Social Behaviour in an Australian Allodapine Bee Exoneura (Brevineura) xanthoclypeata (Hymenoptera : Apidae)

1997 ◽  
Vol 45 (4) ◽  
pp. 385 ◽  
Author(s):  
Simon M. Tierney ◽  
Michael P. Schwarz ◽  
M. Adams
Keyword(s):  
Social Behaviour ◽  
Social Evolution ◽  
Extended Period ◽  
Sensu Stricto ◽  
Extensive Study ◽  
Egg Laying ◽  
Brood Production ◽  
Brood Rearing ◽  
Reproductive Differentiation ◽  
Two Factors

The allodapine bees are well suited for comparative studies of social evolution because of the wide variation in social behaviour within and between genera. There are three main clades in the endemic Australian genus Exoneura. Two groups (Exoneura sensu stricto and Exoneurella) have received extensive study. In this paper we provide the first detailed study of social behaviour in the third group, Brevineura, based on a heathland population of Exoneura (B.) xanthoclypeata Rayment. This species has two seasonal pulses of egg-laying and brood rearing occurs throughout most of the year, including winter. This extended period of egg-laying and brood development differs from the two other Australian Exoneura subgenera and provides extensive opportunities for eusocial-like sib-rearing. Dissection data indicate that reproductive differentiation among adult nestmates is well developed and dependent on body size, with smaller females being mostly or entirely non-reproductive. Per capita brood production is dramatically higher in multi-female nests than in single-female nests and relatedness between adult nestmates is moderately high (r ≈ 0·5). These two factors suggest that local fitness enhancement may be occurring and our limited sex allocation data suggest female-biased ratios. Because of the opportunities for sib-rearing in this species, local fitness enhancement has the potential to lower selective thresholds for eusociality.

Biology of a weakly social bee, Exoneura (Exoneurella) setosa (Hymenoptera : Apidae) and implications for social evolution in Australian allodapine bees

1998 ◽  
Vol 46 (3) ◽  
pp. 221 ◽  
Author(s):  
Tania Neville ◽  
Michael P. Schwarz ◽  
Simon M. Tierney
Keyword(s):  
Group Size ◽  
Social Evolution ◽  
Sensu Stricto ◽  
Brood Production ◽  
Brood Rearing ◽  
Large Group ◽  
Basal Position ◽  
Social Bee

Australian allodapine bees provide excellent material for comparative approaches to understanding social evolution. The subgenus Exoneurella occupies a cladistically basal position in the Australian Exoneura group and comprises only four species. We describe sociality in one Exoneurella species, E. setosa, and combine this with other data to infer some patterns of social evolution in allodapines. E. setosa rears a first brood solitarily, although staggered brood production and the production of a second brood in some nests leads to a situation where older, recently emerged brood have the ability to help rear their younger siblings and this overlaps with opportunities to lay eggs. This is similar to the situation for two other phylogenetically distal species of Exoneurella, as well as for members of the genus Braunsapis, which is used as an outgroup for Exoneura. When combined with other studies, our results suggest that the opportunity for sib-rearing is a plesiomorphic trait for Australian allodapines and this has been largely lost in a distal subgenus, Exoneura sensu stricto. Instead, multifemale brood-rearing colonies in this latter group mostly comprise individuals of the same generation, and species exhibit large group size, univoltinism and kin cofounding. This suggests that evolution can favour semisociality and quasisociality, even when eusociality has already arisen.

Social Evolution, Hamilton’s Rule, and Inclusive Fitness

2018 ◽  
Author(s):  
Samir Okasha
Keyword(s):  
Social Behaviour ◽  
Social Evolution ◽  
Inclusive Fitness ◽  
Popular Approach ◽  
Hamilton’S Rule ◽  
Inclusive Fitness Theory ◽  
The Social ◽  
Social Encounters ◽  
The Individual ◽  
Hamilton's Rule

Inclusive fitness theory, originally due to W. D. Hamilton, is a popular approach to the study of social evolution, but shrouded in controversy. The theory contains two distinct aspects: Hamilton’s rule (rB > C); and the idea that individuals will behave as if trying to maximize their inclusive fitness in social encounters. These two aspects of the theory are logically separable but often run together. A generalized version of Hamilton’s rule can be formulated that is always true, though whether it is causally meaningful is debatable. However, the individual maximization claim only holds true if the payoffs from the social encounter are additive. The notion that inclusive fitness is the ‘goal’ of individuals’ social behaviour is less robust than some of its advocates acknowledge.

Laboratory Colonisation of the Mosquito, Eretmapodites chrysogaster Grah

1958 ◽  
Vol 49 (2) ◽  
pp. 287-290 ◽  
Author(s):  
J. D. Gillett
Keyword(s):  
Blood Meal ◽  
Free Water ◽  
Sensu Stricto ◽  
Egg Laying ◽  
Cotton Wool ◽  
Female Mosquito ◽  
Male Progeny ◽  
Single Batch

SummaryA colony of Eretmapodites chrysogaster Grah., sensu stricto, was maintained successfully for over a year without any reinforcement.Identity of the mosquitos was established by starting the colony from a single batch of eggs laid by a single wild-caught female mosquito, and subsequent examination of the genitalia of the male progeny.Mating occurred regularly after the first blood-meal of the female. In fact the females would not accept the males until they had started, or had finished, their first blood-meal.Eggs were laid on the sterilised, water-filled bracts of banana flowers. Moist paper, moist cotton-wool or free water above paper or cotton-wool proved unsatisfactory as egg-laying media.Larvae fed largely on the substance of the banana bracts on which the eggs had been laid. The banana bract also provided cover and so reduced the incidence of cannibalism among larvae.

Study on a sequencing batch membrane bioreactor for wastewater treatment

2000 ◽  
Vol 41 (10-11) ◽  
pp. 227-234 ◽  
Author(s):  
W.J. Ng ◽  
S.L. Ong ◽  
M.J. Gomez ◽  
J.Y. Hu ◽  
X.J. Fan
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Extended Period ◽  
Cod Removal ◽  
Nitrification Inhibition ◽  
Test Results ◽  
Two Factors ◽  
High Feed ◽  
Average Flux

This study investigated the effect of MLSS concentration in a sequencing batch membrane bioreactor on COD and nitrogen removal as well as flux. Two values of MLSS (5 g/l and 10 g/l) were investigated in this study. The strength of the feed was varied to achieve a target F/M ratio of 0.5 based on COD. Accordingly, the concentration of COD was determined as 3.5 and 7.0 g/l for the 5 and 10 g/l MLSS targets, respectively. The test results showed that an average COD removal of 98.5% was achievable. However, it was noted that nitrification inhibition occurred. Nitrification inhibition occurred because of two factors, namely high NH4+–N concentration and high DO demand. High NH4+–N in the feed led to the inhibition of nitratation and thus high nitrites are found in the effluent. High DO demand due to high feed COD concentration led to an extended period with low DO levels inside the reactor thus retarding the conversion of NH4+–N. The increase in the MLSS concentration from 5 to 10 g/l led to a decrease in the average flux from11.1 l/m2 · h to 9.6 l/m2 · h. An increase in aeration, from 2.0 to 8.0 l/min, did not lead to any significant improvement in terms of fouling.

scholarly journals Growth of Nestling Thick-billed Murres (Uria lomvia) in Relation toParental Experience and Hatching Date

The Auk ◽  
2002 ◽  
Vol 119 (3) ◽  
pp. 827-832 ◽  
Author(s):  
J. Mark Hipfner ◽  
Anthony J. Gaston
Keyword(s):  
Extended Period ◽  
Egg Laying ◽  
Avian Species ◽  
Parental Age ◽  
Hatching Date ◽  
Direct Effects ◽  
Breeding Performance ◽  
Uria Lomvia ◽  
Nestling Growth ◽  
Parental Experience

Abstract In many avian species, reproductive success increases with parental age and experience, and declines seasonally. However, it is difficult to evaluate how parental attributes affect reproduction independently of date effects, because young, inexperienced pairs generally lay later than older, experienced pairs. We examined how parental experience and timing affected nestling growth in the Thick-billed Murre (Uria lomvia), an Arctic seabird that lays a single-egg clutch, by taking advantage of a natural contrast made possible by marked within-group synchrony. That is a common feature at murre colonies, and enabled us to monitor the breeding performance of experienced pairs over an extended period that overlapped with breeding by inexperienced pairs late in the season. Whereas growth of offspring raised by experienced parents was unaffected by their hatching date, offspring raised by inexperienced parents grew more slowly than those raised concurrently by experienced parents. Therefore, parental experience influenced nestling growth rates whereas timing did not, a result that accords with previous studies on this species. Absence of direct effects of timing of egg-laying on breeding success of Thick-billed Murres stands in sharp contrast to many other avian species, and seems surprising for an Arctic-nesting species often assumed to be strictly time-constrained in its breeding.

Endocrine correlates of territoriality, breeding stage, and body molt in free-living willow ptarmigan of both sexes

1990 ◽  
Vol 68 (10) ◽  
pp. 2130-2134 ◽  
Author(s):  
Susan J. Hannon ◽  
John C. Wingfield
Keyword(s):  
Luteinizing Hormone ◽  
Aggressive Behaviour ◽  
Follicle Stimulating Hormone ◽  
Plasma Concentrations ◽  
Egg Laying ◽  
Plasma Testosterone ◽  
Willow Ptarmigan ◽  
Free Living ◽  
Brood Rearing ◽  
Egg Formation

Concentrations of plasma testosterone, estradiol, corticosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were measured by radioimmunoassay in wild willow ptarmigan (Lagopus lagopus) of both sexes over the breeding season. In males, plasma concentrations of testosterone and LH increased once they became territorial, and this was paralleled by increases in comb size and initiation of molt into courtship plumage. A decline of testosterone and circulating LH levels during late territoriality and egg laying coincided with molt into summer plumage. FSH titers did not vary significantly through the season, but there was a trend for higher levels during the territorial period. Plasma concentrations of corticosterone were highest during pre- and late territoriality and brood rearing. In females, testosterone levels were about 13 times lower than in males and did not vary significantly, whereas LH was high from pre- to mid-territoriality and again in the brood season. Elevated LH levels may be correlated with aggressive behaviour in females. FSH and estradiol concentrations were highest during the period of egg formation. Corticosterone was correlated with chase time in both sexes.

scholarly journals Adaptation and the genetics of social behaviour

2009 ◽  
Vol 364 (1533) ◽  
pp. 3209-3216 ◽  
Author(s):  
Laurent Keller
Keyword(s):  
Social Behaviour ◽  
Social Evolution ◽  
Division Of Labour ◽  
Chemical Signalling ◽  
Insect Societies ◽  
Genetic Mechanisms ◽  
Selective Forces ◽  
Group Members ◽  
Reproductive Division Of Labour ◽  
Reproductive Division

In recent years much progress has been made towards understanding the selective forces involved in the evolution of social behaviour including conflicts over reproduction among group members. Here, I argue that an important additional step necessary for advancing our understanding of the resolution of potential conflicts within insect societies is to consider the genetics of the behaviours involved. First, I discuss how epigenetic modifications of behaviour may affect conflict resolution within groups. Second, I review known natural polymorphisms of social organization to demonstrate that a lack of consideration of the genetic mechanisms involved may lead to erroneous explanations of the adaptive significance of behaviour. Third, I suggest that, on the basis of recent genetic studies of sexual conflict in Drosophila , it is necessary to reconsider the possibility of within-group manipulation by means of chemical substances (i.e. pheromones). Fourth, I address the issue of direct versus indirect genetic effects, which is of particular importance for the study of behaviour in social groups. Fifth, I discuss the issue of how a genetic influence on dominance hierarchies and reproductive division of labour can have secondary effects, for example in the evolution of promiscuity. Finally, because the same sets of genes (e.g. those implicated in chemical signalling and the responses that are triggered) may be used even in species as divergent as ants, cooperative breeding birds and primates, an integration of genetic mechanisms into the field of social evolution may also provide unifying ideas.

scholarly journals Lower pollen nutritional quality delays nest building and egg laying in Bombus terrestris audax micro-colonies leading to reduced biomass gain

Apidologie ◽  
2021 ◽  
Author(s):  
Jordan T. Ryder ◽  
Andrew Cherrill ◽  
Helen M. Thompson ◽  
Keith F. A. Walters
Keyword(s):  
Bombus Terrestris ◽  
Essential Amino Acids ◽  
Egg Laying ◽  
Nest Building ◽  
Colony Development ◽  
Total Biomass ◽  
Brood Production ◽  
Pollen Species ◽  
Colony Performance ◽  
Selection Of

AbstractThe performance of Bombus terrestris micro-colonies fed five diets differing in pollen species composition and level of nine essential amino acids (EAA; leucine, lysine, valine, arginine, isoleucine, phenylalanine, threonine, histidine, methionine) was assessed for 37 days by recording total biomass gain, nest building initiation, brood production (eggs, small and large larvae, pupae, drones), nectar, and pollen collection. Stronger colony performance was linked to higher amino acid levels but no consistent differences in biomass gain were recorded between mono- and poly-species diets. Poorest performance occurred in micro-colonies offered pure oilseed rape (OSR) pollen which contained the lowest EAA levels. Reduced micro-colony development (delayed nest initiation and lower brood production) was related to OSR proportion in the diet and lower EAA levels. Results are discussed in relation to selection of plant species in the design of habitats to promote bee populations.

scholarly journals Repellency and Toxicity of Conophthorus ponderosae Hopkins (Coleoptera: Scolytidae) by the Host Monoterpene Myrcene

2007 ◽  
Vol 22 (4) ◽  
pp. 241-247
Author(s):  
Brian M. Shirley ◽  
Stephen Cook
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Seed Orchard ◽  
Brood Production ◽  
Seed Orchards ◽  
Male Attractant ◽  
Attractant Pheromone ◽  
Two Factors ◽  
High Quality Seed ◽  
Average Brood

Abstract Seed orchards produce high-quality seed from selected tree genotypes. In the intermountain west, Conophthorus ponderosae Hopkins (Coleoptera: Scolytidae) is a pest in seed orchards of ponderosa pine, Pinus ponderosa (Laws). The effect of myrcene as a deterrent to coneattack by C. ponderosae in a ponderosa pine seed orchard was examined. Two factors were considered, timing of cone cluster attack and average brood production per cone cluster. There was a delayed attack by C. ponderosae on cones treated with vials of myrcene attached at thebase of cone clusters. During both 2003 and 2004, final brood production per cone was not affected significantly by the presence of myrcene. During 2003, brood production was influenced by the timing of attack, with later attacks resulting in fewer brood adults per cone cluster. The toxicity of myrcene to adult C. ponderosae was examined in a laboratory and compared with that of (+)-α-pinene, another host-produced monoterpene that acts as a synergist for the male attractant pheromone pityol.

Latitudinal variation in the sociality of allodapine bees (Hymenoptera: Apidae): sex ratios, relatedness and reproductive differentiation

2001 ◽  
Vol 49 (1) ◽  
pp. 1 ◽  
Author(s):  
Adam L. Cronin ◽  
Michael P. Schwarz
Keyword(s):  
Sex Allocation ◽  
Sympatric Species ◽  
Egg Laying ◽  
Reproductive Skew ◽  
Brood Development ◽  
Eastern Australia ◽  
Reproductive Differentiation ◽  
Allocation Patterns ◽  
One Year ◽  
Latitudinal Range

Variation in sociality of two Australian allodapine bees was investigated over a latitudinal range of 10˚, spanning subtropical to cool temperate forests in eastern Australia. Exoneura robusta is univoltine and singly brooded in southern populations but is able to produce two broods per season in northern populations, leading to opportunities for sib rearing by older brood members. In contrast, sympatric colonies of E. angophorae show no such variation with latitude, and all populations exhibit some colonies where opportunities for sib rearing arise. Patterns of ovarian differentiation, relatedness and sex allocation were examined over a one-year period for these two sympatric species in four populations. Within each species, the timing of ovarian development and the degree of reproductive skew were similar at all sites, but the onset of egg-laying and brood development was earlier in E. angophorae than in E. robusta. Relatedness and sex allocation patterns in northern populations of these species were not markedly different from southern populations. Selection for female-biased sex allocation and high reproductive skew in Exoneura probably stems from strong benefits from cooperative nesting, and our results suggest that opportunities for sib rearing (and eusociality) in these species may depend on latitudinally mediated brood development rates, and are unrelated to levels of sex bias and relatedness.

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