between pollinators, as time-of-day had a marked influence on pollen deposition in these studies.}, number={1-2}, journal={JOURNAL OF APICULTURAL RESEARCH}, author={Stanghellini, MS and Ambrose, JT and Schultheis, JR}, year={2002}, pages={27–34} }
 @article{stanghellini_schultheis_ambrose_2002, title={Pollen mobilization in selected cucurbitaceae and the putative effects of pollinator abundance on pollen depletion rates}, volume={127}, ISSN={["2327-9788"]}, DOI={10.21273/jashs.127.5.729}, abstractNote={Very little is known about the rate at which pollen grains are mobilized within insect-pollinated crop systems, and this is especially true the for commercial production of field-grown cucumber (Cucumis sativus L.), monoecious muskmelon (Cucumis melo L.), and triploid watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai]. The rates of pollen depletion for these crops were therefore investigated on plots simulating commercial crop production using a mixed honey bee (Apis mellifera L.) and bumble bee (Bombus impatiens Cresson) pollinator complex. At anthesis, staminate cucumber, muskmelon, and watermelon flowers contained on average 10539, 11176, and 30739 pollen grains/flower, respectively. At the time flowers closed in the early afternoon (1300 to 1400 hr), only 61% of the total pollen produced had been removed from staminate cucumber flowers, 44% to 62% from muskmelon, and 81% from watermelon flowers. The results suggest that total pollen production in these crops may not necessarily reflect total pollen availability to floral visitors (bees). However, of the total amount of pollen actually removed per flower, >57% occurred during the 2 h following flower anthesis of cucumber and muskmelon, and >77% occurred during the 2 h following flower anthesis of watermelon. Thus, most of the accessible pollen was removed shortly after anthesis, which is when these crops are most receptive to pollination. Nonviable triploid and viable diploid watermelon pollen were removed at similar rates (P = 0.4604). While correlation analyses were not possible for the influence of variable bee abundance on pollen depletion rates, higher bee populations in one year appeared to increase the rate at which pollen grains were removed from staminate flowers.}, number={5}, journal={JOURNAL OF THE AMERICAN SOCIETY FOR HORTICULTURAL SCIENCE}, author={Stanghellini, MS and Schultheis, JR and Ambrose, JT}, year={2002}, month={Sep}, pages={729–736} }
 @article{ambrose_2002, title={Telling the bees: NC beekeepers dedicate 2002 calendar of beekeeping to the victims and heroes of the September 11 terrorist attacks}, volume={142}, number={3}, journal={American Bee Journal}, author={Ambrose, J. T.}, year={2002}, pages={163–164} }
 @article{tabor_ambrose_2001, title={The use of heat treatment for control of the honey bee mite, Varroa destructor}, volume={141}, number={10}, journal={American Bee Journal}, author={Tabor, K. L. and Ambrose, J. T.}, year={2001}, pages={733–736} }
 @article{ambrose_stanghellini_hopkins_2000, title={A scientific note on the threat of small hive beetles (Aethina tumida Murray) to bumble bee (Bombus spp.) colonies in the United States}, volume={31}, ISSN={["0044-8435"]}, DOI={10.1051/apido:2000136}, abstractNote={Note scientifique sur la menace que represente le petit coleoptere des ruches (Aethina tumida Murray) pour les colonies de bourdons (Bombus spp.) aux Etats-Unis.}, number={3}, journal={APIDOLOGIE}, author={Ambrose, JT and Stanghellini, MS and Hopkins, DI}, year={2000}, pages={455–456} }
 @article{stanghellini_ambrose_hopkins_2000, title={Bumble bee colonies as potential alternative hosts for the small hive beetle (Aethina tumida Murray)}, volume={140}, number={1}, journal={American Bee Journal}, author={Stanghellini, M. S. and Ambrose, J. T. and Hopkins, D. I.}, year={2000}, pages={71–75} }
 @article{stanghellini_ambrose_schultheis_1998, title={Seed production in watermelon: A comparison between two commercially available pollinators}, volume={33}, ISSN={["2327-9834"]}, DOI={10.21273/hortsci.33.1.28}, abstractNote={The number of honey bees (Apis mellifera L.) continues to decline due to parasitic mite pests and other factors. Honey bees and bumble bees (Bombus impatiens Cresson) were therefore compared for their effects on the seed set of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] in a 2-year field experiment. The experiment was a 2 x 4 + 2 factorial, comparing bee type (honey bee or bumble bee) at four visitation levels (1, 6, 12, and 18 bee visits) to pistillate flowers, with two controls: a no-visit treatment and an open-pollinated treatment. Bee visitation level had a strong positive influence on seed set (P ≤ 0.0001). All flowers bagged to prevent insect visitation aborted, demonstrating the need for active pollen transfer between staminate and pistillate watermelon flowers. Flowers visited by B. impatiens consistently contained more seed than those visited by A. mellifera, when compared at equal bee visitation levels (P ≤ 0.0001). We conclude that bumble bees have great potential to serve as a supplemental pollinator for watermelon when honey bees available for rental are in limited supply.}, number={1}, journal={HORTSCIENCE}, author={Stanghellini, MS and Ambrose, JT and Schultheis, JR}, year={1998}, month={Feb}, pages={28–30} }
 @article{stanghellini_ambrose_schultheis_1998, title={Using commercial bumble bee colonies as backup pollinators for honey bees to produce cucumbers and watermelons}, volume={8}, DOI={10.21273/horttech.8.4.590}, abstractNote={The effectiveness of bumble bees, Bombus impatiens Cresson, and honey bees, Apis mellifera L., on the pollination of cucumber, Cucumis sativus L., and watermelon, Citrullus lanatus (Thunb.) Matsum. & Nakai, was compared under field conditions. Comparisons were based on fruit abortion rates and seed set as influenced by bee type (honey bee or bumble bee) and the number of bee visits to treatment flowers (1, 6, 12, and 18 bee visits), plus two controls: a no-visit treatment and an open-pollinated (unrestricted visitation) treatment. For both crops, an increased number of bee visits had a strong positive effect on fruit and seed set. All cucumber and watermelon flowers bagged to prevent insect visitation aborted, demonstrating the need for active transfer of pollen between staminate and pistillate flowers. Bumble bee-visited flowers consistently had lower abortion rates and higher seed sets in the cucumber and watermelon studies than did honey bee-visited flowers when compared at the same bee visitation level. Only slight differences in fruit abortion rates were detected between bee types in the watermelon study. However, abortion rates for bumble bee-visited flowers were consistently less than those for honey bee-visited flowers when compared at equal bee visitation levels, with one exception at the 12 bee visit level. As the number of honey bee colonies continues to decline due to parasitic mite pests and based on the data obtained, we conclude that bumble bees have a great potential to serve as a supplemental pollinator for cucumbers, watermelons, and possibly other vine crops, when honey bees available for rental are in limited supply.}, number={4}, journal={HortTechnology}, author={Stanghellini, M. S. and Ambrose, J. T. and Schultheis, J. R.}, year={1998}, pages={590–594} }
 @article{ambrose_1997, title={Hurricane Fran, mosquitoes, and honey bees--a success story}, volume={137}, number={2}, journal={American Bee Journal}, author={Ambrose, J. T.}, year={1997}, pages={117–119} }
 @article{ambrose_1997, title={Pollination article table correction}, volume={137}, number={9}, journal={American Bee Journal}, author={Ambrose, J. T.}, year={1997}, pages={630} }
 @article{stanghellini_ambrose_schultheis_1997, title={The effects of honey bee and bumble bee pollination on fruit set and abortion of cucumber and watermelon}, volume={137}, number={5}, journal={American Bee Journal}, author={Stanghellini, M. S. and Ambrose, J. T. and Schultheis, J. R.}, year={1997}, pages={386–391} }
 @article{ambrose_1991, title={An assortment of timely and practical beekeeping videotapes -- a review}, volume={131}, number={5}, journal={American Bee Journal}, author={Ambrose, J. T.}, year={1991}, pages={325} }