Physiological state influences the social interactions of two honeybee nest mates

Physiological state profoundly influences the expression of the behaviour of individuals and can affect social interactions between animals. How physiological state influences food sharing and social behaviour in social insects is poorly understood. Here, we examined the social interactions and food sharing behaviour of honeybees with the aim of developing the honeybee as a model for understanding how an individual's state influences its social interactions. The state of individual honeybees was manipulated by either starving donor bees or feeding them sucrose or low doses of ethanol to examine how a change in hunger or inebriation state affected the social behaviours exhibited by two closely-related nestmates. Using a lab-based assay for measuring individual motor behaviour and social behaviour, we found that behaviours such as antennation, willingness to engage in trophallaxis, and mandible opening were affected by both hunger and ethanol intoxication. Inebriated bees were more likely to exhibit mandible opening, which may represent a form of aggression, than bees fed sucrose alone. However, intoxicated bees were as willing to engage in trophallaxis as the sucrose-fed bees. The effects of ethanol on social behaviors were dose-dependent, with higher doses of ethanol producing larger effects on behaviour. Hungry donor bees, on the other hand, were more likely to engage in begging for food and less likely to antennate and to display mandible opening. We also found that when nestmates received food from donors previously fed ethanol, they began to display evidence of inebriation, indicating that ethanol can be retained in the crop for several hours and that it can be transferred between honeybee nestmates during trophallaxis.     

Food-attraction conditioning in the snail,Helix pomatia

Adult pulmonate snails (Helix pomatia) were released equidistant between two types of food, carrot and potato, respectively. Naive snails moved in different directions and did not locate either food above chance, although both foods were readily eaten upon direct contact. After a single carrot feeding episode, 75% of the carrot-fed snails moved directly towards the carrot and ate it. Conversely, potato-fed snails located the potato in 67% of the cases. Snails that were fed apple or lettuce behaved like naive animals, with the majority of animals (75% in both cases) locating neither the carrot nor the potato.The ability of snails to locate this particular food after a single feeding episode was maintained for at least 11 days, provided that the snails were not exposed to other foods in the interim. If the animals were fed a different food (but still tested for food-finding ability to the initially conditioned food) their orientation preference decreased gradually over a period of 5 days.Although the snails' orientation is based upon olfactory cues, exposure to food odor alone is not sufficient to enable food-finding; additional feeding related stimuli are necessary.These findings indicate that Helix do not possess a predisposition for the foods tested, and further suggest that processes underlying food-finding and food selection are strongly influenced by learning experiences. The conditioning phenomenon underlying food-finding behavior has been called Food-Attraction Conditioning, and appears to be a crucial link between the ecologies of learning and foraging behaviors. The accessibility of the snail's nervous system should permit neuronal analysis of the mechanisms underlying such a unique and complex learning phenomenon.     

Neuropeptide Y: Behavioral effects in the golden hamster

Neuropeptide Y (NPY) is found abundantly in nervous tissues of vertebrate species including the golden hamster. Centrally-administered NPY has been reported to elicit ingestive behaviors in the rat, squirrel, pig, mouse, and chick. To assess NPY's behavioral effects in a New World rodent that does not increase food intake after deprivation, NPY was injected intracerebroventricularly (10.0-0.04 μg/5 μl) in home-caged golden hamsters with ad lib access to food, water and 5% w/v ethanol solution. Food and fluid intakes, and behavior displays were monitored after NPY injection. NPY promptly increased short-term food intake and observed feeding behaviors at 10.0, 3.3, 1.1, and 0.37 μg NPY, but there was no effect on 24 hr food intake. Water and ethanol intakes were increased only at 10.0 and 0.37 μg NPY, respectively. Resting behaviors decreased at NPY doses that increased feeding, but there were no consistent effects of NPY on any other category of behavior. Results demonstrate that NPY potently stimulates short-term food intake and decreases resting behavior in the golden hamster. The lack of compensatory food intake in deprived hamsters cannot be explained as an insensitivity to the putative orexigenic function of endogenous neuropeptide Y.     

The facilitation of defensive reactions during food consumption in the snail helix: the participation of glucose and gastrin/cholecystokinin-like peptide]

Molecular and cellular mechanisms of the interrelations between the feeding and defense behaviour were studied in a snail Helix lucorum. The dynamics of defense reactions was investigated in snails with different levels of feeding motivation. Defense reactions were suppressed in hungry snails, while 15-20 min after the beginning of food intake they were facilitated. The facilitation depended on a duration of starvation. Injection of 0.5 ml of 5 mM glucose solution (up to the glucose level in the haemolymph of a food satiated snail, 1.6-2.0 mM) or injections of 20-30 ng of synthetic analogues of the gastrointestinal peptides (pentagastrin of octapeptide cholecystokinin, CCK-8) facilitated the defense reaction in a hungry snail. Parameters of the facilitation were similar to those in the period of food intake. Activity of the command neurons of defense behaviour (L-PPL1) after the carrot juice application to the lip of a semi-intact preparation from a hungry snail was glucose-dependent. Similar glucose-dependent changes of L-PPL1 activity were found after CCK-8, but not FMRFamide application during the perfusion with 0.5 mM glucose. L-PPL1, but not L-PPa2-3 neurons were most sensitive to glucose and CCK-8 level changes in the Ringer solution. Adaptive significance of the behavioural phenomena as well as glucose and gastrin/CCK-like peptide participation in these processes are discussed.     

The effect of the acute administration of ethanol on the realization of behavior and its neuronal support

In experiments on rabbits trained to instrumental food procuring behaviour it was cleared up, which changes of activity of neurones of the limbic cortical area corresponded to disturbances of this behaviour (increase in time of realization and in the number of errors) caused by intraperitoneal injection of 12% ethanol solution in a dose of 1 g/kg. In comparison with control (administration of isotonic solution), the number of active cells singled out in the microelectrode track was reduced by 1/3; the pattern of behavioural specialization of neurones involved in provision of the disturbed behaviour was changed. The content of neurones of the most recent systems formed during animals learning instrumental behaviour, decreased from 27 to 11%, and of neurones providing for realization of systems formed at previous stages of individual development increased from 18 to 36%.     

Screening of antifeedant activity in brain extracts led to the identification of sulfakinin as a satiety promoter in the German cockroach. Are arthropod sulfakinins homologous to vertebrate gastrins-cholecystokinins?

The feeding cycle of the adult female cockroach Blattella germanica parallels vitellogenesis. The study of the mechanisms that regulate this cycle led us to look for food-intake inhibitors in brain extracts. The antifeedant activity of brain extracts was tested in vivo by injecting the extract and measuring the carotenoids contained in the gut from carrot ingested after the treatment. By HPLC fractionation and tracking the biological activity with the carrot test, we isolated the sulfakinin EQFDDY(SO3H) GHMRFamide (Pea-SK). A synthetic version of the peptide inhibited food intake when injected at doses of 1 microg (50% inhibition) and 10 microg (60% inhibition). The sulfate group was required for food-intake inhibition. These biological and structural features are similar to those of the gastrin-cholecystokinin (gastrin-CCK) family of vertebrate peptides. However, heterologous feeding assays (human CCK-8 tested on B. germanica, and Pea-SK tested on the goldfish Carassius auratus) were negative. In spite of this, alignment and cluster analysis of these and other structurally similar peptide families suggest that sulfakinins and gastrin-CCKs are homologous, and that mechanisms of feeding regulation involving these regulatory peptides may have been conserved during evolution between insects and vertebrates.     

Feeding responses of adult butterflies, Nymphalis xanthomelas, Kaniska canace and Vanessa indica, to components in tree sap and rotting fruits: synergistic effects of ethanol and acetic acid on sugar responsiveness

Exuded tree sap and rotting fruits are important feeding sources for adults of many butterfly species. However, the chemical composition of such rotting foods and the effects of these constituents on butterfly feeding behaviour have rarely been investigated. Chemical analyses revealed that these food sources contain several major components, including fructose, glucose, ethanol and acetic acid. Moreover, 15 amino acids were identified from the exuded tree sap. The gustatory responsiveness to these components was examined in the proboscis of nymphalid adults of three species (Nymphalis xanthomelas, Kaniska canace and Vanessa indica). The first two species primarily feed on sap and rotting fruits, while V. indica frequently visits flowers. Fructose elicited larger feeding responses from these saprophagous butterflies than glucose, which had a feeding-stimulatory effect only on N. xanthomelas at a concentration equivalent to that of the food. Ethanol, acetic acid and the five major amino acids identified in tree sap did not elicit feeding responses by themselves. However, ethanol and/or acetic acid, when mixed with these sugars at equivalent concentrations, evoked feeding and enhanced probing responses in K. canace and V. indica. These results suggest that ethanol and acetic acid, together with sugars at low concentrations, synergistically stimulate butterfly feeding behaviour.     

Larval ethanol exposure alters adult circadian free-running locomotor activity rhythm in Drosophila melanogaster

Alcohol consumption causes disruptions in a variety of daily rhythms, including the sleep-wake cycle. Few studies have explored the effect of alcohol exposure only during developmental stages preceding maturation of the adult circadian clock, and none have examined the effects of alcohol on clock function in Drosophila. This study investigates developmental and behavioral correlates between larval ethanol exposure and the adult circadian clock in Drosophila melanogaster, a well-established model for studying circadian rhythms and effects of ethanol exposure. We reared Drosophila larvae on 0%, 10%, or 20% ethanol-supplemented food and assessed effects upon eclosion and the free-running period of the circadian rhythm of locomotor activity. We observed a dose-dependent effect of ethanol on period, with higher doses resulting in shorter periods. We also identified the third larval instar stage as a critical time for the developmental effects of 10% ethanol on circadian period. These results demonstrate that developmental ethanol exposure causes sustainable shortening of the adult free-running period in Drosophila melanogaster, even after adult exposure to ethanol is terminated, and suggests that the third instar is a sensitive time for this effect.     

Olfactory experience modifies the effect of odour on feeding behaviour in a goal-related manner

Natural food odours elicit different behavioural responses in snails. The tentacle carries an olfactory organ, and it either protracts toward a stimulating carrot odour or retraces in a startle-like fashion away from a cucumber odour. The tentacle retraction to cucumber was still present after the snails were fed cucumber during inter-trial periods. Also, snails without any food experience displayed a longer latency to the first bite of cucumber than of carrot and rejected cucumber more often. After tasting these foods, the latency to carrot was not affected while the latency to and number of rejections of cucumber decreased. These results suggest that initial repulsive features of food odour can be only partially compensated by olfactory learning and feeding experience. In the present study, we demonstrated that an invertebrate can be repulsed or attracted by the same natural odour at the same time and that these behavioural responses are likely aimed at achieving different physiologically relevant goals.     

Varying responses to feeding competition in a group of rhesus monkeys (Macaca mulatta)

The behaviour of members of a group of rhesus monkeys was observed in experimentally created, competitive feeding situations. Socially dominant members of the group tended to start eating before lower-ranking subjects, and generally ate more. Dominants sometimes used aggression to control access to food, but overall, intermediate-ranking monkeys were involved in most agonistic episodes. Non-dominant subjects improved their feeding performance when food was presented in three piles rather than one pile, often by snatching food and consuming it away from the pile. These general patterns were less evident when realistic snake models were placed on some of the food piles. Feeding was disrupted by the presence of snakes, but notably, subordinates risked feeding in these conditions. Piles containing preferred foods and snakes were eaten from, but a low-preference food (carrot) under snakes went untouched by all subjects. The results suggest that group-members evaluate potential risks and benefits of competing for a restricted resource, and that dominance status, while an important factor, is only one element in the equation.     

Interrelationship between grape snail alimentary and defense behavior command neurons]

Food stimulus (carrot juice), releasing feeding behaviour in intact snails, evoked spike discharges in giant meta-erebral cells (considered to be command neurones of feeding behaviour) and subthreshold EPSPs in giant parietal cells (command neurones of avoidance behaviour) of a half-intact preparation. Tactile stimulation, eliciting avoidance reactions in intact snails, evoked hyperpolarization in command neurones of feeding behaviour and a spike discharge in command neurones of avoidance behaviour. Spikes induced into either of command neurones produced no changes in activity of other command cells. Inhibition of command neurones of feeding behaviour is assumed to be the basis of behavioural choice when food and tactile stimulus are presented simultaneously.     

Effect of gamma globulins against brain-specific non-histone chromosomal proteins on the reproduction of a conditioned response in grape snails

The effects of gamma-globulins to brain specific nonhistone chromatin proteins (BSNCP-3.5;-3.6) on conditioned food avoidance behaviour (carrot or apple) was studied in the garden snail. It was found that half an hour later the intracorporeal injection of BSNCP-3.5 inhibited conditioned carrot, but not apple avoidance reaction. Injection of BSNCP-3.6 was ineffective in avoidance behaviour induced by both conditioned stimuli. BSNCP-3.5 is suggested to be specifically involved in the process of information recollection.     

Bait consumption and residual concentrations of diphacinone in the Wellington tree weta (

To investigate the potential for mortality or sublethal effects in the tree weta (Hemideina crassidens) as the result of exposure to baits used for rodent control, and the potential secondary hazard to non-target species, captive weta were offered Ditrac® wax block bait containing the anticoagulant diphacinone. Bait consumption was recorded daily for the first week and then weekly. Weta were sampled in groups of four following 1, 4, 8, 6, 3, and 64 days of exposure to bait and analysed to determine the concentration of diphacinone residues in their bodies. Any changes in feeding behaviour, survival, and bodyweight were recorded. Weta found Ditrac wax block baits palatable even in the presence of natural plant food, showing steady consumption of bait over time. No mortality or weight loss was attributable to the intake of Ditrac bait. All weta that ate bait had detectable diphacinone in their bodies, but did not accumulate diphacinone, i.e. whole-body concentrations did not increase with the amount of diphacinone bait eaten over time. Field use of diphacinone bait is likely to present a low risk of mortality to weta, but the risk posed by secondary diphacinone exposure to non-target species that eat weta requires further investigation.     

In Ovo Olfactory Experience Influences Post‐hatch Feeding Behaviour in Young Chickens

In several mammalian species, prenatal exposure to odours can elicit later positive consummatory behaviour in response to substrates bearing that odorant. In birds, the sense of smell has been considerably underestimated, and very little is known about the effects of early sensory experience on the regulation of feeding behaviour. We tested the hypothesis that the feeding behaviour of the domestic chicken could be regulated by olfactory learning during the embryonic life. To that end, chicken embryos were exposed to an olfactory stimulus (blend of essential oil of orange and nature identical vanillin) from embryonic day (ED) 12 to ED20, and chicks were tested between 4 and 9 d of age. In short‐term choice tests, at day 4 and 5, chickens previously exposed to a low concentration (LC) of the olfactory stimulus spent a higher proportion of time eating a familiar or an unfamiliar food bearing the olfactory stimulus compared to non‐exposed control chickens. Conversely, chickens previously exposed to a high concentration (HC) of the olfactory stimulus were found to avoid all foods bearing the olfactory stimulus. On a 24‐ h time scale at day 7–8, LC and HC birds, but not controls, ingest significantly less familiar food containing the olfactory stimulus. This result indicated a long‐term effect of the early olfactory experience on feeding preferences. We demonstrated that chickens can utilize information from their pre‐hatch chemosensory environment to guide their later feeding behaviour. A pre‐hatch effect of the intensity of odour signals in the regulation of feeding behaviour is reported here for the first time.     

Food deprivation and the regulation of meal size in larvae of Chrysopa carnea

ABSTRACT. The course of repletion and the effects of food deprivation on meal size were explored in three experiments on larvae of Chrysopa carnea (Neuroptera). Feeding to repletion was found to occur within the first 30 min of exposure to food. Meal size increased as an ogival function of deprivation, up to the limit of gut capacity. Behavioural components involved in the initiation of feeding were little affected by deprivation and did not appear to be inhibited by distention of the gut. Termination of a meal may be mediated by the stimulation of prey-release behaviour, rather than by inhibition of feeding.     

Changes in cardiac activity, oxygen uptake and perfusion indices in Carcinus maenas (L.) exposed to crude oil and dispersant

Cardiac activity and oxygen consumption increased when C. maenas were exposed to a 20% solution of the water-soluble fraction of Fortes crude oil, a 10% solution of the dispersant BP1100WD or a combination of both. Normal feeding behaviour was disrupted. Perfusion indices (Q/VO2) decreased as locomotor activity increased following exposure to crude oil. However, exposure to dispersant or dispersant + crude oil resulted in elevation of perfusion index despite crabs becoming active. All test animals survived for at least 6 weeks following exposure to the pollutants. The acute, sublethal effects of dispersant and dispersant + crude oil were more severe than the effects of crude oil alone.     

阿特拉津和林丹对紫贻贝生长与繁殖净能的影响

本研究评估了亚致死浓度的林丹(1/2的60dLC50,0.935mg/L)和阿特拉津(1/2的60dLC50,3.585mg/L)对海洋性贝类影响的生理学反应。林丹和阿特拉津是已被公认的环境污染物质。56d的实验表明,这两种农药在贝类体内具有积累作用,而且在体内各器官的积累程度与其作用的靶器官相一致。林丹在体内的积累浓度(每克干重372μg)比阿特拉津(每克干重137μg)更高。该贝类在林丹中暴露56d,其氧的消耗比对照组降低10%,而在阿特拉津中则比对照组提高了29%。经林丹和阿特拉津暴露后,增加了氨排泄物。但是,两种农药均使贝类的取食率和吸收率下降。林丹会降低贝类的取食率、氧消耗、氨排泄、食物吸收率以及生长范围。在形式上,阿特拉津对贝类的影响与林丹的影响有不同之处,它会降低贝类的取食率和食物吸收率,但与林丹不同的是,它会提高贝类的氧消耗和氨排泄。总之,阿特拉津会明显地减小贝类繁殖净能。因此,阿特拉津暴露与林丹暴露的毒性症状是一致的。结合组织化学分析,贝类的生理学反应可作为一种理想的环境监测工具。研究结果表明,在二分之一的半致死浓度下暴露两个月,不仅能有效地证明林丹和阿特拉津在贝类组织内具有积累作用,而且对这些积累能产生生理反应。     

Assimilation efficiencies of slugs on different food materials

Summary The relative assimilation efficiencies of two common British species of slug, Limax flavus (L.) and Arion hortensis (Fér.), were studied in the laboratory using a gravimetric method. Results are given for adult slugs feeding on carrot root and potato tuber at 5°, 10°, 15°, and 20° C, and for L. flavus juveniles of known age feeding on potato at 10° and 15° C. A few results are also provided for Agriolimax reticulatus (Müller) feeding on both potato and carrot at 15° C.High mean assimilation efficiencies of 76.94 and 76.87% were obtained for L. flavus feeding on carrot and potato respectively. The equivalent results for A. hortensis were 88.60 and 89.42%. For A. reticulatus at 15° C the figures were 76.1 and 71.9%. Ingestion rates and assimilation rates are given for the first two species at all temperatures. Assimilation efficiency was found to be independent of temperature for L. flavus but not for A. hortensis. Ingestion rate and assimilation rate were temperature dependent in all cases except for A. hortensis feeding on potato. A. hortensis was more efficient at consuming both carrot and potato per gram live weight. All species consumed more potato than carrot per gram live weight.Juvenile L. flavus were found to have higher assimilation efficiencies and ingestion rates than the adults per gram live weight.Linear regression equations were determined from the relationship between dry weight of food consumed, and dry weight of faeces produced from that food for L. flavus.It is concluded that food quality and age of slug may be the factors most strongly influencing assimilation efficiency in this group.     

Compensatory feeding in response to variable food quality by Melanoplus differentialis

Abstract. The behavioural mechanisms driving compensatory food consumption in response to dietary dilution as well as the relationship between feeding time and food residence time (i.e. digesta retention time in the gut) were studied using the non-diapausing strain of the grasshopper Melanoplus differentialis (Thomas) (Orthoptera: Acrididae). 3-day-old, sixth-instar nymphs and 3-day-old adults were fed artificial diets containing 1%, 3% and 5% total nitrogen (N) at 30C, LD 14:10h; the feeding behaviour was recorded using electronic monitoring devices connected to microcomputers for 24 h. The percentage of time spent feeding increased linearly as diets were diluted using non-digestible cellulose from 5% to 1% N. This response was due to an increase in the number of meals while the meal duration of a feeding bout was unaltered. Sixth-instar nymphs spent about 40% more time feeding than the larger adults. The increased feeding time in nymphs resulted from both more frequent feeding bouts and longer meal duration. Feeding time and food residence time were highly negatively related.     

Effects of copper and zinc on growth, feeding and oxygen consumption of Farfantepenaeus paulensis postlarvae (Decapoda: Penaeidae)

The effect of chronic exposure (35 days) to sub-lethal concentrations of copper (17-212 ppb) and zinc (41-525 ppb) on growth of Farfantepenaeus paulensis postlarvae 17 days old (PL(17)) was analysed. The effects of acute exposure of PL(17) to the same metal on food ingestion and oxygen consumption were also evaluated. Studies were performed using copper and zinc singly, and in a mixture of equipotent concentrations (1:2.5). Chronic exposure to copper (85 and 212 ppb) and zinc (106, 212 and 525 ppb) reduced PL(17) growth. Acute exposure to copper (212 ppb) and zinc (525 ppb) reduced the number of Artemia sp. predated during 30 min and the positive feeding response induced by L-isoleucine. Despite of the lower positive feeding response when PL(17) were exposed to zinc, a significant difference from control condition was not seen. Oxygen consumption was reduced by all copper and zinc concentrations tested. The mean reduction was approximately 32%. The copper zinc-mixture did not modify food consumption and feeding response, or the oxygen consumption of the PL(17). The inhibition of food and oxygen consumption induced by copper and zinc could explain, at least in part, the long-term reduction of growth observed in chronically exposed PL(17). Our results also suggest that the inhibition of food consumption induced by copper is possibly due to an effect on chemosensory mechanisms. Finally, an antagonism between copper and zinc was observed, when were employed to analyse feeding behaviour and aerobic metabolism after acute exposure.