Life cycle of the tick Haemaphysalis leporis-palustris (Acari: Ixodidae) under laboratory conditions.

ABSTRACT

The life cycles of two separate populations (colonies A and B) of the rabbit tick, Haemaphysalis leporis-palustris, were studied under laboratory conditions. Domestic New Zealand rabbits, Oryctolagus cuniculus, and wild rabbits, Sylvilagus brasiliensis, were used as hosts for ticks from colony B and only O. cuniculus rabbits were used as hosts for ticks from colony A. Developmental periods were observed in an incubator at 27+/-1 degrees C and RH 90+/-5%. Larvae from colonies A and B fed for 8.0+/-3.7 days and 8.5+/-1.3 days, respectively, on O. cuniculus. On S. brasiliensis larvae from colony B fed for 7.2+/-1.3 days. Nymphs from colony A fed for 8.1+/-1.4 days on O. cuniculus and nymphs from colony B fed for 8.1+/-1.0 days on S. brasiliensis. Only one engorged nymph from colony B was recovered from O. cuniculus. Females from colony A fed for 20.9+/-5.9 days on O. cuniculus and females from colony B fed for 18.6+/-2.4 days on O. cuniculus and 18.7+/-3.7 days on S. brasiliensis. Engorged larvae from colony A required 13.7+/-3.7 days to molt while engorged larvae from colony B required 11.8+/-3.0 and 11.5+/-1.8 days to molt, after having fed on O. cuniculus and S. brasiliensis, respectively. Engorged nymphs from colonies A and B required 16.3+/-1.9 days and 14.7+/-1.4 days to molt, respectively. Engorged females from colonies A and B required 4-7 and 3-5 days, respectively, to start oviposition. Mean egg incubation periods lasted for 33-34 days. For ticks from colony B, host species accounted for significant differences (p < 0.05) in larval and nymphal feeding periods, oviposition weights and CEIs. Significant differences (p < 0.05) between the two colonies when ticks fed on O. cuniculus were observed for larval and nymphal feeding and premolt periods, engorged female and oviposition weights and conversion efficiency indexes (CEI). S. brasiliensis were always a more suitable host for H. leporis-palustris than O. cuniculus. Significantly more larvae and nymphs engorged and molted when fed on S. brasiliensis (p < 0.001). Females fed S. brasiliensis were more successful to lay fertile eggs and showed the highest engorged and egg mass weights, and the highest CEIs. Data of H. leporis-palustris fed on wild rabbits (one of its natural host species) are reported for the first time.