Evidence of Nasonov Scenting in Colony Defence of the Giant Honeybee Apis dorsata

Participation of the Nasonov scent in the defence waving behaviour of Apis dorsata is demonstrated. The Nasonov scent seems to act as a superior pheromone for the control and promotion of individual defensive reaction, synchronizing and maximizing the defensive response on colony level. The role of Nasonov scenting in defensive behaviour is discussed, being in keeping with its usual role in attraction and coordination of social behaviour, as known from A. mellifera.     

Larval feeding behaviour of Tetanocera elata (Diptera: Sciomyzidae): potential biocontrol agent of pestiferous slugs

Examining predatory behaviour is useful for determining the potential of novel biocontrol agents. We investigated the predatory behaviour of Tetanocera elata (Fabricius) larvae on the pestiferous slug Deroceras reticulatum (Müller). Results indicate three prey-finding strategies, including the predator reaching its prey without previous contact with it or its mucus trail.     

Use of artificial arenas to predict the social organisation of halictine bees: Data for fourteen species from Chile

I studied the behavioural profiles of fourteen species of Chilean halictine bee using the circle tube apparatus. Interactions were classified as aggressive, avoidance or cooperative. One species, Corynura chloris, is believed to be semisocial and its behaviour was largely aggressive, Ruizantheda mutabilis is known to be communal and its behaviour was predominantly cooperative whereas Penapis toroi is a member of a subfamily from which only solitary behaviour is known and it primarily exhibited avoidance behaviours. As a result, I suggest that the relative frequency of these different behaviours may be useful in establishing the social organisation of species. Based upon comparisons of behavioural profiles, I predict the social organizations of the remaining species and suggest that at least some of the bees in the populations of Ruizantheda proxima, Caenohalictus dolator, Ca. species A and Pseudagapostemon pississi investigated exhibit communal behaviour; those of Co. patagonica and Co. herbsti likely have a reproductive division of labour, probably within semisocial societies, and that the populations of Co. corinogaster, Co. melanocladius, Ca. pygosinuatum, Ca. cuprellus and Lasioglossum aricense studied are probably solitary. Phylogenies suggest that solitary behaviour in Ca. pygosinuatum and Ca. cuprellus is reversed from communal behaviour and solitary behaviour in L. aricense may be a reversal from eusociality. The response “back and follow” is not indicative of dominance or cooperation as it correlated only with the frequency of avoidance interactions among the taxa studied. I discuss the utility of the circle tube apparatus in the identification of populations worthy of more detailed sociobiological investigation. Received 10 August 2005; revised 8 March 2006; accepted 21 March 2006.     

Aggressive Behaviour Between Gymnocharacinus Bergi (Pisces, Characidae) And Other Neotropical Fishes From A Thermal Stream In Patagonia

Gymnocharacinus bergi is a stenothermal endangered fish only found in the headwaters of a thermal stream within the temperate Somuncurá Plateau (Patagonia, Argentina). In spite of the presence of other fish species in the Valcheta Stream basin, none of these has been found at the headwaters. Temperature and salinity cannot account for the absence of extremely eurytopic Cnesterodon and Jenynsia. In addition, there is no evidence of diet overlapping or territory defence between these species and G. bergi. Therefore, we hypothesise that agonistic behaviour might be related to G. bergi's isolation. Experiments were performed in order to analyse interspecific interaction between G. bergi and individuals of the other two species. Cnesterodon decemmaculatus showed a submissive behaviour while Jenynsia multidentata was clearly aggressive. G. bergi decreased its aggressive behaviour towards C. decemmaculatus throughout the experiment. However, when placed with J. multidentata, its aggressive behaviour did not diminish. We suggest that the characteristics of the agonistic behaviour displayed by J. multidentata, opposite from those displayed by C. decemmaculatus, might account for the absence of J. multidentata in G. bergi's present habitat. With respect to C. decemmaculatus, other factors such as its low counter current swimming ability might play a major role in this phenomenon.     

Cucurbit aphid‐borne yellows virus (CABYV) modifies the alighting,settling and probing behaviour of its vector Aphis gossypii favouring its own spread

Plant pathogens are able to influence the behaviour and fitness of their vectors in such a way that changes in plant–pathogen–vector interactions can affect their transmission. Such influence can be direct or indirect, depending on whether it is mediated by the presence of the pathogen in the vector's body or by host changes as a consequence of pathogen infection. We report the effect that the persistently aphid‐transmitted Cucurbit aphid‐borne yellows virus (CABYV, Polerovirus) can induce on the alighting, settling and probing behaviour activities of its vector, the cotton aphid Aphis gossypii. Only minor direct changes on aphid feeding behaviour were observed when viruliferous aphids fed on non‐infected plants. However, the feeding behaviour of non‐viruliferous aphids was very different on CABYV‐infected than on non‐infected plants. Non‐viruliferous aphids spent longer time feeding from the phloem in CABYV‐infected plants compared to non‐infected plants, suggesting that CABYV indirectly manipulates aphid feeding behaviour through its shared host plant in order to favour viral acquisition. Viruliferous aphids showed a clear preference for non‐infected over CABYV‐infected plants at short and long time, while such behaviour was not observed for non‐viruliferous aphids. Overall, our results indicate that CABYV induces changes in its host plant that modifies aphid feeding behaviour in a way that virus acquisition from infected plants is enhanced. Once the aphids become viruliferous they prefer to settle on healthy plants, leading to optimise the transmission and spread of this phloem‐limited virus.     

Observation of brown-throated three-toed sloths: mating behaviour and the simultaneous nurturing of two young

Bradypus variegatus is a member of the Order Pilosa, Family Bradypodidae, and is distributed in many subtropical and tropical countries in South and Central America. However, studies on this species in the wild are relatively limited and many aspects of its reproductive behaviour are unknown or unclear. The current report presents new observations of the reproductive behaviour of B. variegatus in its natural environment. These include details of both a male–female copulation and the simultaneous nurturing of two young sloths.     

Feeding behaviour of the Japanese loach,Misgurnus anguillicaudatus (Cobitididae)

The feeding behaviour of a Japanese loach,Misgurnus anguillicaudatus was experimentally analyzed. From observations the behaviour patterns were described. The adult fish responded to a piece of thread soaked with filteredTubifex homogenate (Tubifex solution) and showed feeding behaviour. But they ignored an unsoaked piece of thread. LivingTubifex kept in a glass cell failed to elicit feeding behaviour in the fish. A gauze-covered vessel withTubifex solution buried in the sand substrate released feeding behaviour in fish in its vicinity. It follows that the feeding behaviour of this fish is induced by some chemical stimuli. WhenTubifex solution was introduced at the central area of the plastic vessel with a fish, the fish suddenly started the Feeding-crawl and showed Gulp which was composed of Dig and Twist. Using sand particles, it was shown that intake of materials into the digestive tract occurs only at the moment of Twist and not any other time. The standard feeding patterns ofMisgurnus anguillicaudatus are thus quick inhalation of organic matter together with substrate, occurring at the moment of Twist, which is released at the place where the fish received the appropriate chemical stimuli.Misgurnus anguillicaudatus is regarded as a typical “detritus feeder”.     

Étude de la distribution des organes sensoriels de l'antenne et de leurs relations possibles avec le comportement chez deux fourmis myrmicines:Myrmica lævinodis Nyl. etAphænogaster gibbosa Latr. récoltées dans la région des Eyzies

Conclusion. Summary Morphological and statistical researches on the sensory equipment of the Ant's antennæ in chapter I of this work have enabled us to interpret some biological phenomena to be enlarged upon in the next chapters.The part played by the champagne cork shaped organs in the trophallaxic behaviour has been shown by ablations ofMyrmica lævinodis Nyl. antennæ.Aphænogaster gibbosa Latr., a species which does not practise the stomodeal exchanges, possesses twice less numerous champagne cork shaped organs on its antennæ.Besides, in those mixed colonies where the two species are bred together,Aphænogaster sometimes receives food fromMyrmica.However the importance of those needful organs should hot be overvalued becauseMyrmica is partly able to practise the trophallaxic behaviour whithout its feelers. Moreover, ifAphænogaster does not exchange food in its nests, this is certainly not due to a defect of its sensory equipment but very likely to the disappearance of the innate behaviour of «agiver», an inductor of the one of a «receiver». ThusAphænogaster's sensory equipment does need to become as evolued as the one ofMyrmica. The importance (very likely of an olfactory nature) of those organs in other behaviours may have caused its persistence onAphænogaster's antennæ. The crop of that ant has grown much less extensible than the one ofMyrmica.It is further to be noticed that the behaviour ofMyrmica as agiver when its feelers have been cut-off proves easier to carry out but more difficult to acquire or to preserve on the evolutive plane, and thus seems to be more basic as regards trophallaxy.Finaly, beyard the knowledge of the sensory qualities, the interest of the myrmecological material lies in that it affords a new method of approach for the study of the determinism of the behaviour.

---

---

Adresse au moment de la parution de l'article: Laboratoire d'Ethologie Expérimentale «Les Sources», 78-Mittainville.     

The Effects of Food Deprivation in Dyadic Encounters in Apodemus sylvaticus

The nature of dominance in relationships among male Apodemus sylvaticus was investigated using multivariate analysis and by experimental manipulation of the behaviour of dominants. The behaviour of dominant mice was typified by greater frequencies and durations of exploration, approach and pursuit of subordinates in short encounters in a small arena. The direction of encounters normally remained constant over 48 h. When the dominant mouse in a dyad was deprived of food there was a change in its behaviour and an immediate change in the behaviour of the subordinate. Subordinates showed greater interest in starving, though known, dominants, explored more freely and indulged more in pursuit than control subordinate mice i. e. those matched with dominants on an adequate diet. Results suggest that in A. sylvaticus, dominance is associated with the inhibition of the activity of a subordinate and the relationship is maintained by the behaviour of the dominant rather than the deference of the subordinate.     

THE PROBLEM OF CHICK LOSS IN THE SOUTH POLAR SKUA CATHARACTA MACCORMICKI

Hunger releases the aggressive behaviour commonly shown by the first chick of the two-chick brood of the South Polar Skua Catharacta maccormicki. Hunger also releases aggressive behaviour in the second chick, but asynchronous hatching usually restricts this behaviour to the first chick. The degree of hunger experienced by the first chick regulates the intensity of its aggressive behaviour, which in turn affects the second chick's survival. Aggressive behaviour restricts the second chick's access to the nest area and deprives it of parental attention, increasing its susceptibility to starvation, exposure and predation. Weight and age differences between the chicks affect neither the release of aggressive behaviour, nor the survival of the second chick.     

The natural history of Myrmarachne melanotarsa,a social ant‐mimicking jumping spider

Abstract

Myrmarachne melanotarsa, an ant‐like jumping spider (Salticidae) from East Africa, is an accurate mimic of Crematogaster sp. and associates unusually closely with its models. M. melanotarsa is remarkable in that it forms dense aggregations and builds large nest complexes (numerous individually‐occupied nests connected to each other by silk). Other salticids (Pseudicius spp., Menemerus spp.) live with M. melanotarsa in the same nest complex. These aggregations, which can exceed 50 conspecific individuals per colony, are considerably larger than those few previously described, and seem to have primarily a protective function. We provide baseline information on the natural history of M. melanotarsa, paying particular attention to predatory behaviour and association with Crematogaster sp., and fit this within current theory on the function of sociality in spiders. Other unusual behaviour of M. melanotarsa includes “mouthing”, in which the spider opens and closes its chelicerae while pressing its mouthparts against nest silk. We investigated the role of prior presence of Crematogaster sp. on nest silk in eliciting this previously unreported behaviour.     

Report of opportunistic feeding habits by Vences’ river crab Hydrothelphusa vencesi (Brachyura: Potamoidea: Potamonautidae)

Hydrothelphusa vencesi is an endemic Madagascan freshwater crab whose ecology and behaviour are largely unknown. We report here on an episode of the feeding habits of two individuals of H. vencesi on a giant fire millipede (Aphistogoniulus infernalis) and on a cicada (Malagasia inflata) in south-east Madagascar. This represents a first report on the diet of this species and an example of its opportunistic feeding behaviour, shedding some light on the possible trophic link between an aquatic and a terrestrial system.     

A Quantitative Analysis of Secretion-Grooming Behaviour in the Water Bug Plea minutissima Leach (Heteroptera,Pleidae): Control by Abiotic Factors

The pigmy backswimmer, Plea minutissima, from time to time leaves the water to apply its antimicrobial metathoracic gland secretion to its water-repellent ventral pubescence (“secretion-grooming”) which is enclosed by an air sheath when submerged and has a respiratory function. Secretion-grooming keeps the hairs free of microbial contamination and thus hydrophobous and functional. The grooming behaviour is regulated by abiotic factors. It is released by an increase in light intensity or water temperature, with a sudden rise in temperature being particularly effective. The higher the temperature and light intensity, the faster the grooming act is performed and completed. The grooming motivation is higher at a higher ambient temperature, but declines once the behaviour has been brought to completion. As a consequence the highest grooming activity in the field is observed in summer on the first sunny day after a prolonged period of overcast days. The tying of secretion-grooming to abiotic factors probably serves to destroy epizoic microorganisms before they begin to multiply more rapidly at higher temperatures. The mechanisms regulating the secretion-grooming behaviour of Plea may be of significance also for the regulation of certain other insect behaviours (e.g., flight behaviour).     

Observation on the life cycle of Bulbochaete allahabadensis sp. nov. (Chlorophyta,Oedogoniacea)

Bulbochaete allahabadensis sp. nov. is described from a temporary pond at Allahabad. Most of its life-cycle stages have been observed. It differs from other known species of the genus Bulbochaete in having characteristic oospores and interesting behaviour of androspores. Andropores after liberation from normal vegetative cells may germinate anywhere and form dwarf males or produce several celled branched germlings with precocious formation of antheridia. Such zoospore-like behaviour of androspores confirms the observations made by other workers under culture conditions.     

A relative shortage of nitrogenous food in the ecology of the koala (Phascolarctos cinereus)

The disparity between the distribution and abundance of the koala (Phascolarctos cinereus) and its major food trees (Eucalyptus spp.) is examined in terms of the essential oil content of the leaves, the influence of weather, social behaviour, and the level of available nitrogenous food. The essential oils are considered to be relatively unimportant since the koala has the ability to detoxify them. It is proposed that the level of available nitrogenous food is the major limiting influence on the abundance of the koala. Social behaviour enables a few koalas to acquire sufficient food while the majority of the population is subject to a relative shortage of food. The weather varies the local availability of adequate nitrogenous food by its influence on leaf growth in the eucalypts. Unusually favourable weather or inappropriate management which lead to a local increase in the availability of young growing leaves (flush growth) may result in outbreaks in koala numbers.     

First record of the mating behaviour of the spotted surubim Pseudoplatystoma corruscans in the Uruguay River

The spotted surubim Pseudoplatystoma corruscans is a large migratory catfish native to the La Plata and San Francisco basins. Nonetheless, its reproductive dynamics and behaviour remain poorly understood. This brief note provides the first record of the mating behaviour of P. corruscans in natural conditions. This behaviour was observed in the main channel of the Middle Uruguay River (Brazil). A school of approximately 25 fish, 5 females (with protruding abdomen and larger body size) and 20 males, were followed and videotaped. The largest female led the school, followed by other fish. Some males disputed repeatedly the posterior region of the females, whereas other males continuously repelled them. Eventually, some males, apparently exhausted, floated belly up. During this event, males were in a state of pronounced agitation, and some had abrasions in the head. Polygamy characterized the mating behaviour of P. corruscans.     

Analysis of meiosis and non-random bivalent formation in desynaptic mutants of Pennisetum americanum (L.) Leeke

Meiotic behaviour of induced desynaptic mutants of Pennisetum americanum (L.) Leeke in general was described.The frequency distribution of bivalents in induced desynaptic mutants was compared with that expected on the basis of the binomial series. The deviation from the binomial distribution was tested as to its conformity with models based on intra-and intercellular differences in bivalent formation. It is suggested that in these desynaptic mutants of Pennisetum americanum bivalent formation is non-random, which is largely due to the result of intracellular differences in chromosome behaviour regarding their requirements for chiasma formation.     

Going down together: invasive host,Charybdis longicollis (Decapoda: Brachyura: Portunidae) and invasive parasite,Heterosaccus dollfusi (Cirripedia: Rhizocephala: Sacculinidae) on the upper slope off the Mediterranean coast of Israel

The swimming crab Charybdis longicollis, native to the western Indian Ocean, was first recorded in the Mediterranean in 1954. It is now established from Egypt to Greece, and dominates the sandy-mud bottoms at 25–80?m in the southeastern Mediterranean. The success of C. longicollis is attributed to its high fecundity, agonistic behaviour and omnivorous diet, as well as the rise in seawater temperature. Since the early 1990s its populations in Israel and Turkey have been heavily parasitized by the alien rhizocephalan Heterosaccus dollfusi, which impacts its host’s behaviour, growth and fecundity, and causes mortality. Yet, 60 years after its first record in the Mediterranean, the population of C. longicollis seems durable, and has recently spread to the lower shelf and upper slope off Israel, where it is common at 80?m and is found down to 250?m, greatly increasing its spatial spread. The maximal percentage of parasitization was 87.2%, 88.8%, 75.5% and 81.8% at depths of 40, 60, 80, 100?m, respectively, and 50% at 120 and 250?m. Here, we hypothesize on the possible contribution of the depletion of its putative fish predators, mainly rays, to the prevalence of C. longicollis on the lower shelf.     

Precocious Courtship and Play in Emydid Turtles

In many mammal species, precocious sexual behaviour is a component of play. A recent model for the evolution of play fighting behaviour in muroid rodents by Pellis (1993) proposes that social play in those species has its origin in precocious sexual behaviour. Captive juvenile emydid turtles perform precocious sexual behaviour. After reviewing its occurrence, we focus on detailed observations of Pseudemys nelsoni. Precocious sexual behaviour in these turtles is characterized by the striking ‘titillation’ display, usually observed only when adult males court females. In this display, the digits of the front feet are rapidly vibrated above the eyes of the female. In our observations, both sexes performed the display, which was energetic, spontaneous, and inconclusive (in that sequences of precocious courtship typically ended when either the displayer or recipient stopped and rested, left, or started some other unrelated non-social behaviour). Displaying individuals clearly preferred conspecific recipients and often appeared to seek out specific individuals. We discuss several plausible explanations for precocious courtship in these turtles but find none entirely satisfying. The characteristics of the precocious courtship behaviour we observed most closely match those commonly listed for social play. Thus, we conclude that the most likely explanation for this behaviour is that it is a component of social play.