Experimental and Applied Acarology最新文献

Plant diversity can enhance natural pest control in agriculture by providing resources and conditions that are not regularly available in conventional crops to natural enemies of crop pests. Extrafloral nectar-producing plants, for example, might cause reduction of pest densities on neighboring plants because the nectar can increase the performance of natural enemies. Coffee agroforestry systems often contain extrafloral-nectar-producing Inga spp. trees that serve several purposes. Recent studies suggest that they attract and arrest a diversity of natural enemies that contribute to the control of coffee pests. Mites from the Phytoseiid family are key natural enemies of coffee pest mites, but no study has investigated whether Inga extrafloral nectar increases the performance of predatory mites in coffee ecosystems. Thus, here, we assessed whether the extrafloral nectar of Inga edulis Mart. (Fabaceae) can be considered a suitable nutritional resource for the predatory mite Amblyseius herbicolus (Chant), one of the most abundant phytoseiids in coffee crops. We found that feeding on extrafloral nectar allows for development and survival, but not reproduction, of A. herbicolus. Whereas individuals that fed on a diet of nectar during their immature development could subsequently only oviposit after having fed on a pollen diet, individuals that had developed on pollen stopped ovipositing when fed nectar. Our findings suggest that interplanted Inga trees can help to conserve populations of predatory mites in crop ecosystems through the provision of nectar and may boost biological control services. Future research should investigate the effects of extrafloral nectar-producing trees on coffee pest control by these predatory mites.

Diatomaceous earth (DE) recently was shown to rapidly kill ticks. Proof of concept for use of DE to kill the American dog tick, Dermacentor variabilis, the most widely distributed native three-host tick in North America, has not been investigated. Unfed D. variabilis nymphs dipped into DE and incubated at 30 °C and 50 versus 70% relative humidity (RH) had an estimated median survival time of 5 h and 4 h, respectively, with mortality starting within 1 h. There was no difference in survival time at the 50 and 70% RH. In a two-choice assay at 30 °C and 50% RH, ticks walked freely onto DE treated surfaces; the estimated median survival time was 3 h, indicating that DE is not a repellent. There was no difference in locomotor activity between DE-treated nymphs and untreated controls. In simulated-field experiments, pine straw infested with nymphs and then treated with DE at 5.00, 2.50, 1.25, 0.63 and 0.31 g DE/m² resulted in 100% mortality and 81.40% (± 4.13%) mortality at 0.15 g DE/m² after 24 h. Scanning electron microscopy of the dead ticks in the 0.15 g DE/m² treatments showed most of the cuticle surface was devoid of DE except for the hypostome. The rapid time to first death by dipping, the no effect of RH on survival time, the small amounts of mineral on the tick body and no visible scarring on the tick cuticle questions the generally accepted mode of action for DE, that is, cuticle damage and dehydration.

Post-agricultural land differs from typical forest land in physical, chemical and biological features. In addition, the environment of this land type is determined, among other things, by the introduced tree species. These differences may be revealed by the biodiversity and abundance of the soil fauna. We analysed the abundance, species richness and diversity of different instars of mesostigmatid mites inhabiting three different habitat types on post-agricultural land (shaped by pure Pinus sylvestris L., Tilia cordata Mill. and Betula pendula Roth stands). We collected 288 soil samples from eight plots in three stands. The collection was conducted in July and October in two consecutive vegetation seasons (2021 and 2022) for Mesostigmata mites community. Soil characteristics (determination of soil group and analysis of physical and chemical properties of soil and litter) were done in July 2021. In total, 399 individuals (266 females, 50 males and 83 juveniles) were classified into 38 taxa (33 species, five genera). Most individuals belonged to the Parasitidae, Laelapidae and Veigaiidae families. The most abundant species were Hypoaspis aculeifer (Canestini) (21.6% of all recorded mites), Veigaia nemorensis (C.L.Koch) (7.8%) and Trachytes aegrota (C.L.Koch) (7.0%). Abundance, species richness and diversity were shaped by collection month and Fe content in soil. The abundance was influenced by N litter content and was significantly lower in P. sylvestris stand in July (0.57 ± 0.23; mean ± SE) than in P. sylvestris (2.17 ± 0.54) and T. cordata (2.15 ± 0.48) stands in October. Moreover, abundance in P. sylvestris stand in October was higher than in B. pendula stand in July (0.78 ± 0.26). Similarly, species richness was significantly lower in P. sylvestris stand in July than in P. sylvestris and T. cordata stands in October (2.17 ± 0.54 and 2.15 ± 0.48, respectively). Higher Shannon's diversity of mite communities was reported in P. sylvestris stand in October (0.40 ± 0.10) than in P. sylvestris and B. pendula stands in July (0.12 ± 0.06 and 0.14 ± 0.08, respectively). Large fluctuations of abundance, species richness and diversity of soil mite communities in P. sylvestris and B. pendula stands between collection months give the insights for creating mixed stands on post-agricultural land. It is worth noticing that the wet season creates the most favourable living environment for mesostigmatid mites in P. sylvestris litter.

The phytoseiid predatory mite Neoseiulus californicus (McGregor) is one of the most efficient biocontrol agents in integrated pest management (IPM) programs of greenhouse pests, with different feeding habits on pollen, thrips, eriophyiids, and spider mites. This study appraised the effect of the age and gender on functional response and age on numerical response of N. californicus fed on larvae and protonymph of Tetranychus urticae Koch under laboratory conditions at 25 ± 1 ℃, 70 ± 5% RH and a photoperiod of 16L: 8D h. In the functional response test, the 2, 4, 8, 16, 32, 64, and 128 densities of prey were offered to 3, 5, 7, 10, 15, 20, 25, 30, 35 and 40-day-old ages of female and 7, 10, 15, 20, 25 and 30-day-old ages of male individuals of N. californicus. The logistic regression was used to recognize the type of functional response. Type II functional response was recognized for all ages of the male and female individuals of N. californicus. The highest predation rate, and searching efficiency (a) was observed in the middle ages of the predator. A significant increase in oviposition was shown with increasing T. urticae density and increasing ages of the predator. Furthermore, in the middle age with low prey density, the efficiency of conversion of ingested food (ECI) was the highest. The results of this study showed that the different ages of N. californicus are influencing factors on its predation capacity and oviposition rate.

Raoiella indica Hirst has rapidly and widely spread throughout the New World since 2004, primarily infesting coconut palms and interacting with the predator Amblyseius largoensis (Muma). Although A. largoensis feeds on R. indica at all stages of development, it cannot naturally reduce its population to levels that do not impact the host plant. Raoiella indica possesses dorsal setae that secrete exudates during all post-embryonic developmental stages, and females have a behavior that deliberately deposits droplets on the freshly laid egg, possibly as a defense strategy against predation in vulnerable stages. In this context, we analyzed whether the presence or absence of droplets in R. indica eggs affects predation using A. largoensis as a biological model. Thus, we evaluated whether some biological and behavioral characteristics of A. largoensis could be affected by the consumption of R. indica egg masses washed or unwashed with water. Also, we performed a chemical analysis of the droplets exuded by R. indica and provided a description of the oviposition behavior of R. indica. The predator showed a higher consumption rate and preference for washed eggs. The results suggest that the exudate droplets have defensive functions, which are incorporated by the female onto the egg during oviposition and subsequently during a patrolling behavior, as they lose their effect after being washed with water. Although the droplets do not prevent the predator from feeding, they reduce the number of R. indica eggs consumed without affecting the growth of A. largoensis.

Toxoplasma gondii occurs in a wide range of intermediate hosts, whose blood may be a meal for different tick species. A few studies have examined the role of ticks in the life cycle of T. gondii. This one includes the largest number and all stages of Ixodes ricinus collected from the widest area, covering seven recreational localities within a forest biotope in Northern Poland. This study aimed to determine the prevalence of T. gondii DNA in 2144 collected questing ticks to establish whether they may be involved in T. gondii life cycle. The additional goal was to genotype the detected T. gondii, as knowledge about its genotypes occurring in European ticks is insufficient. A further purpose was to detect coinfection with T. gondii and Borreliaceae in the collected ticks, as all of them have previously been tested for the presence of bacteria DNA. Nested PCR and sequencing of the obtained B1 gene fragment were conducted. T. gondii DNA was detected in 0.9% of all ticks (1.1% of nymphs and 0.7% of larvae). The presence of T. gondii in unfed larvae and nymphs may indicate the possibility of its vertical transmission. The prevalence of T. gondii DNA in ticks collected from individual sites was focal (0-4.3%) and seems to depend on local climatic conditions. Among all examined ticks, 0.3% were coinfected with T. gondii and Borreliella spp., vs. 0.6% of specimens with a single T. gondii infection. The obtained B1 sequences showed the greatest similarity (99.71-100%) to the sequence representing type III.

In this study, we evaluated the role of the gnathosoma (mouthparts) in chemosensing of the most devastating honey bee parasite, Varroa destructor mite. Through transcriptomic analysis, we compared the expression of putative chemosensory genes between the body parts containing the main chemosensory organs (the forelegs), gnathosoma and the rest of the body devoid of these two body parts. Furthermore, we checked the presence of chemosensory-related transcripts in the proteome of the gnathosoma. Our comparative transcriptomic analysis revealed the presence of 83 transcripts with known characteristic conserved domains belonging to eight chemosensory gene families in the three Varroa transcriptomes. Among these transcripts, 11 were significantly upregulated in the mite's forelegs, compared to 8 and 10 in the gnathosoma and body devoid of both organs, respectively. Whilst the gnathosoma and the forelegs share similar expression of some putative lipid carrier proteins, membrane-bound receptors, and associated proteins, they also differ in the expression profiles of some transcripts belonging to these protein families. This suggests two functional chemosensory organs that may differ in their chemosensory function according to specific characteristics of compounds they detect. Moreover, the higher expression of some chemosensory transcripts in the body devoid of forelegs and gnathosoma compared to the gnathosoma alone, may suggest the presence of additional function of these transcripts or alternatively presence of additional external or internal chemosensory organs. Insights into the functional annotation of a highly expressed gustatory receptor present in both organs using RNA interference (RNAi) are also revealed.

The two-spotted spider mite (Tetranychus urticae Koch, TSSM) is recognized as one of the most problematic spider mite pests. However, the precise gene expression patterns across its key developmental stages remain elusive. Here, we performed a comprehensive transcriptome analysis of TSSM eggs, nymphs and adult females using publicly available RNA sequencing (RNA-seq) data to elucidate the overarching transcriptomic differences between these developmental stages. Principal component analysis and hierarchical clustering analysis unveiled distinct separations among samples across different developmental stages, regardless of their Wolbachia infection status. Differential expression analysis revealed 4,089,2,762, and 1,282 core genes specifically enriched in eggs, nymphs, and adults, respectively. KEGG and GO enrichment analyses showed upregulation of genes in eggs are associated with proteolysis, Wnt signaling pathway, DNA transcription, RNA biosynthetic and metabolic processes, as well as protein folding, sorting, and degradation pathways. Meanwhile, nymphs exhibited increased abundance of genes related to chitin/amino sugar metabolic processes, G protein-coupled receptor signaling pathways, monoatomic ion transport, and neurotransmitter transport pathways. Pathways involving sphingolipid and carbohydrate metabolic processes, proteolysis, lipid transport, and localization were particularly enriched in older females. Altogether, our findings suggest that the egg stage exhibits higher activity in cell differentiation processes, the nymph stage is more involved in chitin development, and the adult stage shows increased metabolic and reproductive activity. This study enhances our understanding of the molecular mechanisms underlying TSSM development and paves the way for further research into the intricate physiological processes of TSSM.

A reliable phylogeny is crucial for understanding the evolution and radiation of animal taxa. Phylogenies based on morphological data may be misleading due to frequent convergent evolution of traits-a problem from which molecular phylogenies suffer less. This may be particularly relevant in oribatid mites, an ancient soil animal taxon with more than 11,000 species, where the classification of species into high-ranking taxa such as superfamilies is equivocal. Here, we present a molecular phylogeny of 317 oribatid, 4 astigmatid and 17 endeostigmatid mite species/taxa based on 18S rDNA sequences. We aimed at testing the validity of the 41 superfamilies of oribatid mites recognized by Norton and Behan-Pelletier (in Krantz and Walter, A manual of Acarology, 3rd ed., Texas Technical University Press, Lubbock, 2009). The results indicate that 17 of the 41 oribatid mite superfamilies are monophyletic but that 18 superfamilies are paraphyletic or polyphyletic (5 superfamilies were only included with one species and Microzetoidea were not included). Our findings point to the importance of convergent evolution in polyphyletic oribatid mite taxa. Convergent evolution and the old age of mites likely resulted in a mosaic-like distribution of morphological characters impeding phylogenetic reconstructions based on morphology, calling for molecular approaches to improve oribatid mite systematics.

Piroplasmosis, a disease of domestic and wild animals, is caused by tick-borne protozoa of the genera Babesia and Theileria, while anaplasmosis is caused by tick-borne bacteria of genera Anaplasma. Hyalomma dromedarii is the most dominant tick species infesting camels in Egypt and act as a vector of piroplasms, Anaplasma, Rickettsia and Ehrlichia spp. The available information concerning the detection of these pathogens in H. dromedarii infesting camels is limited. The present study aimed to evaluate the status of these pathogens in H. dromedarii ticks over four seasons of a year, in addition to investigate the infections of piroplasms and Anaplasmataceae besides their genetic diversity starting from June 2021 till April 2022. A total of 275 semi-engorged females of H. dromedarii were collected from different slaughtered camels, Toukh city slaughterhouse then investigated by Polymerase Chain Reaction (PCR) to detect piroplasms (Babesia spp., Theileria spp.) and Anaplasmataceae DNA targeting 18 S rRNA and 16 S rRNA genes, respectively followed by sequencing and phylogenetic analyses. Overall, piroplasms were detected in 38 ticks (13.8%), Babesia spp. was detected in 35 ticks (12.7%), while Theileria spp. was detected in one tick (0.4%). Anaplasmataceae was detected in 57 ticks (20.7%). Mixed infections of piroplasms and Anaplasmataceae were detected in 13 ticks (5%). Single infection either with piroplasms or Anaplasmataceae was detected in 25 (9%) and 44 (16%) ticks, respectively. The highest monthly rate of piroplasms was in April (spring) and Anaplasmataceae was in July (summer). Sequence analysis revealed that Babesia bigemina, Wolbachia spp. and Anaplasma marginale are the most dominant species in the examined tick samples. To the best of our knowledge, this study confirms the presence of B. bigemina, Wolbachia spp. and A. marginale in H. dromedarii in Egypt by sequencing.