Specialization on pollen or nectar in bumblebee foragers is not associated with ovary size, lipid reserves or sensory tuning

Foraging specialization allows social insects to more efficiently exploit resources in their environment. Recent research on honeybees suggests that specialization on pollen or nectar among foragers is linked to reproductive physiology and sensory tuning (the Reproductive Ground-Plan Hypothesis; RGPH). However, our understanding of the underlying physiological relationships in non-Apisbees is still limited. Here we show that the bumblebeeBombus terrestrishas specialist pollen and nectar foragers, and test whether foraging specialization inB. terrestrisis linked to reproductive physiology, measured as ovarian activation. We show that neither ovary size, sensory sensitivity, measured through proboscis extension response (PER), or whole-body lipid stores differed between pollen foragers, nectar foragers, or generalist foragers. Body size also did not differ between any of these three forager groups. Non-foragers had significantly larger ovaries than foragers. This suggests that potentially reproductive individuals avoid foraging.

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Ovary activation does not correlate with pollen and nectar foraging specialization in the bumblebeeBombus impatiens

PeerJ ◽

10.7717/peerj.4415 ◽

2018 ◽

Vol 6 ◽

pp. e4415

Author(s):

Meagan A. Simons ◽

Adam R. Smith

Keyword(s):

Foraging Activity ◽

Sensory Sensitivity ◽

Reproductive Conflict ◽

Proboscis Extension Response ◽

Ovary Activation ◽

Ground Plan ◽

Nectar Preference ◽

Mixed Support ◽

Proboscis Extension ◽

Foraging Specialization

Social insect foragers may specialize on certain resource types. Specialization on pollen or nectar among honeybee foragers is hypothesized to result from associations between reproductive physiology and sensory tuning that evolved in ancestral solitary bees (the Reproductive Ground-Plan Hypothesis; RGPH). However, the two non-honeybee species studied showed no association between specialization and ovary activation. Here we investigate the bumblebeeB. impatiensbecause it has the most extensively studied pollen/nectar specialization of any bumblebee. We show that ovary size does not differ between pollen specialist, nectar specialist, and generalist foragers, contrary to the predictions of the RGPH. However, we also found mixed support for the second prediction of the RGPH, that sensory sensitivity, measured through proboscis extension response (PER), is greater among pollen foragers. We also found a correlation between foraging activity and ovary size, and foraging activity and relative nectar preference, but no correlation between ovary size and nectar preference. In one colony non-foragers had larger ovaries than foragers, supporting the reproductive conflict and work hypothesis, but in the other colony they did not.

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Pollen reinforces learning in honey bee pollen foragers but not in nectar foragers

Journal of Experimental Biology ◽

10.1242/jeb.230250 ◽

2020 ◽

Vol 223 (22) ◽

pp. jeb230250

Author(s):

Denise Nery ◽

Emilia Moreno ◽

Andrés Arenas

Keyword(s):

Honey Bees ◽

Physiological Mechanism ◽

Simultaneous Presentation ◽

Division Of Labour ◽

Proboscis Extension Response ◽

Reinforced Learning ◽

Proboscis Extension ◽

Foraging Specialization ◽

Better Than

ABSTRACTSearching for reward motivates and drives behaviour. In honey bees Apis mellifera, specialized pollen foragers are attracted to and learn odours with pollen. However, the role of pollen as a reward remains poorly understood. Unlike nectar, pollen is not ingested during collection. We hypothesized that pollen (but not nectar) foragers could learn pollen by sole antennal or tarsal stimulation. Then, we tested how pairing of pollen (either hand- or bee-collected) and a neutral odour during a pre-conditioning affects performance of both pollen and nectar foragers during the classical conditioning of the proboscis extension response. Secondly, we tested whether nectar and pollen foragers perceive the simultaneous presentation of pollen (on the tarsi) and sugar (on the antennae) as a better reinforcement than sucrose alone. Finally, we searched for differences in learning of the pollen and nectar foragers when they were prevented from ingesting the reward during the conditioning. Differences in pollen-reinforced learning correlate with division of labour between pollen and nectar foragers. Results show that pollen foragers performed better than nectar foragers during the conditioning phase after being pre-conditioned with pollen. Pollen foragers also performed better than nectar foragers in both the acquisition and extinction phases of the conditioning, when reinforced with the dual reward. Consistently, pollen foragers showed improved abilities to learn cues reinforced without sugar ingestion. We discussed that differences in how pollen and nectar foragers respond to a cue associated with pollen greatly contribute to the physiological mechanism that underlies foraging specialization in the honeybee.

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Responsiveness to sucrose and habituation of the proboscis extension response in honey bees

Journal of Comparative Physiology A ◽

10.1007/s00359-004-0531-6 ◽

2004 ◽

Vol 190 (9) ◽

Cited By ~ 32

Author(s):

Ricarda Scheiner

Keyword(s):

Honey Bees ◽

Proboscis Extension Response ◽

Proboscis Extension

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Developmental study of the Proboscis Extension Response to heat in Rhodnius prolixus along the life cycle

Journal of Insect Physiology ◽

10.1016/j.jinsphys.2016.11.010 ◽

2017 ◽

Vol 98 ◽

pp. 55-58 ◽

Cited By ~ 3

Author(s):

Carole Labrousse ◽

Claudio R. Lazzari ◽

Nadine Fresquet

Keyword(s):

Life Cycle ◽

Rhodnius Prolixus ◽

Developmental Study ◽

Proboscis Extension Response ◽

Proboscis Extension

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Farnesoid X Receptor an Emerging Target to Combat Obesity

Digestive Diseases ◽

10.1159/000450909 ◽

2017 ◽

Vol 35 (3) ◽

pp. 185-190 ◽

Cited By ~ 18

Author(s):

C. Daniel De Magalhaes Filho ◽

Michael Downes ◽

Ronald M. Evans

Keyword(s):

Type 2 Diabetes ◽

Bile Acid ◽

Treatment Options ◽

Farnesoid X Receptor ◽

Whole Body ◽

Body Lipid ◽

Associated Diseases ◽

Attractive Candidate ◽

Potential Use

Obesity and its associated diseases, including type 2 diabetes, have reached epidemic levels worldwide. However, available treatment options are limited and ineffective in managing the disease. There is therefore an urgent need for the development of new pharmacological solutions. The bile acid (BA) Farnesoid X receptor (FXR) has recently emerged as an attractive candidate. Initially described for their role in lipid and vitamin absorption from diet, BAs are hormones with powerful effects on whole body lipid and glucose metabolism. In this review, we focus on FXR and how 2 decades of work on this receptor, both in rodents and humans, have led to the development of drug agonists with potential use in humans for treatment of conditions ranging from obesity-associated diseases to BA dysregulation.

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Dose-dependent effect of insulin on plasma free fatty acid turnover and oxidation in humans

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1990.259.5.e736 ◽

1990 ◽

Vol 259 (5) ◽

pp. E736-E750 ◽

Cited By ~ 14

Author(s):

R. C. Bonadonna ◽

L. C. Groop ◽

K. Zych ◽

M. Shank ◽

R. A. DeFronzo

Keyword(s):

Fatty Acid ◽

Free Fatty Acid ◽

Lipid Oxidation ◽

Plasma Insulin ◽

Plasma Free Fatty Acid ◽

Whole Body ◽

Glucose Disposal ◽

Body Lipid ◽

Plasma Ffa ◽

Dose Dependent

Methodology for measuring plasma free fatty acid (FFA) turnover/oxidation with [1–14C]palmitate was tested in normal subjects. In study 1, two different approaches (720-min tracer infusion without prime vs. 150-min infusion with NaH14CO3 prime) to achieve steady-state conditions of 14CO2 yielded equivalent rates of plasma FFA turnover/oxidation. In study 2, during staircase NaH14CO3 infusion, calculated rates of 14CO2 appearance agreed closely with NaH14CO3 infusion rates. In study 3, 300-min euglycemic insulin clamp documented that full biological effect of insulin on plasma FFA turnover/oxidation was established within 60–120 min. In study 4, plasma insulin concentration was raised to 14 +/- 2, 23 +/- 2, 38 +/- 2, 72 +/- 5, and 215 +/- 10 microU/ml. A dose-dependent insulin suppression of plasma FFA turnover/oxidation was observed. Plasma FFA concentration correlated positively with plasma FFA turnover/oxidation in basal and insulinized states. Total lipid oxidation (indirect calorimetry) was significantly higher than plasma FFA oxidation in the basal state, suggesting that intracellular lipid stores contributed to whole body lipid oxidation. Hepatic glucose production and total glucose disposal showed the expected dose-dependent suppression and stimulation, respectively, by insulin. In conclusion, insulin regulation of plasma FFA turnover/oxidation is maximally manifest at low physiological plasma insulin concentrations, and in the basal state a significant contribution to whole body lipid oxidation originates from lipid pool(s) that are different from plasma FFA.

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The proboscis extension response

Honey Bees ◽

10.1201/9780203218655.ch5 ◽

2002 ◽

pp. 67-84 ◽

Cited By ~ 2

Author(s):

M Pham-Del√®gue ◽

A Decourtye

Keyword(s):

Proboscis Extension Response ◽

Proboscis Extension

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Behavioral responses of the invasive fly Philornis downsi to stimuli from bacteria and yeast in the laboratory and the field in the Galapagos Islands

10.1101/696492 ◽

2019 ◽

Author(s):

Boaz Yuval ◽

Paola Lahuatte ◽

Arul J. Polpass ◽

Charlotte Causton ◽

Edouard Jurkevitch ◽

...

Keyword(s):

Integrated Management ◽

Gut Bacteria ◽

Growth Media ◽

Proboscis Extension Response ◽

Galapagos Archipelago ◽

Philornis Downsi ◽

Baited Traps ◽

Proboscis Extension ◽

Future Work ◽

Bird Feces

AbstractPhilornis downsi (Diptera: Muscidae) is a nest parasitic fly that has invaded the Galapagos archipelago and exerts an onerous burden on populations of endemic land birds. As part of an ongoing effort to develop tools for the integrated management of this fly, our objective was to determine its long and short-range responses to bacterial and yeast cues associated with adult P. downsi. We hypothesized that the bacterial and yeast communities will elicit attraction at distance through volatiles, and appetitive responses upon contact. Accordingly, we amplified bacteria from guts of adult field-caught individuals and bird feces, and yeasts from fermenting papaya juice (a known attractant of P. downsi), on selective growth media, and assayed the response of flies to these microbes or their exudates. In the field, we baited traps with bacteria or yeast and monitored adult fly attraction. In the laboratory, we used the Proboscis Extension Response (PER) to determine the sensitivity of males and females to tarsal contact with bacteria or yeast. Long range trapping efforts yielded two female flies over 112 trap nights (one in extracts from bird faeces and one in extracts from gut bacteria from adult flies). In the laboratory, tarsal contact with bacterial stimuli from gut bacteria from adult flies elicited significantly more responses than did yeast stimuli. We discuss the significance of these findings in context with other studies in the field and identify targets for future work.

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Behavioral Responses of the Invasive Fly Philornis downsi to Stimuli from Bacteria and Yeast in the Laboratory and the Field in the Galapagos Islands

Insects ◽

10.3390/insects10120431 ◽

2019 ◽

Vol 10 (12) ◽

pp. 431

Author(s):

Boaz Yuval ◽

Paola Lahuatte ◽

Polpass Arul Jose ◽

Charlotte E. Causton ◽

Edouard Jurkevitch ◽

...

Keyword(s):

Integrated Management ◽

Growth Media ◽

Proboscis Extension Response ◽

Galapagos Archipelago ◽

Philornis Downsi ◽

Baited Traps ◽

Proboscis Extension ◽

Males And Females ◽

Future Work ◽

Bird Feces

Philornis downsi Dodge and Aitken (Diptera: Muscidae) is an avian parasitic fly that has invaded the Galapagos archipelago and exerts an onerous burden on populations of endemic land birds. As part of an ongoing effort to develop tools for the integrated management of this fly, our objective was to determine its long- and short-range responses to bacterial and fungal cues associated with adult P. downsi. We hypothesized that the bacterial and fungal communities would elicit attraction at distance through volatiles, and appetitive responses upon contact. Accordingly, we amplified bacteria from guts of adult field-caught flies and from bird feces, and yeasts from fermenting papaya juice (a known attractant of P. downsi), on selective growth media, and assayed the response of flies to these microbes or their exudates. In the field, we baited traps with bacteria or yeast and monitored adult fly attraction. In the laboratory, we used the proboscis extension response (PER) to determine the sensitivity of males and females to tarsal contact with bacteria or yeast. Long range trapping efforts yielded two female flies over 112 trap-nights (attracted by bacteria from bird feces and from the gut of adult flies). In the laboratory, tarsal contact with stimuli from gut bacteria elicited significantly more responses than did yeast stimuli. We discuss the significance of these findings in context with other studies in the field and identify targets for future work.

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