Honeybees are the most critical pollinators providing key ecosystem services that underpin crop production and sustainable agriculture. Amidst a backdrop of rapid global change, this eusocial insect encounters a succession of stressors during nesting, foraging, and pollination. Ectoparasitic mites, together with vectored viruses, have been recognized as central biotic threats to honeybee health, while the spread of invasive giant hornets and small hive beetles also increasingly threatens colonies worldwide. Cocktails of agrochemicals, including acaricides used for mite treatment, and other pollutants of the environment have been widely documented to affect bee health in various ways. Additionally, expanding urbanization, climate change, and agricultural intensification often result in the destruction or fragmentation of flower‐rich bee habitats. The anthropogenic pressures exerted by beekeeping management practices affect the natural selection and evolution of honeybees, and colony translocations facilitate alien species invasion and disease transmission. In this review, the multiple biotic and abiotic threats and their interactions that potentially undermine bee colony health are discussed, while taking into consideration the sensitivity, large foraging area, dense network among related nestmates, and social behaviors of honeybees.

Honeybees (Apis mellifera) are indispensable pollinators vital to global biodiversity, ecosystem stability, and agricultural productivity, and they promote over 35% of food crops and 75% of flowering plants. Yet, they are in unprecedented decline, partly as a result of neonicotinoid pesticide use elsewhere. These effects on honey bee health are synthesized in this paper through molecular, physiological, and behavioral data showing that sublethal effects of neonicotinoids impair honey bee health. As neurotoxic insecticides that target nicotinic acetylcholine receptors (nAChRs), these insecticides interfere with neurotransmission and underlie cognitive impairment, immune suppression, and oxidative stress. Developmental toxicity is manifested in larvae as retarded growth, reduced feeding, and increased death; queen and drone reproduction are impaired, lowering colony viability. As a result, adult bees have shortened lives and erratic foraging, are further disoriented, and experience impaired navigation, communication, and resource collection. Together, these effects cascade to reduced brood care, thermoregulatory failure, and heretofore unrecognized increased susceptibility to pathogens, increasing the probability of colony collapse at the colony level. Contaminants such as pesticides may cause pollinator exposure and, in turn, may cause their population to be undermined if they are not mitigated; therefore, urgent mitigation strategies, including integrated pest management (IPM), regulatory reforms, and adoption of biopesticides, are needed to mitigate pollinator exposure. The focus of this review lies in the ecological necessity of restructuring how agriculture is managed to simultaneously meet food security and the conservation of honeybee health, the linchpin of global ecosystems.

The health status of the honey bee Apis mellifera has been challenged globally by the ubiquitous ectoparasitic mite Varroa destructor over the past several decades. The resistance of the mite to and residue accumulation of the traditional acaricidal treatment call for more natural and safer alternatives to control this parasite in colonies. Essential oils originating from plant foliage are considered to be a potential substitute. In this study, we evaluated the fumigant activities of eleven essential oils derived from Chinese crude medicines. Appropriate dosages that did not severely harm honey bees were applied in a toxicity screening test of V. destructor mites. Six essential oils had significant acaricidal activities against the mites, and Odoriferous Rosewood oil and Fennel oil caused more than 65% V. destructor mortality. Meanwhile, the fumigant toxicity of all of the essential oils on adult honey bee workers was not significantly different from that of controls. We then measured the selectivity indexes of the six essential oils mentioned above by determining the LD₅₀ values for honey bees and for V. destructor mites. Considering both the toxicity to the bees and to the mites, Odoriferous Rosewood oil and Fennel oil showed great potential for varroacidal application as a fumigant agent. This study identified new essential oils with acaricidal properties that might contribute to mitigating the poor health status of A. mellifera colonies due to V. destructor infestation.

In this study, we investigated the presence of piggyBac (PB) transposons in 44 bee genomes from the Apoidea order, which is a superfamily within the Hymenoptera, which includes a large number of bee species crucial for pollination. We annotated the PB transposons in these 44 bee genomes and examined their evolution profiles, including structural characteristics, distribution, diversity, activity, and abundance. The mined PB transposons were divided into three clades, with uneven distribution in each genus of PB transposons in Apoidea. The complete PB transposons we discovered are around 2.23–3.52 kb in length and encode transposases of approximately 580 aa, with terminal inverted repeats (TIRs) of about 14 bp and 4 bp (TTAA) target-site duplications. Long TIRs (200 bp, 201 bp, and 493 bp) were also detected in some species of bees. The DDD domains of the three transposon types were more conserved, while the other protein domains were less conserved. Generally, most PB transposons showed low abundance in the genomes of Apoidea. Divergent evolution dynamics of PB were observed in the genomes of Apoidea. PB transposons in some identified species were relatively young, whiles others were older and with some either active or inactive. In addition, multiple invasions of PB were also detected in some genomes of Apoidea. Our findings highlight the contribution of PB transposons to genomic variation in these species and suggest their potential as candidates for future gene transfer tools.

Honey bees, Apis mellifera , have for millennia been managed and exploited by humans and introduced into most suitable regions worldwide. However, given the lack of records for many introduction events, treating A. mellifera populations as native would predictably bias genetic studies regarding origin and evolution. Here, we used the Dongbei bee, a well-documented population, introduced beyond the natural distribution range approximately 100 years ago, to elucidate the effects of local domestication on animal population genetic analyses. Strong domestication pressure was detected in this population, and the genetic divergence between Dongbei bee and its ancestral subspecies was found to have occurred at the lineage level. Results of phylogenetic and time divergence analyses could consequently be misinterpreted. Proposing new subspecies or lineages and performing analyses of origin should thus strive to eliminate anthropogenic effects. We highlight the need for definitions of landrace and breed in honey bee sciences and make preliminary suggestions.

Pseudoscorpions, considered to be beneficial to human beings, are a class of tiny predatory arachnids. They have been reported to be associated with honey bees and were regarded as a potential biocontrol agent against Varroa destructor mites, the most severe biotic threat to apiculture. Here, we found three pseudoscorpions in Apis cerana colonies in Southeast China. The appearance and the sizes of each body part of the samples were recorded. After sequencing the cox1 gene fragment in the mtDNA, the collected pseudoscorpions were assigned to the genus Ellingsenius. Furthermore, phylogenetic analyses indicated that our samples might be a new pseudoscorpion species. To our knowledge, this is the first report of pseudoscorpions in Apis cerana colonies in China, providing new evidence for the symbiosis of native honey bees and their inhabitants.