What is a pig tick? - briefly
A pig tick (Haemaphysalis suis) is a hard, blood‑feeding ectoparasite that mainly infests domestic swine and can transmit diseases such as African swine fever virus. It inhabits temperate zones, completing its life cycle on pigs and occasionally on wildlife.
What is a pig tick? - in detail
Pig ticks are arthropod ectoparasites belonging to the family Ixodidae that specialize in feeding on swine. The most frequently encountered species is Haemaphysalis suis, although Ixodes ricinus and Rhipicephalus (Boophilus) microplus also infest domestic pigs in various regions.
Morphologically, adult pig ticks possess a dorsally flattened body, a scutum covering the dorsal surface, and four pairs of legs. Females are larger than males, measuring up to 6 mm when unfed and expanding to 12 mm after engorgement. The mouthparts consist of chelicerae and a hypostome equipped with backward‑directed barbs that anchor the parasite to host tissue during blood ingestion.
The life cycle comprises egg, larva, nymph, and adult stages. Each active stage requires a blood meal to molt or reproduce:
- Eggs hatch into six‑legged larvae within 2–3 weeks under suitable temperature and humidity.
- Larvae attach to a host, feed for 2–4 days, then detach to molt into nymphs.
- Nymphs repeat the feeding‑detachment process, usually on the same or a different host, before molting into adults.
- Adults feed for 5–10 days; engorged females lay thousands of eggs in the environment, completing the cycle.
Geographically, pig ticks are prevalent in temperate and subtropical zones of Europe, Asia, and parts of the Americas where swine production is intensive. Their distribution correlates with the presence of suitable habitats—dense vegetation, moist soil, and livestock shelters—that support off‑host development.
Pathogen transmission is a primary concern. Haemaphysalis suis vectors Babesia spp. and Theileria spp., agents of babesiosis and theileriosis in pigs. Rhipicephalus microplus can transmit Anaplasma marginale and Ehrlichia spp., leading to anemia and immunosuppression. Tick‑borne viruses, such as African swine fever virus, may also be mechanically transferred during feeding.
Control strategies focus on environmental management and chemical interventions:
- Habitat modification: regular removal of leaf litter, mowing of grass, and drying of pens reduce off‑host survival.
- Acaricide application: systemic agents (e.g., ivermectin) and topical formulations (e.g., permethrin) applied to animals or premises interrupt feeding cycles.
- Biological control: entomopathogenic fungi (e.g., Metarhizium anisopliae) and predatory mites can suppress tick populations without chemical residues.
- Integrated pest management: combining regular monitoring, strategic treatment timing, and sanitation yields sustained reductions in infestation levels.
Understanding the biology, ecology, and disease potential of pig ticks enables targeted interventions that protect swine health and minimize economic losses in pig farming operations.