Apidologie最新文献

The western honeybee Apis mellifera is perhaps the best-known example of an advanced eusocial species displaying temporal polyethism, a process in which workers perform different tasks in the colony as they age. Previous studies demonstrated that this temporal division of labour is not only regulated by the age of the bees but also by the proportion of workers performing the required tasks in the colony. As we progress through the Anthropocene, the Intergovernmental Panel on Climate Change predicted that a significant increase in both the frequency and intensity of severe weather events can be expected in the coming decades. Here, we performed a controlled interrupted time series experiment with the objective of quantifying the possible effects that these weather events might have in the honeybee colony dynamics. By simulating a significant loss of foragers in the colony, we observed that honeybee workers quickly replaced the missing foragers by accelerating their transition to a subsequent task and, in some cases, completely skipped several of the natural task transitions with respect to their age. In addition, we analysed how the colony social network structure is affected by the sudden loss of foragers. Indeed, our data show that honeybee colonies increased their network cohesion with workers having a higher number of interactions as well as becoming more closely connected to one another soon after the disturbance. Overall, our data shows that even when faced with a substantial perturbation, honeybees can respond swiftly in order to maintain colony homeostasis and likely increase their resilience against future perturbations.

The honey bee Apis mellifera has shown a great intraspecific diversity, together with a variability of its life history traits. The development of the brood has been well documented in temperate but much less in tropical subspecies, but a limited number of studies focused on tropical subspecies. This study measures the post-capping period of A. mellifera unicolor, an African lineage subspecies living in a tropical and insular environment. The post-capping period was measured on 15 colonies distributed on two apiaries located at different altitudes (150 m and 900 m) in La Réunion. The mean post-capping period of A. mellifera unicolor was 280.1 ± 0.12 h and was significantly shorter in colonies at low altitude. A comparative analysis of the literature on the post-capping period for different subspecies showed that the post-capping period of the African lineage was significatively shorter than that of European lineage. A. mellifera unicolor post-capping period belonged to the hybrid cluster between them. Knowledge of such life history traits of A. mellifera unicolor may have implications for beekeeping practices and should be considered as one of the potential resistance traits to be evaluated in Varroa destructor breeding programmes.

In this study, we identified candidate genes associated with the reproductive success of Varroa destructor in Apis mellifera brood cells at a key point in time, the 4^th day after host cell capping. First-life cycle reproducing (R) and non-reproducing (NR) mites obtained by applying a semi-field rearing protocol were analyzed by RNA-Seq and qPCR. We observed a general under-expression of genes associated with metabolism and a few over-expressed genes putatively involved in signal transduction and DNA-binding transcription factor activity in R compared to NR mites. Specifically, PTCH1 and AP-1 genes, associated with embryonic segmentation and apoptosis, emerged as the best candidates for reproductive success in R mites and the early abortion of reproduction in NR mites. We also detected differentially transcribed long non-coding RNAs between R and NR mites with cis target genes annotated as regulators of replication, transcription, and translation pathways. Some of these genes were specifically associated with embryonic development and apoptosis. We discuss putative metabolic pathways associated with V. destructor reproduction to provide novel information for developing innovative and environmentally friendly mite control strategies.

We evaluated the genetic structure and ecological niche segregation of Apis florea Fabricius 1787 (Apidae: Apini) across its native range using genetic and ecological niche data. The bee samples were from 62 colonies representing 40 localities across Iran, Iraq, Pakistan, Oman, and Egypt. Ecological niche divergence was estimated based on a principal component analysis of climatic/ecological variables. We confirmed the presence of two distinct lineages (eastern and western) for the species using mtDNA. There was no significant climatic heterogeneity between the lineages and their ecological niches are likely to be somewhat conserved. They were probably separated from each other during the Pleistocene and evolved in isolation. The two lineages of A. florea can be considered separate conservation units and used to develop strategies for effectively conserving this keystone pollinator species in Asia.

tau–Fluvalinate (fluvalinate) is a commonly used miticide (Varroa destructor), the major driver of colony collapse disorder (CCD), in the apicultural industry. Despite the relatively high tolerance of honey bees to this miticide, recent studies showed several adverse effects. The side effect on cognitive abilities, however, remains still elusive. Here, we aimed to investigate the effects of fluvalinate on the cognitive abilities of honey bees, especially associative learning, and memory. We tested the proboscis extension response (PER) to sugar taste and Pavlovian conditioning in forager bees that received a sub-lethal dose of fluvalinate on the abdomen. The current study demonstrated that sub-lethal fluvalinate induced cognitive impairment in bees. Furthermore, the comparison of gene expression patterns showed that this disorder was caused by changes in the energy metabolism associated with the subsets of specific neuropeptides that are indirectly involved in detoxification processes. Taken together, our findings are strong evidence that xenobiotics affect sensory cognition through indirect effects as well as direct damage. It might be applicable as a novel approach to exploring the mechanisms underlying the side effects of xenobiotics in various organisms.

Geometric morphometrics is an approach widely used in biological research. For bees, wing landmarks are applied to investigate several questions, such as species identification and population dynamics, yet other morphological structures remain understudied. Megalopta Smith reunite species that forage at dim-light conditions having heads with modifications on shape and size associated with specialized compound eyes and ocelli. In this study, we selected both sexes of 14 species to test if head landmarks can successfully differentiate Megalopta sexes, species, and taxonomic groups. We found that head and eye centroid size and Mahalanobis and Procrustes distances were consistently different between males and females. Male and female differed on lower head landmarks. When contrasting both species and taxonomic groups, canonical variate analysis could differentiate species pairs for most comparisons, while principal component and cluster analysis did not recover such taxonomic groups. Species differences were linked to variation in upper eye landmarks. We conclude that head and wing geometric morphometrics have similar potential and constraints, and response subjects should be selected based on underlying biological questions rather than convenience alone.

The nests of social insects have favorable characteristics for the maintenance of inquilines, including beetle species of various families. Although some species of stingless bees are hosts to beetles, this interaction has been little studied. Certain Scotocryptini beetles are inquilines of stingless bee nests and possess morphological adaptations to live in these environments. Here, we review the interactions between bees and beetles, specifically those of Neotropical stingless bees and Scotocryptini. In addition, we provide new data and an interaction network between the species of these taxa, and analyze their interaction frequency. Finally, we discuss the importance of taxonomic studies on scotocryptines to better understand the evolution of this type of association.

Little is known about the molecular mechanisms that underlie the division of labor in stingless bees. We investigated the expression of a set of candidate genes associated with the nurse-to-forager transition in the honey bee in two stingless bee species, Melipona quadrifasciata and Frieseomelitta varia. These species differ with respect to worker reproduction. The workers of M. quadrifasciata lay trophic and reproductive eggs, but those of F. varia are completely sterile. For M. quadrifasciata nurses, we found elevated vitellogenin (Vg) and low juvenile hormone esterase (jhe) transcript levels in the abdomen, in agreement with their reproductive potential. In F. varia, Vg and methyl farnesoate epoxidase (mfe) transcript levels were high in the heads of foragers, indicating an association with foraging behavior. For malvolio (mvl) and foraging (for), both involved with food search behavior, mvl showed persistent low expression in the head, but increasing levels in the abdomen of both species, speaking against a role in behavioral development. The for transcript levels in F. varia were higher in foragers, both in the head and the abdomen, i.e., consistent with foraging. In M. quadrifasciata, however, for expression was higher in the heads of nurse bees, and, thus, is unlikely to play a role in foraging. The results for the two stingless bee species, in comparison with honey bees and bumble bees, indicate that the degree of worker sterility appears to be the primary factor that shapes the expression pattern of key genes in the life history of social bees.