Michael D. Breed

Nestmate recognition in honey bees

Abstract The recognition cues by which nestmate worker honeybees are discriminated from nonnestmates were investigated using new experimental techniques. The experiments described in this paper support the contention that the recognition cue is acquired prior to emergence as an adult. The cue probably has a genetic, rather than an environmental, source. Previous findings, which indicated that worker honeybees are recognized on the basis of environmentally acquired odours, do not contradict this result. Rather, bees probably use whatever cues are available for recognition. When environmental odour sources are carefully controlled, cues remain that allow discrimination of nestmate versus nonnestmate individuals.

Division of labor during honey bee colony defense

SummarySome worker honey bees respond to major disturbances of the colony by flying around the assailant and possibly stinging; they are a subset of the bees involved in colony defense. These defenders have an open-ended age distribution similar to that of foragers, but defensive behavior is initiated at a younger age than foraging is. Behavioral and genetic evidence shows that defenders and foragers are distinct groups of older workers. Behaviorally, defenders have less worn wings than foragers, suggesting less flight activity. Genetically, defenders differ in allozyme frequencies, demonstrating different subfamily composition from foragers in the same colony. They also differ in allozyme frequencies from guards in the same colony, providing further evidence for division of labor associated with colony defense. We use this information to develop a model for honey bee colony defense involving at least two distinct groups of workers and we propose that the non-guard defenders be called “soldiers”, due to their important role in colony defense.

RECOGNITION PHEROMONES OF THE HONEY BEE

Social recognition is the tool that allows animals to act appropriately toward other animals; animals survive as individuals because they are able to recognize the salient features of other animals, with whom they interact accordingly. Recognition systems provide the information animals need to make decisions about their behavior: whether to cooperate, to fight, to flee, or to court. Animals use recognition systems to determine the species of another animal, its sex, its age, or its fighting ability. In addition, animals recognize one another as individuals, as offspring, as sibs, as mates, or as members of a dominance hierarchy. Social recognition is an essential piece of the puzzle of understanding behavioral interactions between animals in populations. Many basic issues concerning kin and other types of recognition are not yet resolved; it has generally been easy to test whether recognition is present but much more difficult to discover the underlying mechanisms of recognition (Fletcher and Michener 1987, Hepper 1991, Pfennig and Sherman 1995). In fact, the actual biochemical mechanisms of recognition have never been determined for any species. In this article, I explore the nature and evolution of social recognition in honey bees, Apis

The guard honey bee: ontogeny and behavioural variability of workers performing a specialized task

Abstract Guarding is a relatively unstudied aspect of honey bee, Apis mellifera L., worker behaviour. The aim of this study was to characterize quantitatively the ontogeny and individual variability of guarding behaviour, the allocation of workers to the guard population in a colony, and the intercolonial variability of guarding behaviour. Guarding is a discrete task performed by a distinct group of workers that are younger than foragers and older than house bees. Workers that guarded initiated the behaviour between the ages of 7 and 22 days. The mean age of the onset of guarding varied; the minimum mean age of guards for a colony was 13·6 days and the maximum was 16·0 days. Workers varied in the length of time they spent as a guard. Most bees guarded for less than 1 days; however, some guarded up to 6 consecutive days. The more time a bee spent guarding during a day the more likely that bee was to guard for more than 1 day. Bees that guarded for more than 1 day also had longer and more frequent individual guarding bouts. All colonies that were studied had guard populations, but not all workers guarded. A relatively small proportion of any age cohort was observed to guard. The percentage of an age cohort that guarded varied among colonies, as did the size of the guard population. Guarding is a specialized task in that few bees guard, but guarding does not appear to require experience because so few bees remained as guards for very long. There was intercolonial variation in all aspects of the ontogeny of guarding and in allocation of workers to guarding. This variation is discussed in the light of other studies of variation in worker behaviour.

Graded recruitment in a ponerine ant

Summary(1) The giant tropical ant, Paraponera clavata, exhibits graded recruitment responses, depending on the type, quantity, and quality of a food source. More ants are initially recruited to a large prey or scavenge item than to a large quantity of sugar water. (2) Individual ants encountering prey items gauge the size and/or unwieldiness of the item, regardless of the weight, when determining whether to recruit. (3) The trail pheromone of this species is often used as an orientation device by individual ants, independent of recruitment of nestmates. (4) It is proposed that the foraging behavior of P. clavata represents one of the evolutionary transitions from the independent foraging activities of the primitive ants to the highly coordinated cooperative foraging activities of many “higher” ants.

Kin discrimination within honey bee (Apis mellifera) colonies: An analysis of the evidence

Compelling evolutionary arguments lead to the prediction that honey bee workers should discriminate between supersisters and half-sisters within colonies. We review the theoretical support for discrimination during swarming, queen rearing, feeding, and grooming. A survey of the data that tests whether such discrimination takes place shows that, despite substantial effort in a number of laboratories, there is no conclusive evidence for intracolony discrimination in any of the postulated contexts. The strongest suggestive data is in the critical context of queen rearing, but flaws in experimental design or analysis make the best available tests inconclusive. We present new data that shows that cues exist on which discriminations can be made among adult workers in nestmate recognition interactions and in feeding interactions, but our data does not differentiate between subfamily recognition and recognition associated with color phenotypes. We conclude that while selection may favor discrimination between supersisters and half-sisters, as a practical matter such discriminations play no role, or only a minor role, in the biology of the honey bee.

Honey bee, Apis mellifera, nestmate discrimination: hydrocarbon effects and the evolutionary implications of comb choice

Abstract Comb wax in honey bee colonies serves as a source and medium for transmission of recognition cues. Worker honey bees learn the identity of their primary nesting material, the wax comb, within an hour of emergence. In an olfactometer, bees discriminate between combs on the basis of odour; they prefer the odours of previously learned combs. Representatives of three of the most common compound classes in bees wax were surveyed for effects on nestmate discrimination behaviour. Hexadecane, octadecane, tetracosanoic acid and methyl docosanoate make worker honey bees less acceptable to their untreated sisters. Other similar compounds did not have this effect. These findings support the hypothesis that nestmate recognition in honey bees is mediated by many different compounds, including some related to those found in comb wax.

Testing the blank slate hypothesis: why honey bee colonies accept young bees

SummarySpecial features facilitate the admission of new members, such as neonates, to otherwise closed animal societies. In eusocial insects, such as honeybees and paper wasps, young adults acquire a colony recognition phenotype from other colony members or nesting materials. Older adults must exempt them from expulsion during the acquisition period. Newly emerged adult honeybees gain tolerance in their colony before their acquisition of the colony recognition phenotype by presenting a blank slate, absent recognition cues. This makes them generically acceptable in honey bee colonies. This strategy is analogous to the easily recognizable phenotypes associated with juvenility in birds and mammals.

The contributions of kinship and conditioning to nest recognition and colony member recognition in a primitively eusocial bee, Lasioglossum zephyrum (Hymenoptera: Halictidae)

Summary1.In the primitively social halictine bee, Lasioglossum zephyrum, colony unity is maintained through an interplay of both nest recognition and nest mate recognition, using odor cues.2.Nests have odors which are attractive to members of their colonies and also to bees from other colonies. Bees are, however, usually able to distinguish between their own nest and a foreign nest if given a choice.3.Bees from colonies which are relatively homogeneous genetically and in which the bees share a common larval environment recognize their own nest with less difficulty than bees from genetically heterogenous colonies in which a common early environment is lacking among member bees.4.A significant component of nest recognition behavior is based on genetic homogeneity, and/or larval conditioning, perhaps a form of imprinting to chemical cues.5.Recognition of nestmates by guards, essential for intraspecific nest defense, seems not to be based on the aphrodisiac secreted by females.6.Guards apparently learn individual odors of residents or a combination of the odors of several residents, providing a mechanism for distinguishing between nest mates and intruders attempting to enter the nest.7.Though adult learning is important in nest mate recognition, an overriding contribution from genetic similarity or early conditioning also occurs.

The Chemical Basis for Nestmate Recognition and Mate Discrimination in Social Insects

In this chapter we discuss the chemical basis for nestmate recognition in social insects. Animals that live in family groups are often able to discriminate family members from non-family members. For example, humans and other mammals can use a variety of cues—visual, auditory, and perhaps olfactory—to learn the identities of family members. Birds, on the other hand, rely primarily on auditory cues (Beecher, 1988). While any phenotypic trait that is associated with group membership could be utilized in nestmate recognition, studies of social insects have shown that they depend solely on olfactory cues to discriminate family members from other conspecifics.