Incidence of the Parasitism of Chicken Mite Dermanyssus gallinae Parasitizing and Propagating on Chicken Even in the Daytime and Their Life Cycle

The incidence of the parasitism of chicken mites Dermanyssus gallinae parasitizing and propagating on chickens day and night was observed in a chicken farm. The incidence of the parasitism was induced by the artificial inoculation of protonymphs hatched from eggs of chicken mites parasitizing in the daytime on chickens. Furthermore, their life cycle was clarified.1. It was observed in a chicken farm that the parasitism of northern fowl mites occurred on chickens, subsequently northern fowl mites and chicken mites were found on the same chickens and finally the chickens were parasitized with chicken mites alone. Chicken mites parasitized and propagated on the chickens day and night without leaving the chickens before daybreak.2. The parasitism of chicken mites on chickens even in the daytime was established irrespective of the presence or absence of parasitic northern fowl mites when the protonymphs of chicken mites parasitizing in the daytime were inoculated artificially on chickens. The number of chicken mites parasitized on the chickens increased when the chickens were parasitized preliminarily with northern fowl mites.3. The life cycle of the chicken mites parasitizing and propagating on the chickens day and night was the same as that of common chicken mites which sucked blood from chickens at night and left them before daybreak.