Mixture of neonicotinoid and fungicide affects foraging activity of honeybees.

The use of plant protection products (PPPs) is a major factor contributing to global insect decline. We here use the honeybee (Apis mellifera) as a model to study combined effects of the last neonicotinoid in the EU (acetamiprid) and different fungicides on live-long foraging flights using radio frequency identification. The mixture of the sterol-biosynthesis-inhibiting fungicide difenoconazole and the insecticide acetamiprid significantly reduced the number of foraging trips per day compared to the control and each PPP alone, while a mixture of the insecticide with the non-sterol-biosynthesis inhibiting fungicide boscalid/dimoxystrobin did not affect behaviour.

The neonicotinoid acetamiprid reduces larval and adult survival in honeybees (Apis mellifera) and interacts with a fungicide mixture.

Plant protection products (PPPs), which are frequently used in agriculture, can be major stressors for honeybees. They have been found abundantly in the beehive, particularly in pollen. Few studies have analysed effects on honeybee larvae, and little is known about effects of insecticide-fungicide-mixtures, although this is a highly realistic exposure scenario.

Bumblebees are resilient to neonicotinoid-fungicide combinations.

Bumblebees are among the most important wild bees for pollination of crops and securing wildflower diversity. However, their abundance and diversity have been on a steady decrease in the last decades. One of the most important factors leading to their decline is the frequent use of plant protection products (PPPs) in agriculture, which spread into forests and natural reserves.

Heritability of recapping behavior and suppressed mite reproduction as resistance traits towards .

The selection of honeybee strains resistant to the ectoparasitic mite is generally considered as one of the most sustainable ways of coping with this major bee parasite. Thus, breeding efforts increasingly focus on resistance parameters in addition to common beekeeping traits like honey yield and gentleness. In every breeding effort, the success strongly depends on the quantifiability and heritability of the traits accounted.

Reproduction of Varroa destructor depends on well-timed host cell recapping and seasonal patterns.

Resistance traits of honeybees (Apis mellifera) against their major parasite Varroa destructor have fascinated scientists and breeders for long. Nevertheless, the mechanisms underlying resistance are still largely unknown. The same applies to possible interactions between host behaviours, mite reproduction and seasonal differences.

Solitary Bees Host More Bacteria and Fungi on Their Cuticle than Social Bees.

Bees come into contact with bacteria and fungi from flowering plants during their foraging trips. The Western honeybee () shows a pronounced hygienic behavior with social interactions, while the solitary red mason bee () lacks a social immune system. Since both visit the same floral resources, it is intriguing to speculate that the body surface of a solitary bee should harbor a more complex microbiome than that of the social honeybee.

Fungicides and insecticides can alter the microbial community on the cuticle of honey bees.

Honey bees are crucial for our ecosystems as pollinators, but the intensive use of plant protection products (PPPs) in agriculture poses a risk for them. PPPs do not only affect target organisms but also affect non-targets, such as the honey bee and their microbiome. This study is the first of its kind, aiming to characterize the effect of PPPs on the microbiome of the cuticle of honey bees.

New insight into molecular mechanisms underlying division of labor in honeybees.

Honeybees are highly organized eusocial insects displaying a distinct division of labor. Juvenile hormone (JH) has long been hypothesized to be the major driver of behavioral transitions. However, more and more experiments in recent years have suggested that the role of this hormone is not as fundamental as hypothesized.

The ant's weapon improves honey bee learning performance.

Formic acid is the main component of the ant's major weapon against enemies. Being mainly used as a chemical defense, the acid is also exploited for recruitment and trail marking. The repelling effect of the organic acid is used by some mammals and birds which rub themselves in the acid to eliminate ectoparasites.

A combination of the frequent fungicides boscalid and dimoxystrobin with the neonicotinoid acetamiprid in field-realistic concentrations does not affect sucrose responsiveness and learning behavior of honeybees.

The increasing loss of pollinators over the last decades has become more and more evident. Intensive use of plant protection products is one key factor contributing to this decline. Especially the mixture of different plant protection products can pose an increased risk for pollinators as synergistic effects may occur.

Intrasexual cuticular hydrocarbon dimorphism in a wasp sheds light on hydrocarbon biosynthesis genes in Hymenoptera.

Cuticular hydrocarbons (CHCs) cover the cuticle of insects and serve as desiccation barrier and as semiochemicals. While the main enzymatic steps of CHC biosynthesis are well understood, few of the underlying genes have been identified. Here we show how exploitation of intrasexual CHC dimorphism in a mason wasp, Odynerus spinipes, in combination with whole-genome sequencing and comparative transcriptomics facilitated identification of such genes.

Corrigendum: Honeybees are buffered against undernourishment during larval stages.

[This corrects the article DOI: 10.3389/finsc.2022.

Sugar perception in honeybees.

Honeybees () need their fine sense of taste to evaluate nectar and pollen sources. Gustatory receptors (Grs) translate taste signals into electrical responses. experiments have demonstrated collective responses of the whole Gr-set.

Individual consistency in the learning abilities of honey bees: cognitive specialization within sensory and reinforcement modalities.

The question of whether individuals perform consistently across a variety of cognitive tasks is relevant for studies of comparative cognition. The honey bee (Apis mellifera) is an appropriate model to study cognitive consistency as its learning can be studied in multiple elemental and non-elemental learning tasks. We took advantage of this possibility and studied if the ability of honey bees to learn a simple discrimination correlates with their ability to solve two tasks of higher complexity, reversal learning and negative patterning.

Honeybees are buffered against undernourishment during larval stages.

The negative impact of juvenile undernourishment on adult behavior has been well reported for vertebrates, but relatively little is known about invertebrates. In honeybees, nutrition has long been known to affect task performance and timing of behavioral transitions. Whether and how a dietary restriction during larval development affects the task performance of adult honeybees is largely unknown.

Interaction of Insecticides and Fungicides in Bees.

Honeybees and wild bees are among the most important pollinators of both wild and cultivated landscapes. In recent years, however, a significant decline in these pollinators has been recorded. This decrease can have many causes including the heavy use of biocidal plant protection products in agriculture.

In Vitro Rearing Changes Social Task Performance and Physiology in Honeybees.

In vitro rearing of honeybee larvae is an established method that enables exact control and monitoring of developmental factors and allows controlled application of pesticides or pathogens. However, only a few studies have investigated how the rearing method itself affects the behavior of the resulting adult honeybees. We raised honeybees in vitro according to a standardized protocol: marking the emerging honeybees individually and inserting them into established colonies.

Evidence of cognitive specialization in an insect: proficiency is maintained across elemental and higher-order visual learning but not between sensory modalities in honey bees.

Individuals differing in their cognitive abilities and foraging strategies may confer a valuable benefit to their social groups as variability may help them to respond flexibly in scenarios with different resource availability. Individual learning proficiency may either be absolute or vary with the complexity or the nature of the problem considered. Determining whether learning ability correlates between tasks of different complexity or between sensory modalities is of high interest for research on brain modularity and task-dependent specialization of neural circuits.

Opposing Actions of Octopamine and Tyramine on Honeybee Vision.

The biogenic amines octopamine and tyramine are important neurotransmitters in insects and other protostomes. They play a pivotal role in the sensory responses, learning and memory and social organisation of honeybees. Generally, octopamine and tyramine are believed to fulfil similar roles as their deuterostome counterparts epinephrine and norepinephrine.

Comparing the Appetitive Learning Performance of Six European Honeybee Subspecies in a Common Apiary.

The Western honeybee ( L.) is one of the most widespread insects with numerous subspecies in its native range. How far adaptation to local habitats has affected the cognitive skills of the different subspecies is an intriguing question that we investigate in this study.

Tyramine 1 Receptor Distribution in the Brain of Corbiculate Bees Points to a Conserved Function.

Sucrose represents an important carbohydrate source for most bee species. In the Western honeybee (Apis mellifera) it was shown that individual sucrose responsiveness correlates with the task performed in the colony, supporting the response threshold theory which states that individuals with the lowest threshold for a task-associated stimuli will perform the associated task. Tyramine was shown to modulate sucrose responsiveness, most likely via the tyramine 1 receptor.

Survival rate and changes in foraging performances of solitary bees exposed to a novel insecticide.

Solitary bees are among the most important pollinators worldwide however population declines especially in croplands has been noticed. The novel pesticide sulfoxaflor is a competitive modulator of nicotinic acetylcholine receptors (nAChR) in insects. While there is evidence of a negative impact of neonicotinoids on bees of several social organization levels, our overall knowledge on the impact of sulfoxaflor on bees is poor.