Contribution to the knowledge of the host spectrum of Trombidium brevimanum- data from laboratory experiment and field studies.

Knowledge of host range and of host specificity is often based on limited evidence and needs critical reappraisal. Trombidium brevimanum (Trombidiidae) host range is considered to be restricted to arachnids and, according to the published field data, encompasses 29 species of spiders assigned to nine families, and two species of pseudoscorpions representing the family Neobisiidae. To further understand the parasite-host interactions between T. brevimanum and its hosts, laboratory reared larvae were experimentally exposed to various species of field-collected spiders and field-collected or laboratory-reared false scorpions. Further development of specimen after termination of parasitic phase constituted the criterion of host suitability. Out of 86 analyzed spider (67 genera, 25 families) and six pseudoscorpion species (five genera and three families), altogether 36 species were found to be suitable hosts, of which 31 species (27 genera, 16 families) are reported new host-parasite associations. Hitherto unrecorded associations pertained to the members of Agelenidae, Anyphaenidae, Cheiracanthiidae, Cicurinidae, Gnaphosidae, Pholcidae, Salticidae (Araneae), and Cheliferidae (Pseudoscorpiones). The hosts of T. brevimanum include spiders with different hunting strategies. Data relating to measures of host-parasite interactions like intensity of infestation, attachment site preferences, and duration of parasitism are summarized. Potential factors influencing the actual host spectrum of T. brevimanum are discussed. We hypothesize that the host species influences the body color of the mites.