New records and laboratory-rearing data for Ixodes schulzei (Acari: Ixodidae) in Brazil

Abstract

Ixodes schulzei Aragão and Fonseca was described from Brazil in 1951 based on female ticks collected on wild rats from the states of Rio de Janeiro and Santa Catarina. Since that time, there have been no additional reports of I. schulzei in the literature. We report two new records of I. schulzei: a female collected on the water rat Nectomys squamipes (Brants) from Minas Gerais State, and another female from this same host species from São Paulo State. This last specimen was engorged and oviposited fertile eggs in the laboratory. Larvae hatched from these eggs were used for subsequent infestations under laboratory conditions, as were nymphs obtained from the engorged larvae. Naive laboratory rats (Rattus norvegicus Berkenhout) and wild mice (Calomys callosus Rengger) were used to feed ticks. C. callosus was a more suitable host than R. norvegicus, as significantly more ticks (P < 0.05) were recovered and successfully molted after feeding on the former host species. A significantly (P < 0.05) greater proportion of larvae detached from C. callosus during daylight (71.3%) when compared with those that detached from R. norvegicus in the same period (54.8%). A total of nine engorged nymphs (one from R. norvegicus, and eight from C. callosus) were recovered in the infestations. All of them successfully molted to adults, which were all females. The male of I. schulzei remains unknown.