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An island-wide study on ticks that infest the domestic goat, Capra aegagrus hircus was carried out from June 2011 to May 2013. A total of 2,628 ticks were collected in 22 districts within the three agro-climatic zones in Sri Lanka from 740 goats belonging to various breeds. Eight species of ticks belonging to the two genera Haemaphysalis and Rhipicephalus (Family Ixodidae) including Haemaphysalis bispinosa, H. intermedia, H. cuspidata, Rhipicephalus sanguineus, R. haemaphysaloides, R. turanicus, R. (Boophilus) annulatus and R. (Boophilus)microplus were recorded. The most common species in the overall collection were H. intermedia (44.0 %) and H. bispinosa (43.8 %). Haemaphysalis bispinosa was the dominant species in the Wet and Intermediate Zones, except in a few locations. In these exceptions H. intermedia was the dominant species, which was also the most abundant species found in the Dry Zone. Haemaphysalis bispinosa and R. sanguineus were restricted only to the Wet and Intermediate Zones. Of the eight tick species found, the two species, R. turanicus and R. microplus were new host records from Sri Lanka. More adult stages (70.8 %) were found in goats, where nymphs and larvae formed 25.9 and 3.3 %, respectively. All three stages of the dominant tick species were found on goats except for immature stages of R. haemaphysaloides and R. sanguineus. Most ticks preferred the anterior side of the body with one exception, R. microplus, which was more attracted to the posterior side of the host. This study reports the tick species infesting goats with zoonotic potential and also known vectors of many tick borne diseases of human and livestock.

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Spinose ear tick, Otobius megnini (Family Argasidae) is a one-host soft tick that parasitizes domesticated animals and occasionally humans. It causes otoacariasis or parasitic otitis in humans and animals and also known to carry infectious agents. Intra aural infestations of O. megnini is a serious health problem in the well-groomed race horses in Nuwara Eliya. Otobius megnini collected from the ear canal of stabled horses in Nuwara Eliya racecourse were tested for three possible infections, Rickettsia, Theileria and Babesia. Genomic DNA was extracted from 22 ticks collected from 11 horses and then pathogen-specific DNA was amplified using PCR. Ticks from two horses (one thoroughbred and one stallion) tested PCR positive for Babesia but not for other infections. None of the horses however, showed any clinical symptoms of babesiosis. This is the first record of Babesia infections in O. megnini. However, the presence of Babesia DNA in O. megnini doesn't qualify it as the vector of equine babesiosis, horse blood has to be tested for the presence of parasite DNA or antibodies.

Rhipicephalus haemaphysaloides Supino, 1897 (Ixodida: Ixodidae) is a three-host hard tick widely distributed in Sri Lanka. The lifecycle of the R. haemaphysaloides population in Sri Lanka was studied under laboratory conditions using fully engorged females collected from dogs. Larvae, nymphs and adults were reared on New Zealand rabbits. Engorged females weighed a mean ± standard deviation (SD) of 470.1 ± 106.5 mg and laid a mean ± SD of 4067.4 ± 3136.2 eggs within 16.1 ± 3.7 days. The mean ± SD preoviposition period was 6.5 ± 1.1 days. The mean ± SD reproductive efficiency index was 8.5 ± 4.1, and was higher in heavier females (Pearson correlation, r = 0.8; P = 0.001). The incubation period of eggs was shorter at higher temperatures. The majority (86.9%) of larvae successfully moulted after a mean ± SD premoulting period of 7.9 ± 0.7 days following a parasitic period of 3.2 ± 0.5 days. Unfed larvae survived a mean ± SD of 103.4 ± 19.8 days. Nymphs completed the bloodmeal after 3.7 ± 0.9 days, weighed 5.7 ± 1.7 mg and demonstrated a premoulting period of 15.1 ± 1.9 days. Unfed nymphs survived a mean ± SD of 45.8 ± 3.8 days. Heavier nymphs moulted into females, whereas lighter nymphs moulted into males (two-sample t-test, P < 0.001). The bodyweight of adult females increased more than 100-fold after feeding. The lifecycle of R. haemaphysaloides was successfully completed on rabbits within a mean of 91.3 days (range: 69-117 days) under laboratory conditions.

Many pathogens, parasitoids and predators have been documented as natural enemies of ticks, but their impact on tick populations are rarely evaluated. Here, we report the predatory behaviour of ants on the spinose ear tick, Otobius megnini. Ticks were collected from the ear canal of stabled horses in Nuwara Eliya and were brought to the laboratory. Eggs, unfed and engorged larvae, engorged nymphs and adults were naturally exposed to ants under laboratory conditions and the predatory behaviour of the different species and their feeding preferences were observed. Five ant species were found feeding on different life stages of O. megnini including eggs, larvae (fed/unfed) and adults; ants did not feed on the nymphal stages. Ant species were identified as Tapinoma melanocephalum, two species of Monomorium, one species of Pheidole and one species of Crematogaster. The predatory preference differed among the five ant species, with T. melanocephalum being identified as the best predator as it fed on eggs and adults, the non-parasitic stages of O. megnini. Different strategies have been used to control the infestations of O. megnini in the stabled horses but none of them were successful. Although we cannot extrapolate our empirical findings to a natural context, observations suggest that these ant species may be potential bio-suppressors of this tick species.

Three species of stingless bees are documented from Sri Lanka, namely, Tetragonula iridipennis (Smith), Lisotrigona cacciae (Nurse) and the endemic Tetragonula praeterita (Walker). Tetragonula irdipennis is the well-known, widely distributed stingless bee in Sri Lanka while L. cacciae is a recent record of a tear drinking stingless bee from a single site in Sri Lanka. Until the recent rediscovery, T. praeterita was known only from its type specimen deposited in the British Natural History Museum, London with Sri Lanka as its locality and 1860 as its date of description. Location of several stingless bee nests, with an entrance different to that of the well-known T. iridipennis, led to the re-discovery of T. praeterita. Its nesting sites, characteristics of the nest entrance tube and the morphological and morphometric differences of the worker caste compared to those of T. iridipennis are presented in the paper. Eight species of stingless bees have been reported from the Indian subcontinent. It is possible that more than three species of stingless bees occur in Sri Lanka.

The spinose ear tick Otobius megnini is a causative agent of otoacariasis in horses and jockeys in the Nuwara Eliya racecourses. The present study aimed at investigating the status of acaricide resistance and underlying mechanisms in this tick species under laboratory conditions. Live ticks collected from the ear canal of horses were used to establish a laboratory colony. Larval bioassays were carried out with an organophosphate (malathion), pyrethroids (flumethrin and permethrin), and an organochlorine (DDT) using Larval Packet Tests (LPT). The LC 50 (24 h) values for malathion, flumethrin, permethrin and DDT were recorded as 0.11%, 0.0003%, 0.008% and 0.124%, respectively, and the respective values for LC 90 were 0.722%, 0.004%, 0.300% and 3.049%. Biochemical assays revealed that the mean specific activity levels of esterase, glutathione S-transferases (GSTs), and monooxygenase amounts were 0.064 ± 0.008 μmol min -1 mg -1 , 0.104 ± 0.050 μmol min -1 mg -1 , and 0.068 ± 0.020 equivalent units of cytochrome P450, respectively. The percentage remaining activity of the propoxur-inhibited Acetylcholinesterase (AChE) was 33.88 ± 13.60%. Our data indicated that the O. megnini population of Nuwara Eliya, Sri Lanka was most susceptible to flumethrin and showed resistance to DDT. Development of resistance to malathion through increased activity of esterase and insensitive AChEs was evident. Since the activities of monooxygenases and GSTs were not enhanced, permethrin and DDT resistance may have developed through target site insensitivity.