Life cycle and parasitic competence of Dermacentor nitens Neumann, 1897 (Acari: Ixodidae) on different animal species.

The research highlights the life cycle and parasitic competence of Dermacentor nitens ticks on different animal species. It suggests that these ticks most effectively parasitize horses and rabbits, while cows, sheep, guinea pigs, dogs, and birds are not competent hosts.

Research Methodology

• The researchers used seven species of animals to study the effectiveness of parasitization by Dermacentor nitens, a type of tick species: rabbits, horses, sheep, cows, guinea pigs, birds, and dogs.
• They induced experimental infestations on five specimens of each animal species.
• For infestations, researchers placed ticks on different parts of the animals, either with or without the use of artificial feeding chambers.
• Daily inspections of all infested animals were conducted until the end of each parasitic phase, which occurred when engorged female ticks detached from the hosts.

Findings

• The study showed that the average engorgement period of ticks on horses was 25.1 days, in which larvae took 8 days and nymphs took 9 days to reach full engorgement. The average weight of engorged female ticks on horses was 271.4mg, and they produced an average egg mass of 159.3mg.
• In contrast, on rabbits, the average engorgement period was slightly longer – 27.6 days with larvae and nymphs taking 7.4 and 11 days, respectively, to become fully engorged. The average weight of an engorged female tick on a rabbit was 108.4mg, and she produced an average egg mass of 30.6mg.
• Of note, the conversion rate of feed into body weight (feed conversion rate) was higher in ticks on horses than on rabbits – 56.8% compared to 30%.
• None of the other animal species (cows, sheep, guinea pigs, dogs and birds) hosted engorged female ticks, making them incompetent hosts for D. nitens.

Conclusion

• Based on these findings, the researchers suggested that when infested artificially, rabbits could serve as an alternative host for maintaining tick populations in laboratory settings.
• Data from the study revealed a specific parasitic affinity of D. nitens for horses, as they demonstrated the most optimal conditions for the tick’s life cycle.