title: Biological and physiological characterization of in vitro blood feeding in nymph and adult stages of Ornithodoros turicata (Acari: Argasidae).
abstract: Biological and physiological aspects of blood feeding in nymph and adult Ornithodoros turicata were investigated using an in vitro technique combined with electrophysiological recordings and respirometry. The duration of blood feeding through a Parafilm® membrane was similar (19.2-22.6 min) in both developmental stages. The mean (±SD) size of blood meal ingested by nymphs, females, and males was 44.2±17.9, 150.6±48.7, and 74.2±36.9 mg, respectively, representing a 2.5-, 2.8- and 3.0-fold increase from their respective unfed weights. Electrophysiological recordings of the pharyngeal pump during blood feeding revealed that ticks ingested blood at a rate of 6.1-6.4 suctions per second. Mean blood volume ingested per suction was 0.013 μl in females and 0.007 μl in both males and nymphs. Blood meal size (mg) correlated with unfed body weight (mg) (r(2)=0.50, p<0.05) and with blood volume ingested per suction (r(2)=0.71, p<0.05). Unfed ticks exhibited a circadian ventilation rhythm with discontinuous gas exchange pattern during the daytime and continuous pattern during nighttime. Mean standard metabolic rates (SMR, V̇(CO2)) in unfed nymphs, females and males of 1.4, 3.0 and 0.9 μl h(-1) increased to 2.0, 5.7 and 2.4 μl h(-1), respectively, after a blood meal. SMR correlated positively with blood meal size (r(2)=0.89, p<0.05). Mean coxal fluid weight excreted after a blood meal in nymphs, females, and males was 8.7, 20.0, and 7.7 mg, respectively, which represents 27.0%, 23.4% and 26.7% of their blood meal size. This study revealed biological and physiological characteristics of soft tick blood feeding and metabolism important to tick survival.
authors.affiliation: USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory, Kerrville, TX 78028, USA; Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050016, China.
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Zheng
authors.affiliation: USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory, Kerrville, TX 78028, USA. Electronic address: Andrew.Li@ars.usda.gov.
authors.forename: Andrew Y
authors.initials: AY
authors.lastname: Li
authors.affiliation: Texas A&M AgriLife Research, Department of Entomology, Texas A&M University, College Station, TX 77843, USA.
authors.forename: Pete D
authors.initials: PD
authors.lastname: Teel
authors.affiliation: USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory, Kerrville, TX 78028, USA.
authors.forename: Adalberto A
authors.initials: AA
authors.lastname: Pérez de León
authors.affiliation: South Texas Center for Emerging Infectious Diseases and Department of Biology, University of Texas at San Antonio, San Antonio, TX 78249, USA.
authors.forename: Janakiram
authors.initials: J
authors.lastname: Seshu
authors.affiliation: Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang 050016, China.
authors.forename: Jingze
authors.initials: J
authors.lastname: Liu
mesh_terms: D000818:Animals; D001769:Blood; D002940:Circadian Rhythm; D055724:Electrophysiological Phenomena; D004734:Energy Metabolism; D005247:Feeding Behavior; D005260:Female; D008297:Male; D009758:Nymph / Q000502:physiology; D026861:Ornithodoros / Q000502:physiology*; D010614:Pharynx / Q000502:physiology; D012143:Respiratory Physiological Phenomena
keywords: Blood feeding; Gas exchange; Ornithodoros turicata; Pharyngeal pump; Relapsing fever tick; Water loss