Drone Comb Research Articles

Caging the queen with and without a comb section to achieve high efficacy of Varroa destructor control

We investigated the application of queen caging to prevent autumn brood rearing. In comparative experiments, cages equipped with queen excluders on both sides were used. Only cages of the experimental group were supplied with comb sections. Survival of queens and the influence of various factors on brood rearing in cages and in the nest after the queen had been released were compared. The factors included the position of caged queens in the nest (in the middle or in the periphery), comb sections with empty or honey-filled cells, or with drone cells. The queens did not perish in cages supplied with a worker comb section, but 8% of them perished in cages without it. One queen perished in the cage with drone comb section. The number of colonies rearing brood and the brood area in the nest was higher than those in the cage. There was no correlation between the position of the caged queen in the nest and brood production in the cage and later in the nest. Comb section fullness had no impact on brood rearing in the cage. In cages with a drone comb section, no brood was observed besides eggs, but the total brood area (including eggs) did not differ from the worker comb section group in cages and later in the nest. Caging of the queens on an empty worker comb section for 21 days supports their survival and enables the beekeeper to carry out successful Varroa control earlier in autumn.

Effect of Using Drone Brood Cells as Traps Against Varroa destructor (Varroa Mite)

Today, the honeybee parasite Varroa destructor is thought to be the most dangerous creature in the beekeeping industry worldwide. In this study, the efficacy of using drone brood cells (known to have no residue concerns in bee products and harmless on bee health) as traps against V. destructor was investigated. A total of 16 honeybee (Apis mellıfera) colonies with V. destructor infestation percentage of less than 5% were used for the trial. The treatment group consisted of 8 colonies that were randomly assigned to molded drone comb (comb with 5.4 mm hexagonal cells). The other 8 were assigned to unmolded comb to form the control group. In the trial groups, after 20 days (from 10th May), all drone combs with complete pupation were removed and destroyed on 30th May, 20th June, 10th July, 30th July, and 20th August. During the trial, varroa mite infestation rate (mean abundance), colony development, and varroa mite preference for drone and work bee brood cells were determined. The results showed that the application of drone brood cells as a control method was statistically significant against V. destructor, and did not negatively affect colony development. On the other hand, V.destructor's preference for both drone and worker bee brood cells among the groups was not statistically significant. In conclusion, drone brood cells ensured an approximately 43% success rate as traps against V. destructor compared to the control group. The effective application of drone brood cells as traps in combination with other Varroa mite control methods should be investigated.

Queenless honey bees build infrastructure for direct reproduction until their new queen proves her worth.

The terminal investment hypothesis predicts that individuals will alter their reproductive investments based on reproductive prospects. This hypothesis, however, has never been tested at the colony-level, where reproductive prospects for thousands of individuals can change instantly with the death of a single individual: the queen. A honey bee queen's death also changes the reproductive mechanism; if the queen is not replaced, then workers reproduce directly, by producing males in reproductive comb-drone comb-before the colony dies. To test how workers respond to reproductive uncertainty, I made colonies queenless and measured comb building throughout the stages of rearing a replacement queen. Queenless workers built only drone comb throughout queen rearing, even when the colony possessed a virgin or mated queen. Only when the new queen started laying fertilized eggs did workers stop building drone comb. Despite queenless colonies being more likely to eventually rear a replacement queen (88%), than to fail (12%), workers still built drone comb for direct reproduction, even when the colony was provided with ample drone comb. Therefore, workers "pessimistically" invest in drone comb to prepare for direct reproduction, even while rearing a replacement queen to prevent that outcome. When faced with reproductive uncertainty, honey bees may "hope" for the best, but they prepare for the worst.

The effect of queen insemination volume on the growth of newly established honey bee (Apis mellifera) colonies

The number of female progeny that a honey bee (Apis mellifera) queen produces in her lifetime is directly dependent on the amount of semen she collects upon mating (i.e., insemination volume) and the number of viable sperm cells contained within the semen (i.e., sperm viability). Queen insemination volume has been shown to alter queen mandibular pheromone profiles, as well as worker behavior and physiology at the individual level. In order to determine if queen insemination volume has any colony-level effects, we compared the growth of newly established colonies headed by queens instrumentally inseminated with either a low volume (1.5 μL) or a high volume (9.0 μL) of pooled semen from May to October in 2013 and 2015. We did not find a significant effect of queen insemination volume on the production of worker comb, drone comb, stored food, worker population, or seasonal queen or colony survivorship. Therefore, we concluded that queen insemination volume does not seem to directly affect growth at the colony level, at least during a colony’s first year.

Using drone brood in the control of the Varroa disease of bees in Greece

The use of drone brood to control the Varroa disease (Varroa jacobsoni Ouds) was tested in twenty bee colonies (ten as control) which had a very low Varroa mite infestation. The experiment started in winter 1981-82. Early in spring 1983 the brood was removed from ten hives and later during April, May and June it was replaced by drone combs (trap combs) which were also removed when drone cells were capped. The same treatment was repeated during spring 1984. In July 31, 1984, the adult bee infestation was 0 to 7%, while the worker brood’s infestation was 0 to 17%. The data show that, after two and half years without any acaricidal treatment, six out of the ten bee colonies continued to have a very low mite infestation, while three showed high infestation and had to be treated with acaricide. One of the three colonies was treated by acaricide in the winter 1983-84, that is two years from the beginning of this experiment. On the contrary, in the ten control colonies (with the same low infestation in spring 1982) the mite infestation reached catastrophic levels by August 1983.

The cues of colony size: how honey bees sense that their colony is large enough to begin to invest in reproduction.

As organisms develop, they first invest resources in survival and growth, but after reaching a certain condition they start to also invest in reproduction. Likewise, superorganisms, such as honey bee colonies, first invest in survival and growth, and later commit resources to reproduction once the number of workers in the colony surpasses a reproductive threshold. The first form of reproductive investment for a honey bee colony is the building of beeswax comb made of special large cells used for rearing males (drones). How do the workers sense that their colony is large enough to start building this 'drone comb'? To address this question, we experimentally increased three possible cues of colony size - worker density, volatile pheromone concentration and nest temperature - and looked for effects on the bees' comb construction. Only the colonies that experienced increased worker density were stimulated to build a higher proportion of drone comb. We then monitored and quantified potential cues in small and large colonies, to determine which cues change with colony size. We found that workers in large colonies, relative to small ones, have increased contact rates, spend more time active and experience less variable worker density. Whereas unicellular and multicellular organisms use mainly chemical cues to sense their sizes, our results suggest that at least one superorganism, a honey bee colony, uses physical cues to sense its size and thus its developmental state.

In-Hive Miticides and their Effect on Queen Supersedure and Colony Growth in the Honey Bee (Apis mellifera)

Honey bees (Apis mellifera) contribute an estimated $200 billion annually to the global economy, primarily through crop pollination. Despite their importance, the number of managed honey bee colonies continues to decline. Recent surveys have shown that colony losses are attributed in great part to problems associated with the ectoparasitic mite Varroa destructor, and with issues related to poor queen quality (particularly premature queen replacement), which often result in decreased colony productivity and increased risk of mortality. We aimed to investigate how sublethal exposure to beekeeper-applied miticides affects honey bees at both the individual (queen) and colony levels. We did so by comparing the growth (comb built, brood produced, food stored, and worker population), queen supersedure rates, and winter survival probabilities of colonies that were headed by queens that were raised in either miticide-laden or miticide-free beeswax cups then housed in hives that were either treated with miticides or left untreated. Contrary to our prediction, we found that treated colonies headed by queens raised in miticide-laden beeswax built significantly more worker and drone comb, and stored more food, than any other colony treatment. We did not, however, observe any other significant effect of colony treatment on the amount of brood production, worker population size, queen supersedure rate, or colony winter survival. Thus, we failed to observe a direct negative effect of miticide exposure at the colony level. More studies are needed to further test the potentially detrimental synergistic effects of in-hive miticides on honey bee health at the colony level.

Adaptive tuning of an extended phenotype: honeybees seasonally shift their honey storage to optimize male production

Organisms face the challenge of optimally allocating limited resources among investments that promote survival, growth or reproduction. In species whose members build complex nests, this resource allocation problem also applies to the building and use of the nest structure, a critical part of an individual's extended phenotype. Honeybee colonies face an acute problem of properly allocating one nest resource in particular, large cells of drone comb built for rearing drones, between reproduction (rearing drones) and survival (storing honey). Here the trade-off is inescapable, because a drone cell cannot be used simultaneously for drone production and honey storage. We predicted that the workers in a honeybee colony would solve this problem by preferentially using drone comb for producing drones when their mating opportunities are good (spring and early summer) and for honey storage when the drones' mating opportunities are poor (late summer and autumn). To test our prediction, we experimentally tested how drone comb and worker comb were used for honey storage from April to September. In spring and early summer, workers preferentially removed honey from drone comb, making it available for producing drones. In late summer and autumn, workers did not preferentially remove honey from drone comb. This study shows that a honeybee colony is able to fine-tune its extended phenotype by adaptively allocating a key nest resource, its drone comb, between survival and reproduction.

A critical number of workers in a honeybee colony triggers investment in reproduction.

Social insect colonies, like individualorganisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that their colony has reached the state where it is adaptive to begin investing in reproduction? Previous work has shown that larger honeybee colonies invest more in reproduction (i.e., the production of drones and queens), however, the term 'larger' encompasses multiple colony parameters including number of adult workers, size of the nest, amount of brood, and size of the honey stores. These colony parameters were independently increased in this study to test which one(s) would increase a colony's investment in reproduction via males. This was assayed by measuring the construction of drone comb, the special type of comb in which drones are reared. Only an increase in the number of workers stimulated construction of drone comb. Colonies with over 4,000 workers began building drone comb, independent of the other colony parameters. These results show that attaining a critical number of workers is the key parameter for honeybee colonies to start to shift resources towards reproduction. These findings are relevant to other social systems in which a group's members must adjust their behavior as a function of the group's size.

The effects of honey bee (Apis mellifera L.) queen reproductive potential on colony growth

Reproduction in species of eusocial insects is monopolized by one or a few individuals, while the remaining colony tasks are performed by the worker caste. This reproductive division of labor is exemplified by honey bees (Apis mellifera L.), in which a single, polyandrous queen is the sole colony member that lays fertilized eggs. Previous work has revealed that the developmental fate of honey bee queens is highly plastic, with queens raised from younger worker larvae exhibiting higher measures in several aspects of reproductive potential compared to queens raised from older worker larvae. Here, we investigated the effects of queen reproductive potential (“quality”) on the growth and winter survival of newly established honey bee colonies. We did so by comparing the growth of colonies headed by “high-quality” queens (i.e., those raised from young worker larvae, which are more queen-like morphologically) to those headed by “low-quality” queens (i.e., those raised from older worker larvae, which are more worker-like morphologically). We confirmed that queens reared from young worker larvae were significantly larger in size than queens reared from old worker larvae. We also found a significant positive effect of queen grafting age on a colony’s production of worker comb, drone comb, and stored food (honey and pollen), although we did not find a statistically significant difference in the production of worker and drone brood, worker population, and colony weight. Our results provide evidence that in honey bees, queen developmental plasticity influences several important measures of colony fitness. Thus, the present study supports the idea that a honey bee colony can be viewed (at least in part) as the expanded phenotype of its queen, and thus selection acting predominantly at the colony level can be congruent with that at the individual level.

Morphometry and number of spermatozoa in drone honeybees (Hymenoptera: Apidae) reared under different conditions

The effects of three factors operating during pre-emergence development period on some characteristics of drones were studied. Weight of newly emerged drones, length of forewing, length of tibia, length of femur, length and width of basitarsus and number of spermatozoa in drones from colonies in which the workers had access to drone brood (A), the size of brood cells differed (B) or the colony had a queen or was queenless (C), were determined. For this purpose, 9 colonies were chosen at random from the test apiary and prepared so that each contained one empty Langstroth frame with six small sub-frames containing drone combs, three of which were used to test the effect of one level and the other three the other level of each factor. The results showed that, colony status had a greater effect on the parameters measured than either the size of the brood cells or whether the workers had access to sealed brood cells. Most of the parameters were significantly different in C, whereas only a few in B and non in A were significantly different. The distance between discriminant scores in each experiment enhanced the previous results, as it was highest in C, followed by B and then A. Optimal drone characteristics may be recorded for colonies in which the queens were induced to lay unfertilized eggs in newly built drone combs, and then removed and the drone brood reared in a queen less colony.

Evaluation of Drone Brood Removal for Management of <I>Varroa destructor</I> (Acari: Varroidae) in Colonies of <I>Apis mellifera</I> (Hymenoptera: Apidae) in the Northeastern United States

The efficacy of drone brood removal for the management of Varroa destructor Anderson & Trueman in colonies of the honey bee, A. mellifera L., was evaluated. Colonies were treated with CheckMite+ in the fall of 2002. The following spring, quantities of bees and brood were equalized, but colonies were not retreated. The brood nest of each colony consisted of 18 full-depth worker combs and two full-depth drone combs. Each worker comb had <12.9 cm2 of drone cells. Standard management practices were used throughout the season. Colonies were randomly assigned to one of two groups. In the control group, drone combs remained in place throughout the season. In the treatment group, drone combs were removed on 16 June, 16 July, 16 August, and 16 September and replaced with empty drone combs (16 June) or with drone combs removed on the previous replacement date. In the early fall, the average mite-to-bee ratio in the control group was significantly greater than the corresponding ratio in the treatment group. Drone brood removal did not adversely affect colony health as measured by the size of the worker population or by honey production. Fall worker populations were similar in the two groups. Honey production in treatment colonies was greater than or similar to production in control colonies. These data demonstrate that drone brood removal can serve as a valuable component in an integrated pest management program for V. destructor and may reduce the need for other treatments on a colony-by-colony basis.

Reproductive and morphological comparisons of drones reared in queenright and laying worker colonies

SUMMARYDrones reared in queenright colonies (QRC), in drone combs (DC) and in laying worker colonies (LWC) both in worker combs (WC) and in DC were compared with respect to their live weights at different ages, reproductive capacities, and morphological characters. Depending on the comb and colony type (DC-QRC, DC-LWC and WC-LWC), the weights of newly emerged drones varied. At emergence, the drones from DC- QRC were 17.0% heavier than drones from DC-LWC, while the drones from WC-LWC were 36.6% and 23.7% lighter than drones from DC-QRC and DC-LWC, respectively. The drones sampled from DC-QRC, DC-LWC and WC-LWC lost 18.8%, 16.1% and 13.3% of their initial weights during maturation from emergence to 18-day old, respectively. The mean number of spermatozoa in drones from DC-QRC (12.01 × 106) was significantly greater than that of drones from DC-LWC (10.17 × 106) and from WC-LWC (8.62 × 106) The other reproductive and morphological characters, such as weight of mucus glands and seminal vesicles and extent of hamuli, lengths of hind leg parts, total length of hind leg and head width, all were significantly greatest in drones from DC-QRC and smallest in WC-LWC drones. This led us to assign individual drones to three distinct categories; large, medium and small drones.

Collective control of the timing and type of comb construction by honey bees (Apis mellifera)

This review considers how a honey bee colony optimally controls the timing and type of new comb construction. Optimal timing requires bees to balance the energy costs of construction with the opportunity costs of lacking storage space during nectar flows. They do so by conditioning the start of building on (1) the attainment of a fullness threshold, and (2) the availability of nectar. A dynamic optimization model has suggested that this rule is slightly suboptimal, but may compensate for this by its simplicity and generality. The emergence of this collective strategy from the decisions of individual bees is poorly understood, but recent experiments have cast doubt on the long-standing idea that building is triggered by increased distension of the crops of nest bees. Bees also regulate the relative amounts of drone and worker comb in their nests, with important consequences for their sex investment strategy. Regulation depends on the inhibitory effect of drone comb on further drone comb construction, mediated through a decentralized process requiring that workers have direct contact with the comb. Contact by the queen is not required, nor is the presence of drone brood, although the latter may enhance the strength of inhibition. honey bee / comb / drone / decentralized control / life history / self-organization

Do policing honeybee ( Apis mellifera ) workers target eggs in drone comb?

Honey bee (Apis mellifera) workers police each other's reproduction by eating worker-laid eggs while preferentially leaving queen-laid eggs. Policing effort is presumably associated with biological costs, including those of search time and of errors of identification of eggs so that the wrong eggs are retained or eaten. Selection should act to minimise these costs. One way costs can be reduced is to focus policing effort on eggs that are most likely to be worker laid. We show here, in accordance with this prediction, that policing effort is focussed on drone cells where workers are more likely to lay eggs, rather than on worker cells which are more likely to contain queen-laid eggs.

The effect of drone comb on a honey bee colony's production of honey

This study examined the impact on a colony's honey production of providing it with a nat- ural amount (20%) of drone comb. Over 3 summers, for the period mid May to late August, I mea- sured the weight gains of 10 colonies, 5 with drone comb and 5 without it. Colonies with drone comb gained only 25.2 ± 16.0 kg whereas those without drone comb gained 48.8 ± 14.8 kg. Colonies with drone comb also had a higher mean rate of drone flights and a lower incidence of drone comb build- ing. The lower honey yield of colonies with drone comb apparently arises, at least in part, because drone comb fosters drone rearing and the rearing and maintenance of drones is costly. I suggest that providing colonies with drone comb, as part of a program of controlling Varroa destructorwithout pesticides, may still be desirable since killing drone brood to kill mites may largely eliminate the neg- ative effect of drone comb on honey yields. comb foundation / drone / drone comb / honey bee / honey production

Varroa mite infestations in elevated honey bee brood cells: effects of context and caste.

The Varroa mite infestation level of honey bee, Apis mellifera, worker larvae reared in individual raised cells was 6-fold higher than in the adjacent six cells surrounding them; this differential infestation rate is similar to published values of higher mite infestations of drone cells compared to worker cells. Infestation levels in control cells were the same as in the surrounding cells. In contrast to infestation of these individually raised cells, Varroa mites invaded worker larvae in raised cells along the perimeter of a patch of raised cells (10 by 21 rows) 2.5 times more often than surrounding unraised cells, and similarly ca. 2.5 times more often than in the remaining raised cells (interior) of this patch. In similarly prepared frames of drone comb, Varroa mites invaded individually raised drone cells 3.3-fold more often than the adjacent surrounding cells and control cells. On the other hand, Varroa mites infested drone larvae in the interior of the raised-patch area as often as drones in raised cells along the perimeter of the raised-patch, and this rate was ca. 2.5-fold higher than for drone larvae in unraised cells surrounding the raised-patch and drone larvae in control cells. The higher levels of infestation of raised cells did not come at the expense of the surrounding cells, i.e., the infestation levels of the adjacent surrounding cells were the same as in control cells. For worker larvae, the increased number of mites invading individual raised cells and edge cells of the raised patch were proportional to the number of surrounding nonraised cells. The relationship between raised cell-edges, observations of mite walking behavior on comb surfaces, and larval-to-cell-rim distances are discussed in relation to their possible roles in eliciting mite invasion of honey bee larval cells and contrasted to the putative role of kairomones in larval-host location.

Decentralized control of drone comb construction in honey bee colonies

Honey bee colonies furnish their nests with two types of comb distinguished by cell size: large cells for rearing males (drone comb) and small cells for rearing workers (worker comb). The bees actively regulate the relative quantity of each type, a behavior likely to be important in setting a colony's sex ratio. Experimental analysis of the information pathways and control mechanisms responsible for this regulation found the following results. The amount of drone comb in a nest is governed by negative feedback from drone comb already constructed. This feedback depends on the workers having direct contact with the drone comb in their nest, but does not depend on the queen's contact with the comb. The comb itself, rather than the brood within it, is sufficient to provide the negative feedback, although the brood may also contribute to the effect. These findings show that drone comb regulation does not depend on the queen acting as a centralized information gatherer and behavioral controller. Instead, the evidence points to a decision-making process distributed across the population of worker bees, a control architecture typical of colony organization in honey bees and other large-colony insect societies.

Invasion of Varroa jacobsoni into drone brood cells of the honey bee, Apis mellifera

Invasion of Varroa mites into drone brood cells of honey bees was studied in colonies without worker brood. The probability for a mite to invade was dependent on the brood/bees ratio, which is defined as the number of drone brood cells capped per kg of bees. When compared with invasion in colonies with exclusively worker cells, Varroa mites invaded drone cells 11.6 times more frequently. This suggests that the biased distribution of mites over drone and worker cells in colonies with both types of brood cells results predominantly from the higher rate of invasion into a drone cell per se, when compared to that into a worker cell per se. Since the rate of invasion is high in drone cells, a trapping method using drone combs may be very effective in controlling the Varroa mite. When no other brood is present, 462 drone cells are estimated to be sufficient to trap 95% of the mites in a colony of 1 kg of bees

FARKLI TİP PETEK KULLANIMININ BAL ARISI (Apış mellifera L.) KOLONİLERİNDE AĞIRLIK KAZANCI, YAVRU YETİŞTİRME VE PETEK İŞLEMEYE ETKİSİ / EFFECT OF USING VARIOUS COMBS ON THE COMB BUILD, BROOD REARING AND WEIGHT GAIN IN HONEY BEE {Apis mellifera L.) COLONIES

OZET : Bu arastirma, farkli tip petek kullaniminin bal arisi (Apis mellifera L) kolonilerinin nektar akimi donemindeki agirlik kazanci, yavru yetistirme ve petek isleme aktivitesine etkilerini belirlemek amaciyla yapilmistir. Arastirma, herbirisinde 10 koloni bulunan A, B ve C muamele gruplarinda toplam 30 koloniyle yurutulmustur. A grubu kolonilerinde eski petek, B grubunda temel petek ve C grubunda ise baslatici petek kullanilmistir. A,B veC muamele gruplarinin ortalama agirlik kazanclari sirasiyla 44.80 ± 1.46 kg, 31.46 ± 1.86 kg ve 21.90 ± 1.36 kg olmus ve gruplarin birbirinden farki cok onemli (P < 0.01) bulunmustur. B grubu kolonilerin isci ari kapali yavru alam diger gruplarinkinden daha fazla (P < 0.05) bulunmus; fakat en yuksek erkek ari kapali yavru orani (% 28) C grubunda olculmustur. Petek orme bakimindan B ve C muamele gruplarinin gosterdikleri farkliligin istatistiksel olarak cok onemli (P < 0.01) oldugu tespit edilmistir. B grubunda daha fazla petek islenirken; C grubunda islenen erkek art gozlu petek orani daha yuksek olmustur. EFFECT OF USING VARIOUS COMBS ON THE COMB BUILD, BROOD REARING AND WEIGHT GAIN IN HONEY BEE {Apis mellifera L.) COLONIES SUMMARY : This research was carried out to determine the effects of using various comb on the comb build, brood rearing and weight gain in honey bee (Apis mellifera L.) colonies during honey flow. The experiment was conducted in three treatment groups (A, B and C) consisting of 10 colonies each and totalling 30 colonies. Old comles previously used for brood rearing were supplied to colonies in group of A; but sheets offoundation in group of B and only pieces offoundation (1 cm in width) called starter strips in group ofC. The average weight gains of the treatment groups of A, B and C were 44.80 ± 1.46 kg, 31.46 ± 1.86 kg and 21.90 ± 1.36 kg respectively and the difference between groups was highly significant (P < 0.01). A re a of capped worker brood in old comb group was larger than those of others (P < 0.05); but the highest ratefor area of capped drone brood (28 %) was measured in group ofC. The difference regarding comb built by colonies of group B atid C was highly significant (P < 0.01). Larger comb was built by colonies in group ofB; but there was higher ratefor drone comb built in group of C.