The effect of the dispersion of rewarding and rewardless flowers on visitation and constancy by bumblebees (Bombus impatiens)

Abstract In the face of insect declines, identifying phases of the life cycle when insects are particularly vulnerable to mortality is critical to conservation efforts. For numerous annual insect groups, diapause is both a key adaptation that allows survival of inhospitable conditions and a physiologically demanding life stage that can result in high rates of mortality. As bees continue to garner attention as a group experiencing high rates of decline, improving our understanding of how annual bees prepare for diapause and identifying factors that reduce survival is imperative. Here, we studied factors affecting diapause survival length and their underlying mechanisms using an economically and ecologically important annual bee species, Bombus impatiens. We examined how age and mass upon diapause onset correlate with diapause survival length, and the mechanistic role of nutrient acquisition and oxidative stress post pupal eclosion in mediating these effects. Our findings show that both age and mass were strong predictors of diapause survival length. Heavier queens or queens in the age range of ~6–17 days survived longer in diapause. Mass gain was attributed to increases in lipid, protein and glycerol amounts following pupal eclosion, and the ability to deal with oxidative stress was significantly compromised in older pre-diapause queens. Our results demonstrate that age-related shifts in bee physiology and timing of nutrient acquisition may both be critical factors driving diapause survival.

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Comparison of the Effect of Insecticides on Bumble Bees (Bombus impatiens) and Mosquitoes (Aedes aegypti and Culex quinquefasciatus) by Standard Mosquito Research Methods

Journal of Economic Entomology ◽

10.1093/jee/toaa282 ◽

2020 ◽

Author(s):

Bethany L McGregor ◽

Bryan V Giordano ◽

Alfred E Runkel ◽

Herbert N Nigg ◽

H Lee Nigg ◽

...

Keyword(s):

Aedes Aegypti ◽

Culex Quinquefasciatus ◽

Mosquito Control ◽

The United States ◽

Field Trials ◽

Bombus Impatiens ◽

Acute Effects ◽

Nontarget Effects ◽

Native North American ◽

Significant Mortality

Abstract Mosquito control districts in the United States are limited to two main classes of adulticides, pyrethroids and organophosphates, to control mosquitoes. Two adulticides used to control domestic mosquitoes are Fyfanon EW (malathion, organophosphate) and DeltaGard (deltamethrin, pyrethroid). While the effect of these pesticides on European honeybees (Apis mellifera L., Hymenoptera: Apidae) has been investigated, effects on native pollinators need additional research. The purpose of this study was to investigate the acute nontarget effects of these pesticides on Bombus impatiens Cresson (Hymenoptera: Apidae), a native North American bumble bee species, and compare these effects to wild and laboratory strains of mosquitoes (Aedes aegypti (L.) and Culex quinquefasciatus Say, Diptera: Culicidae) through field and laboratory assays. Bombus impatiens was found to be resistant to Fyfanon EW (x̅ = 6.7% mortality at 50-µg malathion per bottle) at levels that caused significant mortality to study mosquitoes (86.2 ≥ x̅ ≥ 100% mortality) in laboratory bottle bioassays. Comparatively, B. impatiens demonstrated greater mortality to DeltaGard (93.3%) at 2.5-µg deltamethrin/bottle than any mosquito colony assayed (14.1 ≥ x̅ ≥ 87.0% mortality). Only DeltaGard was tested in field applications. In the field, we observed acute effects of DeltaGard on mosquitoes and B. impatiens at 25- and 75-m distance from a truck-mounted ultra-low volume fogger, although treatment effects were not significant for B. impatiens. Additional wild-caught nontarget mortality to DeltaGard field trials was also evaluated. This study indicated that common mosquito control adulticides do cause nontarget mortality to B. impatiens but that impacts are variable depending on pesticide and further studies are needed.

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Percent lipid is associated with body size but not task in the bumble bee Bombus impatiens

Journal of Comparative Physiology A ◽

10.1007/s00359-011-0670-5 ◽

2011 ◽

Vol 197 (11) ◽

pp. 1097-1104 ◽

Cited By ~ 14

Author(s):

Margaret J. Couvillon ◽

Jennifer M. Jandt ◽

Jennifer Bonds ◽

Bryan R. Helm ◽

Anna Dornhaus

Keyword(s):

Body Size ◽

Bombus Impatiens ◽

Bumble Bee

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Mirror Image Pattern Matching By Bumble Bees

Behaviour ◽

10.1163/156853995x00306 ◽

1995 ◽

Vol 132 (1-2) ◽

pp. 87-93 ◽

Cited By ~ 5

Author(s):

C.M.S. Plowright ◽

Y.G. Korneluk

Keyword(s):

Pattern Matching ◽

Honey Bees ◽

Mirror Image ◽

Bumble Bees ◽

Bombus Impatiens ◽

Artificial Flower ◽

Choice Tests ◽

Image Transformations ◽

Image Pattern

AbstractBumble bees (Bombus impatiens) were trained to discriminate between a rewarding and non-rewarding artificial flower that differed only in their configuration of four identical petals. On choice tests between 2 empty flowers, the bees chose the flower with the configuration of the rewarding flower over the mirror image, but the mirror image over a novel flower. This behaviour is the same as has been observed with honey bees and functional interpretations are considered. The problem of distinguishing between left-right pattern reversals and true mirror image transformations is discussed.

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