Seasonal dynamics of spinose ear tick Otobius megnini associated with horse otoacariasis in Sri Lanka.
Abstract: Otobius megnini is a one host, nidicolous soft tick (Family Argasidae) whose larvae and nymphs parasitize the external ear canal of many wild and domestic animals and occasionally humans. The present study was conducted to determine the seasonal dynamics of O. megnini infesting stabled horses in Nuwara Eliya racecourses. Ticks were sampled biweekly for two years from May 2013 to May 2015 from the ear canal of seven thoroughbred male horses. Weather data: temperature, rainfall and humidity for the study period were obtained from the Meteorological Department, Colombo. A total of 23, 287 ticks of O. megnini were collected from the ear canal of horses and all of which were immature stages comprising 41.4% larvae and 59.6% nymphs. Larval counts were high during warmer months of the year with minimum numbers recording September-November. High larval abundance may be due to the high hatching rate of eggs at high temperatures. Larval abundance was significantly affected by maximum temperature, minimum relative humidity and average relative humidity (Multiple regression; r(2)=0.5, F=3.7, p=0.01). Population peaks for nymphs occurred in May, October and January. Nymph counts were low in March and April. Weather conditions did not have any correlation with the abundance of nymphs. Rainfall had no effect on both larvae and nymph counts. Even though control measures have been taken, O. megnini infestation is a serious problem for the stable owners especially because these horses are used in racing and other recreational purposes. Further, there is a high risk of spreading this tick within the country due to the presence of suitable hosts and the adaptability of the tick to survive in changing climatic conditions. Information on the seasonal dynamics of the tick population is important for employing control measures.
Copyright © 2016 Elsevier B.V. All rights reserved.
Publication Date: 2016-03-21 PubMed ID: 27012721DOI: 10.1016/j.actatropica.2016.03.025Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research investigates the seasonal cycle of the spinose ear tick species (Otobius megnini) that affects horses in Sri Lanka and studies its correlation with weather patterns. The analysis reveals high tick infestation during warmer months while showing negligible impact of rainfall on larvae and nymph counts.
Research Objective
- The primary objective of the research was to understand the seasonal dynamics of Otobius megnini, a tick species that infests horses’ ear canals in the Nuwara Eliya racecourses of Sri Lanka.
Methods
- The study spanned over two years (May 2013 to May 2015), conducting biweekly sampling of ticks from the ear canals of seven thoroughbred male horses.
- Data on weather conditions, such as temperature, rainfall, and humidity during this period, was collected from the Meteorological Department, Colombo.
Findings
- A total of 23,287 ticks of O. megnini were collected, all of which were in the immature stage, with 41.4% being larvae and 59.6% nymphs.
- The research found high larval counts during the warmer months of the year with low numbers recorded from September to November, hinting at a possible high egg hatching rate in high temperatures.
- Various variables like maximum temperature and average and minimum relative humidity significantly affected larval abundance.
- Population peaks for nymphs occurred in May, October, and January, but weather conditions did not seem to correlate with nymph abundance.
- Rainfall was found to have no impact on the infestation of both larvae and nymphs.
Conclusions
- The presence of Otobius megnini represents a significant problem for stable owners, especially considering that these horses are used for racing and recreation. Measures to control infestation have so far been inadequate.
- Moreover, there is a serious risk of this tick spreading within the country due to suitable hosts and the tick’s adaptability to survive changing climatic conditions.
- Understanding the seasonal dynamics of the tick population can greatly assist in developing more effective control measures.
Cite This Article
APA
Diyes GC, Rajakaruna RS.
(2016).
Seasonal dynamics of spinose ear tick Otobius megnini associated with horse otoacariasis in Sri Lanka.
Acta Trop, 159, 170-175.
https://doi.org/10.1016/j.actatropica.2016.03.025 Publication
Researcher Affiliations
- Postgraduate Institute of Science and Department of Zoology, University of Peradeniya, Peradeniya, 20400, Sri Lanka. Electronic address: gcp_diyes@yahoo.com.
- Postgraduate Institute of Science and Department of Zoology, University of Peradeniya, Peradeniya, 20400, Sri Lanka. Electronic address: rupikar@pdn.ac.lk.
MeSH Terms
- Animals
- Argasidae / growth & development
- Horses / parasitology
- Male
- Mite Infestations / epidemiology
- Mite Infestations / veterinary
- Seasons
- Sri Lanka / epidemiology
- Tick Infestations / epidemiology
- Tick Infestations / veterinary
- Weather
Citations
This article has been cited 4 times.- Asya O, Karaketir S, Görçin Karaketir Ş, Yılmaz AB. From Diagnosis to Treatment of Human Otoacariasis: Demographic and Clinical Characteristics of Patients.. Turk Arch Otorhinolaryngol 2022 Sep;60(3):134-141.
- Miller SM. Putative Otobius megnini-associated clinical signs in horses in South Africa (2012-2018).. J S Afr Vet Assoc 2020 Jul 7;91(0):e1-e6.
- Soundararajan C, Nagarajan K, Muthukrishnan S, Arul Prakash M. Tick infestation on sheep, goat, horse and wild hare in Tamil Nadu.. J Parasit Dis 2018 Mar;42(1):127-129.
- Ariyarathne S, Apanaskevich DA, Amarasinghe PH, Rajakaruna RS. Diversity and distribution of tick species (Acari: Ixodidae) associated with human otoacariasis and socio-ecological risk factors of tick infestations in Sri Lanka.. Exp Appl Acarol 2016 Sep;70(1):99-123.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
