Queen Replacement Research Articles

The evolution of food‐producing glands in eusocial bees (Apoidea, Hymenoptera)1

AbstractA food‐producing role for cephalic exocrine glands has arisen independently in both taxa of highly eusocial bees, Apis and Meliponini. With several exceptions, there is little evidence that food is produced by glands of solitary bees or by most bees at lower levels of sociality. We suggest that this association with sociality is due to four adaptive features of these glands: (1) food from the glands allows feces from queens and larvae to have a small volume, (2) the queen's fecundity can be increased, (3) nutrient recovery via cannibalism can be facilitated, and (4) rearing of emergency replacement queens is accelerated. Acceleration of the rearing of other castes and of queens in the normal process of colony fission is not clearly an advantage ascribed to these glands. Trophic eggs produced by meliponine colony workers are analogous to the secretions from food‐producing glands in Meliponini and Apis workers.

Queen Replacement in Dequeened Colonies of the Argentine Ant Iridomyrmex Humilis (Mayr)

Queen Replacement in Dequeened Colonies of the Argentine Ant Iridomyrmex Humilis (Mayr)

Age Is More Important Than Size in Determining Dominance Among Workers in the Primitively Eusocial Wasp, Polistes Instabilis

In primitively eusocial wasps, dominance hierarchies predict which female will become queen when the original queen is removed. At each of 3 latitudes spanning a range from temperate sites to tropical ones, an older, dominant, worker of the primitively social wasp, P. instabilis, became the replacement queen. Thus, even in the tropics, this species follows a temperate queen replacement pattern rather than the standard tropical pattern in which young non-foragers have the highest rank and replace the queen. Old individuals are dominant even though they are often smaller than their subordinates. These results are surprising because large size increases the chance of winning fights for queenship among Polistes females in other circumstances. Age-based dominance hierarchies may be stable in Polistes because colony members resist larger individuals' attempts to win high dominance rank by fighting.

Replacement queens in the neotropical termiteNasutitermes coxipoensis

The production of replacement queens in experimentally orphaned colonies was investigated in the neotropical termiteNasutitermes coxipoensis holmgren. A single adultoid replacement queen was produced with six weeks in more than 50% of the nests. The new queen begins oviposition extremely quickly. Replacement kings are seldom seen but must be present since brood in the nest in atribuable to the replacement queen. InN. coxipoensis, replacement adultoid queens and kings seem to develop preferentially from the few aged nymphs which are present in the nest throughout the year.

The social consequences of honey bee polyandry: the effects of kinship on worker interactions within colonies

Honey bees, Apis mellifera L., are polyandrous and several males simultaneously father offspring within a single colony. The relatedness of female colony members therefore varies with their paternity: workers encounter both patrilineal full sister ( r¯=0·75) and non-patrilineal half-sister ( r¯=0·25) nestmates. The impact of this intra-colony genetic variation on social grooming and trophallaxis (liquid food exchange) among workers in colonies consisting of two phenotypically-distinct worker patrilines was examined. Workers in these colonies groomed and fed a disproportionately large number of full sisters despite a tendency to encounter a disproportionately large number of half-sisters. Thus, workers actively discriminated between full and half-sisters. This patrilineal discrimination occurred both in colonies with laying queens and in a queenless colony rearing replacement queens. These results suggest that intracolony genetic variation may have a major effect on colony social organization.

Queen Succession in the Social Wasp, Polistes annularis

AbstractOutcomes of conflicts among social animals can strongly affect individual fitness and therefore partly determine how sociality evolves. In the social wasp, Polistes annularis, conflicts over egg laying result in a linear dominance hierarchy discernible from which wasps attack which others. We investigated the structure and maintenance of dominance hierarchies in colonies containing both nest foundresses and workers. We also investigated the outcome of a potential conflict between foundresses and workers over the identity of the female which becomes queen after the original queen disappears. To investigate queen replacement we recorded individuals' behavior before and after removal of the queen from 13 nests. This experiment simulated natural queen disappearance which occurs frequently. All foundresses were ranked over workers; high ranking females were most aggressive and directed most of their attacks to the female directly beneath them in the hierarchy. This hierarchy determined succession to queenship; the beta female became queen within 3 h. Therefore a foundress became the new queen whenever one was present. There was no evidence of conflict between workers and foundresses when a foundress became queen. This chance of becoming queen contributes to the expected fitness of a female that accepts a subordinate role in spring.

First Steps into Eusociality: The Sweat Bee Dialictus lineatulus

The primitively eusocial halictid bee Dialictus lineatulus has two generations per year in New York. Spring nests are initiated by one to six female bees; in multifoundress nests all bees are potentially reproductive but the largest individual doesn't forage. Summer nests contain an average of seven female bees which occur in reproductive castes, with workers almost the same size as queens. Some summer nests briefly form eusocial colonies where the foundress queen lives with her worker daughters. Foundress bees soon die in the summer, and most nests are then semisocial and contain only summer generation bees. The replacement queens are the dominant and older sisters of the workers. I hypothesize that reproductive castes first evolved in such sister associations due to environmental factors that prohibit subordinate bees from leaving and successfully starting their own nests.

Differences in inhibitory capability among queens of the ant Solenopsis invicta

ABSTRACT. The abilities of various categories of queens of the fire ant, Solenopsis invicta Buren, to inhibit de‐alation by virgin queens are compared by means of a standardized bioassay that detects the presence of an inhibitory pheromone. Highly fecund (high weight) queens of monogynous colonies and virgin replacement queens in queenless colonies have a significantly greater inhibitory capability than queens of lower fecundity (lower weight). In polygynous colonies, inhibitory effectiveness is also positively related to the fertility of individual queens, although no pheromone can be detected in queens that lay few eggs. Alate virgin queens that have overwintered in the parental nest, and sexually mature spring‐reared virgin queens, either do not produce the pheromone, or produce too little to be detected. These results are discussed in relation to the degree of ovarian development of different queen categories and in relation to the social status of these queens.

The social organisation of Halictus ligatus (Hymenoptera; Halictidae) in southern Ontario

The social organisation of Halictus ligatus was studied at Victoria, southern Ontario. At this locality, the one worker brood has a protracted period of emergence; this results in small colony populations throughout the summer activity phase. Workers average 12.7% smaller than their queens, 60% of them have some ovarian development, and 42% of them mate. More males are produced towards the very end of the first brood than earlier in the spring provisioning phase. These late first brood males probably survive to mate with reproductive brood females. In orphaned nests, one worker dominates the others to become a replacement queen. Most replacement queens are mated and orphaned colonies produce reproductives of both sexes. Data from this population are compared with those of other studies of this, and other, halictine species.

Replacement of reproductives in Nasutitermes princeps (Desneux) (Isoptera: Termitidae)

The production of replacement reproductives in experimentally orphaned societies was investigated in Nasutitermes princeps (Desneux). From 1 to 180 replacement queens and multiple kings, all adultoids, were found in the 13 nests that were re-collected. Normal imagos, microimagos, or a mixture of the two forms were present, depending on colony composition at the time of orphaning. In colonies with alates, the corresponding forms were found as replacement reproductives. Where only young nymphs were present, microimagos differentiated. Neither the number of queens nor their level of physogastry was correlated with the time elapsed since orphaning, but the total egg-laying rates were. We suggest that competition among queens rather than time determines individual physogastric development. Observations show that the most likely cause of accidental queen death in nature is probably nest fall from the supporting tree. Even in this case, the queen may be able to migrate to a newly rebuilt nest. An experimental simulation of this situation showed that colony migration can occur. The data indicate that the replacement of the primary queen after her accidental death cannot by itself account for the high rate of polygyny (60%) encountered in N. princeps. Two other possible causes are the replacement of the ageing foundress as a normal event of colony life, and colony reproduction by budding off new nests with adultoid reproductives.

Closed Population Honeybee Breeding 4. The Distribution of Sex Alleles with Top Crossing

SummaryComputer simulation was used to investigate the efficacy of top crossing within closed breeding populations of honeybees. Top crossing is carried out by selecting a single breeder queen (top-cross parent) to contribute all or a significant proportion of the drones needed to inseminate the virgin queens of a closed population. Different population-genetic models were tested by varying the number of queens selected as breeders, the source and relative contribution of the selected top-cross parent and the method of queen replacement each generation. It was demonstrated that acceptable levels of brood viability, as a consequence of genie sex determination, can be maintained for 20 generations of random mating and top crossing in closed populations of at least 50 breeder queens.

Do Worker Honey Bees Discriminate among Unrelated and Related Larval Phenotypes?

Experiments were designed to test the hypothesis that worker honey bees can recognize the phenotype of larvae and use this information to favor closely related individuals when rearing queens. Three experimental designs were employed. The first required colonies to rear emergency queen cells; this represents a “natural” context. Queenless bees of one sibling group were given the choice of rearing queens from larvae of the same or a different sibling group. In the second and third experiments larvae were grafted using standard commercial techniques for rearing queens. In one experiment, worker bees could choose between rearing larvae from their own or a different racial group, in the other the choice was between their own and genetically similar larvae. The results of these experiments do not support the original hypothesis; no phenotypic preference in rearing emergency replacement queens or in choosing grafted larvae was noted. We conclude from these experiments that under normal conditions information concerning the phenotype of honey bee larvae does not allow discrimination between related (half- or full-sister) and completely unrelated individuals.

Gerontocracy in the social wasp, Polistes exclamans

We observed three naturally occurring Polistes exclamans nests in Austin, Texas for 139 h through a succession of 13 queens. Nine of the 13 replacement queens were the oldest individuals on the nest, forming a system of queen replacement that may be described as a gerontocracy. Before becoming queen, replacement queens foraged more and were more aggressive than females who never became queen. This system of old forager supersedure was similar to that found in other temperate species but contrasted with that reported for tropical species of wasps in which younger females who are not workers occupy the higher ranks just beneath the queen.

The inhibitory pheromone of queen fire ants: effects of disinhibition on dealation and oviposition by virgin queens

1. Virgin queen fire ants,Solenopsis invicta Buren, that overwintered in parental nests participated in mating flights in early spring, and some were shown to have been laying eggs in queenright colonies before leaving. Virgin queens reared in spring had immature oocytes in their ovarioles when they left on mating flights. 2. When released from pheromonal queen influence by isolation, 98% of both overwintered and spring-reared virgin queens oviposited and exhibited colony founding behavior, but only 73% dealated. The alary muscles of all of them histolyzed, however, whether or not they dealated. The eggs laid by both the overwintered and springreared virgin queens were larger than those laid by physogastric mated queens, and less than 1% were viable. 3. When spring-reared virgin queens were disinhibited by dividing colonies into queenright and queenless halves, some virgin queens in the queenless halves dealated and oviposited. A frequency distribution of the sizes of eggs laid by these virgin replacement queens was bimodal. The larger eggs were similar in size to those laid by spring-reared virgin queens in isolation and less than 1% were embryonated. They served a trophic function. The smaller eggs were not as small as those laid by mated queens, but the majority were embryonated. The number of eggs laid by virgin replacement queens in 5 h was positively correlated with the maximum number of oocytes/ovariole. The size of eggs laid by virgin and mated queens was a function of the oviposition rate. 4. The results demonstrate that the inhibitory pheromone of queen fire ants acts directly on virgin queens and that it prevents muscle histolysis and rapid oogenesis. The former hypothesis that the pheromone acts mainly on workers and prevents them from causing virgin queens to dealate is, therefore, disproved. 5. A new working hypothesis consistent with the experimental results and with previously published information is that a single queen pheromone regulates the secretion, and titer, of juvenile hormone.

Replacement of the royal pair in Macrotermes michaelseni

At intervals of 2 months over 1 year, 64 royal cells were removed from mounds of Macrotermes michaelseni to find out whether a new royal pair was produced. In five mounds replacement reproductives were found. Young reproductives from incipient laboratory colonies were never accepted as replacements if they were introduced after the removal of the primary reproductives. One out of 10 royal pairs was accepted if the royal cell was introduced immediately after removal of the original one, and three out of 10 survived if the royal cell was introduced 1 week after the removal of the original one. Replacement reproductives were only produced when nymphs or alates were in the nest at the time the primary reproductives were removed. It was not possible to find out at what time after the removal a new royal pair was accepted but measurements of the replacement queens showed that they can become fully physogastric within 7 months.

Inhibition of worker mating by queens in a sweat bee,Lasioglossum zephyrum

About 18 percent ofLasioglossum zephyrum workers mate in the field. In the laboratory female mating receptivity varied with age and caste: 1) sixty-nine percent of bees less than 3 days old mated when kept isolated from other females, 2) in six-bee colonies all of the queens, but only 7,7 percent of their workers, mated, 3) in queen removal experiments involving 10 colonies, all the replacement queens mated (these same individuals were not receptive to mating as workers), 4) in one colony of 5 bees, consecutive queen removal showed that each of the four bees identified as the queen mated, while none of the remaining workers did so. The results indicate that queen inhibition governs behavior of the workers even outside the nest. The inhibition may involve more than differences in ovarian size.

Queen numbers in colonies of ants of the genusMyrmica

The effects upon the structure of a population ofMyrmica colonies is examined under the assumption that colonies adopt a strategy of persistent exclusive monogyny. The effects of various queen mortality curves are examined. It is concluded that field data does not support a hypothesis based on this strategy and it is suggested that allMyrmica colonies recruit replacement queens. The effects of different queen recruitment efficiencies are examined for haplometrotic and pleometrotic species. It is concluded that if all species have a capacity to recruit queens then all are potentially secondarily polygynous. The evolutionary significance of the social status ofMyrmica ants is discussed.

Events following queen removal in colonies of Africanized honeybees in South America

The timing of queen rearing and swarming are described after queens were removed from colonies of Africanized bees. New queens were reared from newly hatched to three day old worker larvae, many of which were moved in the egg or newly eclosed larval stages by workers into newly constructed queen cells. Mortality of worker eggs and larvae following dequeening was high, averaging 50%. When new queens emerged, swarms issued from two-thirds of the colonies. This process of queen replacement and queen-loss swarming differs from that of reproductive swarming in the lack of preparation before queen loss, longer queenless interval, lack of correlation between number of swarms and sealed brood area or number of queen cells, and lack of Congestion in colonies when swarms issued.

Queen replacement in orphaned colonies of the fire ant, Solenopsis invicta

1. When field colonies of Solenopsis invicta Buren were orphaned by removing the functioning queen, re-collection 8–10 weeks later showed that 61% had replacement queens that were physogastric and attractive to workers. The weight of the original colony queens increases with the colony mound volume. The weight of replacement queens is inversely related to the number of such queens in the colony (1 to 99, but over half had only 1). 2. Laboratory rearing and later spermathecal dissections of these replacement queens established that 21% of the colonies had an inseminated queen and produced worker pupae. Of the remaining uninseminated replacement queens, about 20% nevertheless produced 1–25 worker pupae, probably by thelytokous parthenogenesis. Checking the brood present in orphaned field colonies showed that about 35% produced worker pupae, indicating an inseminated replacement queen was present. The remainder of the orphaned colonies produced all-male sexual broods only, a conditions not found in unorphaned colonies. 3. Combining the lab and field evidence, 27% of the orphaned colonies produced fertile replacements, and these were concentrated among the smaller, younger colonies. The hypothesis is developed that the inseminated replacements are surviving foundresses from pleometrotic colony founding, and that S. invicta is often polygynous but functionally monogynous.

Pheromonal Control of Queen Rearing in Honeybee Colonies

SummaryExtracts of queens or synthetic 9-oxo-trans-2-decenoic acid (9-ODA) partially inhibited queen replacement in colonies following the removal of the queen. Synthetic 9-hydroxy-trans-2-decenoic acid (9-HDA) was ineffective and not synergistic with 9-ODA. During the swarming season, a continuous treatment with 9-ODA did not decrease the number of queen cups and queen cells built by queenright colonies.