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The Tropilaelaps spp. (Mesostigmata: Laelapidae), an ectoparasitic mite originally associated with such Asian giant honey bees as Apis dorsata, A. breviligula and A. laboriosa, has increasingly become a focus of global concern due to its severe effects on Western honey bee colonies (Apis mellifera) and its recent geographic expansion. This study documents the first reported presence of Tropilaelaps mercedesae in Western Georgia's Samegrelo-Zemo Svaneti region, specifically in seven honey bee colonies (A. mellifera caucasica) from three apiaries. We conducted brood sample inspections, DNA barcoding and morphological measurements to confirm mite identification. Our findings revealed high infestation rates of T. mercedesae, co-infestation with Varroa destructor and notable mite reproductive success. These results underscore the threat posed by T. mercedesae to Georgian apiculture and highlight the potential for further spread across Europe. Immediate action and vigilant monitoring by national and international authorities are crucial to mitigate the impact on beekeeping and agriculture. [ABSTRACT FROM AUTHOR]

Background: Leptotrombidium scutellare is one of the six main vectors of scrub typhus in China and is a putative vector of hemorrhagic fever with renal syndrome (HFRS). This mite constitutes a large portion of the chigger mite community in southwest China. Although empirical data on its distribution are available for several investigated sites, knowledge of the species' association with human well-being and involvement in the prevalence of mite-borne diseases remains scarce. Methods: Occurrence data on the chigger mite were obtained from 21 years (2001–2021) of field sampling. Using boosted regression tree (BRT) ecological models based on climate, land cover and elevation variables, we predicted the environmental suitability for L. scutellare in Yunnan and Sichuan Provinces. The potential distribution range and shifts in the study area for near-current and future scenarios were mapped and the scale of L. scutellare interacting with human activities was evaluated. We tested the explanatory power of the occurrence probability of L. scutellare on incidences of mite-borne diseases. Results: Elevation and climate factors were the most important factors contributing to the prediction of the occurrence pattern of L. scutellare. The most suitable habitats for this mite species were mainly concentrated around high-elevation areas, with predictions for the future showing a trend towards a reduction. Human activity was negatively correlated with the environmental suitability of L. scutellare. The occurrence probability of L. scutellare in Yunnan Province had a strong explanatory power on the epidemic pattern of HFRS but not scrub typhus. Conclusions: Our results emphasize the exposure risks introduced by L. scutellare in the high-elevation areas of southwest China. Climate change may lead to a range contraction of this species towards areas of higher elevation and lessen the associated exposure risk. A comprehensive understanding of the transmission risk requires more surveillance efforts. [ABSTRACT FROM AUTHOR]

Varroa destructor, an ectoparasite of Apis cerana (the Eastern honeybee), has attained global notoriety following the decimation caused by its host shift to Apis mellifera. Previous studies indicated that Varroa mites have geographic and host-specific mitochondrial haplotypes (mitotypes) in A. mellifera colonies, suggesting that only a few genetic strains (i.e., Korean and Japanese mitotypes) can effectively infest A. mellifera. However, growing evidence indicates that native mite populations of A. cerana can hybridize with the mites imported with A. mellifera colonies. This raises the possibility for continuous host shifts of Varroa mites and the consequential hybridizations among mites from different localities, leading to erasure of host specificity among mites of different mitotypes. We compared mitochondrial sequence data with restriction site-associated DNA sequencing (RAD-seq) to test the veracity of the patterns indicated by mitochondrial data and to clarify the genetic differentiation of Varroa mites in Vietnam and Taiwan. Our mitotype analyses replicate previous studies, indicating that only a few Varroa mite mitotype lineages parasitize A. mellifera. However, our RAD-seq data reveal little evidence of the genetic isolation as suggested by the mitotype analyses, instead indicating that hybridization is likely occurring among Varroa mites from multiple different hosts and localities. This indicates that the local mite community of A. cerana might contribute to the genetic pool of mites parasitizing A. mellifera. Our findings suggest that the Varroa mite control strategies and the risk estimation of international apicultural trade should be reassessed. [ABSTRACT FROM AUTHOR]

Simple Summary: The deformed wing virus (DWV) has been detected in Apis florea and its ectoparasite Euvarroa sinhai since they invaded Taiwan. Using a reverse transcription-PCR with specific primers enabled us to ascertain that DWV type A was prevalent among A. florea samples. Homology analysis and maximum-likelihood phylogenetic tree between different genotypes disclosed a complete polyprotein nucleotide sequence identity of 88% between isolates from A. florea, E. sinhai, and DWV type A strains from GenBank. The results demonstrated that a novel variant of deformed wing viruses exists in the invasive species A. florea and E. sinhai. The invasion of Apis florea in Taiwan was first recorded in 2017. The deformed wing virus (DWV) has been identified as a common bee virus in apiculture around the world. Ectoparasitic mites are the main DWV vector for horizontal transmission. However, there are few studies about the ectoparasitic mite of Euvarroa sinhai, which has been found in A. florea. In this study, the prevalence of DWV among four hosts, including A. florea, Apis mellifera, E. sinhai, and Varroa destructor, was determined. The results showed that a high DWV-A prevalence rate in A. florea, ranging from 69.2% to 94.4%, was detected. Additionally, the genome of DWV isolates was sequenced and subjected to phylogenetic analysis based on the complete polyprotein sequence. Furthermore, isolates from A. florea and E. sinhai both formed a monophyletic group for the DWV-A lineage, and the sequence identity was 88% between the isolates and DWV-A reference strains. As noted above, two isolates could be the novel DWV strain. It cannot be excluded that novel DWV strains could pose an indirect threat to sympatric species, such as A. mellifera and Apis cerana. [ABSTRACT FROM AUTHOR]

The western honeybee (Apis mellifera L.) is one of the most important insect species that, unfortunately, is being confronted with multiple biological stressors that threaten their existence. Varroa destructor (Anderson and Trueman) is the most devastating ectoparasitic mite known today. In this review, we offer an up-to-date review of the literature on the use of essential oils (EOs) against V. destructor, particularly the last decade (2010-onwards). We find that 40 aromatic plants were extracted for EOs and screened for their varroacidal activity under laboratory and/or field conditions. Through this review, we urge the scientific community to pay more attention to the following points: 1) the laboratory bioassays should be completed with field trials as they are the ones capable of revealing the true potency of the studied EO, 2) sub-lethal effects of the screened EO on honeybees as non-target organisms as well as their residual activity should also be investigated, and finally 3) more inquiries are required in regard to the mode of action of these substances to reveal their molecular targets in V. destructor. [ABSTRACT FROM AUTHOR]

Parasites exert numerous effects upon their hosts, including physiological and metabolic changes that can in turn influence various aspects of host life history. Using flow‐through respirometry, we investigated how infection intensity of an ectoparasitic mite (Macrocheles subbadius) affects the respiratory rate (CO2 production) of its host Drosophila nigrospiracula. Mean fly respiratory rate increased with infection intensity with the strongest effect, a 40% increase relative to uninfected controls, occurring with three mites attached. We also verified the causal relationship between elevated respiration rate and mite attachment by examining changes in host respiration before and after mite exposure. We found that the rate of CO2 production increased by 11% for individual flies following parasite attachment. Fly locomotor activity was not significantly different between infected and uninfected individuals. Metabolic rate of hosts increased as a result of infection in an intensity dependent manner and was not simply due to changes in host activity. These results demonstrate that parasites can have a significant influence on the energy requirements of their host, which may account for the parasite‐mediated loss in host fitness. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) are a large class of non-protein-coding transcripts that are involved in a diverse spectrum of regulatory mechanisms across a broad range of biological processes. To date, however, few studies on circRNAs have investigated their role in the biology of invertebrate parasites. The ectoparasitic mite Varroa destructor is perceived as the principal biotic threat towards global honey bee health. This parasite cannot be sustainably controlled partially due to the lack of knowledge about its basic molecular biology. In this paper, we unveil the circRNA profile of V. destructor for the first time and report the sources, distribution, and features of the identified circRNAs. Exonic, intronic, exon-intron, and intergenic circRNAs were discovered and exon-intron circRNAs were the most abundant within the largest spliced length. Three hundred and eighty-six (8.3%) circRNAs were predicted to possess translational potential. Eleven circRNAs, derived from six parental genes, exhibited strong bonds with miRNAs as sponges, suggesting an efficient post-transcriptional regulation. GO term and KEGG pathway enrichment analyses of the parental genes of the identified circRNAs showed that these non-coding RNAs were mainly engaged in protein processing, signal transduction, and various metabolism processes. To our knowledge, this is the first catalog of a circRNA profile of parasitiformes species, which reveals the prevalence of circRNAs in the parasite and provides biological insights for future genetic studies on this ubiquitous parasitic mite. [ABSTRACT FROM AUTHOR]