Population fluctuation of predatory and sanitary importance mites (Acari) in commercial laying hens: Ecological interactions.

This study aimed to evaluate the mite fauna and their ecological interactions in commercial laying hen farms in the state of Rio Grande do Sul, Brazil. It was conducted from August 2013 through August 2014 with two sampling strategies (feathers and traps) in three different production systems: automated (A), semi-automated (S) and free-range (FR). A total of 38,383 mites were collected belonging to 23 families and 33 species, most of which were collected in feathers (74%) followed by traps (26%). There was higher abundance at S (10,774-28.1%) and S (11,023-28.7%) followed by FR (6972-18.2%), A (1896-4.9%), A (4775-12.4%), and A (2943-7.7%). Higher richness was observed at S (23 species), S (18 species), and FR (19 species). Megninia ginglymura (Mégnin) (Analgidae) was the species with the highest health importance, eudominant on feathers, and its populations seems to be related with increased temperature. Tuccioglyphus setosus Horn et al. (Pyroglyphidae) seems to be influenced by relative air humidity and temperature. Predators with the highest populations were Cheyletus malaccensis (Oudemans) (Cheyletidae), Typhlodromus transvaalensis (Nesbitt) (Phytoseiidae), Blattisocius keegani (Fox), and Blattisocius dentriticus (Berlese) (Blattisocidae).