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Pollination services provided by bees in pumpkin fields supplemented with either Apis mellifera or Bombus impatiens or not supplemented.

Petersen JD, Reiners S, Nault BA - PLoS ONE (2013)

Bottom Line: We compared pumpkin yield, A. mellifera flower visitation frequency and B. impatiens flower visitation frequency between treatments.Results indicated that supplementing pumpkin fields with either A. mellifera or B. impatiens hives did not increase their visitation to pumpkin flowers or fruit yield compared with those that were not supplemented.These results suggest that supplementation with managed bees may not improve pumpkin production and that A. mellifera and B. impatiens are important pollinators of pumpkin in our system.

View Article: PubMed Central - PubMed

Affiliation: Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America. jessica.petersen@cornell.edu

ABSTRACT
Pollinators provide an important service in many crops. Managed honey bees (Apis mellifera L.) are used to supplement pollination services provided by wild bees with the assumption that they will enhance pollination, fruit set and crop yield beyond the levels provided by the wild bees. Recent declines in managed honey bee populations have stimulated interest in finding alternative managed pollinators to service crops. In the eastern U.S., managed hives of the native common eastern bumble bee (Bombus impatiens Cresson) may be an excellent choice. To examine this issue, a comprehensive 2-yr study was conducted to compare fruit yield and bee visits to flowers in pumpkin (Cucurbita pepo L.) fields that were either supplemented with A. mellifera hives, B. impatiens hives or were not supplemented. We compared pumpkin yield, A. mellifera flower visitation frequency and B. impatiens flower visitation frequency between treatments. Results indicated that supplementing pumpkin fields with either A. mellifera or B. impatiens hives did not increase their visitation to pumpkin flowers or fruit yield compared with those that were not supplemented. Next, the relationship between frequency of pumpkin flower visitation by the most prominent bee species (Peponapis pruinosa (Say), B. impatiens and A. mellifera) and fruit yield was determined across all pumpkin fields sampled. Fruit yield increased as the frequency of flower visits by A. mellifera and B. impatiens increased in 2011 and 2012, respectively. These results suggest that supplementation with managed bees may not improve pumpkin production and that A. mellifera and B. impatiens are important pollinators of pumpkin in our system.

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Related in: MedlinePlus

Relationship between yield and bee visitation frequency.Relationship between fruit yield and flower visitation frequency by Apis mellifera in 2011 (y = 5.02+11.53×) (A), and Bombus impatiens in 2012 (y = 4.11+19.82×) (B). Supplementation treatment (circle = A. mellifera supplementation, triangle = B. impatiens supplementation, square = nonsupplemented) was illustrated to show the lack of pattern among treatment groups, reinforcing that the point that fruit yield was not influenced by supplementation with managed bees. Supplementation treatment was not included as a factor in these regressions.
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pone-0069819-g004: Relationship between yield and bee visitation frequency.Relationship between fruit yield and flower visitation frequency by Apis mellifera in 2011 (y = 5.02+11.53×) (A), and Bombus impatiens in 2012 (y = 4.11+19.82×) (B). Supplementation treatment (circle = A. mellifera supplementation, triangle = B. impatiens supplementation, square = nonsupplemented) was illustrated to show the lack of pattern among treatment groups, reinforcing that the point that fruit yield was not influenced by supplementation with managed bees. Supplementation treatment was not included as a factor in these regressions.

Mentions: Full models that included visitation frequency for A. mellifera, B. impatiens, and P. pruinosa, supplementation treatment and field size significantly predicted fruit yield (2011: P = 0.04; 2012: P = 0.05). Only two variables were highly correlated in both years: P. pruinosa visitation frequency and total bee visitation frequency (Table S1 and S2). Total bee visitation frequency was not included in the model selection. In 2011, model selection and model average results indicated that A. mellifera visits per flower was the most important predictor of pumpkin yield (Table 1). The top model included both A. mellifera and P. pruinosa visits per flower, but only A. mellifera had a significant and positive association with pumpkin yield (Fig. 4A). In addition to the top model, there was one competing model including A. mellifera visits per flower (Table 2). In 2011, P. pruinosa visits per flower was marginally important in fitting the model, but was not a significant predictor of yield (Table 1). In 2012, model selection indicated that B. impatiens visits per flower was the most important predictor of pumpkin yield (Table 3) and was positively correlated with pumpkin yield (Fig. 4B). There were no competing models in 2012, and the next best models had low model weights (Table 4). Overall, only A. mellifera and B. impatiens visits per flower were important predictors of pumpkin yield in 2011 and 2012, respectively. Other covariates in the full model including supplementation treatment and field size were poor predictors of pumpkin yield in this 2-yr study.


Pollination services provided by bees in pumpkin fields supplemented with either Apis mellifera or Bombus impatiens or not supplemented.

Petersen JD, Reiners S, Nault BA - PLoS ONE (2013)

Relationship between yield and bee visitation frequency.Relationship between fruit yield and flower visitation frequency by Apis mellifera in 2011 (y = 5.02+11.53×) (A), and Bombus impatiens in 2012 (y = 4.11+19.82×) (B). Supplementation treatment (circle = A. mellifera supplementation, triangle = B. impatiens supplementation, square = nonsupplemented) was illustrated to show the lack of pattern among treatment groups, reinforcing that the point that fruit yield was not influenced by supplementation with managed bees. Supplementation treatment was not included as a factor in these regressions.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3722171&req=5

pone-0069819-g004: Relationship between yield and bee visitation frequency.Relationship between fruit yield and flower visitation frequency by Apis mellifera in 2011 (y = 5.02+11.53×) (A), and Bombus impatiens in 2012 (y = 4.11+19.82×) (B). Supplementation treatment (circle = A. mellifera supplementation, triangle = B. impatiens supplementation, square = nonsupplemented) was illustrated to show the lack of pattern among treatment groups, reinforcing that the point that fruit yield was not influenced by supplementation with managed bees. Supplementation treatment was not included as a factor in these regressions.
Mentions: Full models that included visitation frequency for A. mellifera, B. impatiens, and P. pruinosa, supplementation treatment and field size significantly predicted fruit yield (2011: P = 0.04; 2012: P = 0.05). Only two variables were highly correlated in both years: P. pruinosa visitation frequency and total bee visitation frequency (Table S1 and S2). Total bee visitation frequency was not included in the model selection. In 2011, model selection and model average results indicated that A. mellifera visits per flower was the most important predictor of pumpkin yield (Table 1). The top model included both A. mellifera and P. pruinosa visits per flower, but only A. mellifera had a significant and positive association with pumpkin yield (Fig. 4A). In addition to the top model, there was one competing model including A. mellifera visits per flower (Table 2). In 2011, P. pruinosa visits per flower was marginally important in fitting the model, but was not a significant predictor of yield (Table 1). In 2012, model selection indicated that B. impatiens visits per flower was the most important predictor of pumpkin yield (Table 3) and was positively correlated with pumpkin yield (Fig. 4B). There were no competing models in 2012, and the next best models had low model weights (Table 4). Overall, only A. mellifera and B. impatiens visits per flower were important predictors of pumpkin yield in 2011 and 2012, respectively. Other covariates in the full model including supplementation treatment and field size were poor predictors of pumpkin yield in this 2-yr study.

Bottom Line: We compared pumpkin yield, A. mellifera flower visitation frequency and B. impatiens flower visitation frequency between treatments.Results indicated that supplementing pumpkin fields with either A. mellifera or B. impatiens hives did not increase their visitation to pumpkin flowers or fruit yield compared with those that were not supplemented.These results suggest that supplementation with managed bees may not improve pumpkin production and that A. mellifera and B. impatiens are important pollinators of pumpkin in our system.

View Article: PubMed Central - PubMed

Affiliation: Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America. jessica.petersen@cornell.edu

ABSTRACT
Pollinators provide an important service in many crops. Managed honey bees (Apis mellifera L.) are used to supplement pollination services provided by wild bees with the assumption that they will enhance pollination, fruit set and crop yield beyond the levels provided by the wild bees. Recent declines in managed honey bee populations have stimulated interest in finding alternative managed pollinators to service crops. In the eastern U.S., managed hives of the native common eastern bumble bee (Bombus impatiens Cresson) may be an excellent choice. To examine this issue, a comprehensive 2-yr study was conducted to compare fruit yield and bee visits to flowers in pumpkin (Cucurbita pepo L.) fields that were either supplemented with A. mellifera hives, B. impatiens hives or were not supplemented. We compared pumpkin yield, A. mellifera flower visitation frequency and B. impatiens flower visitation frequency between treatments. Results indicated that supplementing pumpkin fields with either A. mellifera or B. impatiens hives did not increase their visitation to pumpkin flowers or fruit yield compared with those that were not supplemented. Next, the relationship between frequency of pumpkin flower visitation by the most prominent bee species (Peponapis pruinosa (Say), B. impatiens and A. mellifera) and fruit yield was determined across all pumpkin fields sampled. Fruit yield increased as the frequency of flower visits by A. mellifera and B. impatiens increased in 2011 and 2012, respectively. These results suggest that supplementation with managed bees may not improve pumpkin production and that A. mellifera and B. impatiens are important pollinators of pumpkin in our system.

Show MeSH
Related in: MedlinePlus