Occasional and constant exposure to dietary ethanol shortens the lifespan of worker honey bees.

Honey bees (Apis mellifera) are one of the most crucial pollinators, providing vital ecosystem services. Their development and functioning depend on essential nutrients and substances found in the environment. While collecting nectar as a vital carbohydrate source, bees routinely encounter low doses of ethanol from yeast fermentation.

Small workers are more persistent when providing and requiring help in a monomorphic ant.

The common sand-dwelling Formica cinerea ants possess monomorphic workers, yet with considerable and easily identified size variation. Considering the importance of body size in polymorphic ants and other animals, we test whether size-dependent differences in behaviour occur in this species. We focus on the behaviour of large and small foragers in the context of rescue occurring between nestmates when one of them is entrapped and requires help.

Injury shortens life expectancy in ants and affects some risk-related decisions of workers.

The Formica cinerea ants are known to be highly territorial and aggressively defend their nest and foraging areas against other ants. During the foraging, workers engage in large-scale battles with other colonies of ants and injuries often occur in the process. Such injuries open the body up to pathologies and can lead to costs expressed in lower survival.

Heat stress during development makes antlion larvae more responsive to vibrational cues.

We investigated the effects of heat stress on the responsiveness to vibrational cues, our measure of perceptual ability, in antlion larvae (Neuroptera: Myrmeleontidae). We reared these trap-building predatory larvae under 2 heat stress regimes (mild, 30°C, and harsh, 36°C), and after they progressed from one instar stage to another, we tested their perceptual ability in common unchallenging conditions. We hypothesized that exposure to the harsh heat stress regime would impose costs resulting in handicapped vibration responsiveness.

Behavioral differences between pit-building antlions and wormlions suggest limits to convergent evolution.

Antlions and wormlions are distantly related insect taxa, both digging pits in loose soil and ambushing arthropod prey. Their hunting method, which is rare in the animal kingdom, is a clear example of convergent evolution. There is little research directly comparing the 2 pit-building taxa.

Comparative analysis of experimental testing procedures for the elicitation of rescue actions in ants.

Rescue behavior is observed when 1 individual provides help to another individual in danger. Most reports of rescue behavior concern ants (Formicidae), in which workers rescue each other from various types of entrapment. Many of these entrapment situations can be simulated in the laboratory using an entrapment bioassay, in which ants confront a single endangered nest mate entrapped on a sandy arena by means of an artificial snare.

"O Sister, Where Art Thou?"-A Review on Rescue of Imperiled Individuals in Ants.

Altruism is defined as an action that decreases the lifetime direct fitness of an actor and benefits one or more recipients. This phenomenon, which is generally difficult to understand and explain, requires special research attention. The subject of this review, rescue, is a type of altruistic behavior in which the actor puts itself at risk to save another individual, the recipient, that is in danger.

Operant conditioning in antlion larvae and its impairment following exposure to elevated temperatures.

Although ambush predators were previously considered limited in their cognitive abilities compared to their widely foraging relatives, there is accumulating evidence it does not hold true. Pit-building antlions are already known to associate vibrations in the sand with the arrival of prey. We used a T-maze and successfully trained antlions to turn right or left against their initial turning bias, leading to a suitable substrate for digging traps.

Past thermal conditions affect hunting behaviour in larval antlions.

Some sit-and-wait predators, such as antlion larvae, construct traps to capture passing prey. The location of these traps depends on many abiotic and biotic factors, including temperature and the presence of conspecifics, which probably stimulate behaviours that minimize the costs and maximize the benefits of trap building. Here, we exposed second instar antlion larvae to elevated temperatures of 25°C (mild treatment) or 31°C (harsh treatment) for one month and then transferred them to common conditions (20°C) to examine the effects of previous thermal treatment on aggregation tendency and trap size.

Discontinued alcohol consumption elicits withdrawal symptoms in honeybees.

The honeybee continues to be developed as a model species in many research areas, including studies related to the effects of alcohol. Here, we investigate whether workers display one of the key features of alcoholism, namely withdrawal symptoms. We show that workers fed for a prolonged time on food spiked with ethanol, after discontinuation of access to such food, exhibited a marked increase in the consumption of ethanol and a slight increase in mortality.

Heat wave effects on the behavior and life-history traits of sedentary antlions.

Research on the behavioral responses of animals to extreme weather events, such as heat wave, is lacking even though their frequency and intensity in nature are increasing. Here, we investigated the behavioral response to a simulated heat wave in two species of antlions (Neuroptera: Myrmeleontidae). These insects spend the majority of their lives as larvae and live in sandy areas suitable for a trap-building hunting strategy.

Rebel honeybee workers have a tendency to become intraspecific reproductive parasites.

Worker honeybees may reproduce in either their own or foreign colonies; the latter situation is termed intraspecific reproductive parasitism (IRP). In this study, we compared the tendency for IRP between normal honeybee workers, which are characterized by a relatively low reproductive potential, and "rebel workers", a recently discovered subcaste of honeybee workers characterized by a high reproductive potential that develops when the colony is without a queen. We expected that the high reproductive potential of the rebel workers would influence their reproductive strategy and that these individuals would drift to other colonies to lay eggs more often than normal workers.

Honeybee rebel workers invest less in risky foraging than normal workers.

In eusocial insect colonies, workers have individual preferences for performing particular tasks. Previous research suggests that these preferences might be associated with worker reproductive potential; however, different studies have yielded inconsistent results. This study constitutes the first comparison of foraging preferences between genetically similar normal and rebel honeybee workers, which present different reproductive potential.

Honeybees show adaptive reactions to ethanol exposure.

The honeybee is being developed as a simple invertebrate model for alcohol-related studies. To date, several effects of ethanol consumption have been demonstrated in honeybees, but the tolerance effect, one of the hallmarks of alcohol overuse, has never been shown. Here, we confirm our hypothesis that the response to ethanol (in terms of motor impairment) is lower in bees that have previously experienced intoxication than in bees encountering ethanol for the first time, indicating that the chronic tolerance effect occurs in honeybees.

Larval antlions show a cognitive ability/hunting efficiency trade-off connected with the level of behavioural asymmetry.

Recently, antlion larvae with greater behavioural asymmetry were shown to have improved learning abilities. However, a major evolutionary question that remained unanswered was why this asymmetry does not increase in all individuals during development. Here, we show that a trade-off exists between learning ability of larvae and their hunting efficiency.

Thermal dependence of trap building in predatory antlion larvae (Neuroptera: Myrmeleontidae).

Trap-building predators remain under strong selection from thermal microenvironments. To address how soil temperature and body size affect trap building, we conducted a laboratory experiment using larvae of the antlion at six ecologically relevant temperatures. Larger larvae built larger traps, and warmer soil led to more and larger traps.

Increased Risk Proneness or Social Withdrawal? The Effects of Shortened Life Expectancy on the Expression of Rescue Behavior in Workers of the ant (Hymenoptera: Formicidae).

In social insects behavioral consequences of shortened life expectancy include, among others, increased risk proneness and social withdrawal. We investigated the impact of experimental shortening of life expectancy of foragers of the ant achieved by their exposure to carbon dioxide on the expression of rescue behavior, risky pro-social behavior, tested by means of two bioassays during which a single worker (rescuer) was confronted with a nestmate (victim) attacked by a predator (antlion larva capture bioassay) or immobilized by an artificial snare (entrapment bioassay). Efficacy of carbon dioxide poisoning in shortening life expectancy was confirmed by the analysis of ant mortality.

Pro-social behaviour of ants depends on their ecological niche-Rescue actions in species from tropical and temperate regions.

Some ants display rescue behaviour, which is performed by nearby nestmates and directed at individuals in danger. Here, using several ant species, we demonstrate that rescue behaviour expression matches predicted occurrences based on certain aspects of species' ecological niches. Rescue occurred in sand-dwelling ants exposed both to co-occurring antlion larvae, representing the threat of being captured by a predator, and to nest cave-ins, representing the threat of being trapped in a collapsed nest chamber.

Honeybee workers with higher reproductive potential live longer lives.

Social insects, especially honeybees, have received much attention in comparative gerontology because of their peculiar and flexible ageing patterns that differ across genetically similar individuals. The longevity of honeybee individuals varies and depends on patterns of gene expression during development; females developing into reproductive individuals (queens) live longer than facultatively sterile workers. Here, we show that rebel workers, which develop under queenless conditions after swarming and have high reproductive potential, live approximately 4days longer in hives and approximately 3days longer in cages than individuals that develop in queenright colonies and have lower reproductive potential; this difference in longevity occurs in both free-flying and caged workers.

Larval antlions with more pronounced behavioural asymmetry show enhanced cognitive skills.

Brain lateralization is hypothesized to improve the efficiency of information processing. Here, we found that some Myrmeleon bore antlion larvae showed individual asymmetry in righting from a supine to normal position over one side of their body, which can be considered a reflection of greater brain lateralization. We demonstrated that these behaviourally asymmetrical individuals showed improved learning abilities, providing novel evidence that brain lateralization leads to beneficial effects on cognitive functions.

Sedentary antlion larvae (Neuroptera: Myrmeleontidae) use vibrational cues to modify their foraging strategies.

Learning abilities are exhibited by many animals, including insects. However, sedentary species are typically believed to have low capacities and requirements for learning. Despite this view, recent studies show that even such inconspicuous organisms as larval antlions, which employ an ambush predation strategy, are capable of learning, although their learning abilities are rather simple, i.

Moribund Ants Do Not Call for Help.

When an antlion captures a foraging ant, the victim's nestmates may display rescue behaviour. This study tested the hypothesis that the expression of rescue behaviour depends on the life expectancy of the captured ant. This hypothesis predicts that the expression of rescue behaviour will be less frequent when the captured ant has a lower life expectancy than when it has a higher life expectancy because such a response would be adaptive at the colony level.

Selection for alternative male reproductive tactics alters intralocus sexual conflict.

Intralocus sexual conflict (IASC) arises when fitness optima for a shared trait differ between the sexes; such conflict may help maintain genetic variation within populations. Sex-limited expression of sexually antagonistic traits may help resolve the conflict, but the extent of this resolution remains a subject of debate. In species with alternative male reproductive tactics, unresolved conflict should manifest more in a more sexually dimorphic male phenotype.