Phenology and phylogeny of Hyalomma spp. ticks infesting one-humped camels (Camelus dromedarius) in the Tunisian Saharan bioclimatic zone

In vitro feeding of all life stages of two-host Hyalomma excavatum and Hyalomma scupense and three-host Hyalomma dromedarii ticks

Ticks are blood-sucking ectoparasites and can transmit various pathogens of medical and veterinary relevance. The life cycle of ticks can be completed under laboratory conditions on experimental animals, but the artificial feeding of ticks has attracted increased interest as an alternative method. This study represents the first report on the successful in vitro feeding of all life stages of two-host tick species, Hyalomma scupense and Hyalomma excavatum, and the three-host tick Hyalomma dromedarii. The attachment and engorgement rates of adults were 84% (21/25) and 76% (19/25) for H. scupense females. For adult H. excavatum and H. dromedarii, 70% (21/30) and 34.4% (11/32) of the females attached and all attached females successfully fed to repletion. The oviposition rates of the artificially fed females were 36.4%, 57.1% and 63.1% for H. dromedarii, H. excavatum and H. scupense, respectively, with a reproductive efficiency index varying between 44.3 and 60.7%. For the larvae, the attachment and engorgement rates were 44.2% (313/708) and 42.8% (303/708) for H. dromedarii, 70.5% (129/183) and 56.8% (104/183) for H. excavatum and 92.6% (113/122) and 55.7% (68/122) for H. scupense. The attachment and engorgement rates for the nymphs were 90.2% (129/143) and 47.6% (68/143) for H. dromedarii, 66.7% (34/51) and 41.2% (21/51) for H. excavatum, and 44.1% (30/68) and 36.8% (25/68) for H. scupense. Molting rates of the immature stages varied between 71.3% (216/303) and 100% (68/68) for the larvae and between 61.9% (13/21) and 96% (24/25) for the nymphs. The successful in vitro feeding of all stages of the three Hyalomma species makes this method a valuable tool for tick research, with potential applications in studies on the pathogens transmitted by these tick species such as Theileria annulata.

Distribution, prevalence and diversity of ticks (Acari: Ixodidae) infesting one-humped camels from Southwest Punjab, Pakistan

In tropical countries like Pakistan, ticks are the most prevalent vectors for transmitting diseases to wild and domestic animals leading to their morbidity and mortality. In the present study, a total of 593 ticks infesting one-humped camels (n = 244) were collected during April till June 2021 from two tehsils of Layyah district located in Punjab (Pakistan) in order to investigate their diversity, prevalence and distribution. Data analysis revealed that camels located in Tehsil Choubara were significantly more tick infested than camels from Tehsil Layyah (P = 0.02). It was observed that the older camels were more prone to tick infestation that younger ones. Hyalomma and Rhipicephalus were the two tick genera identified during the present study and tick specimens of Hyalomma genus were the most prevalent (n = 590, 99.5%). In particular, Hyalomma dromedarii was the most prevalent tick species (n = 559, 94.3%), followed by Hyalomma anatolicum (n = 24, 4%), Hyalomma marginatum (n = 7, 1.2%) and Rhipicephalus sanguineus sensu lato (n = 3, 0.5%). The overall abundance of male ticks was higher than the female ticks with a ratio of 1:2.1. Neck was the most preferred site for the tick infestation followed by ventral, sternum, under tail, head, udder and back of analyzed camels. To our knowledge, this is the first report regarding tick diversity on camels from Layyah district and based on our finding, we recommend large-scale tick control strategies to be implemented in this district to uplift the livestock sector.