Brood raiding and the population dynamics of founding and incipient colonies of the fire ant, Solenopsis invicta

Abstract. 1. One of the first activities of minim workers in incipient fire ant nests is mutual brood raiding, the amalgamation of nests through the reciprocal stealing of brood and defection of workers.
2. Discrete mating flights created cohorts of incipient colonies. About 25% of founding nests survived the claustral period of 16–48 days (depending on season). Early incipient colony mortality was 5–6% per day. Over 60% of this mortality was accounted for through brood raiding. Most colonies raided when each cohort first became active, and many raided more than once. Raid size (number of nests, duration, distance) tended to increase during the summer as colonies grew through raiding. After the raiding period, nest mortality rate dropped 3–10-fold. Only 1–3% of founding nests were still alive at this time.
3. Queens from losing or failed nests tended to abandon their nests and attempted to enter successful ones, often following raiding trails to do so. This emigration was at least as successful as non-emigration in ultimately achieving the status of reproductrix of a successful nest (about 4%).
4. Brood raiding is a dominant process in early population dynamics, probably accounting for most of the early nest mortality. Its effect is to change the venue and unit of competition from nest-against-nest to a shifting aggregation of queens, workers and brood involving entire local populations. Nest thinning is thus very rapid, and the boost to the size of winning nests very large, allowing raiding colonies to win the competition for territory, and to achieve the early colony maturity so important to this, and other, weedy species. The importance of winning brood raids may also have driven increased minim production through the evolution of pleometrosis.     

The behaviour of queen honeybees and their attendants

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

Queen succession in the primitively eusocial tropical waspRopalidia marginata (Lep.) (Hymenoptera: Vespidae)

Females of the primitively eusocial wasp Ropalidia marginata can be classified into three behavioral groups: Sitters, Fighters, and Foragers. It has been speculated that both Sitters and Fighters may be hopeful queens and that the Foragers may have little or no opportunities for direct reproduction. Here we show that in 9 of 12 queen-removal experiments where such a behavioral differentiation could be discerned, the individual that became a queen (the potential queen) was a Sitter in 6 cases, a Fighter in 2 cases, and a Forager in only 1 case. Although potential queens spent significantly more time absent from the nest and showed significantly higher rates of dominance behavior compared to the mean values for nonqueens in their colonies, they were intermediate with respect to all behaviors and age when compared to the range of values for nonqueens in their colonies. Potential queens were not necessarily the highest-ranking individuals among the nonqueens. The pattern of queen succession in this species appears to be quite different from the temperate pattern, where an old and active forager of high dominance rank is the potential queen. Although somewhat similar to the tropical pattern of a relatively younger female that has performed relatively little foraging being the potential queen, it is perhaps more accurate to describe the potential queens of R. marginata as unspecialized intermediates.     

Effects of social conditions on Juvenile Hormone mediated reproductive development in Bombus terrestris workers

Abstract. During the annual life cycle of the bumble bee Bombus terrestris (L.) colony, there is a stage characterized by worker reproduction in the presence of the queen. It has been proposed that this is a result of a decrease in queen inhibition. This hypothesis was examined by studying the effects of queens taken from colonies at different stages of development on several aspects of worker physiology and behaviour: rates of Juvenile Hormone (JH) release in vitro , ovary development, and behaviour associated with reproduction. After optimizing and validating the radiochemical assay for JH release for bumble bee workers, we found that queenless workers had significantly more developed ovaries and higher rates of release of JH than did queenright workers, confirming and extending previous findings that suggest that bumblebee ovarian development is under JH control. Mated queens, separated from their colony and brood, can have the same inhibitory effect on the reproductive development of callow workers. In contrast, workers confined with virgin queens or in queenless groups demonstrated a significantly higher rate of release of JH, overt aggression and threatening behaviours. However, there were no differences in rates of release of JH between workers confined in groups in the laboratory with queens taken from colonies either before or after the onset of worker reproduction. Furthermore, overt aggression and threatening behaviours were similar and low in both types of groups. These results gave no support to the hypothesis that a decrease in queen inhibition is associated with the onset of worker reproduction. We also show that young workers reared in colonies either before or after worker reproduction occurs, or in queenless colonies, all demonstrated similar, low rates of release of JH. These results suggest that older workers may inhibit the corpora allata of younger workers in queenless colonies.     

Ultrastructure and formation of the physogastric termite queen cuticle

The physogastric termite queen is the most striking example in insects of growth in size without cuticular moulting. This phenomenon has been studied with electron microscopy and histochemical tests in two species of higher termites, Cubitermes fungifaber and Macrotermes bellicosus. The abdominal hypertrophy (physogastry) is allowed by growth of the arthrodial membranes of the swarming imago. The growth is slow (over several years) but important: the cuticular dry weight is multiplied by 20 in C. fungifaber, by 100-150 in M. bellicosus. The termite queen cuticle arises from the transformation of the cuticle of the swarming imago or imaginal cuticle (unfolding and growing of the epicuticle, stretching of the endocuticle, resorption of the subcuticle) and from the secretion of a new endocuticle or royal endocuticle. The termite queen is the first example known in insects of epicuticular growth. In the physogastric queen, three cuticular types are observed: the rigid cuticle of the sclerites, the soft cuticle of the arthrodial membranes and the partially rigid cuticle of special structures, the neosclerites, which show both rigidity and growth. The fibrillar architecture varies according to the abdominal zones and the position within the cuticle. It appears to be determined by the forces arising from the musculature and the anisometric abdominal growth. The king does not become physogastric, although its cuticle is also modified.     

Queen polymorphism in the North American harvester ant,Ephebomyrmex imberbiculus

Summary In the North American harvester antEphebomyrmex imberbiculus, in addition to dealate queens, wingless female reproductives occur that have greatly reduced ocelli and thoracic sutures (intermorphic queens). Both queen types are equivalent in function, and do not differ in ovarian morphology. Colonies may contain several inseminated and egg-laying intermorphic queens. We discuss queen polymorphism in respect to the biology of this desert-dwelling species.     

蜜蜂化学生态学化学通讯与信息素研究进展

概括了蜜蜂化学生态学的主要研究内容和领域,重点评述了蜂群内的化学通讯和蜜蜂信息素研究的进展。迄今,已经鉴定的蜂王信息素有９－氧化－（反）－２－癸烯酸（９－ＯＤＡ）,Ｒ（一）－９－羟基癸烯酸Ｒ（一）－９ＨＤＡ）,Ｓ（＋）－９－羟基癸烯酸（Ｓ（＋）－９ＨＤＡ）,对－羟基苯甲酸甲酯（ＨＯＢ）和４－羟基－３－甲本基乙醇（ＨＶＡ）等５种;工蜂那氏信息互膛牛醇,橙花醇,（反,反）－法尼醇,（反）柠檬醛,（顺）     

饲粮蛋白质水平对蜂群繁殖性能的影响

本试验旨在研究饲料蛋白质水平对蜜蜂产浆期繁殖性能的影响。选择35群群势、蜂王年龄和质量一致的意大利蜜蜂Apis mellifera L.,随机分为7组,分别饲喂蛋白质水平为15%、20%、25%、30%、35%及40%的试验饲粮并以油菜花粉作为对照,测定各组蜂群的繁殖性能。结果表明,试验前期,饲粮蛋白质水平对蜂群群势有显著性影响,然而在试验中后期,则无显著影响(P>0.05);随着饲粮蛋白质水平的增加,蜂王产卵力和工蜂初生重呈先升高后降低的变化趋势,与对照组相比差异不显著(P>0.05)。     

小峰熊蜂蜂王蛹期发育蛋白质组分析

为了探明小峰熊蜂Bombus hypocrita蜂王蛹期发育蛋白质表达调控方面的特点,揭示其发育的分子机理。采用双向电泳法对小峰熊蜂蜂王蛹期发育进行蛋白质组研究,结果在小峰熊蜂蜂王蛹期的白眼期(A期)、褐眼期(B期)和黑眼期(C期)分别检测到81、80和75个蛋白点,特有蛋白质分别为8个、7个和2个,共有蛋白质为61个,A期到B期有4个蛋白质显著上调,5个显著下调,B期到C期有7个蛋白质显著上调,1个显著下调,A期到C期有10个蛋白质显著上调,有4个显著下调。此外,3个蛋白质是在A、B期表达C期关闭,6个蛋白质A、C期表达,B期关闭,5个蛋白质A期关闭,而B、C期表达。初步表明小峰熊蜂蜂王从蛹期发育到成蜂过程中,不仅需要一些保守蛋白质来调控,而且还需要一些特异蛋白质。     

婚飞行为影响中华蜜蜂性成熟处女蜂王的基因表达

婚飞是性成熟处女蜂王与雄蜂交配过程中的一个重要前奏, 在该过程中蜂王体内伴随着一系列重要的生理变化。为了探究中华蜜蜂Apis cerana cerana处女蜂王婚飞过程中基因表达变化, 本研究利用数字基因表达谱(digital gene expression, DGE) 技术分析了中华蜜蜂性成熟处女蜂王飞行与未飞行之间的基因表达差异。经DGE测序, 分别从两个样品中获得5.98和6.01 百万条Clean标签。通过分析检测到250个基因有差异表达, 其中133个基因在飞行蜂王中上调表达, 117个基因在飞行蜂王中下调表达。这些差异基因可以归类到348个功能性类别和142个生化途径。结果表明中华蜜蜂性成熟处女蜂王在婚飞过程中大量基因的表达发生了变化。这些结果为进一步研究中华蜜蜂蜂王婚飞过程中生理变化的分子机制提供了重要的基因表达信息。