Kin discriminators in the eusocial sweat bee Lasioglossum malachurum: the reliability of cuticular and Dufour's gland odours

The ability to discriminate degrees of relatedness may be expected to evolve if it allows unreciprocated altruism to be preferentially directed towards kin (Hamilton in J Theor Biol 7:1-16, 1964). We explored the possibility of kin recognition in the primitively eusocial halictid bee Lasioglossum malachurum by investigating the reliability of worker odour cues that can be perceived by workers to act as indicators of either nest membership or kinship. Cuticular and Dufour's gland compounds varied significantly among colonies of L. malachurum, providing the potential for nestmate discrimination. A significant, though weak, negative correlation between chemical distance and genetic relatedness (r = -0.055, p

Mixed colonies of two species of congeneric stingless bees (Hymenoptera: Apinae, Meliponini) display environmentally-acquired and endogenously-produced recognition signals

Nestmate recognition is fundamental for the maintenance of social organization in insect nests. It is becoming well recognized that cuticle hydrocarbons mediate the recognition process, although the origin of recognition cues in stingless bees remains poorly explored. The present study investigates the effects of endogenously-produced and environmentally-acquired components in cuticular hydrocarbons in stingless bees. The tests are conducted using colonies of Plebeia droryana Friese and Plebeia remota Holmberg. Recognition tests are performed with four different groups: conspecific nestmates, conspecific non-nestmates, heterospecifics and conspecific, genetically-related individuals that emerge in a heterospecific nest. This last group is produced by introducing brood cells of P. droryana into a P. remota colony, and the resulting adult bees are tested for acceptance 10 days after emergence. For all groups, 15 individuals are sampled for chemical analysis. The results show the acceptance of all conspecific nestmates, and the rejection of almost every conspecific non-nestmate and every heterospecific bee. Genetically-related individuals emerging from heterospecific nests present intermediate rejection (66.7% rejection). Chemical analysis shows that P. droryana individuals emerging in a P. remota nest have small amounts of alkene and diene isomers found in P. remota cuticle that are not found in workers from the natal nest. The data clearly show that the majority of the compounds present in P. droryana cuticle are endogenously produced, although a few unsaturated compounds are acquired from the environment, increasing the chemical differences and, consequently, the rejection percentages.

镇海棘螈繁殖群体生态和遗传结构研究

genetics, such as: population size, reproduction, mating system, growth, development,genetic structure and systematics status; The main results are presented below: The seasonal variation of the operational sexual ratio of this animal was found in the field and the ration always bias the female in the breeding season. Aiming at this character and considering the distance of time and space of both sexual habitat in breeding season, we census female population first by toe-clipping mark-recapture method, then estimated the population size with the definitive sexual ratio. Up to now, this species was found only at the Beilun district of the Ningbo City. The population size of the Ruiyan Temple Forest Park approximates to 369. The status of this population is extremely endangered, so besides protecting this population at the original locality, we also suggested to breed the salamander in fenced locality and to hatch embryos artificially, and send metamorphosed juveniles back to nature. We can transfer some individuals to other similar habitats or breed them under artificial conditions for saving this species from extinction. The early developmental stage of the Chinhai salamander is the same as its relative species, E. andersoni. Their balanceres are poorly developed and disappear very early. Temperature and moisture significantly influence the embryonic development of the Chinhai salamander. The embryonic stage is approx. 29 days under room temperature. The hatchling grows in a logarithmic curve. The larvae stage in water is approx. 58- 88 days. Many factors influence the nomal development, including two aspects of internal and external. Due to these factors, the effective protected measures were presented in detail. The breeding migration of E. chinhaiensis takes place at late March～late April every year. This salamander's hatching rate is high, but the rate of hatchling migrating into water is low. The average effectiveness of all the nest sites is 36.7%. The maternal self-conservation was contrary to the reproductive success of the egg-laying strategy. In the strategy of egg-laying behavior, the first factor selected by the female was its self-conservation, the second is embryonic survival rate, and the last is rate of hatchling survival rate. The oviposition selection is significant for the survival of the larvae. Based on the analysis of the evolutionary process of reproductive behaviors nad egg-laying site selections of all genera of the family Salamandridae, we deduced that perhaps Echinotriton is a transitional type in the evolutionary process from water to land. Due to its location in the adaptive stage in the terrestrial evolution, Echinotriton chinhaiensis's terrestrial nest may be one of important reason that causes this species to be endangered. The genetic deversity analysis shows that although the population size of the Chinhai salamander is quite small compared to other Chinese salamandrid species, the genetic diversity of this population is not reduce remarkably. We explain this phenomena with the polygamy mating system of this species. The result of 4 families' parenthood determinations shows that the parenhood determination can be taken without any paternal information. The "children" of every female include rich genetic information from at least two "fathers". It implies that female Chinhai salamander mates more than once with different males in a breeding season. The molecular evidence, the behavioral observation evidences and the sperm evidence in the female cloaca proved that this species has a polygamy mating system. The kin recognition in the mating of adult salamander was first discussed. The taxonomic status and phylogenetic relationships of 12 species representing 6 genera in the family Salamandridae were studied using DNA fingerprinting. The results showed that the DNA fingerprinting. The results showed that the DNA fingerprinting patterns demonstrated rich genetic diversity and species diversity, and also revealed the taxonomic status and phylogenetic relationshipes of higher taxa to a certain extent. The results are highly consistent with those obtained from the studies based on the morphology, ecology, cytology and molecular biology. The compreshensive analysis indicate that Tylototrition hainanensis and T. wenxianensis should be valid species; Echinotriton should be a valid genus;Tylotortriton is a natural cluster; Tylotortriton asperrimus should be put in Tylototrition rather than in Echinotriton, Hypselotriton and Allomestriton are synonyms of Cynops and Paramesotriton, respectively. There are three main groups in Chinese salamandride: Cynops, Paramesotriton and Pachytrition from the first group, the species of the Tylototriton from the second, and E. chinhaiensis composes the third.

Female choice in the red mason bee, Osmia rufa (L.) (Megachilidae)

Females are often thought to use several cues and more than one modality in selection of a mate, possibly because they offer complementary information on a mate's suitability. In the red mason bee, Osmia rufa, we investigated the criteria a female uses to choose a mating partner. We hypothesized that the female uses male thorax vibrations and size as signs of male viability and male odor for kin discrimination and assessment of genetic relatedness. We therefore compared males that had been accepted by a female for copulation with those rejected, in terms of their size, their immediate precopulatory vibrations (using laser vibrometry), the genetic relatedness of unmated and mated pairs (using microsatellite markers) and emitted volatiles (using chemical analyses). Females showed a preference for intermediate-sized males that were slightly larger than the modal male size. Furthermore, male precopulatory vibration burst duration was significantly longer in males accepted for copulation compared with rejected males. Vibrations may indicate vigor and assure that males selected by females are metabolically active and healthy. Females preferentially copulated with males that were genetically more closely related, possibly to avoid outbreeding depression. Volatiles of the cuticular surface differed significantly between accepted and rejected males in the relative amounts of certain hydrocarbons, although the relationship between male odor and female preference was complex. Females may therefore also use differences in odor bouquet to select among males. Our investigations show that O. rufa females appear to use multiple cues in selecting a male. Future investigations are needed to demonstrate whether odor plays a role in kin recognition and how the multiple cues are integrated in mate choice by females.

Cooperation among selfish individuals in insect societies

Kin selection is the key to understanding the evolution of cooperation in insect societies. However, kin selection also predicts potential kin conflict, and understanding how these conflicts are resolved is a major goal of current research on social insects

Studies on taxonomy and ecology of Mysidacea from the EEZ of India

Members of the order Mysidacea are important component in marine and estuarine plankton inhabiting all regions of the oceans. There are many brackish water species and few species occur in fresh water, some have become adapted to the specialized environments of caves and wells. They are omnivores, responsible for remineralisation of a substantial portion of the detritus in the water column. They form an important link in the food chain (between microbial producers and secondary consumers) and therefore play a major role in the cycling of energy within the aquatic ecosystem. In tropical and subtropical waters, swarms of mysids are exploited commercially and marketed as preserved cooked food. Mysids have been used in fish farming as live feed resource. They are also excellent experimental organism, extremely useful in the studies of potential impact of various pollutants in the aquatic environment. Mysids are also used in wood pulp effluent plants.Considering the significant role of mysids in the productivity of tropical and coastal ecosystems,the present study has been undertaken to extend our knowledge on the systematics, species composition, distribution,abundance and ecology of mysid fauna of the Indian EEZ and adjoining areas. The present study therefore will undoubtedly fumish valuable information on Mysidacea of the Indian waters.

Chemical Communication in the Gregarious Psocid Cerastipsocus sivorii (Psocoptera: Psocidae)

The objectives of this study were: (1) to test the existence of an aggregation pheromone in the gregarious psocid Cerastipsocus sivorii; (2) to compare the attractiveness of odors from different aggregations; (3) to test whether nymphs are able to chemically recognize damage-released alarm signals. In a choice experiment conducted in the laboratory, we showed that psocids are able to detect chemical cues from groups of conspecifics. Laboratory experiments also showed that nymphs are capable of chemically recognizing the aggregations where they came from. Finally, in a field experiment, most aggregations dispersed when exposed to the body fluids of a crushed conspecific, but no aggregations dispersed upon exposure to a crushed termite. The implications of these results for the evolution of sociality in psocopterans are discussed.

Dufour glands in the hymenopterans (Apidae, Formicidae, Vespidae): a review

Anexas ao aparelho do ferrão dos himenópteros aculeados encontram-se as glândulas de veneno e as de Dufour. A glândula de veneno é originada das glândulas associadas ao ovopositor dos himenópteros ancestrais não aculeados, já a glândula de Dufour é menos derivada, homóloga das glândulas colateriais dos outros insetos, sendo encontrada em todas as fêmeas dos himenópteros. Nestes insetos sua função é, em grande parte, desconhecida, mas, em formigas, parece estar envolvida com a comunicação e a defesa e, nas abelhas não sociais, com a construção e a proteção do ninho. Nas vespas pode estar relacionada ao reconhecimento parental. Foram observadas diferenças morfológicas e na composição química da secreção da glândula de Dufour entre as espécies, bem como na mesma espécie, entre as castas dos himenópteros sociais e entre indivíduos da mesma casta desempenhando diferentes funções ou pertencentes a ninhos diferentes. Portanto, nos himenópteros, sua função original de produzir substâncias para proteger os ovos ou favorecer a ovoposição parece ter sido substituída ou complementada com a função de produzir semioquímicos com função na comunicação.

Comparative study of the cuticular hydrocarbon composition of Melipona bicolor Lepeletier, 1836 (Hymenoptera, Meliponini) workers and queens

In social insects, cuticular hydrocarbons are involved in species, kin, caste and nestmate recognition. Gas chromatography and mass spectrometry were used to compare the cuticular hydrocarbon composition of workers, males and queens of Melipona bicolor. The cuticular hydrocarbon composition of this species was found to consist mainly of C23, C25:1, C25, C27:1, C27, C29:1 and C29, which are already present in imagoes that have not yet abandoned the brood cell. This composition varied quantitatively and qualitatively between and within the castes and sexes. The newly emerged workers and young queens (virgins) had similar cuticular hydrocarbon profiles, which were different from those of the males. When the females start executing their tasks in the colony, the cuticular hydrocarbon profile differences appear. The workers have less variety, while the queens conserve or increase the number of cuticular hydrocarbon compounds. The queens have more abdominal tegumentary glands than the workers, which apparently are the source of the new cuticular compounds.

Auto/não-auto discriminação de raízes e o reconhecimento parental de Eucalyptus urophylla sob diferentes condições ambientais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sibling recognition in the rat

Mechanisms determining the ability of individuals to recognize their kin can be broadly divided into those prenatally determined and those postnatally determined. The role of both of these possibilities was examined in an investigation of sibling recognition in the rat (Rattus norvegicus). Rat pups were tested for their preference for ‘siblings’, (either littermates and genetic siblings—natural siblings; just littermates—any recognition due to postnatal factors; or just genetic siblings—any recognition due to prenatal factors) as opposed to unfamiliar age-mates between the ages of 6 and 22 days, and also for their ability to detect conspecific odour. The results indicate that rats can recognize their siblings (Experiment V) and this can be achieved solely postnatally (Experiments I, VI), or solely prenatally (Experiments II, VII). Other results demonstrated that rats, as early as day 2, and probably earlier, can detect and respond preferentially to conspecific odours (Experiments III, IV and VIII). The possibilities of how these mechanisms, both postnatal and prenatal, function in the acquisition of sibling recognition are discussed. This is the first study in which individuals separated from all genetic relations postnatally are shown to posses the ability to recognize kin.

Nestmate recognition in the large carpenter bee, Xylocopa virginica /

Abstract Many species of social insects have the ability to recognize their nestmates. In bees, sociality is maintained by bees that recognize which individuals should be helped and which should be hanned in order to maximize fitness (either inclusive or individual) (Hamilton 1964; Lin and Michener 1972). Since female bees generally lay eggs in a single nest, it is highly likely that bees found cohabitating in the same nest are siblings. According to the kin selection hypothesis, individuals should cooperate and avoid aggression with same sex nestmates (Hamilton 1964). However, in opposite sex pairs that are likely kin, aggression should increase among nestmates as an expression of inbreeding avoidance (Lihoreau et al. 2007). Female bees often guard nest entrances, recognizing and excluding foreign conspecific females that threaten to steal nest resources (Breed and Page 1991). Conversely, males that aggressively guard territories should avoid aggression towards other males that are likely kin (Shellman-Reeve and Gamboa 1984). In order to test whether Xy/ocopa virginica can distinguish nestmates from non-nestmates, circle tube testing arenas were used. Measures of aggression, cooperation and tolerance were evaluated to detennine the presence of nestmate recognition in this species. The results of this study indicate that male and female X virginica have the ability to distinguish nestmates from non-nestmates. Individuals in same sex pairs demonstrated increased pushing, biting, and C-posturing when faced with non-nestmates. Males in same sex pairs also attempted to pass (unsuccessfully) nOIl-nestmates more often than ncstmates, suggesting that this behaviour may be an cxpression of dominancc in males. Increased cooperation exemplified by successful passes was not observed among nestmates. However, incrcased tolerance in the [onn of head-to-head touching was observed for nestmates in female same sex and opposite sex pairs. These results supported the kin selection hypothesis. Moreover, increased tolerance among opposite sex non-nestmates suggested that X virginica do not demonstrate inbreeding avoidance among nestmates. 3 The second part of this study was conducted to establish the presence and extent of drifting, or travelling to different nests, in a Xylocopa virgillica population. Drifting in flying Hymenoptera is reported to be the result of navigation error and guard bees erroneously admitting novel individuals into the nest (Michener 1966). Since bees in this study were individually marked and captured at nest entrances, the locations where individuals were caught allowed me to determine where and how often bees travelled from nest to nest. Ifbees were captured near their home nests, changing nests may have been deliberate or explained by navigational error. However, ifbees were found in nests further away from their homes, this provides stronger evidence that flying towards a novel nest may have been deliberate. Female bees are often faithful to their own nests (Kasuya 1981) and no drifting was expected in female X virginica because they raise brood and contribute to nest maintenance activities. Contrary to females, males were not expected to remain faithful to a single nest. Results showed that many more females drifted than expected and that they were most often recaptured in a single nest, either their home nest or a novel nest. There were some females that were never caught in the same nest twice. In addition, females drifted to further nests when population density was low (in 2007), suggesting they seek out and claim nesting spaces when they are available. Males, as expected, showed the opposite pattern and most males drifted from nest to nest, never recaptured in the same location. This pattern indicates that males may be nesting wherever space is available, or nesting in benches nearest to their territories. This study reveals that both female and male X virginica are capable of nestmate recognition and use this ability in a dynamic environment, where nest membership is not as stable as once thought.

Exploring the effectiveness of virtual product placement on recall and recognition of new brands

This paper investigates the effectiveness of virtual product placement as a marketing tool by examining the relationship between brand recall and recognition and virtual product placement. It also aims to address a gap in the existing academic literature by focusing on the impact of product placement on recall and recognition of new brands. The growing importance of product placement is discussed and a review of previous research on product placement and virtual product placement is provided. The research methodology used to study the recall and recognition effects of virtual product placement are described and key findings presented. Finally, implications are discussed and recommendations for future research provided.