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Event: 560

Key Event Title

The KE title should describe a discrete biological change that can be measured. It should generally define the biological object or process being measured and whether it is increased, decreased, or otherwise definably altered relative to a control state. For example “enzyme activity, decreased”, “hormone concentration, increased”, or “growth rate, decreased”, where the specific enzyme or hormone being measured is defined. More help

Abnormal, Foraging activity and behavior

Short name
The KE short name should be a reasonable abbreviation of the KE title and is used in labelling this object throughout the AOP-Wiki. The short name should be less than 80 characters in length. More help
Abnormal, Foraging activity and behavior

Biological Context

Structured terms, selected from a drop-down menu, are used to identify the level of biological organization for each KE. Note, KEs should be defined within a particular level of biological organization. Only KERs should be used to transition from one level of organization to another. Selection of the level of biological organization defines which structured terms will be available to select when defining the Event Components (below). More help

Key Event Components

Further information on Event Components and Biological Context may be viewed on the attached pdf.Because one of the aims of the AOP-KB is to facilitate de facto construction of AOP networks through the use of shared KE and KER elements, authors are also asked to define their KEs using a set of structured ontology terms (Event Components). In the absence of structured terms, the same KE can readily be defined using a number of synonymous titles (read by a computer as character strings). In order to make these synonymous KEs more machine-readable, KEs should also be defined by one or more “event components” consisting of a biological process, object, and action with each term originating from one of 22 biological ontologies (Ives, et al., 2017; See List). Biological process describes dynamics of the underlying biological system (e.g., receptor signalling). The biological object is the subject of the perturbation (e.g., a specific biological receptor that is activated or inhibited). Action represents the direction of perturbation of this system (generally increased or decreased; e.g., ‘decreased’ in the case of a receptor that is inhibited to indicate a decrease in the signalling by that receptor).Note that when editing Event Components, clicking an existing Event Component from the Suggestions menu will autopopulate these fields, along with their source ID and description. To clear any fields before submitting the event component, use the 'Clear process,' 'Clear object,' or 'Clear action' buttons. If a desired term does not exist, a new term request may be made via Term Requests. Event components may not be edited; to edit an event component, remove the existing event component and create a new one using the terms that you wish to add. More help
Process Object Action
foraging behavior abnormal

Key Event Overview

AOPs Including This Key Event

All of the AOPs that are linked to this KE will automatically be listed in this subsection. This table can be particularly useful for derivation of AOP networks including the KE. Clicking on the name of the AOP will bring you to the individual page for that AOP. More help
AOP Name Role of event in AOP Point of Contact Author Status OECD Status
nAChR activation - colony death 1 KeyEvent Agnes Aggy (send email) Open for comment. Do not cite
Metabolic stress - Colony loss KeyEvent Brendan Ferreri-Hanberry (send email) Open for comment. Do not cite
Immune system - Colony loss 2 KeyEvent Allie Always (send email) Open for comment. Do not cite
nAChR activation - colony loss 5 KeyEvent Cataia Ives (send email) Open for comment. Do not cite
nAChR activation - colony loss 6 KeyEvent Brendan Ferreri-Hanberry (send email) Open for comment. Do not cite
nAChR activation - colony loss 7 KeyEvent Arthur Author (send email) Open for comment. Do not cite
Varroa mite and abnormal foraging leads to colony loss/failure KeyEvent Cataia Ives (send email) Under Development: Contributions and Comments Welcome
Weather to abnormal foraging to colony loss/failure KeyEvent Arthur Author (send email) Under Development: Contributions and Comments Welcome
Nosema to energy to colony loss/failure KeyEvent Agnes Aggy (send email) Under Development: Contributions and Comments Welcome


This is a structured field used to identify specific agents (generally chemicals) that can trigger the KE. Stressors identified in this field will be linked to the KE in a machine-readable manner, such that, for example, a stressor search would identify this as an event the stressor can trigger. NOTE: intermediate or downstream KEs in one AOP may function as MIEs in other AOPs, meaning that stressor information may be added to the KE description, even if it is a downstream KE in the pathway currently under development.Information concerning the stressors that may trigger an MIE can be defined using a combination of structured and unstructured (free-text) fields. For example, structured fields may be used to indicate specific chemicals for which there is evidence of an interaction relevant to this MIE. By linking the KE description to a structured chemical name, it will be increasingly possible to link the MIE to other sources of chemical data and information, enhancing searchability and inter-operability among different data-sources and knowledgebases. The free-text section “Evidence for perturbation of this MIE by stressor” can be used both to identify the supporting evidence for specific stressors triggering the MIE as well as to define broad chemical categories or other properties that classify the stressors able to trigger the MIE for which specific structured terms may not exist. More help

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) can be selected from an ontology. In many cases, individual species identified in these structured fields will be those for which the strongest evidence used in constructing the AOP was available in relation to this KE. More help

Life Stages

The structured ontology terms for life-stage are more comprehensive than those for taxa, but may still require further description/development and explanation in the free text section. More help

Sex Applicability

The authors must select from one of the following: Male, female, mixed, asexual, third gender, hermaphrodite, or unspecific. More help

Key Event Description

A description of the biological state being observed or measured, the biological compartment in which it is measured, and its general role in the biology should be provided. For example, the biological state being measured could be the activity of an enzyme, the expression of a gene or abundance of an mRNA transcript, the concentration of a hormone or protein, neuronal activity, heart rate, etc. The biological compartment may be a particular cell type, tissue, organ, fluid (e.g., plasma, cerebrospinal fluid), etc. The role in the biology could describe the reaction that an enzyme catalyses and the role of that reaction within a given metabolic pathway; the protein that a gene or mRNA transcript codes for and the function of that protein; the function of a hormone in a given target tissue, physiological function of an organ, etc. Careful attention should be taken to avoid reference to other KEs, KERs or AOPs. Only describe this KE as a single isolated measurable event/state. This will ensure that the KE is modular and can be used by other AOPs, thereby facilitating construction of AOP networks. More help

Text from LaLone et al. (2017) Weight of evidence evaluation of a network of adverse outcome pathways linking activaiton of the nicotinic acetylcholine receptor in honey bees to colony death. Science of the Total Environment 584-585, 751-775:

"As eusocial insects, honey bees rely on theworker bee caste to forage for nectar, pollen, andwater. Foraged water can be used for evaporative cooling of the hive during warm weather (as reviewed by Jones and Oldroyd, 2006). Nectar and pollen collected by the foragers are the sole food source for the colony, with nectar providing carbohydrates and pollen providing lipids, protein, vitamins, and essential minerals (Brodschneider and Crailsheim, 2010). Upon returning to the hive, forager bees identify non-foraging, food-storing hive bees and deliver their collection by regurgitating nectar carried back in their honey stomach (i.e., foregut of proventriculus; Free, 1959). The hive bees place the nectar in wax cells for processing into honey. Hive bees also aid foragers in unloading pollen from the pollen baskets (corbicula) on the forager's hind legs and place it in cells where it is mixed with nectar to form bee bread, which is stored for consumption by the colony (Winston, 1987). Foragers consume only small amounts of the food they collect. Hive bees consume the food they receive in order to produce proteinrich royal jelly and brood food, which they use to nourish both the queen and the developing brood (Winston, 1987). During winter, the colony survives on the pollen and nectar that was stored as bee bread and honey over the spring, summer, and fall seasons (Seeley and Visscher, 1985). The act of foraging is a perilous and metabolically challenging task that is typically carried out by worker bees in the later stages of life (Woyciechowski and Moroń, 2009). However, the timing of the role change from hive bee to forager can vary depending on the needs of the colony. There are environmental, hormonal, and social cues that determine when and how often foragers search for food and fluid, includingweather, abundance or scarcity of food resources, magnitude of food stockpiled in the hive, health of the colony, and size of the brood (Dreller and Tarpy, 2000). Such cues initiate physiological changes involved in the transition of a worker bee to foraging, which include changes to flight muscles andmetabolic rate. These changes accommodate the reported 70-fold increase in oxygen consumption needed to sustain physical and cognitive activities of the forager bee (Kammer and Heinrich, 1978). It has been documented that the volume of neuropil in mushroom bodies is increased by approximately 15%, and the somata of the Kenyon cells decreased by approximately 29% in foragers compared to day-old bees (Withers et al., 1995). Change in lipid stores also occurs in forager bees prior to foraging, whereby their abdominal lipid is reduced to approximately half that of nurse bees (Chang et al., 2015; Toth and Robinson, 2005). Further, there is lowprotein content in the forager's fat body cells, and vitellogenin (Vtg; egg

yolk) protein production is significantly reduced, while juvenile hormone levels are significantly increased (Toth and Robinson, 2005). Another change which occurs at the stage where worker bees become foragers is that their flight muscle fiber thickness decreases and diameter of the myofibrils, which contain the contractile filaments, increases in preparation for prolonged flight during foraging (Correa-Fernandez and Cruz-Landim, 2010)."

How It Is Measured or Detected

One of the primary considerations in evaluating AOPs is the relevance and reliability of the methods with which the KEs can be measured. The aim of this section of the KE description is not to provide detailed protocols, but rather to capture, in a sentence or two, per method, the type(s) of measurements that can be employed to evaluate the KE and the relative level of scientific confidence in those measurements. Methods that can be used to detect or measure the biological state represented in the KE should be briefly described and/or cited. These can range from citation of specific validated test guidelines, citation of specific methods published in the peer reviewed literature, or outlines of a general protocol or approach (e.g., a protein may be measured by ELISA).Key considerations regarding scientific confidence in the measurement approach include whether the assay is fit for purpose, whether it provides a direct or indirect measure of the biological state in question, whether it is repeatable and reproducible, and the extent to which it is accepted in the scientific and/or regulatory community. Information can be obtained from the OECD Test Guidelines website and the EURL ECVAM Database Service on Alternative Methods to Animal Experimentation (DB-ALM). ?

Text from table 2 in LaLone et al. (2017) Weight of evidence evaluation of a network of adverse outcome pathways linking activaiton of the nicotinic acetylcholine receptor in honey bees to colony death. Science of the Total Environment 584-585, 751-775:

"• Radio-frequency identification tagging technology to track the frequency and duration of individual foraging events, flight time, foragers homing ability, duration of time spent at a feeder, and duration between feeding • Video tracking software for measures of total distance traveled and time spent in social interaction • Weigh bee-collected pollen from hive entrance trap • Pollen load can also be assessed by scoring the size of amount of pollen in the forager’s corbiculae (pollen basket) relative to the size of the worker bee • Nectar loads from individual forager bees can be measured with a pocket refractometer after inducing regurgitation • Video foragers returning to hive and measure waggle dance circuits performed • Food storage can be measured by visual inspection or digital imaging of the combs with the objective to estimate the percent of cells filled with nectar (uncapped), honey (capped), or pollen"

Domain of Applicability

This free text section should be used to elaborate on the scientific basis for the indicated domains of applicability and the WoE calls (if provided). While structured terms may be selected to define the taxonomic, life stage and sex applicability (see structured applicability terms, above) of the KE, the structured terms may not adequately reflect or capture the overall biological applicability domain (particularly with regard to taxa). Likewise, the structured terms do not provide an explanation or rationale for the selection. The free-text section on evidence for taxonomic, life stage, and sex applicability can be used to elaborate on why the specific structured terms were selected, and provide supporting references and background information.  More help


List of the literature that was cited for this KE description. Ideally, the list of references, should conform, to the extent possible, with the OECD Style Guide ( (OECD, 2015). More help

LaLone, C.A., Villeneuve, D.L., Wu-Smart, J., Milsk, R.Y., Sappington, K., Garber, K.V., Housenger, J. and Ankley, G.T., 2017. Weight of evidence evaluation of a network of adverse outcome pathways linking activation of the nicotinic acetylcholine receptor in honey bees to colony death. STOTEN. 584-585, 751-775.

Brodschneider, R., Crailsheim, K., 2010. Nutrition and health in honey bees. Apidologie 41 (3), 278–294.

Jones, J.C., Oldroyd, B.P., 2006. Nest thermoregulation in social insects. Adv. Insect Physiol. 33, 153–191.

Free, J.B., 1959. The transfer of food between the adult members of a honeybee community. Bee World 40 (8), 193–201.

Winston, M.L., 1987. The Biology of the Honey Bee. Harvard University Press.

Seeley, T.D., Visscher, P.K., 1985. Survival of honeybees in cold climates: the critical timing of colony growth and reproduction. Ecol. Entomol. 10 (1), 81–88.

Woyciechowski, M., Moroń, D., 2009. Life expectancy and onset of foraging in the honeybee (Apis mellifera). Insect. Soc. 56 (2), 193–201.

Dreller, C., Tarpy, D.R., 2000. Perception of the pollen need by foragers in a honeybee colony. Anim. Behav. 59 (1), 91–96.

Kammer, A.E., Heinrich, B., 1978. Insect flight metabolism. Adv. Insect Physiol. 13, 133–228.

Withers, G.S., Fahrbach, S.E., Robinson, G.E., 1995. Effects of experience and juvenile hormone on the organization of the mushroom bodies of honey bees. J. Neurobiol. 26 (1), 130–144.

Chang, L.H., Barron, A.B., Cheng, K., 2015. Effects of the juvenile hormone analogue methoprene on rate of behavioural development, foraging performance and navigation in honey bees (Apis mellifera). J. Exp. Biol. 218 (11), 1715–1724.

Toth, A.L., Robinson, G.E., 2005. Worker nutrition and division of labour in honeybees. Anim. Behav. 69, 427–435.

Correa-Fernandez, F., Cruz-Landim, C., 2010. Differential flight muscle development in workers, queens and males of the eusocial bees, Apis mellifera and Scaptotrigona postica. J. Insect Sci. 10, 85.