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

Abstract

Exposure to pesticides is a potential concern for pollinators that may forage on plants containing residues. A key element of estimating dietary risk to pollinators is to determine the nature and amount of food consumed by individuals. Recent efforts have focused on honey bees (Apis mellifera), of which nectar foragers are thought to be at greatest risk of dietary exposure due to their foraging behavior and high energy requirements for the flight-foraging activities. At upper tiers of pesticide risk assessment for honey bees, field studies with whole colonies are carried out to gauge effects of expected exposures; however, without knowing how much nectar and pollen is being consumed by colonies and the potential variability in these parameters, it is difficult to accurately assess risk under other untested exposure scenarios. The objective of this review was to collate available data from the literature regarding (1) the quantity of nectar required by nectar foragers and (2) the quantities of nectar, pollen, and supplements that are consumed by colonies; the purposes being to develop a database that can be used to improve exposure and risk assessments, and to identify data gaps for further research. A number of studies investigating honey bee energetics have been identified that can be used to estimate sugar requirements for foragers under different conditions (e.g., resting, flying). A few more recent studies have been able to quantify the amount of time foragers spend outside the hive. Factors requiring further investigation include levels of energy expenditure while outside the hive, and the sugar content of available nectars, which may also affect foraging behavior. At the colony level, data on food consumption are sparse and primarily anecdotal. Colony size, management, and location seem to be major factors contributing to differences in nectar foraging and honey production. Further research is needed to better quantify and predict colony use and storage of food resources.

Comparative assessment of various supplementary diets on commercial honey bee (Apis mellifera) health and colony performance

“…Determining the consumption of foods for honey bees is a complex phenomenon; because nutritional requirements are highly variable between different castes and life stages, inter and intraseasonal variability in terms of food availability. Further, supplemental feeding is highly variable during beekeeping practices [ 18 ]. During winter or the dry season, when food resources become scarce it affects the queen egg-laying capacity, less worker bees availability, and increases the rates of absconding or abandonment [ 19 ].…”

Consumption rate of two different pollen substitute diets and their effects on honey bee (Apis melliferaL.) during the scarcity food time of the year

“…Our study indicates that with a good diet, colonies can increase the consumption and the rate of brood rearing. (Rodney & Purdy, 2020) mentioned that, A key element of estimating diet efficiency is to determine the amount of food consumed. Honey bees rely on pollen as their only natural source of protein as previously found by (Grogan & Hunt, 1979).…”

Where Is the Honey Bee Queen Flying? The Original Case of a Foraging Queen

“…A queen can mate various times during one flight and can perform several consecutive nuptial flights in one day or various days [7,21,[24][25][26]. The number of drones a queen mates with is on average 12-14, ranging from 6 to 26 [27][28][29][30]. However, queen behaviour during free flight remains largely unknown.…”