Adverse effects of the fungal biopesticide Beauveria bassiana on a predatory social wasp.

Biopesticides are considered eco-friendly alternatives to synthetic agrochemicals. However, their impact on non-target organisms is still poorly understood. Social wasps, in particular, are a largely neglected group when it comes to risk assessment of plant protection products, despite the relevant ecological and economic services provided by these insects.

Putting hornets on the genomic map.

Hornets are the largest of the social wasps, and are important regulators of insect populations in their native ranges. Hornets are also very successful as invasive species, with often devastating economic, ecological and societal effects. Understanding why these wasps are such successful invaders is critical to managing future introductions and minimising impact on native biodiversity.

Biopesticides and insect pollinators: Detrimental effects, outdated guidelines, and future directions.

As synthetic pesticides play a major role in pollinator decline worldwide, biopesticides have been gaining increased attention to develop more sustainable methods for pest management in agriculture. These biocontrol agents are usually considered as safe for non-target species, such as pollinators. Unfortunately, when it comes to non-target insects, only the acute or chronic effects on survival following exposure to biopesticides are tested.

Hornets and Honey Bees: A Coevolutionary Arms Race between Ancient Adaptations and New Invasive Threats.

Hornets and honey bees have a long history of coevolution resulting in a plethora of captivating adaptations and counteradaptations between predator and prey. From simple physiological mechanisms to complex behavioral strategies, some hornets have specialized in hunting honey bees, while the latter have put in place effective defenses to counteract their attack. Both hornets and honey bees have evolved the ability to detect the odors and the pheromones emitted by the other to locate the prey or to spot foraging predators.

Differential investment in visual and olfactory brain regions is linked to the sensory needs of a wasp social parasite and its host.

Obligate insect social parasites evolve traits to effectively locate and then exploit their hosts, whereas hosts have complex social behavioral repertoires, which include sensory recognition to reject potential conspecific intruders and heterospecific parasites. While social parasites and host behaviors have been studied extensively, less is known about how their sensory systems function to meet their specific selective pressures. Here, we compare investment in visual and olfactory brain regions in the paper wasp Polistes dominula, and its obligate social parasite P.

Cuticular Hydrocarbon Profile of Parasitic Beetles, (Coleoptera: Nitidulidae).

Cuticular hydrocarbons (CHCs) cover insects' bodies and play important roles in chemical communication, including nestmate recognition, for social insects. To enter colonies of a social host species, parasites may acquire host-specific CHCs or covertly maintain their own CHC profile by lowering its quantity. However, the chemical profile of small hive beetles (SHBs), , which are parasites of honey bee, , colonies, and other bee nests, is currently unknown.

Exposure to a biopesticide interferes with sucrose responsiveness and learning in honey bees.

The entomopathogenic fungus Beauveria bassiana is a widely used biopesticide that is considered as an effective alternative to classical agrochemicals. B. bassiana is thought to be safe for pollinators although little is known about its side-effects on pollinators' behaviour and cognition.

Gut microbial composition in different castes and developmental stages of the invasive hornet Vespa velutina nigrithorax.

Social insects are successful animal invaders. Their survival and success, and in some cases also their impact on invaded ecosystem functioning, is often mediated by symbiosis with microorganisms. Here, we report a comprehensive comparative characterization of the gut microbial communities of different castes and developmental stages of the invasive hornet Vespa velutina nigrithorax.

Increased immunocompetence and network centrality of allogroomer workers suggest a link between individual and social immunity in honeybees.

The significant risk of disease transmission has selected for effective immune-defense strategies in insect societies. Division of labour, with individuals specialized in immunity-related tasks, strongly contributes to prevent the spread of diseases. A trade-off, however, may exist between phenotypic specialization to increase task efficiency and maintenance of plasticity to cope with variable colony demands.

Rethinking recognition: social context in adult life rather than early experience shapes recognition in a social wasp.

Social recognition represents the foundation of social living. To what extent social recognition is hard-wired by early-life experience or flexible and influenced by social context of later life stages is a crucial question in animal behaviour studies. Social insects have represented classic models to investigate the subject, and the acknowledged idea is that relevant information to create the referent template for nest-mate recognition (NMR) is usually acquired during an early sensitive period in adult life.

Assessing immunocompetence in red palm weevil adult and immature stages in response to bacterial challenge and entomopathogenic nematode infection.

Parasites and pathogens can follow different patterns of infection depending on the host developmental stage or sex. In fact, immune function is energetically costly for hosts and trade-offs exist between immune defenses and life history traits as growth, development and reproduction and organisms should thus optimize immune defense through their life cycle according to their developmental stage. Identifying the most susceptible target and the most virulent pathogen is particularly important in the case of insect pests, in order to develop effective control strategies targeting the most vulnerable individuals with the most effective control agent.

Inquiline social parasites as tools to unlock the secrets of insect sociality.

Insect societies play a crucial role in the functioning of most ecosystems and have fascinated both scientists and the lay public for centuries. Despite the long history of study, we are still far from understanding how insect societies have evolved and how social cohesion in their colonies is maintained. Here we suggest inquiline social parasites of insect societies as an under-exploited experimental tool for understanding sociality.

Natural biocide disrupts nestmate recognition in honeybees.

Honeybee colonies are under the threat of many stressors, biotic and abiotic factors that strongly affect their survival. Recently, great attention has been directed at chemical pesticides, including their effects at sub-lethal doses on bee behaviour and colony success; whereas the potential side effects of natural biocides largely used in agriculture, such as entomopathogenic fungi, have received only marginal attention. Here, we report the impact of the fungus Beauveria bassiana on honeybee nestmate recognition ability, a crucial feature at the basis of colony integrity.

Adult-larval vibrational communication in paper wasps: the role of abdominal wagging in .

Communication through vibrational signals is widespread among social insects and regulates crucial social activities. Females of the social wasp produce substrate-borne vibrations on the combs by performing a conspicuous abdominal oscillatory behavior, known as abdominal wagging. Several studies have reported correlative evidence in support of its signaling role, but direct evidence is still lacking.

Social parasitism and the molecular basis of phenotypic evolution.

Contrasting phenotypes arise from similar genomes through a combination of losses, gains, co-option and modifications of inherited genomic material. Understanding the molecular basis of this phenotypic diversity is a fundamental challenge in modern evolutionary biology. Comparisons of the genes and their expression patterns underlying traits in closely related species offer an unrivaled opportunity to evaluate the extent to which genomic material is reorganized to produce novel traits.

Effects of the diet on the microbiota of the red palm weevil (Coleoptera: Dryophthoridae).

Rhynchophorus ferrugineus, also known as the red palm weevil, is regarded as the major pest of palm trees. Although studies of the microbiota associated with this species have been performed in recent years, little attention has been dedicated to the influence of the diet in shaping the host bacterial community. Here, we investigated the influence of food sources (i.

Facial markings in the social cuckoo wasp Polistes sulcifer: No support for the visual deception and the assessment hypotheses.

Insect social parasites have to conquer a host colony by overcoming its defensive barriers. In addition to increased fighting abilities, many social parasites evolved sophisticated sensory deception mechanisms to elude host colonies defenses by exploiting host communication channels. Recently, it has been shown that the conspicuous facial markings of a paper wasp social parasite, Polistes sulcifer, decrease the aggressiveness of host foundresses.

Novel insights into the ontogeny of nestmate recognition in Polistes social wasps.

The importance of early experience in animals' life is unquestionable, and imprinting-like phenomena may shape important aspects of behaviour. Early learning typically occurs during a sensitive period, which restricts crucial processes of information storage to a specific developmental phase. The characteristics of the sensitive period have been largely investigated in vertebrates, because of their complexity and plasticity, both in behaviour and neurophysiology, but early learning occurs also in invertebrates.

Sensing the intruder: a quantitative threshold for recognition cues perception in honeybees.

The ability to discriminate among nestmates and non-nestmate is essential to defend social insect colonies from intruders. Over the years, nestmate recognition has been extensively studied in the honeybee Apis mellifera; nevertheless, the quantitative perceptual aspects at the basis of the recognition system represent an unexplored subject in this species. To test the existence of a cuticular hydrocarbons' quantitative perception threshold for nestmate recognition cues, we conducted behavioural assays by presenting different amounts of a foreign forager's chemical profile to honeybees at the entrance of their colonies.

Alien insects in Italy: comparing patterns from the regional to European level.

The introduction of species outside their native range contributes to the loss of biodiversity, alters the structure and functioning of ecosystems, and damages economy and human health. Insects are one of the taxa with the highest frequency of introduction due to their high diversity, biological properties, and close association with human activities. Here, the allodiversity of Italian entomofauna was analyzed, with a focus on Tuscany (Central Italy).

The chemical basis of host nest detection and chemical integration in a cuckoo paper wasp.

Insect social life is governed by chemicals. A great number of studies have demonstrated that the blend of hydrocarbons present on the cuticle (CHCs) plays a pivotal role in intra- and inter-specific communication. It is not surprising, therefore, that social parasites, specialized in exploiting the costly parental care provided by host workers, exploit the host chemical communication system too.

Cuticular hydrocarbons rather than peptides are responsible for nestmate recognition in Polistes dominulus.

A colony of social insects is like a fortress where access is allowed only to colony members. The epicuticular mixture of hydrocarbons has been widely reported to be involved in nestmate recognition in insects. However, recent studies have shown that polar compounds (mainly peptides) are also present, mixed with hydrocarbons, on the cuticle of various insects, including the paper wasps of the genus Polistes.

Pheromones in social wasps.

Social wasps need an efficient communication system to coordinate their members in the numerous activities of the colony. In this regard, the chemical channel is the most utilized by social wasps to transfer information in intraspecific (pheromones) and interspecific (allomones) communication. In this chapter, we reviewed the main chemical substances which mediate recognition between colony members and coordinate nest defense, alarm and recruitment.