Incidence of infection and host specificity of Cuterebra tenebrosa in bushy-tailed wood rats (Neotoma cinerea) from central Washington.

Cuterebra tenebrosa Coquillett bot flies were studied under natural and laboratory conditions in bushy-tailed wood rats and 7 other small mammal host species. Larvae demonstrated strong host specificity for Neotoma cinerea. Monthly trapping samples of wood rats in central Washington showed infection peaks of 65--70% in May and 30--40% in late summer. In laboratory-induced infections, wood rats supported 7 larvae without host mortality. Natural infections in trapped rats ranged from 1 to 6 per host. Larvae developed in lateral and dorsal warbles in laboratory and natural infections. Few wood rats demonstrated evidence of acquired immunity in repeated infections over 2 years.