Introduction
Ticks are a highly specialized group of obligate, bloodsucking, nonpermanent ectoparasitic arthropods of terrestrial vertebrates with a worldwide distribution. They present a hematophagic behavior in all active phases and parasitize mammals, birds, reptiles, amphibians, and occasionally man.
Unique among Acari, ticks have a large body size being considered large mites with specialized mouthparts (hypostome) and specialized sensory structures on legs (tarsus I, Haller’s organ) [1, 2]. These arthropods are among the most important vectors of human and animal disease. They are associated to the transmission of a great variety of pathogenic agents, including viruses, bacteria, and protozoa [3]. These pathogens are usually acquired by immatures, larvae, or nymphs, when ticks feed on infected hosts being maintained through their life and transmitted to naive animals during the next blood meals, as nymphs and adults (horizontal transmission). Depending on the pathogen, ticks can also pass infection to the offspring (vertical transmission) or even to other ticks by feeding close to them (co-feeding). Ticks may also injure hosts without the involvement of infectious agents, just by the effects of salivary secretions, causing from a simple irritation to allergic reactions, toxicosis, and paralysis [4].Among the family Ixodidae Murray 1877, the genus Ixodes Latreille 1795 is the largest, the broadest distributed, and one of the most important taxon regarding tick-borne diseases. It comprises a total number of 244 species of which 63 have been recorded to feed on humans [5]. Its members are present in all zoogeographic regions, remote islands, and territories close to the poles. In Europe and North Africa, the genus Ixodes is represented by 25 species [5]. Within this genus, several ticks may be considered mega vectors as those that belong to the Ixodes ricinus-I. persulcatus complex, but others are so poorly studied that their vector role is difficult to access. This is the case of Ixodes ventalloi Gil Collado, 1936. This is a species that is infrequently targeted in field trials and laboratory collections are scarce. In Portugal, an expansion of its distribution was observed, most likely as a collateral result of concerted efforts to increase knowledge on the subject [6-12]. The recent interest of other specialists has also generated updated descriptions of the morphological features relevant for diagnosis and the first molecular characterization of I. ventalloi populations with the analysis of its phylogenetic position in the group Ixodes [13, 14]. Regardless of this, information on the vector role of I. ventalloi remains challenging to access and poorly understood. This chapter intends to update information on I. ventalloi in order to call attention to this insufficiently studied tick, revising the available systematic, ecological, and microbiological data, discussing the potential public health relevance.
2.