Trombellidae

Larvae require slide mounting and microscopic examination. Key characters include: scutum shape (often pentagonal or trapezoidal), number and arrangement of sensillae, and details of the gnathosomal base. Adults distinguished from related families by the combination of heavily sclerotized cuticle, leg chaetotaxy, and presence of particular lyrifissures. Separation from Trombiculidae relies on larval scutal setae and cheliceral morphology rather than host association.

Adults inhabit soil, leaf litter, and decaying organic matter in terrestrial environments. Larvae occur on or near host arthropods. Specific microhabitat preferences are poorly documented due to limited study.

Recorded from multiple continents including North America, South America, Europe, and Australia. Distribution records are sparse and likely reflect limited sampling effort rather than actual rarity.

Adult activity patterns unknown; larval parasitism likely seasonal depending on host availability. Insufficient data for reliable phenology.

Adults are predatory, feeding on small invertebrates and possibly eggs in soil and litter. Larvae are ectoparasites, feeding on hemolymph of arthropod hosts including insects and possibly other arachnids.

• Orthoptera - larval hostdocumented host group for some species
• Coleoptera - larval hostdocumented host group for some species

Trombellidae exhibits the typical parasitengone life cycle: egg, inactive pre-larva, parasitic larva, inactive protonymph, active predatory deutonymph, inactive tritonymph, and active predatory adult. Only the larval stage is parasitic; all post-larval instars are free-living predators.

Adults are fast-moving, active predators in soil and litter. Larvae exhibit host-seeking behavior and attach to arthropod hosts to feed. Specific behavioral details are largely unstudied.

Adults function as generalist predators in soil food webs, potentially regulating populations of small invertebrates. Larvae act as ectoparasites that may impact host fitness, though population-level effects are unknown. Role in nutrient cycling through soil predation likely minor compared to other mesofauna.

No known medical or veterinary importance. Not associated with human disease, unlike the related chiggers (Trombiculidae). Occasionally collected in ecological surveys of soil mites. No economic significance documented.

• TrombiculidaeShared superfamily Trombiculoidea; larvae also ectoparasitic. Distinguished by larval scutal setation, cheliceral blade structure, and typically different host associations (Trombiculidae more often on vertebrates). Adults of Trombiculidae generally less heavily sclerotized.
• LeeuwenhoekiidaeRelated prostigmatid family with parasitic larvae. Larvae of Leeuwenhoekiidae have distinct scutal shapes and are often associated with different host groups; adults differ in leg chaetotaxy and cuticular sculpture.

• mites
• parasitengona
• soil fauna
• ectoparasites
• arthropod parasites

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life