The sensitization of young workers to queens in the ant Myrmica rubra L.

The effect of workers, born into a queen-containing society, upon their subsequent broodrearing behaviour, was tested in the polygynous ant Myrmica rubra L., using small summer and large overwintered larvae. Workers, reared from the point of emergence in the presence of queens, had more control over larval growth compared with workers reared without queens. The current presence of queens had little influence. A critical period exists when young workers become sensitized and perhaps imprinted by the presence of queens. The character of the workers, size of the colony and the queen/worker ratio influence the degree of worker response towards queens and are discussed.     

The flight physiology of reproductives of Africanized, European, and hybrid honeybees (Apis mellifera)

Neotropical African honeybees (Apis mellifera scutellata), in the process of spreading throughout tropical and subtropical regions of the Americas, hybridize with and mostly replace European honeybees (primarily Apis mellifera mellifera and Apis mellifera ligustica). To help understand this process, we studied the effect of lineage (African, European, or hybrid) on the flight physiology of honeybee reproductives. Flight metabolic rates were higher in queens and drones of African lineage than in European or hybrid bees, as has been previously found for foraging workers. These differences were associated with higher thorax/body mass ratios and higher thorax-specific metabolic rates in African lineage bees. Queens were reared in common colonies, so these metabolic and morphological differences are likely to be genetic in origin. African drones had higher wing beat frequencies and thorax temperatures than European or hybrid bees. Hybrids were intermediate for many parameters, but hybrid queen mass-specific flight metabolic rates were low relative to Africans and were nonlinearly affected by the proportion of African lineage, consistent with some negative heterosis for this trait.     

Free amino acids in the haemolymph of honey bee queens (Apis mellifera L.)

In queen honey bees the free amino acid content in the haemolymph clearly depends on the physiological function and social environment of the individual. While in drones and workers the content of free amino acids increases after emergence until it reaches a peak in 5-day-old animals and decreases afterwards, the amino acid content in queens reaches its highest level (>60 nmol/ microl haemolymph) with the onset of egg laying (10 d of age). This level is about 2.5 times more than the highest level found in workers. Queens maintain this high level also when they are older (>30 d) and continue to lay eggs in average colonies. As in drones and workers, in queens the predominant amino acid is proline, which accounts for more than 50% of the total content of free amino acids in egg-laying individuals. When 10-day-old queens are prevented from mating and do not lay eggs, their amino acid content is significantly lower compared to laying queens of the same age. Also the social environment influences the contents of free amino acids in queens. When virgin queens were kept for 6 days with 20 worker bees and sufficient honey and pollen in an incubator, they had significantly lower concentrations of amino acids than virgin queens living for the same period with about 8000 workers in a colony. Most probably, the high amino acid concentration in the haemolymph is the basis for the high protein synthesis activity of laying queens.     

Thermal Behaviour of Honeybees During Aggressive Interactions

We report here on the interrelationship of aggressive behaviour and thermoregulation in honeybees. Body temperature measurements were carried out without behavioural disturbance by infrared thermography. Guard bees, foragers, drones, and queens involved in aggressive interactions were always endothermic, i.e. had their flight muscles activated. Guards made differential use of their endothermic capacity. Mean thorax temperature was 34.2–35.1°C during examination of bees but higher during fights with wasps (37°C) or attack of humans (38.6°C). They usually cooled down when examining bees whereas examinees often heated up during prolonged interceptions (maximum >47°C). Guards neither adjusted their thorax temperature (and thus flight muscle function and agility) to that of examined workers, nor to that of drones, which were 2–7°C warmer. Guards examined cool bees (<33°C) longer than warmer ones, supporting the hypothesis that heating of examinees facilitates odour identification by guards, probably because of vapour pressure increase of semiochemicals with temperature. Guards in the core of aggressive balls clinged to the attacked insects to fix them and kill them by heat (maximum 46.5°C). Bees in the outer cluster layers resembled normal guards behaviourally and thermally. They served as active core insulators by heating up to 43.9°C. While balled wasps were cooler (maximum 42.5°C) than clinging guards balled bees behaved like examinees with maximum temperatures of 46.6°C, which further supports the hypothesis that the examinees heat up to facilitate odour identification.     

Heat stress during development affects immunocompetence in workers,queens and drones of Africanized honey bees (Apis mellifera L.) (Hymenoptera: Apidae)

Though social insects generally seem to have a reduced individual immunoresponse compared to solitary species, the impact of heat stress on that response has not been studied. In the honey bee, the effect of heat stress on reproductives (queens and males/drones) may also vary compared to workers, but this is currently unknown. Here, we quantified the activity of an enzyme linked to the immune response in insects and known to be affected by heat stress in solitary species: phenoloxidase (PO), in workers, queens and drones of Africanized honey bees (AHBs) experimentally subjected to elevated temperatures during the pupal stage. Additionally, we evaluated this marker in individuals experimentally infected with the entomopathogenic fungus Metarhizium anisopliae. Differences in PO activity were found between sexes and castes, with PO activity generally higher in workers and lower in reproductives. Such differences are associated with the likelihood of exposure to infection and the role of different individuals in the colony. Contrary to our expectation, heat stress did not cause an increase in PO activity equally in all classes of individual. Heat stress during the pupal stage significantly decreased the PO activity of AHB queens, but not that of workers or drones, which more frequently engage in extranidal activity. Experimental infection with Metarhizium anisopliae reduced PO activity in queens and workers, but increased it in drones. Notably, heat stressed workers lived significantly shorter after infection despite exhibiting greater PO activity than queens or drones. We suggest that this discrepancy may be related to trade-offs among immune response cascades in honey bees such as between heat shock proteins and defensin peptides used in microbial defence. Our results provide evidence for complex relationships among humoral immune responses in AHBs and suggest that heat stress could result in a reduced life expectancy of individuals.     

意蜂（Apis mellifera）蜂王婚飞交尾机制的初探

通过氯气球悬挂意蜂（Apis mellifera）雌蜂及提取物等方法模拟蜂王婚飞交尾试验,比较不同生理状态的雌蜂及其提取物对雄蜂的性引诱力,结果表明：1．在工峰、处女王与产卵王及其提取物中,以产卵王及其提取物对雄峰性诱最大．平均分别为16只和14．3只雄蜂;2．不同数量的处女王提取物对雄蜂引诱力存在差异．以3只处女王提取物对雄蜂引诱力最大,平均引诱31.3只雄蜂;3．1000烛光以上的光照比400烛光以下的光照更有利于雄蜂的水分,且雄蜂集聚的个性体敏越多,相互激活力越强。     

Divergence in Time Apportionments of Tongue Protraction and Retraction Phases for Feeding Honey Bee Drones and Workers

Journal of Insect Behavior - Honey bees have three castes, drones, workers, and queens, that accomplish different tasks. In this research, we revealed the divergence in feeding behavior of drones...     

The influence of drone physical condition on the likelihood of receiving vibration signals from worker honey bees, <Emphasis Type="Italic">Apis mellifera</Emphasis>

Honey bee workers will perform vibration signals on adult drones, which respond by increasing the time spent receiving trophallaxis. Because trophallaxis provides the proteins for sexual maturation, workers could direct vibration signals towards drones showing certain physical characteristics, potentially influencing drone development and colony reproductive output. We examined the influence of drone condition on the likelihood of receiving vibration signals by comparing body weight, protein concentrations, and hemolymph juvenile hormone (JH) titers between drones that received the vibration signal and same-age, non-vibrated controls. Vibrated and control drones did not differ in total body weight, abdomen weight, abdomen-to-body weight ratio, total protein concentrations, or hemolymph JH titers. In contrast, vibrated drones had significantly lower thorax weight and smaller thorax-to-body weight ratios compared with controls. Because relative thorax weight may affect flight ability and mating success, workers could use the vibration signal to increase the care received by less developed drones, potentially contributing to the production of greater numbers of competitive males. However, the differences in thorax weights, while significant, were very small, and it is unknown how such slight differences might be assessed by workers or affect drone performance. Nevertheless, vibration signals performed on drones may provide opportunities for exploring the effect of the quality of reproductive individuals on caste interactions in honey bees.     

Monthly changes in various drone characteristics of Apis mellifera ligustica and Apis mellifera syriaca

This study was conducted to investigate drone rearing activity and semen production of Apis mellifera ligustica and Apis mellifera syriaca . Tendency of worker bees of both subspecies towards egg laying under semiarid conditions were also monitored in the experiments. Differences were not observed in drone brood production between both honeybee subspecies throughout the investigation. Worker bees of both subspecies needed a significantly shorter time to start egg laying during February and March in comparison with the time those workers needed for laying eggs during the remaining months of the study. Syrian bee workers started egg laying earlier than Italian bee workers. Drones from laying workers were much smaller and produced less sperms with more abnormalities than normal drones. Drones produced from queens in May were heavier and produced more sperms with less abnormalities than those produced during the other months. The drone brood rearing of both subspecies tended to follow the same general cycle in 2005 and 2006. The study suggests that virgin queens have a better chance to receive adequate viable sperm amounts from drones in April and May in semiarid Mediterranean conditions.     

Caste, Sex and Strain of Honey Bees (Apis mellifera) Affect Infestation with Tracheal Mites (Acarapis woodi)*

Worker honey bees from genetic strains selected for being resistant (R) or susceptible (S) to tracheal mites typically show large differences in infestation in field colonies and in bioassays that involve controlled exposure to infested bees. We used bioassays exposing newly emerged individuals to infested workers to compare the propensity for tracheal mites to infest queens, drones and workers from R and S colonies. In tests with queens, newly emerged R and S queens were either simultaneously confined in infested colonies (n = 95 and 87 respectively), or individually caged with groups of 5–20 infested workers (n = 119 and 115 respectively). Mite prevalence (percentage of individuals infested) and abundance (foundress mites per individual) after 4–6 days did not differ between R and S queens. In another test, five newly emerged drones and workers from both an R and an S colony, and a queen of one of the two strains, were caged in each of 38 cages with 20 g of workers infested at 60–96% prevalence. Infestations of the R queens (n = 17) and S queens (n = 19) did not differ significantly, but R workers had half the mite abundance of S workers, while R drones received about a third more migrating mites than S drones. In tests to evaluate possible mechanisms, removal of one mesothoracic leg from R and S workers resulted in 2- to 10-fold increase in mite abundance on the treated side, but excising legs did not affect infestation of the corresponding tracheae in drones. This suggests that differences in infestation between R and S workers, but not drones, are largely determined by their ability to remove mites through autogrooming. If autogrooming is the primary mechanism of colony resistance to tracheal mites, selection for resistance to tracheal mites using infestation of hemizygous drones may be inefficient. *The U.S. Government’s right ot retain a non-exclusive, royalty-free licence in and to any copyright is acknowledged.     

Deformed wing virus in western honey bees (Apis mellifera) from Atlantic Canada and the first description of an overtly-infected emerging queen

Deformed wing virus (DWV) in western honey bees (Apis mellifera) often remains asymptomatic in workers and drones, and symptoms have never been described from queens. However, intense infections linked to parasitism by the mite Varroa destructor can cause worker wing deformity and death within 67 h of emergence. Ten workers (eight with deformed wings and two with normal wings) and three drones (two with deformed wings and one with normal wings) from two colonies infected with V. destructor from Nova Scotia, Canada, and two newly-emerged queens (one with deformed wings and one with normal wings) from two colonies infected with V. destructor from Prince Edward Island, Canada, were genetically analyzed for DWV. We detected DWV in all workers and drones, regardless of wing morphology, but only in the deformed-winged queen. This is the first report of DWV from Atlantic Canada and the first detection of a symptomatic queen with DWV from anywhere.     

The behaviour of queen honeybees and their attendants

Abstract. The behaviour of queen and worker honeybees (Apis mellifera L.) was observed using small colonies in observation hives. Workers paid more attention to queens which had been mated for 2 months or more than to those which were newly mated; virgin queens received least attention. Queens received most attention when they were stationary and least when they were walking over the comb; virgin queens were most active. Queen cells had as many attendants as virgin queens and queen larvae were inspected almost continuously. The queen pheromone component 9–oxo-trans-2–decenoic acid stimulated 'court' behaviour when presented on small polyethylene blocks, but workers responded aggressively to complete extracts of queens' heads. Both the heads and abdomens of mated queens received much attention from court workers but the abdomens were palpated by more workers for longer and were licked much more. The queens' thoraces were least attended. Abdominal tergites posterior to tergite glands were licked for longer than those anterior to the glands. Only worker bees very near to the queen reacted to her and joined her 'court'.
No evidence was found of a diel periodicity in the behaviour of a queen or her 'court'. During the winter the queen's court was smaller than in summer and she walked less and laid fewer eggs. When colonies were fed with sucrose syrup in winter, their queens laid more eggs and workers reared more brood but there was no change in the attention received by the queens.
The implications of these findings for the secretion and distribution of queen pheromones are discussed.     

Differences in nestmate recognition for drones and workers in the honeybee, Apis mellifera (L.)

Nestmate recognition is the basic mechanism for rejecting foreign individuals and is essential for maintaining colony integrity in insect societies. However, in honeybees, Apis mellifera, both workers and males occasionally gain access to foreign colonies in spite of nest guards (=drifting). Instead of conducting direct behavioural observations, we inferred nestmate recognition for males and workers from the genotypes of naturally drifting individuals in honeybee colonies. We evaluated the degree of polyandry of the resident queens, because nestmate recognition theory predicts that the genotypic composition of insect colonies may affect the recognition precision of guards. Workers (N=1346) and drones (N=407) from 38 colonies were genotyped using four DNA microsatellite loci. Foreign bees were identified by maternity testing. The proportion of foreign individuals in a host colony was defined as immigration. Putative mother queens were identified if a queen's genotype corresponded with the genotype of a drifted individual. The proportion of a colony's individuals in the total number of drifted individuals was defined as emigration. Drones immigrated significantly more frequently than workers. The impact of polyandry was significantly different between drones and workers. Whereas drones immigrated more readily into less polyandrous colonies, worker immigration was not correlated with the degree of polyandry of the host colony. Furthermore, colonies with high levels of emigrated drones did not show high levels of emigration for workers, and colonies that adopted many workers did not adopt many foreign drones. Our data indicate that genetically derived odour cues are important for honeybee nestmate recognition in drones and show that different nestmate recognition mechanisms are used to identify drones and workers.     

SOME OBSERVATIONS ON THE MALPIGHIAN TUBULES AND OVARIOLES IN MYRMECIA DISPAR (CLARK) (HYMENOPTERA: FORMICIDAE)

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Myrmecia dispar (Clark) workers have a variable number of malpighian tubules; the number counted ranged from 21 to 29. The larger workers tend to have more tubules than smaller workers. Two male specimens had 16 tubules and 3 queen specimens had 23, 23 and 26 tubules respectively. Workers collected in winter and summer had 10 well developed polytrophic ovarioles while the queens had 18 ovarioles.     

Age and Behavior of Honey Bee Workers,Apis mellifera,that Interact with Drones

Colony reproduction in honey bees involves complex interactions between sterile workers and reproductive castes. Although worker–queen interactions have been studied in detail, worker–drone interactions are less well understood. We investigated caste interactions in honey bees by determining the age and behavior of workers that perform vibration signals, trophallaxis, and grooming with drones. Workers of all ages could engage in the different interactions monitored, although workers that performed vibration signals on drones were significantly older than those engaging in trophallaxis and grooming. Only 3–8% of workers engaged in the different behaviors were monitored. Compared with workers that performed vibration signals only on workers (‘worker vibrators’), those that performed signals on both workers and drones (‘drone vibrators’) had greater movement rates inside the nest, higher vibration signaling rates, and were more likely to have an immediate association with foraging. Both worker vibrators and drone vibrators contacted drones of all ages as they moved through the nest. However, drone vibrators contacted drones at higher rates, contacted slightly, but significantly younger drones, and were more likely to engage in trophallaxis and grooming with drones, in addition to vibrating them. Taken together, our results suggest that tiny proportions of workers belonging to separate, but overlapping age groups provide most of the care received by adult drones, and that drone vibrators comprise a subset of signalers within a colony that have an increased tendency to contact and interact with drones. Vibratory, tactile signals are involved in colony reproductive and movement decisions in a number of species of bees, wasps and ants, and may provide valuable tools for investigating caste interactions in many insect societies.     

Caste specific differences in fat body glycogen metabolism of the bumblebee,Bombus terrestris

Bumblebee queens of Bombus terrestris store large amounts of glycogen in the fat body during the first days after eclosion. The accumulation of the reserves is complete prior to hibernation. Comparative studies on the glycogen metabolism in queens and workers show that the increased activity of UDP-glucose: glycogen 4-α-d-glucosyltransferase (EC 2.4.1.11) could account for glycogen accumulation in queens. The enzymatic activities are nearly the same in newly emerged bees, significant differences between castes are detected by day three after eclosion. The activity of glycogen phosphorylase (EC 2.4.1.1), in contrast, is not different between the castes. After injection of juvenile hormone into newly emerged queens the activity of UDP-glucose:glycogen 4-α-d-glucosyltransferase remains low and no glycogen is accumulated in the fat body. Since eggs are formed simultaneously, the lowered activity of the enzyme is thought to depend on the changed metabolism of the fat body related to induced oogenesis.     

Resistance to Varroa destructor (Mesostigmata: Varroidae) when mite-resistant queen honey bees (Hymenoptera: Apidae) were free-mated with unselected drones.

This study demonstrated (1) that honey bees, Apis mellifera L, can express a high level of resistance to Varroa destructor Anderson & Trueman when bees were selected for only one resistant trait (suppression of mite reproduction); and (2) that a significant level of mite-resistance was retained when these queens were free-mated with unselected drones. The test compared the growth of mite populations in colonies of bees that each received one of the following queens: (1) resistant--queens selected for suppression of mite reproduction and artificially inseminated in Baton Rouge with drones from similarly selected stocks; (2) resistant x control--resistant queens, as above, produced and free-mated to unselected drones by one of four commercial queen producers; and (3) control--commercial queens chosen by the same four queen producers and free-mated as above. All colonies started the test with approximately 0.9 kg of bees that were naturally infested with approximately 650 mites. Colonies with resistant x control queens ended the 115-d test period with significantly fewer mites than did colonies with control queens. This suggests that beekeepers can derive immediate benefit from mite-resistant queens that have been free-mated to unselected drones. Moreover, the production and distribution of these free-mated queens from many commercial sources may be an effective way to insert beneficial genes into our commercial population of honey bees without losing the genetic diversity and the useful beekeeping characteristics of this population.     

Ontogeny of queen attraction to workers in the antCataglyphis cursor (Hymenoptera: Formicidae)

Summary The behaviour ofCataglyphis cursor workers towards queens at 15 days, one month or two months after worker emergence was tested. Workers reared entirely with their own maternal queen were tested with this queen or with an unfamiliar alien queen. Workers transferred within 48 h of emerging to a new definitive nest with an alien queen were tested with this queen or with the original maternal queen. The degree of attraction to each of these queens and the workers' behavioural repertoire were measured and analysed. The results showed the following: 1) The attractiveness of queens and the workers' queen recognition behaviour were linked. 2) Although unfamiliar alien queens hardly attract workers, familiar alien queens were as attractive as maternal queens, and induced the same strongly marked and unique worker response, indicating that workers learn queen attractant cues in the days immediately after emergence. 3) Agonistic reactions were observed, but workers continued to be attracted to their maternal queen even after developing an attraction response to an alien queen with which they had been reared. These results agree with the proposal that queens produce two kinds of pheromones, those that attract workers and those that mediate recognition of queens by workers. These results show the ability of workers to discriminate between queens. Workers are attracted to any queen, but recognize as nestmates only maternal or alien queens with which they have been maintained. 4) The differential in worker attraction and recognition from 15 days to 2 months and its modifications by post-imaginal experience illustrate worker behavioural ontogeny, which is a basis of social discrimination.     

The importance of daylength and queens for larval care by young workers of the ant Myrmica rubra L.

ABSTRACT. Workers whilst still less than a month from emergence rear early stage larvae better in a 16h day than in one of 14h. The callows must perceive the diel rhythm directly because there are no foragers to give them a clue, and the larvae are kept in the dark and cannot respond directly. This, and the study of egg-laying by young workers that preceded it, indicates that the extra hours daylight enable the workers to avoid the reproductive diapause that normally prepares them for hibernation. They retain active ovaries, ingest and share food with larvae either as trophic eggs or as a regurgitate from the crop.
In late summer, callows can rear sexual larvae in spring condition. Queens have a small negative effect on this, expressed as a smaller, though still gyne, pupa produced a little earlier. This weak response to queens develops into a strong negative one at a constant temperature of either 10 or 20°C. The workers then behave as they normally do in spring, and feed a watery regurgitate (dietary control) or, if this fails to arrest sexual development, physically harass the larvae by biting them in the ventral thorax (manipulative control). Large workers then result instead of gynes.     

Does the diapause experience of bumblebee queens Bombus terrestris affect colony characteristics?

1. Bumblebee colonies show much variation in the number of workers, drones, and queens produced. Because this variation prevails even when colonies are kept under identical conditions, it does not seem to be caused by extrinsic factors but rather by differences between founding queens. 2. The most likely factor that could cause differences between queens is diapause. Although colonies are raised under standardised conditions, the queens often experience diapause of different length. If there are costs associated with diapause that influence post‐diapause reproduction, the diapause history of the queens could affect colony characteristics. 3. Here, several colony characteristics are compared: number of first and second brood workers; total number of workers, drones, and queens; energy spent on sexuals; sex ratio; rate of worker production; time to emergence of first reproductive; and colony lifetime. Colonies were used where the queens experienced a diapause treatment of 0 (nondiapause queens), 2, and 4 months. 4. Although no proof was found for the existence of costs associated with diapause, the colony characteristics of nondiapause queens were significantly different from those of diapause queens. Colonies of nondiapause queens produced the lowest number of workers but the highest number of young queens. 5. It is argued that these nondiapause colonies are more time‐constrained than diapause colonies because nondiapause colonies produce two generations within the same season and should therefore be more efficient in producing sexual offspring. 6. Moreover, nondiapause colonies should rear a more female‐biased sex ratio because they can be certain of the presence of males produced by other (diapause) colonies.