The Fecundity of Ixodes Ricinus (L.) (Acarina: Ixodidae) and the Mortality of its Developmental Stages Under Field Conditions

Abstract

AbstractThe egg production of females of Ixodes ricinus (L.) was found to be closely related to the engorged body weight. The relationship was due almost entirely to the size of the blood-meal. Smaller ticks seemed to be slightly more efficient than larger ones in converting their blood-meal to eggs. Ticks, especially larvae, that overwintered in diapause did not survive as well as those that fed and then moulted in the same year. Larvae that fed and entered diapause early in the autumn did not survive as well as those that fed later in the season. A very high proportion of tick eggs hatched, either in the same year as they were laid or after overwintering. Almost all nymphs and adults became active and climbed to the top of the tubes after moulting. Although most larvae appeared to become active, only about half of them reached the tops of the tubes. This is thought to be a reflection on the fact that larvae are adapted to parasitise small rodents. It is suggested that winter temperatures may play an important part in determining the mortality rate of larvae that overwinter in the engorged state.