acarine

Acarine, or acarines (plural), refers to members of the subclass Acari of the phylum Arthropoda, which includes mites and ticks. The term acarine can be used as an adjective describing anything related to this group. Acari are extremely diverse in form and ecology; they occupy soils, leaf litter, freshwater and marine environments, as well as the bodies and surfaces of plants and animals.

Morphology and life stages vary, but most acarines have a specialized mouthpart region, the capitulum, and a body region called the idiosoma. In most species, the adults and nymphs possess four pairs of legs; the larval stage typically has three pairs and is often worm-like in appearance. The body often lacks obvious segmentation.

Life cycle and development generally include egg, larva, one or more nymphal instars, and adult. Development can be direct without metamorphosis, though molts occur between stages. Reproduction is sexual in most species, with some capable of parthenogenesis.

Ecology and feeding strategies are diverse. Diets include plant sap, fungi, algae, detritus, nematodes, or vertebrate blood. Many acarines are free-living in soil or on plants, while others are ecto- or endoparasites on animals. Ticks (order Ixodida) are notable blood feeders and disease vectors.

Importance and impact extend across ecosystems and human activities. Mites and ticks play key ecological roles as decomposers and predators and can be pests in agriculture and medicine. Some mites cause allergic reactions or skin conditions; others transmit pathogens. Systematically, Acari is divided into two major lineages, Acariformes and Parasitiformes, which include several orders such as Oribatida, Trombidiformes, and Ixodida; taxonomy remains complex and subject to revision.

---