van Zweden, Jelle Stijn; Heinze, Jürgen; Boomsma, Jacobus Jan;
Background Experiments under controlled laboratory conditions can produce decisive evidence for testing biological hypotheses, provided they are representative of the more complex natural conditions. However, whether this requirement is fulfilled is seldom tested explicitly. Here we provide a lab....../field comparison to investigate the identity of an egg-marking signal of ant queens. Our study was based on ant workers resolving conflict over male production by destroying each other's eggs, but leaving queen eggs unharmed. For this, the workers need a proximate cue to discriminate between the two egg types....... Earlier correlative evidence indicated that, in the ant Pachycondyla inversa, the hydrocarbon 3,11-dimethylheptacosane (3,11-diMeC27) is more abundant on the surface of queen-laid eggs. Methodology We first tested the hypothesis that 3,11-diMeC27 functions as a queen egg-marking pheromone using laboratory...
D'Ettorre, Patrizia; Heinze, Jürgen
recognize each other's unique facial color patterns  . Individual recognition is advantageous when dominance hierarchies control the partitioning of work and reproduction 2 and 4 . Here, we show that unrelated founding queens of the ant Pachycondyla villosa use chemical cues to recognize each other...... individually. Aggression was significantly lower in pairs of queens that had previously interacted than in pairs with similar social history but no experience with one another. Moreover, subordinates discriminated familiar and unfamiliar dominants in choice experiments in which physical contact, but not odor...... perception, was prevented and in tests with anaesthetized queens. The cuticular chemical profiles of queens were neither associated with dominance nor fertility and, therefore, do not represent status badges 5 and 6 , and nestmate queens did not share a common odor. Personal recognition facilitates...
Sumner, Seirian; Hughes, William Owen Hamar; Pedersen, Jes Søe;
A parasitic ant has abandoned the multiple mating habit of the queens of its related host. Multiple mating (polyandry) is widespread among animal groups, particularly insects 1 . But the factors that maintain it and underlie its evolution are hard to verify because benefits and costs are not easily...... quantified and they tend to be similar in related species. Here we compare the mating strategies of the leaf-cutting ant Acromyrmex echinatior and its recently derived social parasite Acromyrmex insinuator, which is also its closest relative 2 (see Fig. 1 ). We find that although the host queens mate with up...... to a dozen different males, the social parasite mates only singly. This rapid and surprising reversion to single mating in a socially parasitic ant indicates that the costs of polyandry are probably specific to a free-living lifestyle....
Offenberg, Joachim; Peng, Renkang; Nielsen, Mogens Gissel;
Incipient ant colonies are often under fierce competition, making fast growth crucial for survival. To increase production, colonies can adopt multiple queens (pleometrosis), fuse with other colonies or rob brood from neighboring colonies. However, different adoption strategies might have different...... impacts such as future queen fecundity or future colony size. O. smaragdina queen production was measured in incipient colonies with 2, 3 or 4 founding queens, following the transplantation of 0, 30 or 60 pupae from a donor colony. Pupae developed into mature workers, resulting in increased worker...... increased the colony’s future production, but not the production of individual queens....
Castella, G; Christe, P; Chapuisat, M
Mating can affect female immunity in multiple ways. On the one hand, the immune system may be activated by pathogens transmitted during mating, sperm and seminal proteins, or wounds inflicted by males. On the other hand, immune defences may also be down-regulated to reallocate resources to reproduction. Ants are interesting models to study post-mating immune regulation because queens mate early in life, store sperm for many years, and use it until their death many years later, while males typically die after mating. This long-term commitment between queens and their mates limits the opportunity for sexual conflict but raises the new constraint of long-term sperm survival. In this study, we examine experimentally the effect of mating on immunity in wood ant queens. Specifically, we compared the phenoloxidase and antibacterial activities of mated and virgin Formica paralugubris queens. Queens had reduced levels of active phenoloxidase after mating, but elevated antibacterial activity 7 days after mating. These results indicate that the process of mating, dealation and ovary activation triggers dynamic patterns of immune regulation in ant queens that probably reflect functional responses to mating and pathogen exposure that are independent of sexual conflict. PMID:19170815
Huszár, Dóra Borbála
mating event in life instead of ongoing events between pairs. Second, by empirical studies on the native ant species Myrmica rubra we were able to demonstrate that the three social syndromes can co-exist within populations, but with possible overlap in certain traits. Genetic and morphology results....... Both genetic (microsatellites, mtDNA) and behavioral studies indicate that supercolonies of M. rubra can maintain gene flow with other colonies in the same population and that they could emerge both by clonal growth and fusion of nests, latter being rarely reported. Ants in supercolonies and polygynous......Ants, like other social insects, have evolved cooperative societies based on kinship. Colonies headed by a single breeding queen (monogyny) was the ancestral state but today ca. half of the ant species live in multi-queen societies (polygyny), which can sometimes reach extreme sizes (supercolony...
The colonies of army ants and some other legionary ant species have single, permanently wingless queens with massive post petioles and large gasters. Such highly modified queens are called dichthadiigynes. This paper presents the unusually rich exocrine gland endowment of dichthadiigynes, which is not found in queens of other ant species. It has been suggested these kinds of glands produce secretions that attract and maintain worker retinues around queens, especially during migration. However...
Holman, Luke; Jørgensen, Charlotte G; Nielsen, John; d'Ettorre, Patrizia
The selective forces that shape and maintain eusocial societies are an enduring puzzle in evolutionary biology. Ordinarily sterile workers can usually reproduce given the right conditions, so the factors regulating reproductive division of labour may provide insight into why eusociality has persisted over evolutionary time. Queen-produced pheromones that affect worker reproduction have been implicated in diverse taxa, including ants, termites, wasps and possibly mole rats, but to date have only been definitively identified in the honeybee. Using the black garden ant Lasius niger, we isolate the first sterility-regulating ant queen pheromone. The pheromone is a cuticular hydrocarbon that comprises the majority of the chemical profile of queens and their eggs, and also affects worker behaviour, by reducing aggression towards objects bearing the pheromone. We further show that the pheromone elicits a strong response in worker antennae and that its production by queens is selectively reduced following an immune challenge. These results suggest that the pheromone has a central role in colony organization and support the hypothesis that worker sterility represents altruistic self-restraint in response to an honest quality signal. PMID:20591861
D'Ettorre, Patrizia; Tofilski, Adam; Heinze, Jürgen;
How biological systems resolve internal conflicts is a major evolutionary question. Social insect workers cooperate but also pursue individual interests, such as laying male eggs. The rewards of this individual selfishness can be reduced by policing, such as by killing worker-laid eggs. However......, selfish individuals may evade policing. What factors prevent individuals from being able to evade policing? In the ant Pachycondyla inversa, workers kill (police) worker-laid eggs. Because the colony keeps eggs in piles and worker-laid and queen-laid eggs are chemically distinct, worker-laid eggs might...... become more acceptable once placed in the egg pile by odour transfer from touching queen-laid eggs. Here, we show that such "cue scrambling" does not occur. Worker-laid eggs that were sandwiched between three queen-laid eggs for 45 min were not more acceptable in a policing bioassay than control worker...
Full Text Available BACKGROUND: According to sexual conflict theory, males can increase their own fitness by transferring substances during copulation that increase the short-term fecundity of their mating partners at the cost of the future life expectancy and re-mating capability of the latter. In contrast, sexual cooperation is expected in social insects. Mating indeed positively affects life span and fecundity of young queens of the male-polymorphic ant Cardiocondyla obscurior, even though males neither provide nuptial gifts nor any other care but leave their mates immediately after copulation and die shortly thereafter. PRINCIPAL FINDINGS: Here, we show that mating with winged disperser males has a significantly stronger impact on life span and reproductive success of young queens of C. obscurior than mating with wingless fighter males. CONCLUSIONS: Winged males are reared mostly under stressful environmental conditions, which force young queens to disperse and found their own societies independently. In contrast, queens that mate with wingless males under favourable conditions usually start reproducing in the safety of the established maternal nest. Our study suggests that males of C. obscurior have evolved mechanisms to posthumously assist young queens during colony founding under adverse ecological conditions.
Castella G.; Christe P.; Chapuisat M.
Mating can affect female immunity in multiple ways. On the one hand, the immune system may be activated by pathogens transmitted during mating, sperm and seminal proteins, or wounds inflicted by males. On the other hand, immune defences may also be down-regulated to reallocate resources to reproduction. Ants are interesting models to study post-mating immune regulation because queens mate early in life, store sperm for many years, and use it until their death many years later, while males typ...
Holman, Luke; Jørgensen, Charlotte G.; Nielsen, John; D'Ettorre, Patrizia
The selective forces that shape and maintain eusocial societies are an enduring puzzle in evolutionary biology. Ordinarily sterile workers can usually reproduce given the right conditions, so the factors regulating reproductive division of labour may provide insight into why eusociality has persisted over evolutionary time. Queen-produced pheromones that affect worker reproduction have been implicated in diverse taxa, including ants, termites, wasps and possibly mole rats, but to date have on...
Brütsch T.; Felden A.; Reber A.; Chapuisat M.
Ant queens that attempt to disperse and found new colonies independently face high mortality risks. The exposure of queens to soil entomopathogens during claustral colony founding may be particularly harmful, as founding queens lack the protection conferred by mature colonies. Here, we tested the hypotheses that founding queens (I) detect and avoid nest sites that are contaminated by fungal pathogens, and (II) tend to associate with other queens to benefit from social immunity when nest sites...
D'Ettorre, Patrizia; Tofilski, Adam; Heinze, Jürgen; Ratnieks, Francis L. W.
How biological systems resolve internal conflicts is a major evolutionary question. Social insect workers cooperate but also pursue individual interests, such as laying male eggs. The rewards of this individual selfishness can be reduced by policing, such as by killing worker-laid eggs. However, selfish individuals may evade policing. What factors prevent individuals from being able to evade policing? In the ant Pachycondyla inversa, workers kill (police) worker-laid eggs. Because the colony keeps eggs in piles and worker-laid and queen-laid eggs are chemically distinct, worker-laid eggs might become more acceptable once placed in the egg pile by odour transfer from touching queen-laid eggs. Here, we show that such “cue scrambling” does not occur. Worker-laid eggs that were sandwiched between three queen-laid eggs for 45 min were not more acceptable in a policing bioassay than control worker-laid eggs. Chemical analyses also showed that the surface hydrocarbon profile of these eggs was unchanged. Policing, therefore, is stable against this potential cheating mechanism probably because queen-laid eggs are made chemically distinct using chemicals, that are not easily transferred by physical contact.
Holman, L.; Leroy, C.; Jørgensen, Charlotte;
. Communication in social insects is predominantly chemical, and the mechanisms regulating processes such as reproductive division of labor are becoming increasingly well understood. Recently, a queen cuticular hydrocarbon (3-MeC31) that inhibits worker reproduction and aggression was isolated in the ant Lasius......Social organisms have evolved diverse and complex regulatory mechanisms that allow them to coordinate group-level functions. Signals and cues produced by other group members facilitate assessment of the group's current state, allowing the receiver to adjust its behavior and physiology accordingly...
Bargum, Katja; Boomsma, Jacobus Jan; Sundström, L.
this study, we present the first evidence of an additive genetic component to queen size in ants, using maternal half sib analysis. We also compared intra-colony size variation in colonies with high (queen doubly mated) versus low (queen singly mated) genetic variability. We found a high and...
D'Ettorre, Patrizia; Kellner, K.; Delabie, J. H. C.;
In the ant Pachycondyla villosa, new colonies are usually started cooperatively by two or more young queens who establish a dominance order with a division of labour. Co-founding can lead to primary polygyny, where queens stay together after workers have emerged. Here we show that two queens...
Dreier, Stéphanie Agnès Jeanine; d'Ettorre, Patrizia
Recognition of group-members is a key feature of sociality. Ants use chemical communication to discriminate nestmates from intruders, enhancing kin cooperation and preventing parasitism. The recognition code is embedded in their cuticular chemical profile, which typically varies between colonies....... variation in chemical profiles of Lasius and Pachycondyla queens is comparable, thus informational constraints are unlikely to apply. We conclude that selection pressure from the social context is of crucial significance for the sophistication of recognition systems.......Recognition of group-members is a key feature of sociality. Ants use chemical communication to discriminate nestmates from intruders, enhancing kin cooperation and preventing parasitism. The recognition code is embedded in their cuticular chemical profile, which typically varies between colonies...
Emilio M Bruna
Full Text Available BACKGROUND: The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants. METHODOLOGY/PRINCIPAL FINDINGS: We used empirical data and inverse modeling--a technique developed by plant ecologists to model seed dispersal--to quantify and compare the dispersal kernels of queens from three Amazonian ant species that compete for access to host-plants. We found that the modal colonization distance of queens varied 8-fold, with the generalist ant species (Crematogaster laevis having a greater modal distance than two specialists (Pheidole minutula, Azteca sp. that use the same host-plants. However, our results also suggest that queens of Azteca sp. have maximal distances that are four-sixteen times greater than those of its competitors. CONCLUSIONS/SIGNIFICANCE: We found large differences between ant species in both the modal and maximal distance ant queens disperse to find vacant seedlings used to found new colonies. These differences could result from interspecific differences in queen body size, and hence wing musculature, or because queens differ in their ability to identify potential host plants while in flight. Our results provide support for one of the necessary conditions underlying several of the hypothesized mechanisms promoting coexistence in tropical plant-ants. They also suggest that for some ant species limited dispersal capability could pose a significant barrier to the rescue of populations in isolated forest fragments. Finally, we demonstrate that inverse models parameterized with field data are an excellent means
Gotoh, Ayako; Billen, Johan; Hashim, Rosli; Ito, Fuminori
In many ant species, the queens can keep spermatozoa alive in their spermatheca for several years, which goes along with unique morphological characteristics of the queen's spermatheca. The relative spermatheca size in ant queens is prominently larger than that in social wasps. Furthermore, the epithelium lining the spermatheca reservoir of ants consists of columnar cells in the hilar region and squamous cells in the distal region, whereas it is formed by columnar cells only in social wasps. To study the evolution of the unique spermatheca morphology in ant queens, we compared the various processes during spermatheca development between two ponerine ant species of the genus Pachycondyla (=Brachyponera) and three polistine wasp species of the genus Polistes. From histological observations, we can define four developmental events in the ant queens: (1) invagination of the spermatheca primordium, (2) the reservoir wall thickness becomes unequal, (3) the reservoir diameter doubles as the lining epithelial cells become flattened except for the hilar region, and (4) the increase in thickness of the reservoir epithelium is limited to the hilar region which doubles in thickness. In polistine wasps, the second and the third developmental events are absent and the entire epithelium of the spermatheca wall becomes thick in the final step. We therefore conclude that for ant queens the second and third steps are crucial for the enlargement of the spermatheca size, and that the second to the fourth steps are crucial for the specialization of the reservoir wall structure. PMID:19720157
Full Text Available Abstract Background Efficient division of reproductive labor is a crucial characteristic of social insects and underlies their ecological and evolutionary success. Despite of the harmonious appearance of insect societies, nestmates may have different interests concerning the partitioning of reproduction among group members. This may lead to conflict about reproductive rights. As yet, few studies have investigated the allocation of reproduction among queens in multi - queen societies ("reproductive skew". In the ant Leptothorax acervorum, reproductive skew varies considerably among populations. While reproduction is quite equally shared among nestmate queens in most populations from boreal Eurasia (low skew, colonies from populations at the edge of the species' range are characterized by "functional monogyny," i.e., high skew. The proximate mechanisms underlying high skew, in particular how workers influence which queen lays eggs, are not well understood. We investigated the behavior of queens and workers in functionally monogynous colonies of L. acervorum from two mountain ranges in central Spain. Results We provide evidence for both queen and worker influence on the outcome of conflict over reproduction in colonies of L. acervorum from Spain. The patterns of queen - queen aggression and worker - queen grooming and feeding after hibernation allowed predicting, which queen later began to lay eggs. In contrast, worker aggression towards queens was not clearly associated with a queen's future reproductive success. Queen - queen and worker - queen aggression differed in quality: queens typically engaged in ritualized dominance behavior, such as antennal boxing, while workers also attacked queens by biting and prolonged pulling on their legs and antennae. In several cases, overt worker aggression led to the expulsion of queens from the nest or their death. Conclusion We conclude that queens of L. acervorum from Spain establish rank orders by
The colonies of army ants and some other legionary ant species have single, permanently wingless queens with massive post petioles and large gasters. Such highly modified queens are called dichthadiigynes. This paper presents the unusually rich exocrine gland endowment of dichthadiigynes, which is not found in queens of other ant species. It has been suggested these kinds of glands produce secretions that attract and maintain worker retinues around queens, especially during migration. However, large worker retinues also occur in non-legionary species whose queens do not have such an exuberance of exocrine glands. We argue and present evidence in support of our previously proposed hypothesis that the enormous outfit of exocrine glands found in dichthadiigynes is due to sexual selection mediated by workers as the main selecting agents. PMID:26986740
We investigated the relative contribution of the queen and workers to colony nestmate recognition cues and on colony territoriality in the ant Camponotus fellah. Workers were either individually isolated, preventing contact with both queen and workers (Colony Deprived, CD), kept in queenless groups,...
Koyama, Satoshi; Matsui, Shingo; Satoh, Toshiyuki; Sasaki, Ken
We investigated whether octopamine (OA) is associated with the disappearance of cooperation in Polyrhachis moesta ant queens. Queens of P. moesta facultatively found the colony with genetically unrelated queens. The founding queens perform frequent food exchange with these non-related queens and partake in cooperative brood rearing, whereas single colony queens exclude non-related queens via aggressive behaviour. Thus, aggression is a factor that reduces cooperation. Given that aggression is generally associated with brain OA in insects, we hypothesized that OA controls the behavioural change in cooperation in the ant queen, via an increase in aggression. To test this hypothesis, we compared the amounts of OA and related substances in the brain between founding and colony queens, and observed the interaction of founding queens following oral OA administration. The brain OA levels in colony queens were significantly higher than those in founding queens. Oral administration of OA to founding queens caused significantly less trophallaxis and allogrooming behaviour than in the control founding queens, but with no significant increase in aggression. These results suggest that OA promotes the disappearance of cooperation in founding queens of P. moesta. This is the first study to reveal the neuroendocrine mechanism of cooperation in ant queens. PMID:26085498
Inui, Y; Itioka, T; Murase, K; Yamaoka, R; Itino, T
The partnership in the Crematogaster-Macaranga ant-plant interaction is highly species-specific. Because a mutualistic relationship on a Macaranga plant starts with colonization by a foundress queen of a partner Crematogaster species, we hypothesized that the foundress queens select their partner plant species by chemical recognition. We tested this hypothesis with four sympatric Macaranga species and their Crematogaster plant-ant species. We demonstrated that foundress Crematogaster queens can recognize their partner Macaranga species by contact with the surface of the seedlings, that they can recognize compounds from the stem surface of seedlings of their partner plant species, and that the gas chromatographic profiles are characteristic of the plant species. These findings support the hypothesis that foundress queens of the Crematogaster plant-ant species select their partner Macaranga species by recognizing nonvolatile chemical characteristics of the stem surfaces of seedlings. PMID:11710609
Bernadou, Abel; Ruther, Joachim; Heinze, Jürgen
In ants, mating and colony founding are critical steps in the life of ant queens. Outside of their nests, young queens are exposed to intense predation. Therefore, they are expected to have evolved behavior to accurately and quickly locate a nesting place. However, data on the early life history of female reproductives are still lacking. Leptothorax gredleri is a suitable model organism to study the behavior of young queens. Reproductives can be reared under artificial conditions and readily mate in the laboratory. After mating, L. gredleri queens have the options to found solitarily, seek adoption into another colony, or return into their natal nest. In this study, we investigated the decision-making processes of female sexuals before and after mating. In particular, we tested whether female sexuals use chemical cues to find their way back to the nest, studied if they prefer their own nest over other nesting sites and followed the adoption dynamics of mated queens over 8 weeks (plus hibernation and spring). We showed that female sexuals and freshly mated queens spent more time on substrate previously used by workers from their own colony and from another colony than on a blank substrate. This discriminatory capability of queens appears to be lost in old, reproductive queens. Nest choice experiments showed that female sexuals and freshly mated queens can distinguish their own nest while old mated queens do not. When reintroduced in their maternal colony, young queens were readily adopted, but a few weeks later aggression against young queens led to their emigration from the maternal nest and eventually also death. PMID:26086676
Villesen, Palle; Murakami, Takahiro; Schultz, Ted R.; Boomsma, Jacobus Jan
Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...
Eelen, Dieter; Børgesen, Lisbeth W.; Billen, Johan
The postpharyngeal gland (PPG) is unique to ants and is the largest exocrine gland in their head. In queens of the pharaoh's ant, Monomorium pharaonis, the gland contains approximately 15 finger-like epithelial extensions on each side and opens dorsolaterally in the posterior pharynx. In these ants...... between nurses and foragers. We suggest the PPG serves different purposes in pharaoh's ants: it is likely that the PPG of workers and virgin queens is used to feed larvae. In mated queens the gland probably plays a role in providing the queen with nutritious oils for egg production. The PPG may also...
Offenberg, Hans Joachim; Nielsen, Mogens Gissel; Peng, Renkang
Weaver ants (Oecophylla spp.) are increasingly being used for biocontrol and are targeted for future production of insect protein in ant farms. An efficient production of live ant colonies may facilitate the utilization of these ants but the production of mature colonies is hampered by the long...... and no transplantation. Thus, in ant nurseries the use of multiple queens during nest founding as well as transplantation of pupae from foreign colonies may be utilised to decrease the time it takes to produce a colony ready for implementation....... time it takes for newly established colonies to grow to a suitable size. In this study we followed the growth of newly founded O. smaragdina colonies with 2, 3 or 4 founding queens during 12 days of development, following the transplantation of 0, 30 or 60 pupae from a mature donor colony. Colony...
Mathieson, Melissa; Toft, Richard; Lester, Philip J
The efficacy of toxic baits should be judged by their ability to kill entire ant colonies, including the colony queen or queens. We studied the efficacy of four toxic baits to the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae). These baits were Xstinguish that has the toxicant fipronil, Exterm-an-Ant that contains both boric acid and sodium borate, and Advion ant gel and Advion ant bait arena that both have indoxacarb. Experimental nests contained 300 workers and 10 queen ants that were starved for either 24 or 48 h before toxic bait exposure. The efficacy of the toxic baits was strongly influenced by starvation. In no treatment with 24-h starvation did we observe 100% worker death. After 24-h starvation three of the baits did not result in any queen deaths, with only Exterm-an-Ant producing an average of 25% mortality. In contrast, 100% queen and worker mortality was observed in colonies starved for 48 h and given Xstinguish or Exterm-an-Ant. The baits Advion ant gel and Advion ant bait arena were not effective against Argentine ants in these trials, resulting in bait uptake, control efficacy may be maximized by applying bait when ants are likely to be starved. Our results suggest queen mortality must be assessed in tests for toxic bait efficacy. Our data indicate that of these four baits, Xstinguish and Exterm-an-Ant are the best options for control of Argentine ants in New Zealand. PMID:22928290
Schrempf, Alexandra; Heinze, Jürgen; Cremer, Sylvia
sterilized male lived considerably longer and started laying eggs earlier than virgin queens. Only queens that received viable sperm from fertile males showed increased fecundity. The lack of a trade-off between fecundity and longevity is unexpected, given evolutionary theories of aging  . Our data...
von Wyschetzki, Katharina; Rueppell, Olav; Oettler, Jan; Heinze, Jürgen
Life-history theory predicts a trade-off between reproductive investment and self-maintenance. The negative association between fertility and longevity found throughout multicellular organisms supports this prediction. As an important exception, the reproductives of many eusocial insects (ants, bees, and termites) are simultaneously very long-lived and highly fertile. Here, we examine the proximate basis for this exceptional relationship by comparing whole-body transcriptomes of differently aged queens of the ant Cardiocondyla obscurior. We show that the sets of genes differentially expressed with age significantly overlap with age-related expression changes previously found in female Drosophila melanogaster. We identified several developmental processes, such as the generation of neurons, as common signatures of aging. More generally, however, gene expression in ant queens and flies changes with age mainly in opposite directions. In contrast to flies, reproduction-associated genes were upregulated and genes associated with metabolic processes and muscle contraction were downregulated in old relative to young ant queens. Furthermore, we searched for putative C. obscurior longevity candidates associated with the previously reported lifespan-prolonging effect of mating by comparing the transcriptomes of queens that differed in mating and reproductive status. We found 21 genes, including the putative aging candidate NLaz (an insect homolog of APOD), which were consistently more highly expressed in short-lived, unmated queens than in long-lived, mated queens. Our study provides clear evidence that the alternative regulation of conserved molecular pathways that mediate the interplay among mating, egg laying, and aging underlies the lack of the fecundity/longevity trade-off in ant queens. PMID:26341296
Holman, Luke; Trontti, Kalevi; Helanterä, Heikki
DNA methylation is emerging as an important regulator of polyphenism in the social insects. Research has concentrated on differences in methylation between queens and workers, though we hypothesized that methylation is involved in mediating other flexible phenotypes, including pheromone-dependent changes in worker behaviour and physiology. Here, we find that exposure to queen pheromone affects the expression of two DNA methyltransferase genes in Apis mellifera honeybees and in two species of Lasius ants, but not in Bombus terrestris bumblebees. These results suggest that queen pheromones influence the worker methylome, pointing to a novel proximate mechanism for these key social signals. PMID:26814223
Martins Segundo, Glauco Bezerra; de Biseau, Jean-Christophe; Quinet, Yves
Some aspects of the biology of Crematogaster pygmaea, a highly polydomous and polygynous ant, are more commonly found in monogynous species. One such characteristic is the high attractiveness of its queens. In this study, this attractiveness was assessed under varying experimental conditions to investigate the factors responsible for its expression and variation, and to identify the nature of queen attractiveness. It was shown (1) that C. pygmaea queens are highly attractive to the workers that cluster on and around them (retinue), (2) that the attractiveness of C. pygmaea queens is context-dependent, i.e., it increases with increasing degree of potential danger to the queen, (3) that the attractiveness signal of C. pygmaea queens is chemically based, and (4) that this signal is persistent and apparently not colony-specific. The proposed hypothesis is that the C. pygmaea queens constantly release an attractiveness signal that is "read" by the workers, in a dependent way linked to the context, and that the main function of this attractiveness is to protect queens. This protection would have a high adaptive value in the context of the social structure and the reproductive strategies in C. pygmaea. PMID:23026145
Julian, Glennis E; Gronenberg, Wulfila
The behavior of reproductive female ants distinctly changes during the transition from virgin to mature, egg-laying queen. A winged female ant flies only once during her lifetime when she engages in the nuptial flight. Once she is mated she sheds her wings, excavates a nest and starts laying eggs, the basis for her future colony. We show for two species of harvester ants that this transition is accompanied by changes in the performance of behavioral tests: flying virgins are positively phototactic and prefer open areas, whereas young queens prefer the dark, avoid open areas and, given the opportunity, dig into the soil. These behavioral changes coincide with morphological changes in the brain. The brains of mature queens are significantly smaller than those of virgin females at the time of their mating flight. A disproportionately large shrinkage occurs in the medulla and other parts of the visual system during the early adult life of the queen. The brain reduction appears to be adaptive as mature queens show reduced behavioral repertoires and live in the dark. In contrast to virgin females, they do not rely on vision and might increase their fitness by reducing metabolically costly neural tissue. PMID:12417820
Oettler, Jan; Schmitt, Thomas; Herzner, Gudrun; Heinze, Jürgen
Many colonies of the North American ant Crematogaster smithi contain a "third female caste" in addition to queens and workers. These "intermorphs" are morphological intermediate of queens and workers and have well-developed ovaries but lack a spermatheca for the storage of sperm. They are specialised for laying large numbers of unfertilised, viable eggs, most of which serve as food for larvae and adults, though a few may eventually develop into males. Based on the assumption that cuticular hydrocarbons (CHCs) in social insects honestly signal the reproductive status of an individual we investigated the CHC of mated mature queens, virgin queens, intermorphs and workers. We expected intermorphs to show chemical profiles intermediate between those of mated queens and non-reproductive workers. A discriminant analysis of the chemical profiles reliably separated queens, virgin queens, and workers, but failed to distinguish between queens and intermorphs even though workers were apparently capable of doing so. PMID:18321526
Motais de Narbonne, Marine; van Zweden, Jelle S; Bello, Jan E; Wenseleers, Tom; Millar, Jocelyn G; d'Ettorre, Patrizia
Queen pheromones are essential for regulation of the reproductive division of labor in eusocial insect species. Although only the queen is able to lay fertilized eggs and produce females, in some cases workers may develop their ovaries and lay male-destined eggs, thus reducing the overall colony efficiency. As long as the queen is healthy, it is usually in the workers' collective interest to work for the colony and remain sterile. Queens signal their fertility via pheromones, which may have a primer effect, affecting the physiology of workers, or a releaser effect, influencing worker behavior. The queen pheromone of the ant Lasius niger was among the first queen pheromones of social insects to be identified. Its major component is 3-methylhentriacontane (3-MeC31), which is present in relatively large amounts on the queen's cuticle and on her eggs. 3-MeC31 regulates worker reproduction by inhibiting ovarian development. Most monomethyl-branched hydrocarbons can exist in two stereoisomeric forms. The correct stereochemistry is fundamental to the activity of most bioactive molecules, but this has rarely been investigated for methyl-branched hydrocarbons. Here, we tested the bioactivity of the (S)- and (R)-enantiomers of 3-MeC31, and found that whereas both enantiomers were effective in suppressing worker ovarian development, (S)-3-MeC31 appeared to be more effective at suppressing aggressive behavior by workers. This suggests that the natural pheromone may be a mixture of the two enantiomers. The enantiomeric ratio produced by queens remains unknown because of the small amounts of the compound available from each queen. PMID:26994182
Den Boer, Susanne Petronella A; Baer, Boris; Dreier, Stéphanie Agnès Jeanine;
In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps), reprodu......In many species, females store sperm between copulation and egg fertilization, but the consequences of sperm storage and patterns of sperm use for female life history and reproductive success have not been investigated in great detail. In hymenopteran insect societies (ants, bees, wasps...
Dreier, Stéphanie Agnès Jeanine; Van Zweden, Jelle Stijn; D'Ettorre, Patrizia
Remembering individual identities is part of our own everyday social life. Surprisingly, this ability has recently been shown in two social insects. While paper wasps recognize each other individually through their facial markings, the ant, Pachycondyla villosa, uses chemical cues. In both species......, individual recognition is adaptive since it facilitates the maintenance of stable dominance hierarchies among individuals, and thus reduces the cost of conflict within these small societies. Here, we investigated individual recognition in Pachycondyla ants by quantifying the level of aggression between pairs...
Kronauer, Daniel J C; Schöning, Caspar; d'Ettorre, Patrizia;
Theory predicts that altruism is only evolutionarily stable if it is preferentially directed towards relatives, so that any such behaviour towards seemingly unrelated individuals requires scrutiny. Queenless army ant colonies, which have anecdotally been reported to fuse with queenright foreign...... colonies, are such an enigmatic case. Here we combine experimental queen removal with population genetics and cuticular chemistry analyses to show that colonies of the African army ant Dorylus molestus frequently merge with neighbouring colonies after queen loss. Merging colonies often have no direct co......-ancestry, but are on average probably distantly related because of overall population viscosity. The alternative of male production by orphaned workers appears to be so inefficient that residual inclusive fitness of orphaned workers might be maximized by indiscriminately merging with neighbouring colonies to...
Lei Wang; Ling Zeng; Jian Chen
Neonicotinoid insecticides are commonly used in managing pest insects, including the imported fire ant, Solenopsis invicta Buren. There is increasing evidence that neonicotinoid insecticides at sublethal concentrations have profound effects on social insects. However, the sublethal effect of neonicotinoids on S. invicta has never been investigated. In this study, the newly mated queens were fed with water containing 0.01 or 0.25 μg/ml imidacloprid. Imidacloprid at both concentrations did not ...
Villesen, Palle; Murakami, Takahiro; Schultz, Ted R;
Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...... is known to include evolutionarily derived genera with obligate multiple mating (the Acromyrmex and Atta leafcutter ants) as well as phylogenetically basal genera with exclusively single mating (e.g. Apterostigma, Cyphomyrmex, Myrmicocrypta). All attine genera share the unique characteristic of...... obligate dependence on symbiotic fungus gardens for food, but the sophistication of this symbiosis differs considerably across genera. The lower attine genera generally have small, short-lived colonies and relatively non-specialized fungal symbionts (capable of living independently of their ant hosts...
Dijkstra, Michiel B.; Boomsma, Jacobus Jan
The fungal cultivars of fungus-growing ants are vertically transmitted by queens but not males. Selection would therefore favor cultivars that bias the ants' sex ratio towards gynes, beyond the gyne bias that is optimal for workers and queens. We measured sex allocation in 190 colonies of six......, colony fecundity, and fungal garden volume for Acromyrmex and Sericomyrmex, but not for Trachymyrmex. Year of collection, worker number and mating frequency of Acromyrmex queens did not affect the colony sex ratios. We used a novel sensitivity analysis to compare the population sex allocation ratios with...... the theoretical queen and worker optima for a range of values of k, the correction factor for sex differences in metabolic rate and fat content. The results were consistent with either worker or queen control, but never with fungal control for any realistic value of k. We conclude that the fungal...
Pull, Christopher D.; Hughes, William O. H.; Brown, Mark J. F.
Pathogens exert a strong selection pressure on organisms to evolve effective immune defences. In addition to individual immunity, social organisms can act cooperatively to produce collective defences. In many ant species, queens have the option to found a colony alone or in groups with other, often unrelated, conspecifics. These associations are transient, usually lasting only as long as each queen benefits from the presence of others. In fact, once the first workers emerge, queens fight to the death for dominance. One potential advantage of co-founding may be that queens benefit from collective disease defences, such as mutual grooming, that act against common soil pathogens. We test this hypothesis by exposing single and co-founding queens to a fungal parasite, in order to assess whether queens in co-founding associations have improved survival. Surprisingly, co-foundresses exposed to the entomopathogenic fungus Metarhizium did not engage in cooperative disease defences, and consequently, we find no direct benefit of multiple queens on survival. However, an indirect benefit was observed, with parasite-exposed queens producing more brood when they co-founded, than when they were alone. We suggest this is due to a trade-off between reproduction and immunity. Additionally, we report an extraordinary ability of the queens to tolerate an infection for long periods after parasite exposure. Our study suggests that there are no social immunity benefits for co-founding ant queens, but that in parasite-rich environments, the presence of additional queens may nevertheless improve the chances of colony founding success.
von Wyschetzki, Katharina; Lowack, Helena; Heinze, Jürgen
The trade-off between reproduction and longevity is widespread among multicellular organisms. As an important exception, the reproductive females of perennial social insects (ants, honeybees, termites) are simultaneously highly fertile and very long-lived relative to their nonreproductive nestmates. The observation that increased fecundity is not coupled with decreased lifespan suggests that social insect queens do not have to reallocate resources between reproduction and self-maintenance. If queens have to compensate for the costs of reproduction on the level of the individual, the activation of other energy-demanding physiological processes might force them to reduce the production of eggs. To test this hypothesis in ant queens, we increased immunity costs by injury and measured the effect of this treatment on egg-laying rates and genomewide gene expression. Amputation of both middle legs led to a temporary decrease in egg-laying rates and affected the expression of 947 genes corresponding to 9% of the transcriptome. The changes comprised the upregulation of the immune and wound healing response on the one hand, and the downregulation of germ cell development, central nervous system development and learning ability on the other hand. Injury strongly influenced metabolism by inducing catabolism and repressing amino acid and nitrogen compound metabolism. By comparing our results to similar transcriptomic studies in insects, we found a highly consistent upregulation of immune genes due to sterile and septic wounding. The gene expression changes, complemented by the temporary decline of egg-laying rates, clearly reveal a trade-off between reproduction and the immune response in social insect queens. PMID:26880273
Schmidt, Anna Mosegaard; Linksvayer, Timothy Arnold; Boomsma, Jacobus Jan;
and body size of eclosing workers, gynes and males. We found that smaller colonies produced more new queens relative to workers, and that these queens and workers both tended to be larger. However, colony size had no effect on the size of males or on the sex ratio of the individuals reared......The success of an ant colony depends on the simultaneous presence of reproducing queens and nonreproducing workers in a ratio that will maximize colony growth and reproduction. Despite its presumably crucial role, queen–worker caste ratios (the ratio of adult queens to workers) and the factors...... affecting this variable remain scarcely studied. Maintaining polygynous pharaoh ant (Monomorium pharaonis) colonies in the laboratory has provided us with the opportunity to experimentally manipulate colony size, one of the key factors that can be expected to affect colony level queen–worker caste ratios...
Van Zweden, Jelle Stijn; Carew, Melissa E.; Henshaw, Michael T.;
reduction of the former. Aggression tests showed that hostility between ants from different nests was minimal. Nests frequently contained numbers of both queen types, with microgynes about twice as numerous as macrogynes. Nestmate workers, microgynes, and macrogynes, were significantly related to others...... also significantly related and there was a weak inverse relationship between pairwise relatedness value between individuals and distance between nests.We conclude that this species is supercolonial and that the two queen morphs are part of the same population....
Edypo Jacob Silva
Full Text Available Protein content of leaf-cutting ant queens before the nuptial flight and during the post-claustral phase. This study evaluated the crude protein content of queens of Atta sexdens before the nuptial flight and after the claustral phase in laboratory and field colonies. The hypothesis was that protein is used for survival of the queen and for early colony growth during the claustral phase. Additionally, the nest morphology, live biomass and adult population of field colonies were evaluated. Crude protein was determined by digestion of the organic material with sulfuric acid at high temperatures. The mean crude protein content was 123.23 ± 11.20 mg for females before the nuptial flight and 70.44 ± 12.21 mg for laboratory-reared queens after the claustral phase. The post-claustral crude protein content of field-collected queen was 55.90 ± 9.18 mg. With respect to the loss of crude protein as a function of duration of the claustral phase, laboratory-reared queens lost 52.79 mg and field-collected queens lost 67.33 mg compared to females before the nuptial flight. A positive linear correlation was observed between the weight of field-collected queens (256.4 ± 36.3 mg and colony biomass (13.02 ± 9.12 g, but there was no correlation between biomass and nest depth (13.11 ± 3.82 cm. As expected, the present results support the hypothesis that protein is used for survival of the queen and for early colony growth, as demonstrated by the reduction in crude protein content as a function of duration of the claustral phase. To our knowledge, this is the first study to provide data of the dynamics of protein reserves in leaf-cutting ant queens during the claustral phase.
Peeters, Christian; Adams, Rachelle M M
Megalomyrmex Forel (Myrmicinae: Solenopsidini) consists of 44 species with diverse life history strategies. Most species are predatory and may also tend honeydew-producing insects. A morphologically derived group of species are social parasites that consume the brood and fungus garden within fungus-growing ant nests. The reproductive strategies of Megalomyrmex queens are somewhat aligned with these life-style patterns. Predatory species in the leoninus species group are large in body size and have ergatoid (i.e., permanently wingless) queens whereas the social parasitic species are smaller and typically have winged queens. We examined two ergatoid phenotypes of Megalomyrmex foreli Emery and Megalomyrmex wallacei Mann and compared them to winged species, one a social lestobiotic or "thief ant" parasite (Megalomyrmex mondabora Brandão) and the other a predator (Megalomyrmex modestus Emery). Megalomyrmex foreli colonies have a single queen with an enlarged gaster that is morphologically distinct from workers. Megalomyrmex wallacei colonies have several queens that are similar in body size to workers. Queens in both species showed a simplification of the thorax, but there was a dramatic difference in the number of ovarioles. Megalomyrmex foreli had 60-80 ovarioles compared to eight in M. wallacei and M. mondabora and M. modestus had 22-28. Along with flight loss in queens, there is an obligate shift to dependent colony founding (also called budding or fission) consequently influencing dispersal patterns. These constraints in life history traits may help explain the variation in nesting biology among Megalomyrmex species. PMID:27620557
Full Text Available Queens of Ponera coarctata show a pronounced variation in size as measured by ommatidia number and Weber's alitrunk length. Isometric size variation and the normal distribution of size categories indicate that, despite these differences, only one queen morph exists. Queen size varies less within colonies than between colonies, and thus appears to be colony specific. Ovary length apparently varies with queen size. Similar size variations as in queens also occured in males, but not in workers.
de Menten, Ludivine; Cremer, Sylvia; Heinze, Jürgen;
restricted to adult sex ratios. With LMC, the primary sex ratio (proportion of haploid eggs laid by the queen) is expected to be female biased, which lowers the conflict between queens and workers over sex allocation. We compared the primary sex ratios laid by queens in monogynous and in polygynous...... of London, Series B, 269, 417-422) showed that colonies responded to increasing queen number by producing a less female-biased sex ratio, as predicted by LMC theory. However, the proximate mechanisms responsible for this variation in the sex ratio could not be determined because the study was...... experimental colonies of C. obscurior. The proportion of haploid eggs laid by queens was significantly lower in single-queen than in multiple-queen colonies. Furthermore, queens rapidly adjusted their primary sex ratios to changes in colony queen number. This is the first report of an adaptive adjustment of...
Miyakawa, Misato O.; Mikheyev, Alexander S.
Evolution of reproduction strategies is affected by both phylogenetic and physiological constraints. Although clonality may benefit females, it may not be selected if a male contribution is necessary to start egg laying and embryo development. In little fire ant, Wasmannia auropunctata, sexual populations employ a typical Hymenopteran system of reproduction. In clonal populations, however, queens and males are produced with only maternal and paternal genomes, respectively, whereas sterile workers are produced sexually. Although this system requires both sexes for worker production, previous work has shown that workers may also be produced clonally by the queens. If so, why are males maintained in this species? Our data suggest that fertilization is necessary to increase the hatching rate of eggs. Although clonal queens can indeed produce both workers and queens without mating, the hatching rate is far below the level necessary to maintain functional colonies. On the other hand, virgin queens from populations exhibiting the original Hymenopteran reproduction system also show low hatching rates, but produce only haploid male eggs. Reasons for the existence of W. auropunctata males have been disputed. However, our data suggest that physiological constraints, such as the requirement for insemination, must be considered in regard to evolution of reproduction systems, in addition to ecological data and theoretical considerations of fitness.
Pamminger, Tobias; Treanor, David; Hughes, William O H
The ubiquitous trade-off between survival and costly reproduction is one of the most fundamental constraints governing life-history evolution. In numerous animals, gonadotropic hormones antagonistically suppressing immunocompetence cause this trade-off. The queens of many social insects defy the reproduction-survival trade-off, achieving both an extraordinarily long life and high reproductive output, but how they achieve this is unknown. Here we show experimentally, by integrating quantification of gene expression, physiology and behaviour, that the long-lived queens of the ant Lasius niger have escaped the reproduction-immunocompetence trade-off by decoupling the effects of a key endocrine regulator of fertility and immunocompetence in solitary insects, juvenile hormone (JH). This modification of the regulatory architecture enables queens to sustain a high reproductive output without elevated JH titres and suppressed immunocompetence, providing an escape from the reproduction-immunocompetence trade-off that may contribute to the extraordinary lifespan of many social insect queens. PMID:26763704
Kronauer, Daniel J C; Schoning, Caspar; Pedersen, Jes S;
-biased sex ratios. This implies that the very high numbers of matings in both groups may be due partly to the relatively low costs of additional matings. Second, we were able to trace recent events of colony fission in four of the investigated colonies, where the genotypes of the two queens were only...... compatible with a mother-daughter relationship. A direct comparison of male production between colonies with offspring from one and two queens, respectively, suggested strongly that new queens do not produce a sexual brood until all workers of the old queen have died, which is consistent with kin selection...
Manfredini, Fabio; Shoemaker, DeWayne; Grozinger, Christina M
The dynamics of host-parasite interactions can change dramatically over the course of a chronic infection as the internal (physiological) and external (environmental) conditions of the host change. When queens of social insects found a colony, they experience changes in both their physiological state (they develop their ovaries and begin laying eggs) and the social environment (they suddenly stop interacting with the other members of the mother colony), making this an excellent model system for examining how these factors interact with chronic infections. We investigated the dynamics of host-viral interactions in queens of Solenopsis invicta (fire ant) as they transition from mating to colony founding/brood rearing to the emergence of the first workers. We examined these dynamics in naturally infected queens in two different social environments, where queens either founded colonies as individuals or as pairs. We hypothesized that stress associated with colony founding plays an important role in the dynamics of host-parasite interactions. We also hypothesized that different viruses have different modalities of interaction with the host that can be quantified by physiological measures and genomic analysis of gene expression in the host. We found that the two most prevalent viruses, SINV-1 and SINV-2, are associated with different fitness costs that are mirrored by different patterns of gene expression in the host. In fact SINV-2, the virus that imposes the significant reduction of a queen's reproductive output is also associated with larger changes of global gene expression in the host. These results show the complexity of interactions between S. invicta and two viral parasites. Our findings also show that chronic infections by viral parasites in insects are dynamic processes that may pose different challenges in the host, laying the groundwork for interesting ecological and evolutionary considerations. PMID:26811788
Holman, Luke; Dreier, Stephanie; d'Ettorre, Patrizia
Social insects offer unique opportunities to test predictions regarding the evolution of cooperation, life histories and communication. Colony founding by groups of unrelated queens, some of which are later killed, may select for selfish reproductive strategies, honest signalling and punishment. ...
Vieira, Alexsandro Santana; Camargo-Mathias, Maria Izabel; Roces, Flavio
Queens of leaf-cutting ants found their nests singly, each consisting of a vertical tunnel and a final horizontal chamber. Because of the claustral mode of nest founding, the queen and/or her initial fungus garden are exposed to threats imposed by several soil pathogens, and the antibiotic secretions produced by their metapleural glands are considered a main adaptation to deal with them. Nests of two Atta leaf-cutting ant species, Atta vollenweideri and Atta sexdens rubropilosa, occur in different soil types, alfisols and oxisols. Their queens are known to excavate the initial nest in different soil horizons, clayish and organic, respectively, which differ in their fertility and associated microbiota. The aim of the present study was to comparatively investigate the morpho-physiology of the metapleural glands in queens of A. vollenweideri and A. sexdens rubropilosa, addressing the question whether the distinct selective pressure imposed by the microbiota in the two different soil types led to morpho-physiological differences in the metapleural glands that were consistent with their antiseptic function. The results revealed that metapleural glands of A. sexdens rubropilosa have a larger number of secretory cells, and consequently a higher production of antibiotic secretions, which may have been selected to allow nest founding at the superficial horizon of oxisols rich in organic matter and microorganisms. Glands of A. vollenweideri, on the contrary, presented fewer secretory cells, suggesting less production of antibiotic secretions. We argue that the excavation of deep founding nests in A. vollenweideri was primarily selected for during evolution to avoid the risk posed by flooding, and further hypothesize that a reduced number of cells in their metapleural glands occurred because of a weak pathogen-driven selective pressure at the preferred soil depth. PMID:26145506
Peng, Renkang; Nielsen, Mogens Gissel; Offenberg, Joachim
Weaver ants (Oecophylla smaragdina Fabricius) have been increasingly used as biocontrol agents of insect pests and as insect protein for human food and animals. For either of these purposes, mature ant colonies are essential. However, for a newly established colony to develop to a suitable mature...
Jones, R.G.; Davis, W.L.; Vinson, S.B.
Potassium pyroantimonate histochemistry, coupled with ethyleneglycoltetraacetic acid (EGTA)-chelation and X-ray microprobe analysis, was employed to localize intracellular calcium binding sites in the normal and degenerating flight musculature in queens of Solenopsis, the fire ant. In normal animals, calcium distribution was light to moderate within myofibrils and mitochondria. In the early contracture stages of the insemination-induced degeneration, both myofilament and mitochondrial calcium loading was markedly increased. In the terminal stages of myofibril breakdown, only Z-lines (isolated or in clusters) with an associated filamentous residue persisted. These complexes were also intensely calcium positive. This study further documents the presence of increased sarcoplasmic calcium during muscle necrosis. Surface membrane defects, mitochondrial calcium overload, and calcium-activated proteases may all be involved in this ''normal'' breakdown process.
Potassium pyroantimonate histochemistry, coupled with ethyleneglycoltetraacetic acid (EGTA)-chelation and X-ray microprobe analysis, was employed to localize intracellular calcium binding sites in the normal and degenerating flight musculature in queens of Solenopsis, the fire ant. In normal animals, calcium distribution was light to moderate within myofibrils and mitochondria. In the early contracture stages of the insemination-induced degeneration, both myofilament and mitochondrial calcium loading was markedly increased. In the terminal stages of myofibril breakdown, only Z-lines (isolated or in clusters) with an associated filamentous residue persisted. These complexes were also intensely calcium positive. This study further documents the presence of increased sarcoplasmic calcium during muscle necrosis. Surface membrane defects, mitochondrial calcium overload, and calcium-activated proteases may all be involved in this ''normal'' breakdown process
Martin, Stephen; Jones, Graeme; Châline, Nicolas; Middleton, Helen; Ratnieks, Francis
Dufour's gland secretion may allow worker honeybees to discriminate between queen-laid and worker-laid eggs. To investigate this, we combined the chemical analysis of individually treated eggs with an egg removal bioassay. We partitioned queen Dufour's gland into hydrocarbon and ester fractions. The bioassay showed that worker-laid eggs treated with either whole gland extract, ester fraction or synthetic gland esters were removed more slowly than untreated worker-laid eggs. However, the effect only lasted up to 20 h. Worker-laid eggs treated with the hydrocarbon fraction were removed at the same rate as untreated eggs. The amount of ester which reduced the egg removal rate was far higher than that naturally found on queen-laid or worker-laid eggs, and at natural ester levels no effect was found. Our results indicate that esters or hydrocarbons probably do not function as the signal by which eggs can be discriminated.
Abstract Why is it that many 'lesbian playwrights' are unwilling to define themselves as such? "Drama Queens: Ruling with a Rod of Irony" attempts to answer this question and to discover what the term 'lesbian playwright' means within contemporary culture. It dissects the dominant homophobic and misogynist mythologies that have outlawed 'queer' girl writers to the underskirts of British theatre, and ultimately denied them either artistic or commercial currency. It examines the history of the label in the context of feminism, gay liberation and positive representation, and queries its aesthetic and economic viability in a climate where the 'lesbian playwright' is not even supported by her own community. Finally, it is an exploration into radical forms, working methodologies and new genres stimulated by being neither semantic Man nor Woman. It is a piece about cultural terrorism-and how to avoid capture. PMID:24785519
Gilley, David C
Nepotism shapes interactions among the members of almost every animal society. However, clear evidence of nepotism within highly cooperative insect societies, such as ant, wasp and honeybee colonies, is rare. Recent empirical findings suggest that nepotism occurs within honeybee colonies where kin-selection theory most strongly predicts its existence: during the lethal queen-queen duels that determine which of several young queens will become the colony's next queen. In this study, I test whe...
Baer, Boris; Collins, Jason; Maalaps, Kristiina; den Boer, Susanne P A
The queens of eusocial ants, bees, and wasps only mate during a very brief period early in life to acquire and store a lifetime supply of sperm. As sperm cannot be replenished, queens have to be highly economic when using stored sperm to fertilize eggs, especially in species with large and long-lived colonies. However, queen fertility has not been studied in detail, so that we have little understanding of how economic sperm use is in different species, and whether queens are able to influence their sperm use. This is surprising given that sperm use is a key factor of eusocial life, as it determines the fecundity and longevity of queens and therefore colony fitness. We quantified the number of sperm that honeybee (Apis mellifera) queens use to fertilize eggs. We examined sperm use in naturally mated queens of different ages and in queens artificially inseminated with different volumes of semen. We found that queens are remarkably efficient and only use a median of 2 sperm per egg fertilization, with decreasing sperm use in older queens. The number of sperm in storage was always a significant predictor for the number of sperm used per fertilization, indicating that queens use a constant ratio of spermathecal fluid relative to total spermathecal volume of 2.364 × 10(-6) to fertilize eggs. This allowed us to calculate a lifetime fecundity for honeybee queens of around 1,500,000 fertilized eggs. Our data provide the first empirical evidence that honeybee queens do not manipulate sperm use, and fertilization failures in worker-destined eggs are therefore honest signals that workers can use to time queen replacement, which is crucial for colony performance and fitness. PMID:27217944
Hooper-Bui, L. M.; Kwok, E. S. C.; Buchholz, B. A.; Rust, M. K.; Eastmond, D. A.; Vogel, J. S.
Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), but dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). The distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. Bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.
Gilley, David C
Nepotism shapes interactions among the members of almost every animal society. However, clear evidence of nepotism within highly cooperative insect societies, such as ant, wasp and honeybee colonies, is rare. Recent empirical findings suggest that nepotism occurs within honeybee colonies where kin-selection theory most strongly predicts its existence: during the lethal queen-queen duels that determine which of several young queens will become the colony's next queen. In this study, I test whether worker bees act nepotistically by hindering duelling queens that are distantly related to themselves. I accomplished this by observing labelled workers harassing duelling queen bees in observation hives and subsequently by determining worker-queen relatedness using DNA microsatellites. I show that the workers that harassed duelling queens were neither more-closely nor more-distantly related to them than were workers selected randomly from the colony. Thus, workers did not behave nepotistically by hindering half-sister queens more than full-sister queens. These results demonstrate that under certain conditions, natural selection limits the evolution of nepotism within animal societies despite strong theoretical predictions for its existence. PMID:14561293
Haag-Liautard, C.; Pedersen, Jes Søe; Ovaskainen, O.;
Factors affecting relatedness among nest members in ant colonies with high queen number are still poorly understood. In order to identify the major determinants of nest kin structure, we conducted a detailed analysis of the breeding system of the ant Formica exsecta. We estimated the number of...... individuals were significantly related to each other. Interestingly, the number of resident queens was a poor predictor of kin structure at the nest level, consistent with the observation that new queens are produced in bursts leading to highly fluctuating queen number across years. Queen number also varied...
Group-living species produce signals that alter the behavior and even the physiology of their social partners. Social insects possess especially sophisticated chemical communication systems that govern every aspect of colony life, including the defining feature of eusociality: reproductive division...... of labor. Current evidence hints at the central importance of queen pheromones, but progress has been hindered by the fact that such pheromones have only been isolated in honeybees. In a pair of papers on the ant Lasius niger, we identified and investigated a queen pheromone regulating worker sterility...
Ebie, Jessica D.; Hölldobler, Bert; Liebig, Jürgen
Although workers in many ant species are capable of producing their own offspring, they generally rear the queen's offspring instead. There are various mechanisms that regulate worker reproduction including inhibitory effects of ant brood. Colonies of the ant Novomessor cockerelli are monogynous and polydomous resulting in a large portion of nest workers being physically isolated from the queen for extended periods of time. Some workers experimentally isolated from the queen in laboratory nests lay viable eggs, which develop into males. We investigate the mechanism that regulates worker fertility in subnests separated from the queen by giving queenless worker groups queen-produced larvae, queen-produced eggs, or no brood. Our findings show that larvae delay the time to worker egg-laying, but eggs have no effect. Larval inhibition is a likely mechanism that contributes to the regulation of worker reproduction in N. cockerellli because larvae are easily transported to subnests that do not contain a queen.
van Zweden, Jelle Stijn; Bonckaert, Wim; Wenseleers, Tom;
sterile (queen control), or if instead queens honestly signal their fertility and workers reproduce according to their own evolutionary incentives (queen signaling). Here, we test these competing hypotheses using data from Vespine wasps. We show that in natural colonies of the Saxon wasp, Dolichovespula...... saxonica, queens emit reliable chemical cues of their true fertility and that these putative queen signals decrease as the colony develops and worker reproduction increases. Moreover, these putative pheromones of D. saxonica show significant conservation with those of Vespula vulgaris and other Vespinae...
This animation consists of two close-up images of 'Snow Queen,' taken several days apart, by the Robotic Arm Camera (RAC) aboard NASA's Phoenix Mars Lander. Snow Queen is the informal name for a patch of bright-toned material underneath the lander. Thruster exhaust blew away surface soil covering Snow Queen when Phoenix landed on May 25, 2008, exposing this hard layer comprising several smooth rounded cavities beneath the lander. The RAC images show how Snow Queen visibly changed between June 15, 2008, the 21st Martian day, or sol, of the mission and July 9, 2008, the 44th sol. Cracks as long as 10 centimeters (about four inches) appeared. One such crack is visible at the left third and the upper third of the Sol 44 image. A seven millimeter (one-third inch) pebble or clod appears just above and slightly to the right of the crack in the Sol 44 image. Cracks also appear in the lower part of the left third of the image. Other pieces noticeably shift, and some smooth texture has subtly roughened. The Phoenix team carefully positioned and focused RAC the same way in both images. Each image is about 60 centimeters, or about two feet, wide. The object protruding in from the top on the right half of the images is Phoenix's thermal and electrical conductivity probe. Snow Queen and other ice exposed by Phoenix landing and trenching operations on northern polar Mars is the first time scientists have been able to monitor Martian ice at a place where temperatures are cold enough that the ice doesn't immediately sublimate, or vaporize, away. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.
Full Text Available The biological potential of a bee family is mainly generated by the biological value of the queen. Whether we grow queens widely or just for our own apiaries, we must consider the acquisition of high-quality biological material, and also the creation of optimal feeding and caring conditions, in order to obtain high genetic value queens. Queen breeding technology starts with the setting of hoeing families, nurse families, drone-breeding families – necessary for the pairing of young queens, and also of the families which will provide the bees used to populate the nuclei where the next queens will hatch. The complex of requirements for the breeding of good, high-production queens is sometimes hard to met, under the application of artificial methods. The selection of breeding method must rely on all these requirements and on the beekeeper’s level of training.
Kronauer, Daniel J C; Schöning, Caspar; Boomsma, Jacobus J
active research in insect sociobiology. Here we present microsatellite data for 176 males from eight colonies of the African army ant Dorylus (Anomma) molestus. Comparison with worker genotypes and inferred queen genotypes from the same colonies show that workers do not or at best very rarely reproduce...
Full Text Available Solenopsis geminata group (Hymenoptera: Formicidae encompasses ant species commonly called fire ants because of their painful sting. The many physiological effects of the venom are caused by 2-methyl-6-alkyl and/or alkenylpiperidine alkaloids. The variation in piperidine alkaloid structures has useful taxonomic characters. The most well studied Solenopsis species is S. invicta, which was accidentally imported into the USA in the 1930s from South America. It quickly spread throughout the southern USA and is now a major invasive pest ant in the USA and in other parts of the world. Interestingly, the invasive S. invicta has largely displaced a native USA fire ant, S. geminata, from the southern USA. We explore the possibility that differences in venom chemistry could be correlated with this displacement. The cis and trans alkaloids from body extracts of workers and alate queens of S. geminata were separated by silica gel chromatography, identified, and quantitated by GC-MS analysis. Both workers and alate queens produce primarily cis- and trans-2-methyl-6-n-undecyl-piperidines, as well as other minor alkaloid components. Imported fire ant, S. invicta, alate queens produce the same alkaloids as S. geminata alate queens, but in contrast S. invicta workers produce piperidine alkaloids with longer side chains, which are purported to be physiologically more effective. These results are discussed in relation to the evolutionary progression of fire ant venom alkaloids and displacement of S. geminata by S. invicta in the USA.
Kellner, K; Trindl, A; Heinze, J; D'Ettorre, P
Social insects, ants in particular, show considerable variation in queen number and mating frequency resulting in a wide range of social structures. The dynamics of reproductive conflicts in insect societies are directly connected to the colony kin structure, thus, the study of relatedness patterns is essential in order to understand the evolutionary resolution of these conflicts. We studied colony kin structure and mating frequencies in two closely related Neotropical ant species Pachycondyla inversa and Pachycondyla villosa. These represent interesting model systems because queens found new colonies cooperatively but, unlike many other ant species, they may still co-exist when the colony becomes mature (primary polygyny). By using five specific and highly variable microsatellite markers, we show that in both species queens usually mate with two or more males and that cofounding queens are always unrelated. Polygynous and polyandrous colonies are characterized by a high genetic diversity, with a mean relatedness coefficient among worker nestmates of 0.27 (+/- 0.03 SE) for P. inversa and 0.31 (+/- 0.05 SE) for P. villosa. However, relatedness among workers of the same matriline is high (0.60 +/- 0.03 in P. inversa, 0.62 +/- 0.08 in P. villosa) since males that mated with the same queen are on average closely related. Hence, we have found a new taxon in social Hymenoptera with high queen-mating frequencies and with intriguing mating and dispersal patterns of the sexuals. PMID:17561897
Kronauer, Daniel Jan Christoph; Berghoff, Stefanie M.; Powell, Scott;
In a recent study, Denny et al. (2004a) showed that queens of the army ant, Eciton burchellii, mate with multiple males and presented estimates suggesting that they mate with more males than queens of any other ant species so far investigated. They also inferred that data were consistent with...
den Boer, Susanne; Stürup, Marlene; Boomsma, Jacobus Jan;
The eusocial ants are unique in that females (queens) acquire and store sperm on a single mating flight early in adult life. This event largely determines the size (possibly millions of workers), longevity (possibly decades) and genetic variation of the colonies that queens found, but our...... understanding of the fundamental biology of ejaculate production, transfer and physiological function remains extremely limited. We studied the ejaculation process in the leafcutter ant Atta colombica and found that it starts with the appearance of a clear pre-ejaculatory fluid (PEF) at the tip of the...
Villesen, Palle; Boomsma, JJ
Ant queens from eight species, covering three genera of lower and two genera of higher attine ants, have exclusively or predominantly single mating. The ensuing full-sib colonies thus have a strong potential reproductive conflict between the queen and the workers over male production. This is...... because, all other things being equal, relatedness incentives should favour traits expressed in both workers and the queen to monopolise the production of the colony's male offspring. Microsatellite genotyping of males from these attine species shows that workers in queenless colonies are able to produce...... males, but that no worker-produced males were found in queenright colonies. Our results suggest that worker reproduction is rare or even absent in colonies with a fertile queen. This indicates that either the queen directly prevents the workers from raising their own sons, or that worker reproduction is...
Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël
Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults.
A. McQueeni moevälisest tegevusest. 'American Express' tellis temalt krediitkaardi kujunduse. 1998. a. suvest ajakirja 'Dazed & Confused' abitoimetaja. A. McQueen on lubanud olla Björki (Island) video kunstiline juht.
Instrumental insemination honey bee queen is in Czech Republic only possibility, how make controlled mating bees. Main significance lies in expanding desirable feature in the bee colony. Instrumental inseminations are thus obtained the required feature, that are the mildness of bees, sitting on the comb, or resistance to disease. Insemination must precede controlled breeding drones and controlled breeding queens. That drones were sexually mature at the time of insemination must be breeding dr...
Full Text Available In wireless sensor networks, sensor nodes are extremely power constrained, so energy efficient clustering mechanism is mainly considered in the network topology management. A new clustering mechanism based on the polymorphic ant colony (PAC is designed for dynamically controlling the networks clustering structure. According to different functions, the nodes of the networks are respectively defined as the queen ant, the scout ant and worker ant. Based on the calculated cost function and real-time pheromone, the queen ant restructures an optimum clustering structure. Furthermore, the worker ants and the scout ants can send or receive sensing data with optional communication path based on their pheromones. With the mechanism, the energy consumption in inter-cluster and intra-cluster communication for the worker ants and scout ants can be reduced. The simulation results demonstrate that the proposed mechanism can effectively remodel the clustering structure and improve the energy efficiency of the networks.
Irradiation is a quarantine treatment option to control ants and other hitchhiker pests on fresh horticultural products exported from Hawaii. The radiotolerance of the big-headed ant, Pheidole megacephala (F.), was studied to determine a dose sufficient for its control. This ant was chosen as a representative species because it is a common hitchhiker and rearing methods in the laboratory have been developed. The desired response with irradiation treatment of ants is sterility of reproductive females. Queens from micro-colonies were irradiated at 60, 90, 120, or 150 Gy or left untreated as controls, then followed for 19 weeks to observe colony growth. In general, queen longevity, and the number of eggs, larvae, and pupae observed in the micro-colonies decreased with increasing irradiation dose. In the 60 Gy treatment, the number of eggs observed was reduced by 89.6% compared with the untreated controls. In the 120 Gy and 150 Gy treatments, the number of eggs observed was reduced by 99.5% and 98.5%, respectively, and no eggs were found after the first observation date at 7 days after treatment. No larvae or pupae were observed in the 90, 120 or 150 Gy treatments, suggesting these irradiation doses sterilized queens. This study suggests the USDA-APHIS-approved generic irradiation dose of 400 Gy is more than sufficient for the Formicidae. Information is needed on the radiotolerance of additional species of ants to confirm our findings. (author)
Villesen, Palle; Gertsch, P J; Frydenberg, Jane;
have lower queen mating frequencies, similar to those found in most other ants. We tested this prediction by analysing queen mating frequency and colony kin structure in three basal attine species: Myrmicocrypta ednaella, Apterostigma collare and Cyphomyrmex longiscapus. Microsatellite marker analyses......Queens of leafcutter ants exhibit the highest known levels of multiple mating (up to 10 mates per queen) among ants. Multiple mating may have been selected to increase genetic diversity among nestmate workers, which is hypothesized to be critical in social systems with large, long-lived colonies...... under severe pressure of pathogens. Advanced fungus-growing (leafcutter) ants have large numbers (104-106 workers) and long-lived colonies, whereas basal genera in the attine tribe have small (< 200 workers) colonies with probably substantially shorter lifespans. Basal attines are therefore expected to...
Ulrich G Mueller
Full Text Available BACKGROUND: Leafcutter ants depend on the cultivation of symbiotic Attamyces fungi for food, which are thought to be grown by the ants in single-strain, clonal monoculture throughout the hundreds to thousands of gardens within a leafcutter nest. Monoculture eliminates cultivar-cultivar competition that would select for competitive fungal traits that are detrimental to the ants, whereas polyculture of several fungi could increase nutritional diversity and disease resistance of genetically variable gardens. METHODOLOGY/PRINCIPAL FINDINGS: Using three experimental approaches, we assessed cultivar diversity within nests of Atta leafcutter ants, which are most likely among all fungus-growing ants to cultivate distinct cultivar genotypes per nest because of the nests' enormous sizes (up to 5000 gardens and extended lifespans (10-20 years. In Atta texana and in A. cephalotes, we resampled nests over a 5-year period to test for persistence of resident cultivar genotypes within each nest, and we tested for genetic differences between fungi from different nest sectors accessed through excavation. In A. texana, we also determined the number of Attamyces cells carried as a starter inoculum by a dispersing queens (minimally several thousand Attamyces cells, and we tested for genetic differences between Attamyces carried by sister queens dispersing from the same nest. Except for mutational variation arising during clonal Attamyces propagation, DNA fingerprinting revealed no evidence for fungal polyculture and no genotype turnover during the 5-year surveys. CONCLUSIONS/SIGNIFICANCE: Atta leafcutter ants can achieve stable, fungal monoculture over many years. Mutational variation emerging within an Attamyces monoculture could provide genetic diversity for symbiont choice (gardening biases of the ants favoring specific mutational variants, an analog of artificial selection.
Cameron, G.; Williams, L.
Fire ants (Solenopsis invicta) were introduced to the US in the early part of the last century. They have spread throughout the southeastern US in the absence of native competitors and predators with a range limited by abiotic factors. Each fire ant mound contains thousands of individuals, can be large, and can be numerous enough to comprise a dominant feature of the landscape. Studies of this species have focused upon its spread, formation of single- and multiple-queen colonies, genetic structure, and impact on native fauna and human health. Some studies have analyzed native fire ant-soil interactions, but few studies have examined the process of bioturbation by introduced fire ants in native ecosystems. Fire ants on the coastal prairie of Texas primarily are of the multiple-queen type that exhibit a much higher density of mounds than the single-queen type. Consequently, mound-building activities by fire ants can have a marked effect upon soil structure and nutrient content and may affect soil organisms and plants. Fire ant activity, mound density, mound dispersion, soil texture, soil permeability, soil moisture content, and soil nutrients were measured. Fire ants mounds are visible aboveground from April-November. Density of mounds was 117-738/ha, and average mound lifespan was 3.6 months with only 9% of the mounds remaining active throughout the entire season. Mounds were dispersed randomly. Foraging activity by fire ants was from June through October with a peak in July. Annual soil turnover was estimated by collecting and weighing mounds. There was no effect of ant mounds on soil texture, but water infiltration was higher in areas with ant mounds. Early-season samples showed no nutrient differences, but late-season samples showed that ant mounds contained higher amounts of micronutrients than random samples of soil. These data are compared to similar data on effects of mounds from native ants and from native and introduced ants in different habitats.
Rueppell, O; Königseder, F; Heinze, J; Schrempf, A
The central trade-off between reproduction and longevity dominates most species' life history. However, no mortality cost of reproduction is apparent in eusocial species, particularly social insects in the order Hymenoptera: one or a few individuals (typically referred to as queens) in a group specialize on reproduction and are generally longer lived than all other group members (typically referred to as workers), despite having the same genome. However, it is unclear whether this survival advantage is due to social facilitation by the group or an intrinsic, individual property. Furthermore, it is unknown whether the correlation between reproduction and longevity is due to a direct mechanistic link or an indirect consequence of the social role of the reproductives. To begin addressing these questions, we performed a comparison of queen and worker longevity in the ant Cardiocondyla obscurior under social isolation conditions. Survival of single queens and workers was compared under laboratory conditions, monitoring and controlling for brood production. Our results indicate that there is no intrinsic survival advantage of queens relative to workers unless individuals are becoming reproductively active. This interactive effect of caste and reproduction on life expectancy outside of the normal social context suggests that the positive correlation between reproduction and longevity in social insect queens is due to a direct link that can activate intrinsic survival mechanisms to ensure queen longevity. PMID:26348543
Andrea Di Giulio
Full Text Available Ants use various communication channels to regulate their social organisation. The main channel that drives almost all the ants' activities and behaviours is the chemical one, but it is long acknowledged that the acoustic channel also plays an important role. However, very little is known regarding exploitation of the acoustical channel by myrmecophile parasites to infiltrate the ant society. Among social parasites, the ant nest beetles (Paussus are obligate myrmecophiles able to move throughout the colony at will and prey on the ants, surprisingly never eliciting aggression from the colonies. It has been recently postulated that stridulatory organs in Paussus might be evolved as an acoustic mechanism to interact with ants. Here, we survey the role of acoustic signals employed in the Paussus beetle-Pheidole ant system. Ants parasitised by Paussus beetles produce caste-specific stridulations. We found that Paussus can "speak" three different "languages", each similar to sounds produced by different ant castes (workers, soldiers, queen. Playback experiments were used to test how host ants respond to the sounds emitted by Paussus. Our data suggest that, by mimicking the stridulations of the queen, Paussus is able to dupe the workers of its host and to be treated as royalty. This is the first report of acoustic mimicry in a beetle parasite of ants.
Frohschammer, Sabine; Heinze, Jürgen
Studies on sex ratios in social insects provide among the most compelling evidence for the importance of kin selection in social evolution. The elegant synthesis of Fisher's sex ratio principle and Hamilton's inclusive fitness theory predicts that colony-level sex ratios vary with the colonies' social and genetic structures. Numerous empirical studies in ants, bees, and wasps have corroborated these predictions. However, the evolutionary optimization of sex ratios requires genetic variation, but one fundamental determinant of sex ratios - the propensity of female larvae to develop into young queens or workers ("queen bias") - is thought to be largely controlled by the environment. Evidence for a genetic influence on sex ratio and queen bias is as yet restricted to a few taxa, in particular hybrids.Because of the very short lifetime of their queens, ants of the genus Cardiocondyla are ideal model systems for the study of complete lifetime reproductive success, queen bias, and sex ratios. We found that lifetime sex ratios of the ant Cardiocondyla kagutsuchi have a heritable component. In experimental single-queen colonies, 22 queens from a genetic lineage with a highly female-biased sex ratio produced significantly more female-biased offspring sex ratios than 16 queens from a lineage with a more male-biased sex ratio (median 91.5% vs. 58.5% female sexuals). Sex ratio variation resulted from different likelihood of female larvae developing into sexuals (median 50% vs. 22.6% female sexuals) even when uniformly nursed by workers from another colony.Consistent differences in lifetime sex ratios and queen bias among queens of C. kagutsuchi suggest that heritable, genetic or maternal effects strongly affect caste determination. Such variation might provide the basis for adaptive evolution of queen and worker strategies, though it momentarily constrains the power of workers and queens to optimize caste ratios. PMID:19863794
Full Text Available Abstract Studies on sex ratios in social insects provide among the most compelling evidence for the importance of kin selection in social evolution. The elegant synthesis of Fisher's sex ratio principle and Hamilton's inclusive fitness theory predicts that colony-level sex ratios vary with the colonies' social and genetic structures. Numerous empirical studies in ants, bees, and wasps have corroborated these predictions. However, the evolutionary optimization of sex ratios requires genetic variation, but one fundamental determinant of sex ratios - the propensity of female larvae to develop into young queens or workers ("queen bias" - is thought to be largely controlled by the environment. Evidence for a genetic influence on sex ratio and queen bias is as yet restricted to a few taxa, in particular hybrids. Because of the very short lifetime of their queens, ants of the genus Cardiocondyla are ideal model systems for the study of complete lifetime reproductive success, queen bias, and sex ratios. We found that lifetime sex ratios of the ant Cardiocondyla kagutsuchi have a heritable component. In experimental single-queen colonies, 22 queens from a genetic lineage with a highly female-biased sex ratio produced significantly more female-biased offspring sex ratios than 16 queens from a lineage with a more male-biased sex ratio (median 91.5% vs. 58.5% female sexuals. Sex ratio variation resulted from different likelihood of female larvae developing into sexuals (median 50% vs. 22.6% female sexuals even when uniformly nursed by workers from another colony. Consistent differences in lifetime sex ratios and queen bias among queens of C. kagutsuchi suggest that heritable, genetic or maternal effects strongly affect caste determination. Such variation might provide the basis for adaptive evolution of queen and worker strategies, though it momentarily constrains the power of workers and queens to optimize caste ratios.
L. gredleri is an ant species that is mating by female calling. Virgin queens attract males with a droplet of a sexual pheromone in the vicinity of their maternal nest. Both sexes are expected to be choosy because females store the semen in their spermatheca throughout their whole lives and do not remate after this initial mating period. Males are short-lived and survive only as sperm in the spermathecae of queens. Furthermore, males possess only a fixed amount of sperm, since their testes de...
Dejean, Alain; Orivel, Jérôme; Azémar, Frédéric; Hérault, Bruno; Corbara, Bruno
In myrmecophilous Lepidoptera, mostly lycaenids and riodinids, caterpillars trick ants into transporting them to the ant nest where they feed on the brood or, in the more derived "cuckoo strategy", trigger regurgitations (trophallaxis) from the ants and obtain trophic eggs. We show for the first time that the caterpillars of a moth (Eublemma albifascia; Noctuidae; Acontiinae) also use this strategy to obtain regurgitations and trophic eggs from ants (Oecophylla longinoda). Females short-circuit the adoption process by laying eggs directly on the ant nests, and workers carry just-hatched caterpillars inside. Parasitized colonies sheltered 44 to 359 caterpillars, each receiving more trophallaxis and trophic eggs than control queens. The thus-starved queens lose weight, stop laying eggs (which transport the pheromones that induce infertility in the workers) and die. Consequently, the workers lay male-destined eggs before and after the queen's death, allowing the colony to invest its remaining resources in male production before it vanishes. PMID:27021621
Kooij, Pepijn Wilhelmus
Fungus-growing ants (Attini) feed off a fungus they cultivate in a mutualistic symbiosis in underground chambers by providing it substrate they collect outside the colony. The tribe of Attine ants ranges from small colonies of the paleo- and basal Attine species with a few hundred workers that...... forage on crude substrates such as insect frass and dry plant material, to large colonies of the leaf-cutting ants with several thousands to several million workers that provide live plant material to their fungus gardens. Leaf-cutting ants are the dominant herbivores of the Neo-tropics, and have a major...... estimate that approximately half of these nuclei were represented by different genomes, giving the fungus a ploidy level of 5n-6n. In mutualistic symbioses it is important the partners stay true to each other. In fungus-growing ants, new founding queens bring a piece of fungus to build up their new colony...
Norman, V. C.; Pamminger, T.; Hughes, W. O. H.
Reproduction-related behaviours are key components determining individual fitness. Many behavioural traits are linked, and such trait associations often affect fitness. Here, we combine behavioural and physiological data during two critical time points of founding queens (early and late nest-founding stage) in the claustral ant Lasius flavus to assess how these factors affect their initial productivity. We show that most behavioural traits, except brood care behaviour, are plastic during queen development and demonstrate that there are alternative behavioural pathways to achieve high productivity under standardised conditions. These results indicate that queens can utilise multiple behavioural trait combinations to maximise reproductive output at the earliest, and arguably most critical, time of colony foundation.
Francis, Roy Mathew; Kryger, Per; Nielsen, Steen Lykke
The well-being of a colony and replenishment of the workers depends on a healthy queen. Diseases in queens are seldom reported, and our knowledge on viral infection in queens is limited. In this study, 86 honey bee queens were collected from beekeepers in Denmark. All queens were tested separately...
Amiri, Esmaeil; Meixner, Marina; Büchler, Ralph;
Chronic bee paralysis virus (CBPV) is known as a disease of worker honey bees. To investigate pathogenesis of the CBPV on the queen, the sole reproductive individual in a colony, we conducted experiments regarding the susceptibility of queens to CBPV. Results from susceptibility experiment showed a...... similar disease progress in the queens compared to worker bees after infection. Infected queens exhibit symptoms by Day 6 post infection and virus levels reach 1011 copies per head. In a transmission experiment we showed that social interactions may affect the disease progression. Queens with forced...... contact to symptomatic worker bees acquired an overt infection with up to 1011 virus copies per head in six days. In contrast, queens in contact with symptomatic worker bees, but with a chance to receive food from healthy bees outside the cage appeared healthy. The virus loads did not exceed 107 in the...
Hughes, William O H; Pagliarini, Roberta; Madsen, Henning Bang; Dijkstra, Michiel B; Boomsma, Jacobus J
exception to this rule because they are a key first-line defense that are fixed in size in adults. Here we conduct a comparative analysis of the size of the gland reservoir across the fungus-growing ants (tribe Attini). Most attines have singly mated queens, but in two derived genera, the leaf-cutting ants...
*S. K. Bariyah
Ocimum sanctum, known as Queen of Herbs, is an important member of the family Lamiaceae due to its use in herbal medication centuries back, especially, in India and other parts of the sub-continent. It is still a subject of immense importance in modern medical research and it is due to the chemical constituents present in it like flavonoids, terpenoids, alkaloids, saponins, vitamins, minerals, proteins, carbohydrates and many others. It has shown a wide range of therapeutic potencies like ant...
King, Joshua R; Tschinkel, Walter R
A key shortcoming in our understanding of exotic species' success is that it is not known how post-introduction dispersal contributes to the success of exotic species and the reassembly of invaded communities. Exotic and native species face poorly understood competition-colonization trade-offs in heterogeneous landscapes of natural and anthropogenic habitats. We conducted three experiments that tested how ant queen behavior during dispersal affects community composition. Using experimental plots, we tested whether (1) different types of habitat disturbance and (2) different sizes of habitat disturbance affected the abundance of newly mated queens landing in the plots. The three most abundant species captured were the exotic fire ant Solenopsis invicta, and the native species Brachymyrmex depilis, and S. pergandei, respectively. When queens were considered collectively, more queens landed in plowed, sand-added, and roadside plots than in control or mow plots, in other words, in the more heavily disturbed plots. We also tested (3) the effect of habitat manipulations on the survival of newly mated fire ant queens (Solenopsis invicta). Soil disturbance (tilling), lack of shade, and removal (poisoning) of the ant community resulted in the greatest fire ant colony survivorship. Collectively, experiments revealed that both exotic and native newly mated ant queens select open, human-altered ecosystems for founding new colonies. The selection of such habitats by fire ant queens leads to their successful colony founding and ultimately to their dominance in those habitats. Selection of disturbed habitats is therefore advantageous for exotic species but is an ecological trap for native species because they do not often succeed in founding colonies in these habitats. PMID:27008792
Himler, Anna G.; Caldera, Eric J.; Baer, Boris C.; Fernández-Marín, Hermógenes; Mueller, Ulrich G.
Asexual reproduction imposes evolutionary handicaps on asexual species, rendering them prone to extinction, because asexual reproduction generates novel genotypes and purges deleterious mutations at lower rates than sexual reproduction. Here, we report the first case of complete asexuality in ants, the fungus-growing ant Mycocepurus smithii, where queens reproduce asexually but workers are sterile, which is doubly enigmatic because the clonal colonies of M. smithii also depend on clonal fungi...
Helms, Jackson A; Godfrey, Aaron P; Ames, Tayna; Bridge, Eli S
Aerial predator-prey interactions may impact populations of many terrestrial species. Here, we use altitude loggers to study aerial foraging in a native insectivore, the purple martin (Progne subis), in the southern USA. Purple martins fed primarily on mating queens and males of the invasive red imported fire ant (Solenopsis invicta), and doubled their foraging efficiency by doing so. Across the USA, purple martins likely eat billions of fire ant queens each year, potentially impacting the spread of this species. Alternatively, predation on fire ants may help sustain populations of purple martins and other aerial insectivores. PMID:27194285
Baer, Boris; Armitage, Sophie A O; Boomsma, Jacobus J
Ant queens are among the most long-lived insects known. They mate early in adult life and maintain millions of viable sperm in their sperm storage organ until they die many years later. Because they never re-mate, the reproductive success of queens is ultimately sperm-limited, but it is not known...... what selective forces determine the upper limit to sperm storage. Here we show that sperm storage carries a significant cost of reduced immunity during colony founding. Newly mated queens of the leaf-cutting ant Atta colombica upregulate their immune response shortly after completing their nest burrow......, probably as an adaptive response to a greater exposure to pathogens in the absence of grooming workers. However, the immune response nine days after colony founding is negatively correlated with the amount of sperm in the sperm storage organ, indicating that short-term survival is traded off against long...
Schönrogge, Karsten; Bonelli, Simona; Barbero, Francesca; Balletto, Emilio
Recent recordings of the stridulations of Myrmica ants revealed that their queens made distinctive sounds from their workers, although the acoustics of queens and workers, respectively, were the same in different species of Myrmica. Queen recordings induced enhanced protective behavior when played to workers in the one species tested. Larvae and pupae of the butterfly genus Maculinea inhabit Myrmica colonies as social parasites, and both stages generate sounds that mimic those of a Myrmica queen, inducing similar superior treatments from workers as their model. We discuss how initial penetration and acceptance as a colony member is achieved by Maculinea through mimicking the species-specific semio-chemicals of their hosts, and how acoustical mimicry is then employed to elevate the parasite’s membership of that society towards the highest attainable level in their host’s hierarchy. We postulate that, if acoustics is as well developed a means of communication in certain ants as these studies suggest, then others among an estimated 10,000 species of ant social parasite may supplement their well-known use of chemical and tactile mimicry to trick host ants with mimicry of host acoustical systems. PMID:20585513
Kronauer, Daniel Jc; Peters, Marcell K; Schöning, Caspar;
Hybridization can have complex effects on evolutionary dynamics in ants because of the combination of haplodiploid sex-determination and eusociality. While hybrid non-reproductive workers have been found in a range of species, examples of gene-flow via hybrid queens and males are rare. We studied...
Dissection of the reproductive system of ant workers and queens can be useful for answering many questions. Observations of ovarian status in both female castes can be used to identify relationships between other factors and the ovaries, determine whether an individual has laid eggs, and, with more ...
The insect growth regulator (IGR) methoprene (isopropyl-(2E,4E,7R,S)-11-methoxy-3,7,11-trimethyldodeca-2,4-dienoate) has been shown to have deleterious effects on red imported fire ants, Solenopsis invicta. It interferes with normal development of worker caste brood and reduces queen egg production...
de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan
The attine ant symbiosis is characterized by ancient but varying degrees of diffuse co-evolution between the ants and their fungal cultivars. Domesticated fungi became dependent on vertical transmission by queens and the ant colonies came to rely on their symbiotic fungus for food and thus......, indirectly, on fungal enzymes to break down the plant material brought in by the ants as fungal substrate. The more than 210 extant fungus-growing ant species differ considerably in colony size, social complexity and substrate-use. Only the derived leaf-cutting ants are specialized on using fresh leaves as...... garden substrate, whereas the more basal genera use leaf litter, insect feces and insect carcasses. We hypothesized that enzyme activity of fungal symbionts has co-evolved with substrate use and we measured enzyme activities of fungus gardens in the field to test this, focusing particularly on plant...
Full Text Available Graphical simulation is an attempt of predicting the aspects of behavior of some system by developing an approximate model of it. Simulations have great impact on education and in training. Simulation based learning is a practical way of learning of practices that involves building connections: connections among what is being learned and what is important to the actor and the situations in which it is applied. N-Queens problem refers to the problem in which one has to place N-Queens on an n*n chess board such that no queen is attacking the other, i.e. no two queens occupy the same row, column or diagonal. Here we use graphical simulation to view various solutions to N-Queens problem. The n-queens problem is implemented by using core java. The packages used in these implementations are java.awt, java.lang, java.applet. The graphical simulation is used because n-queens problem is more complicated. It is easy for any system user or normal user to understand this problem by observing simulations. With the help of simulation the problem is explained very clearly and effectively. This will help in generating interest among perceivers because it has real time applications and will make learning better
Baer, Boris; Collins, Jason; Maalaps, Kristiina;
the fecundity and longevity of queens and therefore colony fitness. We quantified the number of sperm that honeybee (Apis mellifera) queens use to fertilize eggs. We examined sperm use in naturally mated queens of different ages and in queens artificially inseminated with different volumes of semen. We found...
Bernasconi, Giorgina; Bigler, Laurent; Hesse, Manfred; Ratnieks, Francis L. W.
Swarming honey bee (Apis mellifera L.) colonies rear supernumerary young queens that compete for the limited resources (workers) necessary for founding a new colony. Young queens often fight to death. During fights, queens often release rectal fluid with a strong smell of grapes, after which they temporarily stop fighting. This potentially reduces the risk of deadly injury. The fluid and one of its components, ortho-aminoacetophenone, were previously found to have a pheromonal effect on worke...
Frederickson, Megan E
In saturated tropical ant assemblages, reproductive success depends on queens locating and competing for scarce nest sites. Little is known about how this process shapes the life histories of tropical ants. Here I investigate the relationship between nest site availability and an important life history trait, reproductive phenology, in the common Amazonian ant species Allomerus octoarticulatus. A. octoarticulatus is a plant-ant that nests in the hollow, swollen stem domatia on Cordia nodosa. I provide evidence that nest sites are limiting for A. octoarticulatus. Most queens produced by A. octoarticulatus colonies died before locating suitable host plants, and most queens that located hosts died before founding colonies, probably from intraspecific competition among queens for control of host plants. I further show that the reproductive phenology of A. octoarticulatus closely matches the seasonal availability of its nest sites, domatia-bearing C. nodosa saplings. Both the production and flight of A. octoarticulatus reproductives, and the number of C. nodosa saplings available for colonization by ants, peaked from March to May. There was correlative evidence that A. octoarticulatus colonies use temperature as a cue to synchronize their reproduction to the availability of C. nodosa saplings: both the production of reproductives by ant colonies and the number of C. nodosa saplings available for colonization were correlated with temperature, and not with rainfall. All of these results suggest that nest site limitation constrains the reproductive phenology of A. octoarticulatus. PMID:16758217
A scientific breakthrough at Queen's University's Sudbury Neutrino Observatory has received major international recognition. The journal Science ranked the discovery that cracked the "neutrino problem" second, in the journal's top 10 scientific achievements of 2002 (1/2 page).
Vitikainen, Emma I K; Haag-Liautard, Cathy; Sundström, Liselotte
Sex-biased dispersal and multiple mating may prevent or alleviate inbreeding and its outcome, inbreeding depression, but studies demonstrating this in the wild are scarce. Perennial ant colonies offer a unique system to investigate the relationships between natal dispersal behavior and inbreeding. Due to the sedentary life of ant colonies and lifetime sperm storage by queens, measures of dispersal distance and mating strategy are easier to obtain than in most taxa. We used a suite of molecular markers to infer the natal colonies of queens and males in a wild population of the ant Formica exsecta. Dispersal was male biased, with median male dispersal distances (∼140 m) twice those of queens (∼60 m). The results also showed that the population was inbred and that inbreeding avoidance behaviors--sex-biased dispersal, queen dispersal distance, and multiple mating--were all ineffective in reducing homozygosity among colony workers. Queen homozygosity did not affect dispersal behavior, but more homozygous queens had lower colony-founding success and were more incestuously mated themselves, with potentially accumulating effects on colony fitness. We also provide independent evidence that dispersal is sex biased and show that our estimate corresponds well with dispersal estimates derived from population-genetic estimates. PMID:26655979
Full Text Available The modern queens maintenance systems are based on the use of artificial insemination, queens’ maintenance in the so called „queens bank” , in this way assuring an increased economic efficiency in beekeeping. This study aimed to compare the economic efficiency of the implementation of A.I. to various queen bees maintenance systems. Three alternatives have been taken into account: V1-a queen bee in a cage together with her bees, V2- a queen bank system and V3 – a queen bee in a nucleus. For each queen bee maintenance alternative have been evaluated the most important indicators such as: expenses, incomes, profit, number of marketable inseminated and selected queen bees, honey production, cost/queen, revenue/queen, profit/queen, profit rate. The most effective alternative was the queen bank system assuring 2,400 marketable queen bees and 20 kg honey delivered yearly, USD 12,442 incomes, USD 3,400 expenses, USD 9,042 profit, that is USD 3.77/queen bee and 265.72 % profit rate under the condition as A.I. costs are just USD 1,058, representing 31.1 % of total queen bees maintenance costs.
Renthal, Robert; Velasquez, Daniel; Olmos, David; Vinson, S Bradleigh
A previous report of the discovery of exocrine glands in the antennal club of queens and workers of Solenopsis invicta Buren, 1972 left open the question of the extent to which similar glands occur in the Formicidae family. We wanted to know if these antennal glands are unique to Solenopsis, or they are found in a wider taxonomic group. Using scanning electron microscopy, we examined the antennae of 41 ant species. Presence of the antennal glands was indicated by a characteristic circumferential ring of pores in a distal antennal segment of workers. Pores were found in the 9th antennal segment of all 26 species of Solenopsis examined. Pores were absent in the following: Monomorium minimum, M. pharaonis, Pheidole sp., Crematogaster sp., Linepithema humile, Forelius sp., Dorymyrmex sp., Paratrechina sp., Oecophylla smaragdina, Campanotus sp., Ectatomma ruidum, E. tuberlatum, and Pseudomyrmex ferruginea. However, pores were found in the antennal club of Tetramorium bicarinatum workers and queens. After KOH digestion of T. bicarinatum antennae, internal canals were observed in both workers and queens, and the canals are connected to spherical reservoirs in queens. T. bicarinatum was the only non-Solenopsis species examined, which showed evidence for antennal glands in the distal funiculus. PMID:18655135
Popescu, A.; A. SICEANU
The modern queens maintenance systems are based on the use of artificial insemination, queens’ maintenance in the so called „queens bank” , in this way assuring an increased economic efficiency in beekeeping. This study aimed to compare the economic efficiency of the implementation of A.I. to various queen bees maintenance systems. Three alternatives have been taken into account: V1-a queen bee in a cage together with her bees, V2- a queen bank system and V3 – a queen bee in a nucleus. For ea...
Walter R. Tschinkel
Full Text Available The arboreal ant, Crematogaster ashmeadi Emery (Hymenoptera: Formicidae, is the most dominant arboreal ant in the pine forests of the coastal plain of northern Florida. The majority of pine trees harbor a colony of these ants. The colonies inhabit multiple chambers abandoned by bark-mining caterpillars, especially those of the family Cossidae, in the outer bark of living pines. They also inhabit ground level termite galleries in the bark, often locating the queen in galleries. The density of chambers and ants is highest in the base of the tree and drops sharply with height on the trunk. Because chambers are formed in the inner layer of bark, they gradually move outward as more bark layers are laid down, eventually sloughing off the tree's outer surface. Chambers have a mean lifetime of about 25 yr. The abundant chambers in pine bark are excavated by a small population of caterpillars and accumulate over decades. Ant colonies also inhabit abandoned galleries of woodboring beetles in dead branches in the crowns of pines. Because newly mated queens found colonies in abandoned woodboring beetle galleries in the first dead branches that form on pine saplings, C. ashmeadi is dependent on cavities made by other insects throughout its life cycle, and does little if any excavation of its own. Mature colonies nest preferentially in chambers greater than 10 cm2 in area, a relatively rare chamber size. In natural pine forests, this does not seem to limit the ant's populations.
Tofolo, Viviane C; Giannotti, Edilberto; Neves, Erika F; Andrade, Luis H C; Lima, Sandro M; Súarez, Yzel R; Antonialli-Junior, William F
Tropical ants commonly exhibit a hyper-dispersed pattern of spatial distribution of nests. In polydomous species, nests may be satellites, that is, secondary structures of the main nest, where the queen is found. In order to evaluate whether the ant Ectatomma opaciventre Roger (Formicidae: Ectatomminae) uses the strategy of building polydomous nests, the spatial distribution pattern of 33 nests in a 1,800 m(2) degraded area located in Rio Claro, SP, Brazil, were investigated using the nearest neighbor method. To complement the results of this investigation, the cuticular chemical profile of eight colonies was analyzed using Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS). The nests of E. opaciventre presented a hyper-dispersed or regular distribution, which is the most common in ants. The analysis of the cuticular hydrocarbons apparently con-firmed the hypothesis that this species is polydomous, since the chemical profiles of all studied colonies with nests at different sites were very similar to the chemical signature of the single found queen and were also different from those of colonies used as control. PMID:25373168
Matthias Benjamin Barth
Full Text Available The unique nomadic life-history pattern of army ants (army ant adaptive syndrome, including obligate colony fission and strongly male-biased sex-ratios, makes army ants prone to heavily reduced effective population sizes (Ne. Excessive multiple mating by queens (polyandry has been suggested to compensate these negative effects by increasing genetic variance in colonies and populations. However, the combined effects and evolutionary consequences of polyandry and army ant life history on genetic colony and population structure have only been studied in a few selected species. Here we provide new genetic data on paternity frequencies, colony structure and paternity skew for the five Neotropical army ants Eciton mexicanum, E. vagans, Labidus coecus, L. praedator and Nomamyrmex esenbeckii; and compare those data among a total of nine army ant species (including literature data. The number of effective matings per queen ranged from about 6 up to 25 in our tested species, and we show that such extreme polyandry is in two ways highly adaptive. First, given the detected low intracolonial relatedness and population differentiation extreme polyandry may counteract inbreeding and low Ne. Second, as indicated by a negative correlation of paternity frequency and paternity skew, queens maximize intracolonial genotypic variance by increasingly equalizing paternity shares with higher numbers of sires. Thus, extreme polyandry is not only an integral part of the army ant syndrome, but generally adaptive in social insects by improving genetic variance, even at the high end spectrum of mating frequencies.
Barth, Matthias Benjamin; Moritz, Robin Frederik Alexander; Kraus, Frank Bernhard
The unique nomadic life-history pattern of army ants (army ant adaptive syndrome), including obligate colony fission and strongly male-biased sex-ratios, makes army ants prone to heavily reduced effective population sizes (Ne). Excessive multiple mating by queens (polyandry) has been suggested to compensate these negative effects by increasing genetic variance in colonies and populations. However, the combined effects and evolutionary consequences of polyandry and army ant life history on genetic colony and population structure have only been studied in a few selected species. Here we provide new genetic data on paternity frequencies, colony structure and paternity skew for the five Neotropical army ants Eciton mexicanum, E. vagans, Labidus coecus, L. praedator and Nomamyrmex esenbeckii; and compare those data among a total of nine army ant species (including literature data). The number of effective matings per queen ranged from about 6 up to 25 in our tested species, and we show that such extreme polyandry is in two ways highly adaptive. First, given the detected low intracolonial relatedness and population differentiation extreme polyandry may counteract inbreeding and low Ne. Second, as indicated by a negative correlation of paternity frequency and paternity skew, queens maximize intracolonial genotypic variance by increasingly equalizing paternity shares with higher numbers of sires. Thus, extreme polyandry is not only an integral part of the army ant syndrome, but generally adaptive in social insects by improving genetic variance, even at the high end spectrum of mating frequencies. PMID:25144731
Ouagoussounon, Issa; Sinzogan, Antonio; Offenberg, Joachim;
Oecophylla ants are currently used for biological control in fruit plantations in Australia, Asia and Africa and for protein production in Asia. To further improve the technology and implement it on a large scale, effective and fast production of live colonies is desirable. Early colony development...... capita brood production by the resident queen, triggered by the adopted pupae. Thus pupae transplantation may be used to shorten the time it takes to produce weaver ant colonies in ant nurseries, and may in this way facilitate the implementation of weaver ant biocontrol in West Africa....
Actor-Network-Theory (ANT) offers an ‘infra-language’ of the social that allows one to trace social relations very dynamically, while at the same time dissolving human agency, thus providing a flat and de-centred way into sociology. However, ANT struggles with its theoretical design that may lead...... us to reduce agency to causation and to conceptualize actor-networks as homogeneous ontologies of force. This article proposes to regard ANT’s inability to conceptualize reflexivity and the interrelatedness of different ontologies as the fundamental problem of the theory. Drawing on Günther, it...... offers an ‘infra-language’ of reflexive relations while maintaining ANT’s de-centred approach. This would enable us to conceptualize actor-networks as non-homogeneous, dynamic and connecting different societal rationales while maintaining the main strengths of ANT....
G. MURALI; Sadia Naureen; Y.Abhigna Reddy; M.Swetha Reddy
Graphical simulation is an attempt of predicting the aspects of behavior of some system by developing an approximate model of it. Simulations have great impact on education and in training. Simulation based learning is a practical way of learning of practices that involves building connections: connections among what is being learned and what is important to the actor and the situations in which it is applied. N-Queens problem refers to the problem in which one has to place N-Queens on...
Full Text Available Mating has profound effects on the physiology and behavior of female insects, and in honey bee (Apis mellifera queens, these changes are permanent. Queens mate with multiple males during a brief period in their early adult lives, and shortly thereafter they initiate egg-laying. Furthermore, the pheromone profiles of mated queens differ from those of virgins, and these pheromones regulate many different aspects of worker behavior and colony organization. While it is clear that mating causes dramatic changes in queens, it is unclear if mating number has more subtle effects on queen physiology or queen-worker interactions; indeed, the effect of multiple matings on female insect physiology has not been broadly addressed. Because it is not possible to control the natural mating behavior of queens, we used instrumental insemination and compared queens inseminated with semen from either a single drone (single-drone inseminated, or SDI or 10 drones (multi-drone inseminated, or MDI. We used observation hives to monitor attraction of workers to SDI or MDI queens in colonies, and cage studies to monitor the attraction of workers to virgin, SDI, and MDI queen mandibular gland extracts (the main source of queen pheromone. The chemical profiles of the mandibular glands of virgin, SDI, and MDI queens were characterized using GC-MS. Finally, we measured brain expression levels in SDI and MDI queens of a gene associated with phototaxis in worker honey bees (Amfor. Here, we demonstrate for the first time that insemination quantity significantly affects mandibular gland chemical profiles, queen-worker interactions, and brain gene expression. Further research will be necessary to elucidate the mechanistic bases for these effects: insemination volume, sperm and seminal protein quantity, and genetic diversity of the sperm may all be important factors contributing to this profound change in honey bee queen physiology, queen behavior, and social interactions in the
van der Hammen, T; Pedersen, J S; Boomsma, J J
Many ant species have independently evolved colony structures with multiple queens and very low relatedness among nestmate workers, but it has remained unclear whether low-relatedness kin structures can repeatedly arise in populations of the same species. Here we report a study of Danish island populations of the red ant Myrmica sulcinodis and show that it is likely that such repeated developments occur. Two microsatellite loci were used to estimate genetic differentiation (F(ST)) among three populations and nestmate relatedness within these populations. The F(ST) values were highly significant due to very different allele frequencies among the three populations with relatively few common alleles and relatively many rare alleles, possibly caused by single queen foundation and rare subsequent immigration. Given the isolation of the islands and the low investment in reproduction, we infer that each of the populations was most likely established by a single queen, even though all three extant populations now have within-colony relatedness 95%), and the genetic differentiation of nests showed a significantly positive correlation with the distance between them. Both male-biased sex-ratio and genetic viscosity are expected characteristics of populations where queens have very local dispersal and where new colonies are initiated through nest-budding. Based on a comparison with other M. sulcinodis populations we hypothesise a distinct succession of population types and suggest that this may be a possible pathway to unicoloniality, ie, development towards a complete lack of colony kin structure and unrelated nestmate workers. PMID:12136409
Oi, D H; Vail, K M; Williams, D F
Pharaoh ant, Monomorium pharaonis (L.), infestations often consist of several colonies located at different nest sites. To achieve control, it is desirable to suppress or eliminate the populations of a majority of these colonies. We compared the trophallactic distribution and efficacy of two ant baits, with different modes of action, among groups of four colonies of Pharaoh ants. Baits contained either the metabolic-inhibiting active ingredient hydramethylnon or the insect growth regulator (IGR) pyriproxyfen. Within 3 wk, the hydramethylnon bait reduced worker and brood populations by at least 80%, and queen reductions ranged between 73 and 100%, when nests were in proximity (within 132 cm) to the bait source. However, these nest sites were reoccupied by ants from other colonies located further from the bait source. The pyriproxyfen bait was distributed more thoroughly to all nest locations with worker populations gradually declining by 73% at all nest sites after 8 wk. Average queen reductions ranged from 31 to 49% for all nest sites throughout the study. Even though some queens survived, brood reductions were rapid in the pyriproxyfen treatment, with reductions of 95% at all locations by week 3. Unlike the metabolic inhibitor, the IGR did not kill adult worker ants quickly, thus, more surviving worker ants were available to distribute the bait to all colonies located at different nest sites. Thus, from a single bait source, the slow-acting bait toxicant provided gradual, but long-term control, whereas the fast-acting bait toxicant provided rapid, localized control for a shorter duration. PMID:10985038
Kronauer, Daniel J C; O'Donnell, Sean; Boomsma, Jacobus J;
queen mating frequencies, and therefore among the lowest degrees of colony relatedness, occur in Apis honeybees and army ants of the subfamilies Aenictinae, Ecitoninae, and Dorylinae, suggesting that common life history features such as reproduction by colony fission and male biased numerical sex......-ratios have convergently shaped these mating systems. Here we show that ponerine army ants of the genus Simopelta, which are distantly related but similar in general biology to other army ants, have strictly monandrous queens. Preliminary data suggest that workers reproduce in queenright colonies, which is in...
Friedman, D A; Gordon, D M
Many exciting studies have begun to elucidate the genetics of the morphological and physiological diversity of ants, but as yet few studies have investigated the genetics of ant behavior directly. Ant genomes are marked by extreme rates of gene turnover, especially in gene families related to olfactory communication, such as the synthesis of cuticular hydrocarbons and the perception of environmental semiochemicals. Transcriptomic and epigenetic differences are apparent between reproductive and sterile females, males and females, and workers that differ in body size. Quantitative genetic approaches suggest heritability of task performance, and population genetic studies indicate a genetic association with reproductive status in some species. Gene expression is associated with behavior including foraging, response to queens attempting to join a colony, circadian patterns of task performance, and age-related changes of task. Ant behavioral genetics needs further investigation of the feedback between individual-level physiological changes and socially mediated responses to environmental conditions. PMID:27050321
Baer, B.; Dijkstra, M. B.; Mueller, U. G.;
-growing ants, representing 9 of the 12 recognized genera, and mapped these onto the ant phylogeny. We show that average sperm length across species is highly variable and decreases with mature colony size in basal genera with singly mated queens, suggesting that sperm production or storage constraints affect...... the evolution of sperm length. Sperm length does not decrease further in multiply mating leaf-cutting ants, despite substantial further increases in colony size. In a combined analysis, sexual dimorphism explained 63.1% of the variance in sperm length between species. As colony size was not a...... significant predictor in this analysis, we conclude that sperm production trade-offs in males have been the major selective force affecting sperm length across the fungus-growing ants, rather than storage constraints in females. The relationship between sperm length and sexual dimorphism remained robust in...
Francis, Roy Mathew
was developed to diagnose three viruses in honey bees. Quantitative PCR was used to investigate the distribution of two popular viruses in five different tissues of 86 honey bee queens. Seasonal variation of viral infection in honey bee workers and varroa mites were determined by sampling 23 colonies...
Vail, K M; Williams, D F
Pharaoh ant, Monomorium pharaonis (L.), colonies were effectively controlled following ingestion of pyriproxyfen formulated in peanut butter oil. Pyriproxyfen, a juvenile hormone analog, reduced egg production in the queens, decreased the amount of brood due to delayed death in the eggs and larvae, caused death of pupae about 3 wk after treatment, and decreased the number of workers due to attrition and toxic effects. Queens, which continued to produce a small amount of eggs, eventually died. Queen death may have been caused by lack of workers required to tend them, old age or toxic effects. At concentrations of 0.25, 0.5 and 1%, pyriproxyfen was more effective than the once commercially available bait, Pharorid (methoprene) for the control of the Pharaoh ant. PMID:8537545
Berndt, K P
The paper analyses the mode of action of the organic chlorine compound Mirex in laboratory colonies of the pharaoh's ant Monomorium pharaonis under the special view of practical use in control measures in comparison with the related insecticide Chlordecone (Kepone). Similar to Chlordecone the queens are very susceptible towards the action of Mirex. According to the regression lines of the mortality the best concentrations for practical control measures are in the range of 0.1 to 1%, respectively. Under laboratory conditions a reliable eradication is effected by an application of 0.001% Mirex over a period of three weeks. Such a treatment lead to the loss of reproductive capacity of the remaining living queens. These queens do not recover after transmission to normal colonies. The larvae were influenced in the same manner as the adults. At the recommended level of Mirex all of the larvae disappear within the first five days of application of the poison bait. Also a short termed use lead to a long lasting damage of the ant societies. Between different baits no significant difference could be demonstrated even when one bait obviously was better accepted than another. Because of the strong effect on intact colonies Mirex should be recommended for the control of this ant pest. PMID:1008292
Ants provide remarkable examples of equivalent genotypes developing into divergent and discrete phenotypes. Diploid eggs can develop either into queens, which specialize in reproduction, or workers, which participate in cooperative tasks such as building the nest, collecting food, and rearing the yo...
Luiz Carlos Forti
Full Text Available We present a detailed description of the predatory behavior of the beetle Canthon virens Mannerheim, 1829, on the leafcutter ant Atta sp. We observed 51 acts of predation, which were also recorded on film and subjected to behavioral analysis. Canthon virens exhibited 28 behaviors while predating upon Atta sp. queens. Adult beetles search for queens while flying in a zigzag pattern, 15 to 20 cm above the ground. After catching a queen, the predator stands on its back and starts cutting the queen cervix. Once the prey is decapitated, the predator rolls it until an insurmountable obstacle is reached. The distance from the site of predation to the obstacle can vary widely and is unpredictable. The beetle rolling the queen also buries it in a very peculiar way: first, it digs a small hole and pulls the queen inside, while another beetle is attached to the prey. The burial process takes many hours (up to 12 and may depend on the hardness of the soil and the presence of obstacles. In general, one or two beetles are found in a chamber with the queen after it is buried. They make the brood balls, which serve as food for the offspring. This study contributes to the knowledge of the predatory behavior of Canthon virens, a predator poorly studied in Brazil and widespread in the country.
Uses the GEMS guide, "Ants at Home Underground", to explore the life of ants and teach about them in a classroom setting. The activity applies students' knowledge of ants and students learn about ant colonies, what ants eat, and how they live. (SAH)
... Favorite Name: Category: Share: Yes No, Keep Private Fire Ant Bites Share | Fire ants are aggressive, venomous insects that have pinching ... across the United States, even into Puerto Rico. Fire ant stings usually occur on the feet or ...
Full Text Available Abstract Background Many insects, including ants, are infected by maternally inherited Wolbachia endosymbiotic bacteria though other secondary endosymbionts have not been reported in ants. It has been suggested that the ability of Wolbachia to invade and remain in an ant population depends on the number of coexisting queens in a colony. We study the genetic and social structure of populations in the ant Formica cinerea which is known to have populations with either monogynous or polygynous colonies. We screen populations for several endosymbiotic bacteria to evaluate the presence of different endosymbionts, possible association between their prevalence and the social structure, and the association between endosymbiont prevalence and genetic differentiation of ant populations. Results We found three endosymbiotic bacteria; 19% of the nests were infected by Wolbachia, 3.8% by Cardinium and 33% by Serratia. There was significant variation among the populations regarding the proportion of nests infected by Serratia, Wolbachia and the pooled set of all the endosymbionts. Some individuals and colonies carried two of the bacteria, the frequency of double infections agreeing with the random expectation. The proportion of infected ants (individuals or colonies did not correlate significantly with the population level relatedness values. The difference in the prevalence of Wolbachia between population pairs correlated significantly with the genetic distance (microsatellites of the populations. Conclusions The discovery of several endosymbionts and co-infections by Wolbachia and Cardinium demonstrate the importance of screening several endosymbionts when evaluating their possible effects on social life and queen-worker conflicts over sex allocation. The low prevalence of Wolbachia in F. cinerea departs from the pattern observed in many other Formica ants in which all workers have been infected. It is likely that the strain of Wolbachia in F. cinerea
Full Text Available Ants use a great variety of recruitment methods to forage for food or find new nests, including tandem running, group recruitment and scent trails. It has been known for some time that there is a loose correlation across many taxa between species-specific mature colony size and recruitment method. Very small colonies tend to use solitary foraging; small to medium sized colonies use tandem running or group recruitment whereas larger colonies use pheromone recruitment trails. Until now, explanations for this correlation have focused on the ants' ecology, such as food resource distribution. However, many species have colonies with a single queen and workforces that grow over several orders of magnitude, and little is known about how a colony's organization, including recruitment methods, may change during its growth. After all, recruitment involves interactions between ants, and hence the size of the colony itself may influence which recruitment method is used--even if the ants' behavioural repertoire remains unchanged. Here we show using mathematical models that the observed correlation can also be explained by recognizing that failure rates in recruitment depend differently on colony size in various recruitment strategies. Our models focus on the build up of recruiter numbers inside colonies and are not based on optimality arguments, such as maximizing food yield. We predict that ant colonies of a certain size should use only one recruitment method (and always the same one rather than a mix of two or more. These results highlight the importance of the organization of recruitment and how it is affected by colony size. Hence these results should also expand our understanding of ant ecology.
Kavita R. Sharma
Full Text Available The sophisticated organization of eusocial insect societies is largely based on the regulation of complex behaviors by hydrocarbon pheromones present on the cuticle. We used electrophysiology to investigate the detection of cuticular hydrocarbons (CHCs by female-specific olfactory sensilla basiconica on the antenna of Camponotus floridanus ants through the utilization of one of the largest family of odorant receptors characterized so far in insects. These sensilla, each of which contains multiple olfactory receptor neurons, are differentially sensitive to CHCs and allow them to be classified into three broad groups that collectively detect every hydrocarbon tested, including queen and worker-enriched CHCs. This broad-spectrum sensitivity is conserved in a related species, Camponotus laevigatus, allowing these ants to detect CHCs from both nestmates and non-nestmates. Behavioral assays demonstrate that these ants are excellent at discriminating CHCs detected by the antenna, including enantiomers of a candidate queen pheromone that regulates the reproductive division of labor.
Loope, Kevin J.
In many colonies of social insects, the workers compete with each other and with the queen over the production of the colony's males. In some species of social bees and wasps with annual societies, this intra-colony conflict even results in matricide—the killing of the colony's irreplaceable queen by a daughter worker. In colonies with low effective paternity and high worker-worker relatedness, workers value worker-laid males more than queen-laid males, and thus may benefit from queen killing. Workers gain by eliminating the queen because she is a competing source of male eggs and actively inhibits worker reproduction through policing. However, matricide may be costly to workers if it reduces the production of valuable new queens and workers. Here, I test a theoretical prediction regarding the timing of matricide in a wasp, Dolichovespula arenaria, recently shown to have facultative matricide based on intra-colony relatedness. Using analyses of collected, mature colonies and a surgical manipulation preventing queens from laying female eggs, I show that workers do not preferentially kill queens who are only producing male eggs. Instead, workers sometimes kill queens laying valuable females, suggesting a high cost of matricide. Although matricide is common and typically occurs only in low-paternity colonies, it seems that workers sometimes pay substantial costs in this expression of conflict over male parentage.
Loope, Kevin J
In many colonies of social insects, the workers compete with each other and with the queen over the production of the colony's males. In some species of social bees and wasps with annual societies, this intra-colony conflict even results in matricide-the killing of the colony's irreplaceable queen by a daughter worker. In colonies with low effective paternity and high worker-worker relatedness, workers value worker-laid males more than queen-laid males, and thus may benefit from queen killing. Workers gain by eliminating the queen because she is a competing source of male eggs and actively inhibits worker reproduction through policing. However, matricide may be costly to workers if it reduces the production of valuable new queens and workers. Here, I test a theoretical prediction regarding the timing of matricide in a wasp, Dolichovespula arenaria, recently shown to have facultative matricide based on intra-colony relatedness. Using analyses of collected, mature colonies and a surgical manipulation preventing queens from laying female eggs, I show that workers do not preferentially kill queens who are only producing male eggs. Instead, workers sometimes kill queens laying valuable females, suggesting a high cost of matricide. Although matricide is common and typically occurs only in low-paternity colonies, it seems that workers sometimes pay substantial costs in this expression of conflict over male parentage. PMID:27350328
van Zweden, Jelle Stijn
Social insect workers are often capable of reproduction, but will not do so in the presence of a fertile queen. In large societies, queens are expected to produce a pheromone that honestly signals her dominance and/or fertility, to which workers respond by suppressing the development of their...... it is undermined by the fitness benefits of direct reproduction of workers at the individual level. A better explanation may be found in the idea that queen pheromones are difficult to produce for subordinate individuals, either because policing workers attack them, or because queen pheromones are...
Buczkowski, Grzegorz; Roper, Elray; Chin, Darren
Ant management in urban and natural areas often relies on toxic baits. Liquid baits are highly attractive to pest ants because they mimic natural food sources such as honeydew and nectar, the principal dietary components of many ants. However, liquid bait use has been limited owing to the lack of bait dispensers that are effective, inexpensive, and easy to service. The current study evaluated the potential of water-storing crystals (polyacrylamide spheres) to effectively deliver liquid thiamethoxam baits to laboratory colonies of Argentine ants, Linepithema humile Mayr. Results of laboratory trials show that bait crystals saturated in 25% sucrose solution containing 0.007% thiamethoxam are highly attractive to Argentine ants and highly effective against all castes and life stages, including workers, queens, and brood. Fresh bait crystals were highly effective and required approximately 2 d to kill all workers and approximately 6 d to achieve complete mortality in queens and brood. Results of bait aging tests show that the crystals lose approximately 70% of moisture in 8 h and the duration of outdoor exposure has a significant effect on moisture loss and subsequently bait acceptance and bait efficacy. A gradual decrease in mortality was observed for all castes and life stages as bait age increased. In general, fresh baits and those aged for Baits aged longer than 8 h were substantially less attractive and less effective. Horizontal transfer tests examined the transfer of thiamethoxam from live treated donors to live untreated recipients. The results show that donor ants that obtain thiamethoxam by feeding on bait crystals effectively transfer it to untreated recipient ants. The level of secondary mortality depended on the donor:recipient ratio, with approximately 40% recipient worker mortality with the 1:5 ratio and 15% recipient worker mortality with 1:10 or 1:20 ratios. However, no queens died in any transfer tests, suggesting that multiple feedings from multiple
The aim of this work is to investigate Ant Colony Algorithm for the traveling salesman problem (TSP). Ants of the artificial colony are able to generate successively shorter feasible tours by using information accumulated in the form of a pheromone trail deposited on the edges of the TSP graph. This paper is based on the ideas of ant colony algorithm and analysis the main parameters of the ant colony algorithm. Experimental results for solving TSP problems with ant colony algorithm show great...
Zhang, Mingzi; Poulsen, Michael; Currie, Cameron R
actinomycete bacterial mutualist (genus Pseudonocardia). Despite the potential of being infected by phylogenetically diverse strains of parasites, each ant colony maintains only a single Pseudonocardia symbiont strain, which is primarily vertically transmitted between colonies by the founding queens. In this......Symbiont choice has been proposed to play an important role in shaping many symbiotic relationships, including the fungus-growing ant-microbe mutualism. Over millions of years, fungus-growing ants have defended their fungus gardens from specialized parasites with antibiotics produced by an...... study, we show that Acromyrmex leaf-cutter ants are able to differentiate between their native actinomycete strain and a variety of foreign strains isolated from sympatric and allopatric Acromyrmex species, in addition to strains originating from other fungus-growing ant genera. The recognition...
Himler, Anna G; Caldera, Eric J; Baer, Boris C; Fernández-Marín, Hermógenes; Mueller, Ulrich G
Asexual reproduction imposes evolutionary handicaps on asexual species, rendering them prone to extinction, because asexual reproduction generates novel genotypes and purges deleterious mutations at lower rates than sexual reproduction. Here, we report the first case of complete asexuality in ants, the fungus-growing ant Mycocepurus smithii, where queens reproduce asexually but workers are sterile, which is doubly enigmatic because the clonal colonies of M. smithii also depend on clonal fungi for food. Degenerate female mating anatomy, extensive field and laboratory surveys, and DNA fingerprinting implicate complete asexuality in this widespread ant species. Maternally inherited bacteria (e.g. Wolbachia, Cardinium) and the fungal cultivars can be ruled out as agents inducing asexuality. M. smithii societies of clonal females provide a unique system to test theories of parent-offspring conflict and reproductive policing in social insects. Asexuality of both ant farmer and fungal crop challenges traditional views proposing that sexual farmer ants outpace coevolving sexual crop pathogens, and thus compensate for vulnerabilities of their asexual crops. Either the double asexuality of both farmer and crop may permit the host to fully exploit advantages of asexuality for unknown reasons or frequent switching between crops (symbiont reassociation) generates novel ant-fungus combinations, which may compensate for any evolutionary handicaps of asexuality in M. smithii. PMID:19369264
Wheeler, D E; Crichton, E G; Krutzsch, P H
Mature spermatozoa from spermathecae of founding queens were obtained from 5 species of ants, representing the major subfamilies Myrmicinae (Acromyrmex versicolor, Crematogaster sp.) and Dolichoderinae (Tapinoma sessile, Conomyrma insana, Conomyrma wheeleri). The ultrastructure of ant spermatozoa has many features in common with that of higher insects and is similar to that of other Hymenoptera. Structural similarities to spermatozoa of other Hymenoptera include an acrosome containing an internal rod that extends into the nucleus, two elongate mitochondrial derivatives, a centriolar adjunct, and an axonemal arrangement of 9 + 9 + 2 that includes well-developed coarse, or accessory, tubules. Spermatozoa obtained from A. versicolor, a species that is known to store and utilize viable sperm from this supply for over 10 years, show greater development of the mitochondrial derivatives than do the other species. The most distinctive feature of ant spermatozoa in comparison to other Hymenoptera is the large size of the centriolar adjunct relative to the other organelles. The centriolar adjunct is located posterior to the nucleus, anterior to the mitochondrial derivatives, and opposite the axoneme. PMID:2280410
Suckling, David M; Stringer, Lloyd D; Bunn, Barry; El-Sayed, Ashraf M; Vander Meer, Robert K
The fire ant, Solenopsis invicta (Hymenoptera: Formicidae), is considered one of the most aggressive and invasive species in the world. Toxic bait systems are used widely for control, but they also affect non-target ant species and cannot be used in sensitive ecosystems such as organic farms and national parks. The fire ant uses recruitment pheromones to organize the retrieval of large food resources back to the colony, with Z,E-alpha-farnesene responsible for the orientation of workers along trails. We prepared Z,E-alpha-farnesene, (91% purity) from extracted E,E-alpha-farnesene and demonstrated disruption of worker trail orientation after presentation of an oversupply of this compound from filter paper point sources (30 microg). Trails were established between queen-right colony cells and food sources in plastic tubs. Trail-following behavior was recorded by overhead webcam, and ants were digitized before and after presentation of the treatment, using two software approaches. The linear regression statistic, r(2) was calculated. Ants initially showed high linear trail integrity (r(2) = 0.75). Within seconds of presentation of the Z,E-alpha-farnesene treatment, the trailing ants showed little or no further evidence of trail following behavior in the vicinity of the pheromone source. These results show that trailing fire ants become disorientated in the presence of large amounts of Z,E-alpha-farnesene. Disrupting fire ant recruitment to resources may have a negative effect on colony size or other effects yet to be determined. This phenomenon was demonstrated recently for the Argentine ant, where trails were disrupted for two weeks by using their formulated trail pheromone, Z-9-hexadecenal. Further research is needed to establish the long term effects and control potential for trail disruption in S. invicta. PMID:20549330
Berndt, K P; Nitschmann, J
The control of the Pharaoh's ant Monomorium pharaonis is very difficult because of the social way of life in this insect pest. In regard to the reported good suppressing results of Chlordecone we analyzed the mode of action in this compound at laboratory colonies of the pharaoh's ant. Commercial gel and granular formulations as well as selfmade baits have been tested. The best results showed the granular bait on the basis of ground nut butter, while the effects of all of the others was much weaker. The pure gel, developed for cockroach control, was like the application in drinking water without success. The treatment of the colonies after a starvation period of 60 hours improved all of the effects. Sterility (fertility, fecundity) in the surviving queens was not measurable. For practical control measures the often recommended prebaiting is not at all desirable. The action on the worker ants is good, but the special mode of action based on the selective mortality in the queens and its detailed effects are unknown. Through the early absence of queens in the colonies will be induced in many cases a production of new sexuals, which compensate the success of the poison and allow the colonies to recover. The treatment leads faster to an eradiction if the ET90 to workers mortality reached earlier than that in the queens. Successful control of pharaoh's ant will Chlordecone should be considered with reserve. Nethertheless Chlordecone is in the present situation of pharaoh's ant control one of the best so far known organic-synthetically insecticides. PMID:1267219
De La Riva, Deborah G; Trumble, John T
Competitive ability and numerical dominance are important factors contributing to the ability of invasive ant species to establish and expand their ranges in new habitats. However, few studies have investigated the impact of environmental contamination on competitive behavior in ants as a potential factor influencing dynamics between invasive and native ant species. Here we investigated the widespread contaminant selenium to investigate its potential influence on invasion by the exotic Argentine ant, Linepithema humile, through effects on reproduction and competitive behavior. For the fecundity experiment, treatments were provided to Argentine ant colonies via to sugar water solutions containing one of three concentrations of selenium (0, 5 and 10 μg Se mL(-1)) that fall within the range found in soil and plants growing in contaminated areas. Competition experiments included both the Argentine ant and the native Dorymyrmex bicolor to determine the impact of selenium exposure (0 or 15 μg Se mL(-1)) on exploitation- and interference-competition between ant species. The results of the fecundity experiment revealed that selenium negatively impacted queen survival and brood production of Argentine ants. Viability of the developing brood was also affected in that offspring reached adulthood only in colonies that were not given selenium, whereas those in treated colonies died in their larval stages. Selenium exposure did not alter direct competitive behaviors for either species, but selenium exposure contributed to an increased bait discovery time for D. bicolor. Our results suggest that environmental toxins may not only pose problems for native ant species, but may also serve as a potential obstacle for establishment among exotic species. PMID:27038576
Boris H Kramer
Full Text Available The question on how individuals allocate resources into maintenance and reproduction is one of the central questions in life history theory. Yet, resource allocation into maintenance on the organismic level can only be measured indirectly. This is different in a social insect colony, a "superorganism" where workers represent the soma and the queen the germ line of the colony. Here, we investigate whether trade-offs exist between maintenance and reproduction on two levels of biological organization, queens and colonies, by following single-queen colonies of the ant Cardiocondyla obscurior throughout the entire lifespan of the queen. Our results show that maintenance and reproduction are positively correlated on the colony level, and we confirm results of an earlier study that found no trade-off on the individual (queen level. We attribute this unexpected outcome to the existence of a positive feedback loop where investment into maintenance (workers increases the rate of resource acquisition under laboratory conditions. Even though food was provided ad libitum, variation in productivity among the colonies suggests that resources can only be utilized and invested into additional maintenance and reproduction by the colony if enough workers are available. The resulting relationship between per-capita and colony productivity in our study fits well with other studies conducted in the field, where decreasing per-capita productivity and the leveling off of colony productivity have been linked to density dependent effects due to competition among colonies. This suggests that the absence of trade-offs in our laboratory study might also be prevalent under natural conditions, leading to a positive association of maintenance, (= growth and reproduction. In this respect, insect colonies resemble indeterminate growing organisms.
Tschinkel, Walter R
The arboreal ant, Crematogaster ashmeadi Emery (Hymenoptera: Formicidae), is the most dominant arboreal ant in the pine forests of the coastal plain of northern Florida. The majority of pine trees harbor a colony of these ants. The colonies inhabit multiple chambers abandoned by bark-mining caterpillars, especially those of the family Cossidae, in the outer bark of living pines. They also inhabit ground level termite galleries in the bark, often locating the queen in galleries. The density of chambers and ants is highest in the base of the tree and drops sharply with height on the trunk. Because chambers are formed in the inner layer of bark, they gradually move outward as more bark layers are laid down, eventually sloughing off the tree's outer surface. Chambers have a mean lifetime of about 25 yr. The abundant chambers in pine bark are excavated by a small population of caterpillars and accumulate over decades. Ant colonies also inhabit abandoned galleries of woodboring beetles in dead branches in the crowns of pines. Because newly mated queens found colonies in abandoned woodboring beetle galleries in the first dead branches that form on pine saplings, C. ashmeadi is dependent on cavities made by other insects throughout its life cycle, and does little if any excavation of its own. Mature colonies nest preferentially in chambers greater than 10 cm(2) in area, a relatively rare chamber size. In natural pine forests, this does not seem to limit the ant's populations. Founding queens contain about 50% fat and lose about half of their dry weight during the claustral period, converting approximately half of this lost weight into progeny. The claustral period is about 40 to 50 days at 27 degrees C. Mature colonies contain several tens of thousands of workers (est. up to 80,000), and have a life expectancy of 10 to 15 years. Each colony occupies an entire tree, and sometimes two trees if they are close together. Within a colony, there is a single queen capable of
Lorite, P; Renault, S; Rouleux-Bonnin, F; Bigot, S; Periquet, G; Palomeque, T
A satellite DNA family (APSU) was isolated and characterized in the ant Aphaenogaster subterranea. This satellite DNA is organized in tandem repeats of 162 bp and is relatively AT rich (51.9%). Sequence analysis showed a high level of homogeneity between monomers. Loss of satellite DNA has been detected in queens in relation to workers, because the amount of satellite DNA in queens is about 25% of the amount found in workers. Restriction analysis of the total DNA with methylation-sensitive enzymes suggests that this DNA is not methylated. Analysis of the electrophoretic mobility of satellite DNA on non-denaturing polyacrylamide showed that this satellite DNA is only very lightly curved. Their possible transcription was analyzed using reverse transcription and polymerase chain reaction (RT-PCR). The satellite DNA is transcribed on the two DNA strands at the same level in worker and queen pupae, as well as in worker adults. PMID:12175063
Dellinger, Theresa A.; Day, Eric R.
Describes Velvet Ants, their life cycle, habitats, and discusses control if necessary, although they are generally not regarded as pests. Caution is noted in handling velvet ants, since their stings are very painful.
Žumer, Viljem; Brest, Janez; Pešl, Ivan
Ant colony optimization is a relatively new approach to solving NP-Hard problems. It is based on the behavior of real ants, which always find the shortest path between their nest and a food source. Such behavior can be transferred into the discrcte world, were real ants are replaced by simple agents. Such simple agents are placed into the environment where different combinatorial problems can be solved In this paper we describe an artificial ant colony capable of solving the travelling salesm...
Chaiken, Seth; Zaslavsky, Thomas; 10.1007/s00026-011-0068-7
The function that counts the number of ways to place nonattacking identical chess or fairy chess pieces in a rectangular strip of fixed height and variable width, as a function of the width, is a piecewise polynomial which is eventually a polynomial and whose behavior can be described in some detail. We deduce this by converting the problem to one of counting lattice points outside an affinographic hyperplane arrangement, which Forge and Zaslavsky solved by means of weighted integral gain graphs. We extend their work by developing both generating functions and a detailed analysis of deletion and contraction for weighted integral gain graphs. For chess pieces we find the asymptotic probability that a random configuration is nonattacking, and we obtain exact counts of nonattacking configurations of small numbers of queens, bishops, knights, and nightriders.
Valerie S. Banschbach
Full Text Available Determining how ant communities are impacted by challenges from habitat fragmentation, such as edge effects, will help us understand how ants may be used as a bioindicator taxon. To assess the impacts of edge effects upon the ant community in a northern temperate deciduous forest, we studied edge and interior sites in Jericho, VT, USA. The edges we focused upon were created by recreational trails. We censused the ants at these sites for two consecutive growing seasons using pitfall traps and litter plot excavations. We also collected nests of the most common ant species at our study sites, Aphaenogaster rudis, for study of colony demography. Significantly greater total numbers of ants and ant nests were found in the edge sites compared to the interior sites but rarefaction analysis showed no significant difference in species richness. Aphaenogaster rudis was the numerically dominant ant in the habitats sampled but had a greater relative abundance in the interior sites than in the edge sites both in pitfall and litter plot data. Queen number of A. rudis significantly differed between the nests collected in the edge versus the interior sites. Habitat-dependent changes in social structure of ants represent another possible indicator of ecosystem health.
Brandt, Miriam; Foitzik, Susanne; Fischer-Blass, Birgit; Heinze, Jürgen
In this synthesis we apply coevolutionary models to the interactions between socially parasitic ants and their hosts. Obligate social parasite systems are ideal models for coevolution, because the close phylogenetic relationship between these parasites and their hosts results in similar evolutionary potentials, thus making mutual adaptations in a stepwise fashion especially likely to occur. The evolutionary dynamics of host-parasite interactions are influenced by a number of parameters, for example the parasite's transmission mode and rate, the genetic structure of host and parasite populations, the antagonists' migration rates, and the degree of mutual specialisation. For the three types of obligate ant social parasites, queen-tolerant and queen-intolerant inquilines and slavemakers, several of these parameters, and thus the evolutionary trajectory, are likely to differ. Because of the fundamental differences in lifestyle between these social parasite systems, coevolution should further select for different traits in the parasites and their hosts. Queen-tolerant inquilines are true parasites that exert a low selection pressure on their host, because of their rarity and the fact that they do not conduct slave raids to replenish their labour force. Due to their high degree of specialisation and the potential for vertical transmission, coevolutionary theory would predict interactions between these workerless parasites and their hosts to become even more benign over time. Queen-intolerant inquilines that kill the host queen during colony take-over are best described as parasitoids, and their reproductive success is limited by the existing worker force of the invaded host nest. These parasites should therefore evolve strategies to best exploit this fixed resource. Slavemaking ants, by contrast, act as parasites only during colony foundation, while their frequent slave raids follow a predator prey dynamic. They often exploit a number of host species at a given site, and
van Zweden, Jelle S; Dreier, Stephanie; d'Ettorre, Patrizia
diagnostic power between colonies. The presence of a queen had little influence on nestmate discrimination abilities. Our results suggest that heritable cues of workers are the dominant factor influencing nestmate discrimination in these carpenter ants and highlight the importance of colony kin structure for...... variation in cuticular hydrocarbons, which can include heritable cues from the workers, as well as acquired cues from the environment or queen-derived cues. We tracked the profile of six colonies of the ant Camponotus aethiops for a year under homogeneous laboratory conditions. We performed chemical and...... behavioral analyses. We show that nestmate recognition was not impaired by constant environment, even though cuticular hydrocarbon profiles changed over time and were slightly converging among colonies. Linear hydrocarbons increased over time, especially in queenless colonies, but appeared to have weak...
Deshpande, Sujata A.; Sumana, A; Surbeck, Martin; Gadagkar, Raghavendra
Ropalidia marginata and Ropalidia cyathiformis are two Old World, primitively eusocial, tropical polistine wasps that exhibit perennial, aseasonal, indeterminate nesting cycles. Queens are periodically ousted and replaced by one of the workers, whom we refer to as the potential queen. Here we identify the characters of the potential queens by experimentally removing queens from several colonies of both species. Potential queens in R. marginata are specialized, worker-like individuals, not uni...
The ant genus Cardiocondyla is characterised by the occurrence of �workerlike�, ergatoid males that mate inside the nest. In many species of this genus, �normal�, winged males occur in addition, and a dimorphism of wingless and winged males is exhibited. The two male morphs represent alternative reproductive tactics with aggressive territorial males and peaceful disperser males. The latter mate inside the colony and then leave after several days to establish further matings with alien queens....
Dávila, Francisco; Chérasse, Sarah; Boomsma, Jacobus J; Aron, Serge
The prophenoloxidase system (proPO-AS) is a primordial constituent of insect innate immunity. Its broad action spectrum, rapid response time, and cytotoxic by-products induced by phenoloxidase (PO) production contribute to the effective clearing of invading pathogens. However, such immune reactions may not be optimal for insect organs that evolved to have mutualistic interactions with non-self-cells. Ant queens are long-lived, but only mate early in adult life and store the sperm in a specialized organ, the spermatheca. They never re-mate so their life-time reproductive success is ultimately sperm-limited, which maintains strong selection for high sperm viability before and after storage. The proPO-AS may therefore be inappropriate for the selective clearing of sexually transmitted infections, as it might also target sperm cells that cannot be replaced. We measured PO enzymatic activity in the sperm storage organs of three ant species before and after mating. Our data show that no PO is produced in the sperm storage organs, relative to other somatic tissues as controls, and that these negative results are not due to non-detection in small volumes as non-immune-relevant catalase activity in single spermatheca fluid samples of both virgin and mated queens was significant. The lack of PO activity in sperm storage organs across three different ant species may represent an evolutionarily conserved adaptation to life-long sperm storage by ant queens. We expect that PO activity will be similarly suppressed in queen spermathecae of other eusocial Hymenoptera (bees and wasps) and, more generally, of insect females that store sperm for long periods. PMID:25911976
Berghoff, S M; Kronauer, D J C; Edwards, K J;
The army ant Eciton burchellii is probably the most important arthropod predator in the Neotropics, and many animal species depend upon it. Sex-biased dispersal with winged males and permanently wingless queens may render this species especially sensitive to habitat fragmentation and natural...... barriers, which might have severe impacts on population structure and lead to population decline. Using nuclear microsatellite markers and mitochondrial sequences, we investigated genetic differentiation in a fragmented population in the Panama Canal area. While nuclear markers showed little...
dos Santos, Charles F.; Acosta, André L.; Dorneles, Andressa L.; dos Santos, Patrick D. S.; Blochtein, Betina
Bees are important for the world biodiversity and economy because they provide key pollination services in forests and crops. However, pesticide use in crops has adversely affected (decreased) queen production because of increased mortality among larvae. Here, we demonstrated that in vitro-reared queens of a neotropical social bee species (Plebeia droryana) also showed high larval mortality after exposure to an organophosphate pesticide (chlorpyrifos) via larval food. Moreover, most of the surviving larvae that were destined to develop into queens became workers more likely because they ate less food than expected without pesticide skewing thus caste differentiation in this bee species. This adverse effect has not been previously reported for any other social insects, such as honeybees or bumblebees. Queens are essential for breeding and colony growth. Therefore, if our data are applicable to other pantropical social bee species across the globe, it is likely that these bees are at a serious risk of failure to form new colonies. PMID:27530246
Dos Santos, Charles F; Acosta, André L; Dorneles, Andressa L; Dos Santos, Patrick D S; Blochtein, Betina
Bees are important for the world biodiversity and economy because they provide key pollination services in forests and crops. However, pesticide use in crops has adversely affected (decreased) queen production because of increased mortality among larvae. Here, we demonstrated that in vitro-reared queens of a neotropical social bee species (Plebeia droryana) also showed high larval mortality after exposure to an organophosphate pesticide (chlorpyrifos) via larval food. Moreover, most of the surviving larvae that were destined to develop into queens became workers more likely because they ate less food than expected without pesticide skewing thus caste differentiation in this bee species. This adverse effect has not been previously reported for any other social insects, such as honeybees or bumblebees. Queens are essential for breeding and colony growth. Therefore, if our data are applicable to other pantropical social bee species across the globe, it is likely that these bees are at a serious risk of failure to form new colonies. PMID:27530246
National Oceanic and Atmospheric Administration, Department of Commerce — The queen conch is an important cultural component and an extremely valuable coral reef fishery resource throughout the Caribbean, historically second only to the...
Full Text Available Queen fecundity is a critical issue for the health of honeybee (Apis mellifera L. colonies, as she is the only reproductive female in the colony and responsible for the constant renewal of the worker bee population. Any factor affecting the queen's fecundity will stagnate colony development, increasing its susceptibility to opportunistic pathogens. We discovered a pathology affecting the ovaries, characterized by a yellow discoloration concentrated in the apex of the ovaries resulting from degenerative lesions in the follicles. In extreme cases, marked by intense discoloration, the majority of the ovarioles were affected and these cases were universally associated with egg-laying deficiencies in the queens. Microscopic examination of the degenerated follicles showed extensive paracrystal lattices of 30 nm icosahedral viral particles. A cDNA library from degenerated ovaries contained a high frequency of deformed wing virus (DWV and Varroa destructor virus 1 (VDV-1 sequences, two common and closely related honeybee Iflaviruses. These could also be identified by in situ hybridization in various parts of the ovary. A large-scale survey for 10 distinct honeybee viruses showed that DWV and VDV-1 were by far the most prevalent honeybee viruses in queen populations, with distinctly higher prevalence in mated queens (100% and 67%, respectively for DWV and VDV-1 than in virgin queens (37% and 0%, respectively. Since very high viral titres could be recorded in the ovaries and abdomens of both functional and deficient queens, no significant correlation could be made between viral titre and ovarian degeneration or egg-laying deficiency among the wider population of queens. Although our data suggest that DWV and VDV-1 have a role in extreme cases of ovarian degeneration, infection of the ovaries by these viruses does not necessarily result in ovarian degeneration, even at high titres, and additional factors are likely to be involved in this pathology.
Fougeyrollas, Romain; Dolejšová, Klára; Sillam-Dussès, David; Roy, Virginie; Poteaux, Chantal; Hanus, Robert; Roisin, Yves
Asexual queen succession (AQS), in which workers, soldiers and dispersing reproductives are produced sexually while numerous non-dispersing queens arise through thelytokous parthenogenesis, has recently been described in three species of lower termites of the genus Reticulitermes. Here, we show that AQS is not an oddity restricted to a single genus of lower termites, but a more widespread strategy occurring also in the most advanced termite group, the higher termites (Termitidae). We analysed the genetic structure in 10 colonies of the Neotropical higher termite Embiratermes neotenicus (Syntermitinae) using five newly developed polymorphic microsatellite loci. The colonies contained one primary king accompanied either by a single primary queen or by up to almost 200 neotenic queens. While the workers, the soldiers and most future dispersing reproductives were produced sexually, the non-dispersing neotenic queens originated through thelytokous parthenogenesis of the founding primary queen. Surprisingly, the mode of thelytoky observed in E. neotenicus is most probably automixis with central fusion, contrasting with the automixis with terminal fusion documented in Reticulitermes. The occurrence of AQS based on different mechanisms of ploidy restoration raises the hypothesis of an independent evolutionary origin of this unique reproductive strategy in individual lineages of lower and higher termites. PMID:26019158
Queens from three colonies of feral honey bees, Apis mellifera were removed and placed in separate nucleus colonies. For each colony, eggs and larvae were taken from the nucleus and placed in the main hive on each of 3-4 consecutive weeks. Workers in the queenless parts selected young larvae to rear as queens. Queen pupae, together with the surrounding worker pupae, were removed from each colony and analysed at two to three microsatellite loci to determine their paternity. In all three colonies, the paternity of larvae chosen by the bees to rear as queens was not a random sample of the paternities in the worker brood, with certain subfamilies being over-represented in queens. These results support an important prediction of kin selection theory: when colonies are queenless, unequal relatedness within colonies could lead to the evolution of reproductive competition, that is some subfamilies achieving greater reproductive success than others. The mechanism by which such dominance is achieved could be through a system of kin recognition and nepotism, but we conclude that genetically based differential attractiveness of larvae for rearing as queens is more likely.Copyright 1997 The Association for the Study of Animal BehaviourCopyright 1997The Association for the Study of Animal Behaviour. PMID:9521799
Greenfield, Gary; Machado, Penousal
Ant- and ant-colony-inspired ALife art is characterized by the artistic exploration of the emerging collective behavior of computational agents, developed using ants as a metaphor. We present a chronology that documents the emergence and history of such visual art, contextualize ant- and ant-colony-inspired art within generative art practices, and consider how it relates to other ALife art. We survey many of the algorithms that artists have used in this genre, address some of their aims, and explore the relationships between ant- and ant-colony-inspired art and research on ant and ant colony behavior. PMID:26280070
Full text: The fire ants, Solenopsis invicta and Solenopsis richteri, were inadvertently introduced into the United States in the early 1900s and currently inhabit over 150 million ha in Puerto Rico and twelve southern states from Texas to Virginia. Imported fire ants have also become established in isolated sites in California, Arizona, New Mexico, and Maryland. They have also widened their invasive character by accidental importation and establishment in Australia and Taiwan. Fire ant colonies (single queen) can contain up to 250,000 workers and reach infestation rates of over 130 mounds per hectare. More recently, multiple-queen colonies have proliferated in the southern states with even greater population densities. The fire ant's large numbers, resource requirements, aggressive behavior, and potent sting have resulted in many negative interactions with man and the ecosystem. Many ground inhabiting arthropods and other small animals are destroyed, yields of several agricultural crops are reduced, and ca. 1% of the population is at risk from hypersensitivity to fire ant venom. The population densities in the US are 5-10 times higher than in South America, most likely due to their escape from natural enemies. Chemical Control: Several commercial insecticide baits have been developed for fire ant control; however, they are costly, many are not registered for large acreage, and most have adverse environmental impact when used in environmentally sensitive locations. Biological Control: At least 22 species of parasitic Pseudacteon flies have been found attacking fire ants in South America. These flies have been shown to stop fire ant foraging and shift the local competitive balance to other ant species, thus limiting resources to the fire ant. There are also two Protozoan pathogens, Thelohania solenopsae, and Vairimorpha invictae that naturally infect S. invicta in South America. Both have been shown to cause reductions of field populations, and T. solenopsae
This diploma thesis deals with Ant Colony algorithms and their usage for solving Travelling Salesman Problems and Vehicle Routing Problems. These algorithms are metaheuristics offering new approach to solving NP-hard problems. Work begins with a description of the forementioned tasks including ways to tackle them. Next chapter analyses Ant Colony metaheuristic and its possible usage and variations. The most important part of the thesis is practical and is represented by application Ant Colony...
Full Text Available While observing: non-acceptance, frequent replacements, and reduced performance in honey bee (Apis mellifera ligustica queens, we were induced to analyse a certain number of queens to detect the causes. For this purpose, 99 newly mated queens were bought from 20 Italian queen breeders. In addition, 109 older or at-the-end-of-their-career queens, that showed poor productivity, were collected from honey production hives throughout Italy. All the queens were dissected to check the status of their reproductive system and/or the presence of various anomalies and diseases.
Full Text Available It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects.
Muñoz, Irene; Cepero, Almudena; Pinto, Maria Alice; Martín-Hernández, Raquel; Higes, Mariano; De la Rúa, Pilar
Microsporidiosis caused by Nosema species is one of the factors threatening the health of the honeybee (Apis mellifera), which is an essential element in agriculture mainly due to its pollination function. The dispersion of this pathogen may be influenced by many factors, including various aspects of beekeeping management such as introduction of queens with different origin. Herein we study the relation of the presence and distribution of Nosema spp. and the replacement of queens in honeybee populations settled on the Atlantic Canary Islands. While Nosema apis has not been detected, an increase of the presence and distribution of Nosema ceranae during the last decade has been observed in parallel with a higher frequency of foreign queens. On the other hand, a reduction of the number of N. ceranae positive colonies was observed on those islands with continued replacement of queens. We suggest that such replacement could help maintaining low rates of Nosema infection, but healthy queens native to these islands should be used in order to conserve local honeybee diversity. PMID:24568841
Herman; Queller; Strassmann
Social insect queens reproduce while workers generally do not. Queens may also have other behavioural roles in the colony. In small, independent-founding colonies of social wasps, the dominant queen physically enforces her interests over those of the workers and serves as a pacemaker of the colony, stimulating workers to forage and engage in other tasks. By contrast, in large-colony, swarm-founding wasps, the collective interests of the workers are fulfilled in sex allocation and production of males, whether or not they coincide with the interests of the queens. The behavioural role of the queens in such species has not been extensively studied. We investigated the role of the queens both in regulating worker activity and in reducing the numbers of reproductively active queens in the swarm-founding epiponine wasp Parachartergus colobopterus. We found no evidence that queens regulate worker activity, as they were rarely involved in any interactions. Worker activity may be self-organized, without centralized active control by anyone. Furthermore, we found no evidence that the reduction in queen number characteristic of this tribe of wasps occurs in response to aggression among queens. The reduction in queen number may be a result of worker treatment of queens, although worker discrimination against some queens was not obvious in our data. i Copyright 2000 The Association for the Study of Animal Behaviour. PMID:10792939
The Ant Ballet project aims to create a precisely choreographed movement from a colony of ants through the use of artificial pheromones. This article presents an annotated storyboard of the film that documents the first set of experiments within the project. The full film can be viewed online at href="http://www.antballet.org"www.antballet.org.
Giraud, Olivier; Braun, Daniel
We introduce a measure of ''quantumness'' for any quantum state in a finite dimensional Hilbert space, based on the distance between the state and the convex set of classical states. The latter are defined as states that can be written as a convex sum of projectors onto coherent states. We derive general properties of this measure of non-classicality, and use it to identify for a given dimension of Hilbert space what are the "Queen of Quantum" states, i.e. the most non-classical quantum states. In three dimensions we obtain the Queen of Quantum state analytically and show that it is unique up to rotations. In up to 11-dimensional Hilbert spaces, we find the Queen of Quantum states numerically, and show that in terms of their Majorana representation they are highly symmetric bodies, which for dimensions 5 and 7 correspond to Platonic bodies.
Fürst, Matthias Alois; Durey, Maëlle; Nash, David Richard
Social insect colonies are like fortresses, well protected and rich in shared stored resources. This makes them ideal targets for exploitation by predators, parasites and competitors. Colonies of Myrmica rubra ants are sometimes exploited by the parasitic butterfly Maculinea alcon. Maculinea alcon...... gains access to the ants' nests by mimicking their cuticular hydrocarbon recognition cues, which allows the parasites to blend in with their host ants. Myrmica rubra may be particularly susceptible to exploitation in this fashion as it has large, polydomous colonies with many queens and a very viscous...... population structure. We studied the mutual aggressive behaviour of My. rubra colonies based on predictions for recognition effectiveness. Three hypotheses were tested: first, that aggression increases with distance (geographical, genetic and chemical); second, that the more queens present in a colony and...
Full Text Available In this three-year-trial study, we examined the quality of mated queens based on morphological and physiology traits. At each location, sister queen bees were reared each year from one Apis mellifera carnica breeder queen. Queens were also reared and mated in different locations. Altogether, we sampled and analysed 324 queens from 27 apiaries in 2006, 288 queens from 24 apiaries in 2008, and 276 queens from 23 apiaries in 2010. Nine queens from each apiary were sampled and dissected for morphological analyses and Nosema ceranae (N. ceranae spores, if present, were quantified. Three queens from each apiary were prepared and tested for four viruses: acute bee paralysis virus (ABPV, black queen cell virus (BQCV, deformed wing virus (DWV, and sacbrood virus (SBV. The highest average queen weight of 209.49 ± 9.82 mg was detected in 2008. The highest average ovary weight of 78.67 ± 11.86 mg was detected in 2010, and the highest number of ovarioles was 161.59 ± 8.70 in 2006. The average number of spermatozoa in queens ranged from 3.30 x 106 in 2006 to 5.23 x 106 in 2010. Nosema ceranae spores were found in queens sampled in 2008 and 2010. Viruses were discovered sporadically during the queen testing periods from 2006 - 2010. This study importantly demonstrates that queens from rearing stations require regular evaluation for morphological and physiological changes as well as for infection from harmful pathogens. These results could also be used in establishing relevant commercial standards for rearing quality queens.
Tay, J W; Lee, C Y
To evaluate the effects of the juvenile hormone analogue pyriproxyfen on colonies of the Pharaoh ant Monomorium pharaonis (L.), peanut oil containing different concentrations (0.3, 0.6, or 0.9%) of pyriproxyfen was fed to monogynous (1 queen, 500 workers, and 0.1 g of brood) and polygynous (8 queens, 50 workers, and 0.1 g of brood) laboratory colonies of M. pharaonis. Due to its delayed activity, pyriproxyfen at all concentrations resulted in colony elimination. Significant reductions in brood volume were recorded at weeks 3 - 6, and complete brood mortality was observed at week 8 in all treated colonies. Brood mortality was attributed to the disruption of brood development and cessation of egg production by queens. All polygynous colonies exhibited significant reduction in the number of queens present at week 10 compared to week 1. Number of workers was significantly lower in all treated colonies compared to control colonies at week 8 due to old-age attrition of the workers without replacement. At least 98.67 ± 1.33% of workers were dead at week 10 in all treated colonies. Thus, treatment with slow acting pyriproxyfen at concentrations of 0.3 - 0.9% is an effective strategy for eliminating Pharaoh ant colonies. PMID:26695205
Derks, B.; Laar, C. van; Ellemers, N.; Groot, K. de
Queen bees are senior women in male-dominated organizations who have achieved success by emphasizing how they differ from other women. Although the behavior of queen bees tends to be seen as contributing to gender disparities in career outcomes, we argue that queen-bee behavior is actually a result
The effects of sublethal pesticide exposure on queen emergence and virus titers were examined. Queen rearing colonies were fed pollen with chlorpyrifos (CPF) alone (pollen-1) and with CPF and the fungicide Pristine® (pollen-2). Fewer queens emerged when larvae from open foraging (i.e., outside) colo...
Amiri, Esmaeil; Meixner, Marina D; Kryger, Per
Deformed wing virus is an important contributor to honey bee colony losses. Frequently queen failure is reported as a cause for colony loss. Here we examine whether sexual transmission during multiple matings of queens is a possible way of virus infection in queens. In an environment with high prevalence of deformed wing virus, queens (n = 30) were trapped upon their return from natural mating flights. The last drone's endophallus (n = 29), if present, was removed from the mated queens for deformed wing virus quantification, leading to the detection of high-level infection in 3 endophalli. After oviposition, viral quantification revealed that seven of the 30 queens had high-level deformed wing virus infections, in all tissues, including the semen stored in the spermathecae. Two groups of either unmated queens (n = 8) with induced egg laying, or queens (n = 12) mated in isolation with drones showing comparatively low deformed wing virus infections served as control. None of the control queens exhibited high-level viral infections. Our results demonstrate that deformed wing virus infected drones are competitive to mate and able to transmit the virus along with semen, which occasionally leads to queen infections. Virus transmission to queens during mating may be common and can contribute noticeably to queen failure. PMID:27608961
Full Text Available Abstract Background Mutual policing is an important mechanism for reducing conflict in cooperative groups. In societies of ants, bees, and wasps, mutual policing of worker reproduction can evolve when workers are more closely related to the queen's sons than to the sons of workers or when the costs of worker reproduction lower the inclusive fitness of workers. During colony growth, relatedness within the colony remains the same, but the costs of worker reproduction may change. The costs of worker reproduction are predicted to be greatest in incipient colonies. If the costs associated with worker reproduction outweigh the individual direct benefits to workers, policing mechanisms as found in larger colonies may be absent in incipient colonies. Results We investigated policing behaviour across colony growth in the ant Camponotus floridanus. In large colonies of this species, worker reproduction is policed by the destruction of worker-laid eggs. We found workers from incipient colonies do not exhibit policing behaviour, and instead tolerate all conspecific eggs. The change in policing behaviour is consistent with changes in egg surface hydrocarbons, which provide the informational basis for policing; eggs laid by queens from incipient colonies lack the characteristic hydrocarbons on the surface of eggs laid by queens from large colonies, making them chemically indistinguishable from worker-laid eggs. We also tested the response to fertility information in the context of queen tolerance. Workers from incipient colonies attacked foreign queens from large colonies; whereas workers from large colonies tolerated such queens. Workers from both incipient and large colonies attacked foreign queens from incipient colonies. Conclusions Our results provide novel insights into the regulation of worker reproduction in social insects at both the proximate and ultimate levels. At the proximate level, our results show that mechanisms of social regulation, such as
Sagban, Rafid; Ku-Mahamud, Ku Ruhana; Abu Bakar, Muhamad Shahbani
A statistical machine learning indicator, ACOustic, is proposed to evaluate the exploration behavior in the iterations of ant colony optimization algorithms. This idea is inspired by the behavior of some parasites in their mimicry to the queens' acoustics of their ant hosts. The parasites' reaction results from their ability to indicate the state of penetration. The proposed indicator solves the problem of robustness that results from the difference of magnitudes in the distance's matrix, especially when combinatorial optimization problems with rugged fitness landscape are applied. The performance of the proposed indicator is evaluated against the existing indicators in six variants of ant colony optimization algorithms. Instances for travelling salesman problem and quadratic assignment problem are used in the experimental evaluation. The analytical results showed that the proposed indicator is more informative and more robust. PMID:25954768
Nishide, Yudai; Satoh, Toshiyuki; Hiraoka, Tuyosi; Obara, Yoshiaki; Iwabuchi, Kikuo
The queenless ant Pristomyrmex punctatus (Hymenoptera: Myrmicinae) has a unique society that differs from those of other typical ants. This species does not have a queen, and the workers lay eggs and produce their clones parthenogenetically. However, a colony of these ants does not always comprise members derived from a single clonal line. In this study, we examined whether P. punctatus changes its “assembling behavior” based on colony genetic structure. We prepared two subcolonies—a larger one comprising 200 individuals and a smaller one comprising 100 individuals; these subcolonies were established from a single stock colony. We investigated whether these subcolonies assemble into a single nest. The genetically monomorphic subcolonies (single clonal line) always fused into a single nest; however, the genetically polymorphic subcolonies (multiple clonal lines) did not tend to form a single colony. The present study is the first to demonstrate that the colony genetic structure significantly affects social viscosity in social insects.
Full Text Available Abstract Background Animal societies are diverse, ranging from small family-based groups to extraordinarily large social networks in which many unrelated individuals interact. At the extreme of this continuum, some ant species form unicolonial populations in which workers and queens can move among multiple interconnected nests without eliciting aggression. Although unicoloniality has been mostly studied in invasive ants, it also occurs in some native non-invasive species. Unicoloniality is commonly associated with very high queen number, which may result in levels of relatedness among nestmates being so low as to raise the question of the maintenance of altruism by kin selection in such systems. However, the actual relatedness among cooperating individuals critically depends on effective dispersal and the ensuing pattern of genetic structuring. In order to better understand the evolution of unicoloniality in native non-invasive ants, we investigated the fine-scale population genetic structure and gene flow in three unicolonial populations of the wood ant F. paralugubris. Results The analysis of geo-referenced microsatellite genotypes and mitochondrial haplotypes revealed the presence of cryptic clusters of genetically-differentiated nests in the three populations of F. paralugubris. Because of this spatial genetic heterogeneity, members of the same clusters were moderately but significantly related. The comparison of nuclear (microsatellite and mitochondrial differentiation indicated that effective gene flow was male-biased in all populations. Conclusion The three unicolonial populations exhibited male-biased and mostly local gene flow. The high number of queens per nest, exchanges among neighbouring nests and restricted long-distance gene flow resulted in large clusters of genetically similar nests. The positive relatedness among clustermates suggests that kin selection may still contribute to the maintenance of altruism in unicolonial
Oettler, Jan; Dijkstra, Michiel B; Heinze, Jürgen
We study male parentage and between-colony variation in sex allocation and sexual production in the desert ant Crematogaster smithi, which usually has only one singly-mated queen per nest. Colonies of this species are known to temporarily store nutrients in the large fat body of intermorphs, a specialized female caste intermediate in morphology between queens and workers. Intermorphs repackage at least part of this fat into consumable but viable male-destined eggs. If these eggs sometimes develop instead of being eaten, intermorphs will be reproductive competitors of the queen but--due to relatedness asymmetries--allies of their sister worker. Using genetic markers we found a considerable proportion of non-queen sons in some, but not all, colonies. Even though intermorphs produce ∼1.7× more eggs than workers, their share in the parentage of adult males is estimated to be negligible due to their small number compared to workers. Furthermore, neither colony-level sex allocation nor overall sexual production was correlated with intermorph occurrence or number. We conclude that intermorph-laid eggs typically do not survive and that the storage of nutrients and their redistribution as eggs by intermorphs is effectively altruistic. PMID:24130699
Clémencet, Johanna; Rome, Quentin; Fédérici, Pierre; Doums, Claudie
In social hymenoptera, the reproductive division of labor is often linked to differences in individual body size with the reproductive caste (the queen) being larger than the workers. Likewise, the reproductive potential may vary with size within the worker caste and could affect the evolution of worker size in social insects. Here, we tested the relationship between worker size and reproductive potential in the facultative parthenogenetic ant Cataglyphis cursor. Colonies are headed by a multiply mated queen, but workers can produce gynes (virgin queens) and workers by thelytokous parthenogenesis after the queen’s death. We observed the behaviour of workers ( n = 357) until the production of gynes (212 h over 3 months) in an orphaned colony (mated queen not present). The size of workers was measured, and their paternal lineage determined using six microsatellite markers, to control for an effect of patriline. Larger workers were more likely to reproduce and lay more eggs indicating that individual level selection could take place. However, paternal lineage had no effect on the reproductive potential and worker size. From the behavioural and genetic data, we also show for the first time in this species, evidence of aggressive interactions among workers and a potential for nepotism to occur in orphaned colonies, as the five gynes produced belonged to a single paternal lineage.
Sirviö, A.; Gadau, J.; Rueppell, O.;
demonstrated that variation in division of labour and pathogen resistance has a genetic component and that genotypic diversity among workers may thus give colonies of this leaf-cutting ant a functional advantage. The present result is therefore consistent with the hypothesis that complex social life can select...... tested in other social insects. Here, we present a linkage map and an estimate of the recombination rate for Acromyrmex echinatior, a leaf-cutting ant that resembles the honeybee in having multiple mating of queens and colonies of approximately the same size. A map of 145 AFLP markers in 22 linkage...
Purcell, Jessica; Chapuisat, M
Animal societies vary in the number of breeders per group, which affects many socially and ecologically relevant traits. In several social insect species, including our study species Formica selysi, the presence of either one or multiple reproducing females per colony is generally associated with differences in a suite of traits such as the body size of individuals. However, the proximate mechanisms and ontogenetic processes generating such differences between social structures are poorly known. Here, we cross-fostered eggs originating from single-queen (= monogynous) or multiple-queen (= polygynous) colonies into experimental groups of workers from each social structure to investigate whether differences in offspring survival, development time and body size are shaped by the genotype and/or prefoster maternal effects present in the eggs, or by the social origin of the rearing workers. Eggs produced by polygynous queens were more likely to survive to adulthood than eggs from monogynous queens, regardless of the social origin of the rearing workers. However, brood from monogynous queens grew faster than brood from polygynous queens. The social origin of the rearing workers influenced the probability of brood survival, with workers from monogynous colonies rearing more brood to adulthood than workers from polygynous colonies. The social origin of eggs or rearing workers had no significant effect on the head size of the resulting workers in our standardized laboratory conditions. Overall, the social backgrounds of the parents and of the rearing workers appear to shape distinct survival and developmental traits of ant brood. PMID:22998635
Büchler, Ralph; Andonov, Sreten; Bienefeld, Kaspar;
Here we cover a wide range of methods currently in use and recommended in modern queen rearing, selection and breeding. The recommendations are meant to equally serve as standards for both scientific and practical beekeeping purposes. The basic conditions and different management techniques for q...
Researchers at Harbor Branch Oceanographic Institute at Florida Atlantic University found juvenile queen conch fed diets containing added macroalgae had higher survival than a control given catfish feed only, but saw no significant difference in overall growth rates among the treatments. In a secon...
Hannah, Susan; Dworkowitz, Barbara
An evaluation was done of the Queens Tri-School Confederation, three high schools in the New York City Public Schools funded by a federal grant from the Magnet Schools Assistance Program. The grant provided Hillcrest, Jamaica, and Thomas A. Edison High Schools with funds to develop or expand emergency technician programs at Hillcrest; a law…
Bos, Nicky Peter Maria; Lefevre, T.; Jensen, A.B.;
Parasites represent a severe threat to social insects, which form high-density colonies of related individuals, and selection should favour host traits that reduce infection risk. Here, using a carpenter ant (Camponotus aethiops) and a generalist insect pathogenic fungus (Metarhizium brunneum), we...... show that infected ants radically change their behaviour over time to reduce the risk of colony infection. Infected individuals (i) performed less social interactions than their uninfected counterparts, (ii) did not interact with brood anymore and (iii) spent most of their time outside the nest from...... day 3 post-infection until death. Furthermore, infected ants displayed an increased aggressiveness towards non-nestmates. Finally, infected ants did not alter their cuticular chemical profile, suggesting that infected individuals do not signal their physiological status to nestmates. Our results...
A better understanding of Cocktail ant populations (Crematogaster) is engendered by the use of 32P labelling to measure the population density of the colonies, once the biology of the species is known
Fourcassié, Vincent; Dussutour, Audrey; Deneubourg, Jean-Louis
Many animals take part in flow-like collective movements. In most species, however, the flow is unidirectional. Ants are one of the rare group of organisms in which flow-like movements are predominantly bidirectional. This adds to the difficulty of the task of maintaining a smooth, efficient movement. Yet, ants seem to fare well at this task. Do they really? And if so, how do such simple organisms succeed in maintaining a smooth traffic flow, when even humans experience trouble with this task? How does traffic in ants compare with that in human pedestrians or vehicles? The experimental study of ant traffic is only a few years old but it has already provided interesting insights into traffic organization and regulation in animals, showing in particular that an ant colony as a whole can be considered as a typical self-organized adaptive system. In this review we will show that the study of ant traffic can not only uncover basic principles of behavioral ecology and evolution in social insects but also provide new insights into the study of traffic systems in general. PMID:20581264
Nogueira-Ferreira, F H; Silva-Matos, E V; Zucchi, R
We studied the behavior of virgin queens of the stingless bee species Schwarziana quadripunctata, Paratrigona lineata and Tetragona clavipes, investigating internal nest activities, including the cell provisioning and oviposition process. We made direct observation of queen behavior, with the aid of video filming. Forty-four virgin queens of S. quadripunctata were observed; one was larger and more attractive than the others. Miniature queens were more abundant than normal-size queens; both were found in prison chambers. Agonistic behavior between virgin and physogastric queens of P. lineata was observed during attempts at queen supersedure. After the disappearance of the physogastric queen and the appearance of a virgin queen in T. clavipes nests, the brood cells were sealed with pollen alone, but no egg. In all three species, the presence of one or more virgin queens appeared to make the colonies nervous, even though constant production of virgin queens is vital to the survival of the colony and is part of the colony cycle in these bees. PMID:19554769
Alaux, Cédric; Savarit, Fabrice; Jaisson, Pierre; Hefetz, Abraham
Social insects provide a useful model for studying the evolutionary balance between cooperation and conflict linked to genetic structure. We investigated the outcome of this conflict in the bumblebee, Bombus terrestris, whose annual colony life cycle is characterized by overt competition over male production. We established artificial colonies composed of a queen and unrelated workers by daily exchange of callow workers between colony pairs of distinct genetic make-up. Using microsatellite analysis, this procedure allowed an exact calculation of the proportion of worker-derived males. The development and social behavior of these artificial colonies were similar to those of normal colonies. Despite a high worker reproduction attempt (63.8% of workers had developed ovaries and 38.4% were egg-layers), we found that on average 95% of the males produced during the competition phase (CPh) were queen-derived. However, in four colonies, queen death resulted in a considerable amount of worker-derived male production. The different putative ultimate causes of this efficient control by the queen are discussed, and we suggest a possible scenario of an evolutionary arms race that may occur between these two female castes.
Feldhaar, Heike; Fiala, Brigitte; Gadau, Jürgen; Mohamed, Maryati; Maschwitz, Ulrich
To elucidate the evolution of one of the most species-rich ant-plant symbiotic systems, the association between Crematogaster (Myrmicinae) and Macaranga (Euphorbiaceae) in South-East Asia, we conducted a phylogenetic analysis of the ant partners. For the phylogenetic analysis partial mitochondrial cytochrome oxidase I and II were sequenced and Maximum Parsimony analysis was performed. The analyzed Crematogaster of the subgenus Decacrema fell into three distinct clades which are also characterized by specific morphological and ecological traits (queen morphology, host-plants, and colony structure). Our results supported the validity of our currently used morphospecies concept for Peninsula Malaysia. However, on a wider geographic range (including North and North-East Borneo) some morphospecies turned out to be species complexes with genetically quite distinct taxa. Our phylogenetic analysis and host association studies do not indicate strict cocladogenesis between the subgenus Decacrema and their Macaranga host-plants because multiple ant taxa occur on quite distinct host-plants belonging to different clades within in the genus Macaranga. These results support the view that host-shifting or host-expansion is common in the ants colonizing Macaranga. Additionally, the considerable geographic substructuring found in the phylogenetic trees of the ants suggests that allopatric speciation has also played a role in the diversification and the current distribution of the Decacrema ants. PMID:12742749
Dijkstra, Michiel Bendert; Boomsma, Jacobus Jan
ovaries. Workers of Atta leafcutter ants only lay trophic eggs in queenright colonies. Although Atta colonies are commonly kept at universities, museums, and zoos, no reports of worker sons in orphaned colonies exist, suggesting that Atta workers are infertile. To explicitly test this, we created eleven...... orphaned laboratory nests of Atta cephalotes, A. sexdens, and A. colombica, and maintained them for 3-6 months after queen loss. Eight colonies did not produce any brood, but three nests produced 1-4 worker-derived male larvae and pupae. Microsatellite genotyping indicated that these were worker sons...... fertility is low compared to the sister genus Acromyrmex, where workers routinely produce normally-size males after queen loss in the laboratory. We hypothesize that worker reproduction in orphaned Atta field colonies is almost never successful because the last workers die before their sons can be raised to...
Full Text Available Social organisms can surmount many ecological challenges by working collectively. An impressive example of such collective behavior occurs when ants physically link together into floating 'rafts' to escape from flooded habitat. However, raft formation may represent a social dilemma, with some positions posing greater individual risks than others. Here, we investigate the position and function of different colony members, and the costs and benefits of this functional geometry in rafts of the floodplain-dwelling ant Formica selysi. By causing groups of ants to raft in the laboratory, we observe that workers are distributed throughout the raft, queens are always in the center, and 100% of brood items are placed on the base. Through a series of experiments, we show that workers and brood are extremely resistant to submersion. Both workers and brood exhibit high survival rates after they have rafted, suggesting that occupying the base of the raft is not as costly as expected. The placement of all brood on the base of one cohesive raft confers several benefits: it preserves colony integrity, takes advantage of brood buoyancy, and increases the proportion of workers that immediately recover after rafting.
Itterbeeck, Van J.; Sivongxay, N.; Praxaysombath, B.; Huis, van A.
The Asian weaver ant Oecophylla smaragdina is of importance to Southeast Asian livelihoods as a source of human food and animal feed and as biological control agent in tree crops including mango and citrus. The introduction of weaver ants in plantations requires the inclusion of the reproductive que
Ho, Eddie K H; Frederickson, Megan E
Pathogens are predicted to pose a particular threat to eusocial insects because infections can spread rapidly in colonies with high densities of closely related individuals. In ants, there are two major castes: workers and reproductives. Sterile workers receive no direct benefit from investing in immunity, but can gain indirect fitness benefits if their immunity aids the survival of their fertile siblings. Virgin reproductives (alates), on the other hand, may be able to increase their investment in reproduction, rather than in immunity, because of the protection they receive from workers. Thus, we expect colonies to have highly immune workers, but relatively more susceptible alates. We examined the survival of workers, gynes, and males of nine ant species collected in Peru and Canada when exposed to the entomopathogenic fungus Beauveria bassiana. For the seven species in which treatment with B. bassiana increased ant mortality relative to controls, we found workers were significantly less susceptible compared with both alate sexes. Female and male alates did not differ significantly in their immunocompetence. Our results suggest that, as with other nonreproductive tasks in ant colonies like foraging and nest maintenance, workers have primary responsibility for colony immunity, allowing alates to specialize on reproduction. We highlight the importance of colony-level selection on individual immunity in ants and other eusocial organisms. PMID:25540683
Batubara, Irmanida; Wahyuni, Wulan Tri; Firdaus, Imam
Anting-anting (Acalypha indica) plants is a species of plant having catkin type of inflorescence. This research aims to utilize anting-anting as antibacterial toward Streptococcus mutans and degradation of biofilm on teeth. Anting-anting leaves were extracted by maceration technique using methanol, chloroform, and n-hexane. Antibacterial and biofilm degradation assays were performed using microdilution technique with 96 well. n-Hexane extracts of anting-anting leaves gave the best antibacterial potency with minimum inhibitory concentration and minimum bactericidal concentration value of 500 μg/mL and exhibited good biofilm degradation activity. Fraction of F3 obtained from fractionation of n-hexane's extract with column chromatography was a potential for degradation of biofilm with IC50 value of 56.82 μg/mL. Alkaloid was suggested as antibacterial and degradation of biofilm in the active fraction.
Lim, S P; Lee, C Y
Two juvenile hormone analogs (JHAs), pyriproxyfen and S-methoprene, were impregnated into dried tuna fish and fed to colonies of Monomorium pharaonis (L.) at very low concentrations (1.0, 2.0, 3.0, 4.0, and 5.0 microg/ml). Its effects on the production of sexuals and colonial growth were observed. Colonies treated with pyriproxyfen yielded sexuals with physical abnormalities. Both female and male sexuals developed bulbous wings, decreased melanization, and died shortly after emergence. Sexuals emerged from colonies treated with S-methoprene did not possess anomalous characteristics. Both pyriproxyfen and S-methoprene did not have significant effects on colonial growth because of the low concentrations of the baits. A commercial bait containing 0.3% S-methoprene (Bioprene-BM) also was evaluated for its efficacy on Pharaoh's ant colonies. Results showed that Pharaoh's ant colonies succumbed to the lethal effects of S-methoprene. Colony members were reduced significantly. Production of queens also decreased significantly in treated colonies and treated queens were unable to lay eggs. JHAs are slow acting and eliminate ant colonies at a relatively slow rate. At low concentrations, pyriproxyfen recorded baffling results, i.e., bulbous wings and demelanized exoskeleton, and it is vital that further studies are initiated to solidify these findings. PMID:16539147
Full Text Available The effects of sublethal pesticide exposure on queen emergence and virus titers were examined. Queen rearing colonies were fed pollen with chlorpyrifos (CPF alone (pollen-1 and with CPF and the fungicide Pristine® (pollen-2. Fewer queens emerged when larvae from open foraging (i.e., outside colonies were reared in colonies fed pollen-1 or 2 compared with when those larvae were reared in outside colonies. Larvae grafted from and reared in colonies fed pollen-2 had lower rates of queen emergence than pollen-1 or outside colonies. Deformed wing virus (DWV and black queen cell virus were found in nurse bees from colonies fed pollen-1 or 2 and in outside colonies. The viruses also were detected in queen larvae. However, we did not detect virus in emerged queens grafted from and reared in outside colonies. In contrast, DWV was found in all emerged queens grafted from colonies fed pollen-1 or 2 either reared in outside hives or those fed pollen-1 or 2. The results suggest that sublethal exposure of CPF alone but especially when Pristine® is added reduces queen emergence possibly due to compromised immunity in developing queens.
Invasive ants are a worldwide problem that is expanding both geographically and in intensity. Population explosions of invasive ants can overrun landscapes and inundate structures. Pest management professionals are often the first responders to complaints about invading ants. This session will fo...
Johnson, Neil; Botner, Joel; Fontaine, Kyle; Laxague, Nathan; Nuetzel, Philip; Turnley, Jessica; Tivnan, Brian
The Red Queen's notion "It takes all the running you can do, to keep in the same place" has been applied within evolutionary biology, politics and economics. We find that a generalized version in which an adaptive Red Queen (e.g. insurgency) sporadically edges ahead of a Blue King (e.g. military), explains the progress curves for fatal insurgent attacks against the coalition military within individual provinces in Afghanistan and Iraq. Remarkably regular mathematical relations emerge which suggest a prediction formula for the timing of the n'th future fatal day, and provide a common framework for understanding how insurgents fight in different regions. Our findings are consistent with a Darwinian selection hypothesis which favors a weak species which can adapt rapidly, and establish an unexpected conceptual connection to the physics of quasi-random walks.
Hughes, William O H; Boomsma, Jacobus J
Social groups are vulnerable to cheating because the reproductive interests of group members are rarely identical. All cooperative systems are therefore predicted to involve a mix of cooperative and cheating genotypes, with the frequency of the latter being constrained by the suppressive abilities...... by becoming queens whereas their nestmates will generally maximize fitness by forcing larvae to become workers. However, evolutionary constraints are thought to prevent cheating by removing genetic variation in caste propensity. Here, we show that one-fifth of leaf-cutting ant patrilines cheat their...... theory predicts, these "royal" genotypes are rare both in the population and within individual colonies. The rarity of royal cheats is best explained as an evolutionary strategy to avoid suppression by cooperative genotypes, the efficiency of which is frequency-dependent. The results demonstrate that...
Clarke, D. K.; Duarte, E A; Elena, S F; Moya, A.; Domingo, E; Holland, J
Two clonal populations of vesicular stomatitis virus of approximately equal relative fitness were mixed together and allowed to compete during many transfers in vitro as large virus populations. Eventually, one or the other population suddenly excluded its competitor population, yet both the winners and losers exhibited absolute gains in fitness. Our results agree with the predictions of two major theories of classical population biology; the Competitive Exclusion Principle and the Red Queen'...
Musters, J; de Gier, J; Kooistra, H S; Okkens, A C
The lack of scientific data concerning whether parturition in the queen proceeds normally or not may prevent veterinarians and cat owners from recognizing parturition problems in time. A questionnaire-based study of parturition in 197 queens was performed to determine several parameters of parturition and their influence on its progress. The mean length of gestation was 65.3 days (range 57 to 72 days) and it decreased with increasing litter size (P = 0.02). The median litter size was 4.5 kittens (range 1 to 9), with more males (53%) than females (46%) (P = 0.05). Sixty-nine percent of the kittens were born in anterior presentation and 31% in posterior presentation, indicating that either can be considered normal in the cat. Males were born in posterior position (34%) more often than females (26%) (P = 0.03). The mean birth weight was 98 g (range of 35 to 167 g) and decreased with increasing litter size (P < 0.01). Mean birth weight was higher in males and kittens born in posterior presentation (P < 0.01). Forty-four (5%) of the 887 kittens were stillborn. This was not correlated with the presentation at expulsion but stillborn kittens were more often female (P = 0.02) and weighed less than those born alive (P = 0.04). The median interkitten time was 30 min (range 2 to 343 min) and 95% were born within 100 min after expulsion of the preceding kitten. The interkitten time as a measure of the progress of parturition was not influenced by the kitten's gender, presentation at expulsion, birth weight, or stillbirth, or by the parity of the queen. The results of this study can be used to develop reference values for parturition parameters in the queen, both to determine whether a given parturition is abnormal and as the basis for a parturition protocol. PMID:21295830
Full Text Available Protective ant-plant mutualisms that are exploited by non-defending parasitic ants represent prominent model systems for ecology and evolutionary biology. The mutualist Pseudomyrmex ferrugineus is an obligate plant-ant and fully depends on acacias for nesting space and food. The parasite Pseudomyrmex gracilis facultatively nests on acacias and uses host-derived food rewards but also external food sources. Integrative analyses of genetic microsatellite data, cuticular hydrocarbons and behavioral assays showed that an individual acacia might be inhabited by the workers of several P. gracilis queens, whereas one P. ferrugineus colony monopolizes one or more host trees. Despite these differences in social organization, neither of the species exhibited aggressive behavior among conspecific workers sharing a tree regardless of their relatedness. This lack of aggression corresponds to the high similarity of cuticular hydrocarbon profiles among ants living on the same tree. Host sharing by unrelated colonies, or the presence of several queens in a single colony are discussed as strategies by which parasite colonies could achieve the observed social organization. We argue that in ecological terms, the non-aggressive behavior of non-sibling P. gracilis workers--regardless of the route to achieve this social structure--enables this species to efficiently occupy and exploit a host plant. By contrast, single large and long-lived colonies of the mutualist P. ferrugineus monopolize individual host plants and defend them aggressively against invaders from other trees. Our findings highlight the necessity for using several methods in combination to fully understand how differing life history strategies affect social organization in ants.
Full Text Available The general prevalence of sexual reproduction over asexual reproduction among organisms testifies to the evolutionary benefits of recombination, such as accelerated adaptation to changing environments and elimination of deleterious mutations. Documented instances of asexual reproduction in groups otherwise dominated by sexual reproduction challenge evolutionary biologists to understand the special circumstances that might confer an advantage to asexual reproductive strategies. Here we report one such instance of asexual reproduction in the ants. We present evidence for obligate thelytoky in the asexual fungus-gardening ant, Mycocepurus smithii, in which queens produce female offspring from unfertilized eggs, workers are sterile, and males appear to be completely absent. Obligate thelytoky is implicated by reproductive physiology of queens, lack of males, absence of mating behavior, and natural history observations. An obligate thelytoky hypothesis is further supported by the absence of evidence indicating sexual reproduction or genetic recombination across the species' extensive distribution range (Mexico-Argentina. Potential conflicting evidence for sexual reproduction in this species derives from three Mycocepurus males reported in the literature, previously regarded as possible males of M. smithii. However, we show here that these specimens represent males of the congeneric species M. obsoletus, and not males of M. smithii. Mycocepurus smithii is unique among ants and among eusocial Hymenoptera, in that males seem to be completely absent and only queens (and not workers produce diploid offspring via thelytoky. Because colonies consisting only of females can be propagated consecutively in the laboratory, M. smithii could be an adequate study organism a to test hypotheses of the population-genetic advantages and disadvantages of asexual reproduction in a social organism and b inform kin conflict theory.For a Portuguese translation of the
Van Ast, J.M.
The very basis of this thesis is the collective behavior of ants in colonies. Ants are an excellent example of how rather simple behavior on a local level can lead to complex behavior on a global level that is beneficial for the individuals. The key in the self-organization of ants is communication
Blaimer, Bonnie B; Fisher, Brian L
We investigated the species-level taxonomy of the Malagasy Crematogaster (Crematogaster) kelleri-group and an additional more distantly related species of the same subgenus. Morphological data from worker, queen and male ants, as well as genetic data from three nuclear genes (long wavelength rhodopsin, arginine kinase and carbomoylphosphate synthase) and one mitochondrial marker (cytochrome oxidase I) led to the recognition of six species. Within the C. kelleri-group, three new species are described: C. hazolava Blaimer sp. n., C. hafahafa Blaimer sp. n. and C. tavaratra Blaimer sp. n. The previously described taxa C. kelleri Forel and C. madagascariensis André are validated by our analysis. Conversely, our data suggests synonymy of C. adrepens Forel (with C. kelleri) and C. gibba Emery (with C. madagascariensis). A more distantly related and phylogenetically isolated species, C. tsisitsilo Blaimer sp. n., is further described. We report high levels of morphological and molecular variation in C. kelleri and illustrate that this variation can be explained partly by geography. Species descriptions, images, distribution maps and identification keys based on worker ants, as well as on queen and male ants where available, are presented for all six species. Our work highlights the elevated species richness of Crematogaster ants throughout Madagascar's humid forests, especially in the far northern tip of the island, and the need to use multiple data sources to ensure clear demarcation of this diversity. PMID:23874503
Harano, Ken-Ichi; Sasaki, Ken; Nagao, Takashi
To explore neuro-endocrinal changes in the brain of European honeybee (Apis mellifera) queens before and after mating, we measured the amount of several biogenic amines, including dopamine and its metabolite in the brain of 6- and 12-day-old virgins and 12-day-old mated queens. Twelve-day-old mated queens showed significantly lower amounts of dopamine and its metabolite (N-acetyldopamine) than both 6- and 12-day-old virgin queens, whereas significant differences in the amounts of these amines were not detected between 6- and 12-day-old virgin queens. These results are explained by down-regulation of both synthesis and secretion of brain dopamine after mating. It is speculated that higher amounts of brain dopamine in virgin queens might be involved in activation of ovarian follicles arrested in previtellogenic stages, as well as regulation of their characteristic behaviors.
for Tidsskrift for Arbejdsliv at stille skarpt på, hvorledes teknologi kan forstås og udforskes, og her står nyere teoridannelser som STS (Science- and Technology Studies) og ANT (Actor-Network Theory) centralt. Dette temanummer af tidsskriftet har derfor disse teorier og deres anvendelse i studier af...
Peering through a thematic science lens--elementary students embarked on a one-week study of ants during a month-long summer school program. This integrated unit addressed reading and writing skills while developing the science-process skills of observation, inferring, and communicating in a motivating and authentic way. Pre- and post-assessments…
De Souza, Daiana A.; Ying Wang; Osman Kaftanoglu; David De Jong; Amdam, Gro V.; Lionel S. Gonçalves; Francoy, Tiago M.
In vitro rearing is an important and useful tool for honey bee (Apis mellifera L.) studies. However, it often results in intercastes between queens and workers, which are normally are not seen in hive-reared bees, except when larvae older than three days are grafted for queen rearing. Morphological classification (queen versus worker or intercastes) of bees produced by this method can be subjective and generally depends on size differences. Here, we propose an alternative method for caste cla...
Sumana, A; Gadagkar, Raghavendra
Ropalidia marginata is a primitively eusocial polistine wasp widely distributed in peninsular India. As in most other primitively eusocial insects studied so far, colonies are headed by a single queen who monopolizes reproduction while the remaining female wasps in the colony function as sterile workers. Unlike in other species however, R. marginata queens are strikingly docile individuals who show little or no physical dominance. When such a behaviourally docile queen is removed from a colon...
Full Text Available About 10,000 arthropod species live as ants' social parasites and have evolved a number of mechanisms allowing them to penetrate and survive inside the ant nests. Myrmica colonies, in particular, are exploited by numerous social parasites, and the presence of their overwintering brood, as well as of their polygyny, contributes to make them more vulnerable to infestation. Butterflies of the genus Maculinea are among the most investigated Myrmica inquilines. These lycaenids are known for their very complex biological cycles. Maculinea species are obligated parasites that depend on a particular food plant and on a specific Myrmica species for their survival. Maculinea larvae are adopted by Myrmica ants, which are induced to take them into their nests by chemical mimicry. Then the parasite spends the following 11–23 months inside the ants' nest. Mimicking the acoustic emission of the queen ants, Maculinea parasites not only manage to become integrated, but attain highest rank within the colony. Here we review the biology of Maculinea/Myrmica system with a special focus on some recent breakthrough concerning their acoustical patterns.
... Early Renaissance France'' SUMMARY: Notice is hereby given of the following determinations: Pursuant to... the exhibition ``Kings, Queens, and Courtiers: Art in Early Renaissance France'' imported from...
Kevin W Wanner; Nichols, Andrew S.; Walden, Kimberly K. O.; Brockmann, Axel; Luetje, Charles W.; Robertson, Hugh M
By using a functional genomics approach, we have identified a honey bee [Apis mellifera (Am)] odorant receptor (Or) for the queen substance 9-oxo-2-decenoic acid (9-ODA). Honey bees live in large eusocial colonies in which a single queen is responsible for reproduction, several thousand sterile female worker bees complete a myriad of tasks to maintain the colony, and several hundred male drones exist only to mate. The “queen substance” [also termed the queen retinue pheromone (QRP)] is an eig...
Pettis, Jeffery S.; Rice, Nathan; Joselow, Katie; vanEngelsdorp, Dennis; Chaimanee, Veeranan
Queen health is closely linked to colony performance in honey bees as a single queen is normally responsible for all egg laying and brood production within the colony. In the U. S. in recent years, queens have been failing at a high rate; with 50% or greater of queens replaced in colonies within 6 months when historically a queen might live one to two years. This high rate of queen failure coincides with the high mortality rates of colonies in the US, some years with >50% of colonies dying. I...
Nygaard, Sanne; Zhang, Guojie; Schiøtt, Morten; Li, Cai; Wurm, Yannick; Hu, Haofu; Zhou, Jiajian; Ji, Lu; Qiu, Feng; Rasmussen, Morten; Pan, Hailin; Hauser, Frank; Krogh, Anders; Grimmelikhuijzen, Cornelis J P; Wang, Jun; Boomsma, Jacobus J
. The third is sex determination, where we could identify only a single homolog of the feminizer gene. As other ants and the honeybee have duplications of this gene, we hypothesize that this may partly explain the frequent production of diploid male larvae in A. echinatior. The fourth is the evolution...... agricultural food production 50 million years ago, and the transition from single to multiple queen mating 10 million years ago....
Oettler, Jan; Dijkstra, Michiel B.; Heinze, Jürgen
We study male parentage and between-colony variation in sex allocation and sexual production in the desert ant Crematogaster smithi, which usually has only one singly-mated queen per nest. Colonies of this species are known to temporarily store nutrients in the large fat body of intermorphs, a specialized female caste intermediate in morphology between queens and workers. Intermorphs repackage at least part of this fat into consumable but viable male-destined eggs. If these eggs sometimes develop instead of being eaten, intermorphs will be reproductive competitors of the queen but—due to relatedness asymmetries—allies of their sister worker. Using genetic markers we found a considerable proportion of non-queen sons in some, but not all, colonies. Even though intermorphs produce ∼1.7× more eggs than workers, their share in the parentage of adult males is estimated to be negligible due to their small number compared to workers. Furthermore, neither colony-level sex allocation nor overall sexual production was correlated with intermorph occurrence or number. We conclude that intermorph-laid eggs typically do not survive and that the storage of nutrients and their redistribution as eggs by intermorphs is effectively altruistic. PMID:24130699
Peeters, Christian; Lin, Chung-Chi; Quinet, Yves; Martins Segundo, Glauco; Billen, Johan
Among social Hymenoptera, only some ant genera have more than one morphological kind of non-reproductive adults. Individuals that are bigger than ordinary workers can function for defence and/or food storage. In Crematogaster (Orthocrema) smithi from Arizona, a third caste exists in addition to winged queens and workers; it is intermediate in size, weight and morphology, and individuals lay many unfertilized eggs that are mostly eaten by larvae (Heinze et al., 1995, 1999). We studied another three species belonging to the subgenus Orthocrema: Crematogaster pygmaea from Brazil, Crematogaster biroi and Crematogaster schimmeri from Taiwan. Using scanning electron microscopy and ovarian dissections, we show that 'intermediates' are a patchwork of queen-like and worker-like traits, just as in C. smithi; importantly the combinations differ across species. 'Intermediates' are numerically few in the colonies, and in C. pygmaea they are produced seasonally. Using histology we confirmed the lack of a spermatheca, thus they are not ergatoid queens. Based on the similarity of their mosaic phenotypes with those in other ant lineages, we suggest that Orthocrema 'intermediates' are a soldier caste with a specialized trophic function. This soldier caste has been reported in other Orthocrema species from Madagascar, Guinea and Costa Rica, suggesting that it is widespread in this subgenus. PMID:23459016
Sundus Shaukat; Riaz Ahmed Bhatti; Khalid Ibrahim Qureshi; Shafqat Ali Shad
Many optmization algorithms are developed over period of time, among these most famous and widely used is Ant Colony systems (ACA). Ant Colony Systems (ACS) are the collection of different ant colony optimization algorithms. Different algorithms are used for solve the Travelling salesmen Problem (TCP) but ant colony algorithm is more preferred to solve the travelling salesmen problem. In ant colony best solution is found with the help of cooperating agents called ants. Ants cooperate with eac...
Holzer, Barbara; Kümmerli, Rolf; Keller, Laurent; Chapuisat, Michel
In animal societies, cooperation for the common wealth and latent conflicts due to the selfish interests of individuals are in delicate balance. In many ant species, colonies contain multiple breeders and workers interact with nestmates of varying degrees of relatedness. Therefore, workers could increase their inclusive fitness by preferentially caring for their closest relatives, yet evidence for nepotism in insect societies remains scarce and controversial. We experimentally demonstrate that workers of the ant Formica exsecta do not discriminate between highly related and unrelated brood, but that brood viability differs between queens. We further show that differences in brood viability are sufficient to explain a relatedness pattern that has previously been interpreted as evidence for nepotism. Hence, our findings support the view that nepotism remains elusive in social insects and emphasize the need for further controlled experiments. PMID:16846912
No extremo Sul do planeta Terra há a última fronteira ao avanço e controle total do homem. Se já são tantas as dificuldades para a sobrevivência em um ambiente hostil, podemos imaginar o esforço maior para a permanência total e indefinida. Tal território, sempre idealizado pelos antigos gregos, cerca de 300 a.C., mas descoberto há pouco mais de um século é a Antártida. Suas diferenças são marcantes em relação ao seu par, no pólo Norte, em todos os sentidos. O mais importante é o fato de a Ant...
Dr. Lilibeth A. Roxas
Full Text Available The potential of Native Chicken to be processed into palatable ham was conducted making use of Queen Pineapple (QP crude extract as one of the curing ingredients. Primarily, the main goal is to develop a protocol in the manufacture of processed native chicken ham and determine the organoleptic quality of native chicken ham product. The age of the bird and maturity of the fruit were considered for the best organoleptic quality of chicken ham. In this study, the combine injection and dry cure (CIDC method of the conventional formula was adopted. The desired amount of QP crude extract was first determined for the pump pickle. Curing salt was used for the control while different volume of pineapple crude extract was used in two treatments. The protocols for processing native chicken were developed using slaughter native chicken, and QP crude extract as curing ingredient for ham making. Color, flavor, juiciness and tenderness were among the desirable characteristics considered in this study. The sensory evaluation by trained panelists on QP-cured ham samples demonstrated comparable results. All the cooked meat samples were apparently acceptable to the sensory panel. The mean scores for flavor, juiciness and tenderness of meat samples have slight differences; however, they are not statistically significant. Indeed, native chicken can be processed into palatable ham with queen pineapple (Formosa variety extract that served as curing ingredient, flavor enhancer and tenderizer. Native Chicken QP-Cured ham is a commendable value-added product for both native chicken and queen pineapple by-products (butterball size.
Full Text Available Ante las puertas de la ley hay un guardian. Un campesino se llega hasta ese guardian y le pide que le permita entra en la ley, pero el guardian le dice que por ahora no se lo puede permitir. El hombre reflexiona y entonces pregunta si podria entrar despues. Es posible -dice el guardian-; pero no ahora. La puerta de entrada a la ley esta abierta como siempre.
Ho, Eddie K H; Frederickson, Megan E
Pathogens are predicted to pose a particular threat to eusocial insects because infections can spread rapidly in colonies with high densities of closely related individuals. In ants, there are two major castes: workers and reproductives. Sterile workers receive no direct benefit from investing in immunity, but can gain indirect fitness benefits if their immunity aids the survival of their fertile siblings. Virgin reproductives (alates), on the other hand, may be able to increase their investm...
The purpose of this paper is to discuss Spenser’s use of imitation as a literary device in his allegorical epic poem The Faerie Queene, originally published in 1590. The paper begins with a synopsis of Spenser’s general intent behind the poem, as well as his use of the theoretical models of literary excellence proposed by his contemporary Sir Phillip Sidney. The paper then follows Spenser’s reinterpretation of Ariosto, his treatment of Virgil and Ovid, and chronicles his attempts to parody th...
The purpose of this thesis was to conduct a case study through some surveys and recommendations. The aim of the study was to find competitor‟s advantages, then it could provide recommendations and ways to Daisy.Queen beauty salon to be more attractive and competitive. The theoretical part of thesis include the importance of service, the seven P‟s of service marketing, the importance of service marketing in beauty industry. The seven P‟s of service marketing was analyzed and supported to th...
Full Text Available Abstract Background Attine ants live in an intensely studied tripartite mutualism with the fungus Leucoagaricus gongylophorus, which provides food to the ants, and with antibiotic-producing actinomycete bacteria. One hypothesis suggests that bacteria from the genus Pseudonocardia are the sole, co-evolved mutualists of attine ants and are transmitted vertically by the queens. A recent study identified a Pseudonocardia-produced antifungal, named dentigerumycin, associated with the lower attine Apterostigma dentigerum consistent with the idea that co-evolved Pseudonocardia make novel antibiotics. An alternative possibility is that attine ants sample actinomycete bacteria from the soil, selecting and maintaining those species that make useful antibiotics. Consistent with this idea, a Streptomyces species associated with the higher attine Acromyrmex octospinosus was recently shown to produce the well-known antifungal candicidin. Candicidin production is widespread in environmental isolates of Streptomyces, so this could either be an environmental contaminant or evidence of recruitment of useful actinomycetes from the environment. It should be noted that the two possibilities for actinomycete acquisition are not necessarily mutually exclusive. Results In order to test these possibilities we isolated bacteria from a geographically distinct population of A. octospinosus and identified a candicidin-producing Streptomyces species, which suggests that they are common mutualists of attine ants, most probably recruited from the environment. We also identified a Pseudonocardia species in the same ant colony that produces an unusual polyene antifungal, providing evidence for co-evolution of Pseudonocardia with A. octospinosus. Conclusions Our results show that a combination of co-evolution and environmental sampling results in the diversity of actinomycete symbionts and antibiotics associated with attine ants.
Oppelt, Angelika; Heinze, Jürgen
Mating tactics differ remarkably between and within species of social Hymenoptera (bees, wasps, ants) concerning, e.g., mating frequencies, sperm competition, and the degree of male sperm limitation. Although social Hymenoptera might, therefore, potentially be ideal model systems for testing sexual selection theory, the dynamics of mating and sperm transfer have rarely been studied in species other than social bees, and basic information needed to draw conclusions about possible sperm competition and female choice is lacking. We investigated sperm transfer in the ant Leptothorax gredleri, a species in which female sexuals attract males by “female calling.” The analysis of 38 female sexuals fixed immediately or up to 7 days after copulation with a single male each revealed that the sperm is transferred into the female bursa copulatrix embedded in a gelatinous mass, presumably a spermatophore. Sperm cells rapidly start to migrate from the tip of the spermatophore towards the spermatheca, but transfer is drastically slowed down by an extreme constriction of the spermathecal duct, through which sperm cells have to pass virtually one by one. This results in the spermatheca being filled only between one and several hours after mating. During this time, the posterior part of the spermatophore seals the junction between bursa copulatrix and spermathecal duct and prevents sperm loss. The prolonged duration of sperm transfer might allow female sexuals to chose between ejaculates and explain previously reported patterns of single paternity of the offspring of multiply mated queens.
Cnaani, Jonathan; Hefetz, Abraham
In the social bee, Bombus terrestris, the two castes differ in size and physiology, but not in any other morphological and anatomical aspects. The size differences between the castes are the result of longer instar duration in prospective queen larvae. It appears that queen larvae are programmed to have a higher molting weight at the end of the 2nd, 3rd and 4th instars. Calculation of the growth ratio, the ratio between the logarithm of molting weight at two successive instars, revealed that queen larvae have a linear growth ratio over the entire larval development as predicted by Dyar's rule. In the worker larvae, in contrast, linearity of the growth ratio breaks after the second instar, resulting in larval molting at lower weights than expected by Dyar's rule. We therefore suggest that workers' development is abnormally shortened, either by parental manipulation or by adopting a different growth plan in response to the queen's signal.
During the last years several ant-based techniques were involved to solve hard and complex optimization problems. The current paper is a short study about the influence of artificial ant species in solving optimization problems. There are studied the artificial Pharaoh Ants, Lasius Niger and also artificial ants with no special specificity used commonly in Ant Colony Optimization.
Tennenbaum, Michael; Liu, Zhongyang; Hu, David; Fernandez-Nieves, Alberto
Fire ants link their bodies to form aggregations; these can adopt a variety of structures, they can drip and spread, or withstand applied loads. Here, by using oscillatory rheology, we show that fire ant aggregations are viscoelastic. We find that, at the lowest ant densities probed and in the linear regime, the elastic and viscous moduli are essentially identical over the spanned frequency range, which highlights the absence of a dominant mode of structural relaxation. As ant density increases, the elastic modulus rises, which we interpret by alluding to ant crowding and subsequent jamming. When deformed beyond the linear regime, the aggregation flows, exhibiting shear-thinning behaviour with a stress load that is comparable to the maximum load the aggregation can withstand before individual ants are torn apart. Our findings illustrate the rich, collective mechanical behaviour that can arise in aggregations of active, interacting building blocks.
Breeman, G.E.; Lowery, D.; Poppelaars, C.; Resodihardjo, S.; Timmermans, A.; Vries, de J.
At the beginning of each Parliamentary session, the Dutch Queen gives a speech (Troonrede) in which she presents the government's policy goals and legislative agenda for the year to come. The general assumption is that newly elected governments will use agenda-setting moments such as the Queen's spe
Inoue, Maki N.; Saito, Fuki; Tsuchida, Koji; Goka, Koichi
With the exception of several species, bumblebees are monandrous. We examined mating frequency in feral colonies of the introduced bumblebee Bombus terrestris in Japan . Using microsatellite markers, genotyping of sperm DNA stored in the spermatheca of nine queens detected multiple insemination paternities in one queen; the others were singly mated. The average effective paternity frequency estimated from the genotypes of queens and workers was 1.23; that estimated from the workers' genotype alone was 2.12. These values were greater than those of laboratory-reared colonies in the native ranges of B. terrestris. The genotypes of one or two workers did not match those of their queens or showed paternities different from those of their nestmates; this may have arisen from either queen takeover or drifting of workers. These alien workers were responsible for the heterogeneous genotype distribution within each B. terrestris colony, resulting in higher estimates of paternity frequency than of insemination frequency. The high mating frequency of introduced B. terrestris may have occurred by artificial selection through mass breeding for commercialization. Moreover, polyandrous queens may be selectively advantageous, because reproduction by such queens is less likely to be disturbed by interspecific mating than that by monandrous queens.
Armstrong, F E
Two Queen's University researchers are among three Canadian finalists in a contest to win $1 million. Art McDonald, director of the Queen's-run Sudbury Neutrino Observatory Institute, and John Smol, Canada Research Chair in Environmental Change, have been nominated for the Gerhard Herzberg Canada Gold Medal for Science and Engineering (1 page).
Ana Cristina Ignatti
Full Text Available The histological study of the exocrine glands in the swarming females showed the presence of tergal glands, mandibular glands, salivary glands and sternal glands. Tergal and sternal glands are not developed in the physogastric queens, probably, because of a regression process. The development of mandibular glands is similar in swarming females and physogastric queens.
Full Text Available Chronic bee paralysis virus (CBPV is known as a disease of worker honey bees. To investigate pathogenesis of the CBPV on the queen, the sole reproductive individual in a colony, we conducted experiments regarding the susceptibility of queens to CBPV. Results from susceptibility experiment showed a similar disease progress in the queens compared to worker bees after infection. Infected queens exhibit symptoms by Day 6 post infection and virus levels reach 1011 copies per head. In a transmission experiment we showed that social interactions may affect the disease progression. Queens with forced contact to symptomatic worker bees acquired an overt infection with up to 1011 virus copies per head in six days. In contrast, queens in contact with symptomatic worker bees, but with a chance to receive food from healthy bees outside the cage appeared healthy. The virus loads did not exceed 107 in the majority of these queens after nine days. Symptomatic worker bees may transmit sufficient active CBPV particles to the queen through trophallaxis, to cause an overt infection.
Derks, B.; Van Laar, C.; Ellemers, Naomi
This contribution reviews work on the Queen Bee phenomenon whereby women leaders assimilate into masculine organizations, distance themselves from junior women and legitimize gender inequality in their organization. We propose that rather than being a source of gender inequality, the Queen Bee pheno
Gale, David; Propp, James; Sutherland, Scott; Troubetzkoy, Serge
We discuss some properties of a class of cellular automata sometimes called a "generalized ant". This system is perhaps most easily understood by thinking of an ant which moves about a lattice in the plane. At each vertex (or "cell"), the ant turns right or left, depending on the the state of the cell, and then changes the state of the cell according to certain prescribed rule strings. (This system has been the subject of several Mathematical Entertainments columns in the Mathematical Intelli...
Adams, R. M. M.; Liberti, J.; Illum, A. A.; Jones, T H; Nash, D R; Boomsma, J.J.
We document the behavioral interactions among three ant species: a fungus-growing host ant, a permanently associated parasitic guest ant, and a raiding agro-predator ant. We show that the presence of guest ants becomes advantageous when host ants are attacked by raider ants, because guest ants use alkaloid venom to defend their host ant colony. Furthermore, detection of the guest ant odors is sufficient to discourage raider scouts from recruiting nestmates to host colonies. Guest ants likely ...