title: Nymphal diapause and its photoperiodic control in the tick Ixodes scapularis (Acari: Ixodidae).
abstract: It is shown experimentally that the option between developmental diapause and non-diapause development in nymphs of Ixodes scapularis Say, 1821 (Middle Atlantic population) is determined by photoperiodic conditions according to a two-step photoperiodic reaction of short-day long-day type. Diapause arrest of development is induced by an impact of either long day upon unfed nymphs, or short day upon engorged nymphs, while non-diapause development completed in 2-2.5 months at 20 degrees C needs the change from short-day to long-day conditions. Some ecophysiological aspects of mechanisms controlling seasonal development of ticks belonging to Ixodes ricinus complex are discussed.
authors.affiliation: Biological Research Institute, St. Petersburg State University, Oranienbaumskoe Shosse 2, Stary Peterhof, St. Petersburg, 198504, Russia. valentin.belozerov@paloma.spbu.ru
authors.forename: Valentin N
authors.initials: VN
authors.lastname: Belozerov
authors.forename: Rudolf L
authors.initials: RL
authors.lastname: Naumov
mesh_terms: D000818:Animals; D018884:Ixodes / Q000254:growth & development*; D009758:Nymph / Q000254:growth & development; D017440:Photoperiod; D012621:Seasons