Infestation by the nest-dwelling Ixodes hexagonus Leach and the exophilic Ixodes ricinus (Linnaeus) (Ixodida: Ixodidae) on the Northern white-breasted hedgehog, Erinaceus roumanicus (Erinaceomorpha: Erinaceidae), was investigated during a 4-year study in residential areas of the city of Poznań, west-central Poland. Of 341 hedgehogs, 303 (88.9%) hosted 10 061 Ixodes spp. ticks encompassing all parasitic life stages (larvae, nymphs, females). Ixodes hexagonus accounted for 73% and I. ricinus for 27% of the collected ticks. Male hedgehogs carried significantly higher tick burdens than females. Analyses of seasonal prevalence and abundance of I. hexagonus revealed relatively stable levels of infestation of all parasitic stages, with a modest summer peak in tick abundance noted only on male hosts. By contrast, I. ricinus females and nymphs peaked in spring and declined steadily thereafter in summer and autumn, whereas the less abundant larvae peaked in summer. This is the first longterm study to evaluate the seasonal dynamics of both tick species on populations of wild hedgehogs inhabiting urban residential areas.
Insects known as leafhoppers (Hemiptera: Cicadellidae)
produce
hierarchically structured nanoparticles known as brochosomes that
are exuded and applied to the insect cuticle, thereby providing camouflage
and anti-wetting properties to aid insect survival. Although the physical
properties of brochosomes are thought to depend on the leafhopper
species, the structure–function relationships governing brochosome
behavior are not fully understood. Brochosomes have complex hierarchical
structures and morphological heterogeneity across species, due to
which a multimodal characterization approach is required to effectively
elucidate their nanoscale structure and properties. In this work,
we study the structural and mechanical properties of brochosomes using
a combination of atomic force microscopy (AFM), electron microscopy
(EM), electron tomography, and machine learning (ML)-based quantification
of large and complex scanning electron microscopy (SEM) image data
sets. This suite of techniques allows for the characterization of
internal and external brochosome structures, and ML-based image analysis
methods of large data sets reveal correlations in the structure across
several leafhopper species. Our results show that brochosomes are
relatively rigid hollow spheres with characteristic dimensions and
morphologies that depend on leafhopper species. Nanomechanical mapping
AFM is used to determine a characteristic compression modulus for
brochosomes on the order of 1–3 GPa, which is consistent with
crystalline proteins. Overall, this work provides an improved understanding
of the structural and mechanical properties of leafhopper brochosomes
using a new set of ML-based image classification tools that can be
broadly applied to nanostructured biological materials.
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