What kills ticks in nature? - briefly
Predation by birds, small mammals, and insects, together with environmental stresses such as desiccation, flooding, and extreme temperature shifts, causes the majority of mortality in wild «ticks».
What kills ticks in nature? - in detail
Natural mortality factors for ticks operate through predation, environmental stressors, pathogenic infection, and intra‑specific competition.
Predatory organisms include arachnid specialists such as hunting spiders, centipedes, and some ant species that actively capture and consume immature stages. Ground‑dwelling beetles (Carabidae) and certain bird species, especially ground‑foraging passerines, also reduce tick numbers by ingesting engorged individuals. Small mammals, notably shrews, may prey on tick larvae during foraging.
Environmental conditions impose lethal limits. Desiccation caused by low humidity rapidly dehydrates unfed ticks, especially in open, sun‑exposed habitats. Temperature extremes—freezing below ‑10 °C or sustained heat above 45 °C—disrupt metabolic processes and lead to mortality. Ultraviolet radiation on exposed surfaces contributes to DNA damage and dehydration.
Pathogenic agents further diminish tick populations. Entomopathogenic fungi such as Metarhizium anisopliae and Beauveria bassiana infect the cuticle, proliferate internally, and cause death within days. Bacterial pathogens including Rickettsia species and certain Borrelia strains can be lethal when colonizing internal tissues. Viral infections, though less documented, have been observed in laboratory settings.
Intra‑specific factors affect survival rates. High density of larvae on a host leads to competition for blood meals, resulting in starvation for some individuals. Seasonal synchrony of emergence may create overcrowding, increasing exposure to predators and pathogens.
Collectively, these agents shape tick population dynamics by imposing continuous natural mortality across all life stages.