Optimization of an artificial tick feeding assay for Dermacentor reticulatus.
The development of standardized in vitro feeding methods for ixodid ticks has been hampered by their complex feeding behaviour and the long duration of their blood meal. In this study, we aimed to optimize several parameters for the in vitro feeding of adult Dermacentor reticulatus.



Ticks were fed on heparinized bovine blood collected at a slaughterhouse, using a modified silicone membrane feeding assay. Effects on tick feeding and fecundity of different blood meal treatments (freezing, irradiation, addition of antibiotics), ambient conditions (increased CO2concentration) and phagostimulant use (addition of 2 g/l and 4 g/l glucose to the blood meal) were systematically evaluated.



Although fungal growth occurred more frequent in feeding units of ticks fed on defrosted blood, the attachment rate, engorgement mass and fecundity of females fed on defrosted blood did not significantly differ from that of ticks fed on fresh blood. A reduction in the fecundity of female D. reticulatus ticks was observed when ticks were fed with gamma-irradiated blood or untreated blood compared to blood treated with gentamycin. Both the engorgement mass and fecundity increased when ticks were fed at a 5% CO2level. A non-significant increase in the engorgement mass and engorgement rate of D. reticulatus was observed when blood was supplemented with 4 g glucose per litre compared to 2 g/l.



An artificial feeding method was adapted for the feeding of adult D. reticulatus ticks. Of all parameters tested, only the artificial feeding at 5% CO2levels resulted in a significant increase (P < 0.05) in the engorgement mass and fecundity of female D. reticulatus ticks. The supplementation of blood with antibiotics resulted in a significantly higher tick fecundity in comparison to ticks fed with untreated or irradiated blood.
Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163, Berlin, Germany.
Christoph
C
Krull
Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163, Berlin, Germany.
Bettina
B
Böhme
Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163, Berlin, Germany.
Peter-Henning
PH
Clausen
Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163, Berlin, Germany. ard.nijhof@fu-berlin.de.
Ard M
AM
Nijhof
D000821:Animal Feed; D000818:Animals; D001769:Blood; D002417:Cattle; D003870:Dermacentor / Q000502:physiology*; D004772:Entomology / Q000379:methods*; D005248:Feeding Methods; D005298:Fertility
Artificial feeding; CO2; Dermacentor reticulatus; Glucose; Irradiation