Landscape context alters cost of living in honeybee metabolism and feeding

Abstract

Field metabolic rate (FMR) links the energy budget of an animal with the constraints of its ecosystem, but is particularly difficult to measure for small organisms. Landscape degradation exacerbates environmental adversity and reduces resource availability, imposing higher costs of living for many organisms. Here, we report a significant effect of landscape degradation on the FMR of free-flying Apis mellifera , estimated using 86 Rb radio-isotopic turnover. We validated the relationship between 86 Rb k b and metabolic rate for worker bees in the laboratory using flow-through respirometry. We then released radioisotopically enriched individuals into a natural woodland and a heavily degraded and deforested plantation. FMRs of worker bees in natural woodland vegetation were significantly higher than in a deforested landscape. Nectar consumption, estimated using 22 Na radio-isotopic turnover, also differed significantly between natural and degraded landscapes. In the deforested landscape, we infer that the costs of foraging exceeded energetic availability, and honeybees instead foraged less and depended more on stored resources in the hive. If this is generally the case with increasing landscape degradation, this will have important implications for the provision of pollination services and the effectiveness and resilience of ecological restoration practice.

Dietary requirements of individual nectar foragers, and colony-level pollen and nectar consumption: a review to support pesticide exposure assessment for honey bees

“…Recent advances in tracking (e.g., RFID) of honeybees could prove useful to collect some of the above information (see Capaldi et al 2000;Riley et al 2005;Decourtye et al 2011;He et al 2013;Tenczar et al 2014;Perry et al 2015;Liao et al 2017;and particularly, Thompson et al 2016). Further the tracer techniques of Tomlinson et al (2017) could also be effective in deriving more precise estimates of energy requirements of foragers.…”

“…Estimates of nectar ingestion requirements by bees have been derived using two general approaches: (1) the more direct measurements of dietary intake, including methods employing mass differences and tracers (e.g., Nachtigall et al 1989;Balderrama et al 1992;Gmeinbauer and Crailsheim 1993;Tomlinson et al 2017) and 2studies of energetics, including both calorimetric and respirometric measures of heat production and gas exchange, respectively (Coelho and Mitton 1988;Nachtigall et al 1989;Wolf et al 1989;Balderrama et al 1992;Stabentheiner et al 2003a, b;Moffatt and Núῆez 1997;Stabentheiner and Kovac 2016). The latter is more prevalent in the literature.…”

“…In a recent and novel study, average field metabolic rate and nectar consumption was estimated for free flying honey bees over 6 days using flowthrough respirometry and radiolabeled isotopes of 86 Rb and 22 Na, respectively (Tomlinson et al 2017). The study compared results for bees from hives (3 per location) located in a natural woodland where Banksia spp.…”

“…The equivalent amounts of 30% (w/w) sugar content of nectar would be approximately 41.5 and 28.6 mg nectar/bee/day (e.g., 12.45 mg sugar/day ÷ 0.30 = 41.5 mg nectar/ day). With some refinement, the method presented by Tomlinson et al (2017) may be used to better characterize nectar consumption by nectar foragers.…”

Transgenic corn decreased total and key storage and lipid transport protein levels in honey bee hemolymph while seed treatment with imidacloprid reduced lipophorin levels

“…In addition to natural seasonal variations that directly interfere with the availability of nectar and pollen for bees, anthropogenic effects on ecosystems and agroecosystems can result in unfavorable conditions for nutritional subsistence due to intensification of food shortage periods; this includes extensive monoculture plantings with floral features that do not meet the nutritional demand of bees (Cock et al, 2013;Winston, 1987). The use of artificial diets is increasing worldwide in order to maintain the bees and to prepare them for honey production and pollination services (Brodschneider & Crailsheim, 2010;Tomlinson, Dixon, Didham, & Bradshaw, 2017).…”