Seasonal feeding activity of the tree-hole tick, Ixodes arboricola

Abstract

Bird-specific ticks do not infest humans and livestock, but these ticks often share their avian hosts with generalist ticks that do. Therefore, their feeding activity may have an impact on the transmission of pathogens outside bird-tick transmission cycles. Here we examined the seasonal feeding activity of the tree-hole tick (Ixodes arboricola) in relation to the activity of its hole-breeding hosts (Parus major and Cyanistes caeruleus). We analysed data on ticks derived from birds, on the abundance of engorged ticks inside nest boxes, and on bird nests that were experimentally exposed to ticks. We observed a non-random pattern of feeding associated with the tick instar and host age. The majority of adult ticks fed on nestlings, while nymphs and larvae fed on both free-flying birds and nestlings. Due to their fast development, some ticks were able to feed twice within the same breeding season. The highest infestation rates in free-flying birds were found during the pre-breeding period and during autumn and winter when birds roost inside cavities. Except during winter, feeding of I. arboricola overlapped in time with the generalist Ixodes ricinus, implying that tick-borne microorganisms that are maintained by I. arboricola and birds could be bridged by I. ricinus to other hosts.

Population genetic structure of the tree-hole tick Ixodes arboricola (Acari: Ixodidae) at different spatial scales

“…However, instead of decreasing gradually, there was a sudden drop in relatedness after two dispersal opportunities, suggesting that different tick instars may have different dispersal opportunities. Most engorged larvae are found in autumn, when birds may switch between roosting sites, to early spring, when birds inspect possible nesting sites (Gosler, 1993), whereas engorged nymphs and adult females are mainly found during the birds' breeding season, when birds show high nest fidelity (Heylen et al, 2014). Together with the current data, this suggests that the majority of dispersal occurs in autumn, in the early life of ticks.…”

“…High levels of genetic variation among ticks within nest boxes suggest that not all genotypes have been sampled, especially as the number of ticks collected from individual nest boxes is limited. It is known that I. arboricola ticks can be easily overlooked during nest box surveys, especially the small unfed immature instars (Heylen et al, 2014). Nevertheless, because all nest boxes in a woodlot were inspected during nest box surveys (except during III 2013 in WA andIV 2012 in WK), the majority of ticks present in a woodlot will have been collected, and ticks may come from outside the nest boxes in the woodlots.…”

“…I. arboricola infests mainly cavity-nesting birds (mostly great tits Parus major and blue tits Cyanistes caeruleus) (Hudde and Walter, 1988), shows a strong tendency to detach within cavities (Heylen and Matthysen, 2010;White et al, 2012) and infests birds typically from autumn to late spring (Heylen et al, 2014). The feeding activity of larvae increases in late autumn, and the majority of feeding nymphs and adult females can be found during the birds' breeding season, when adult female ticks primarily infest nestlings (Heylen et al, 2014). Whereas female ticks feed in the adult instar, male ticks feed only in the larval and nymphal stages and remain in the host's cavity in the adult stage, where they copulate with both unfed and engorged female ticks .…”

Host specificity of a bird-specialised endophilic ectoparasite, the tree-hole tick Ixodes arboricola

“…Eurasian eagle-owl (Bubo bubo), marsh tit (Parus palustris), great spotted woodpecker (Dendrocopos major), common starling (Sturnus vulgaris) and Eurasian tree sparrow (Passer montanus) (Hudde and Walter 1988). Because I. arboricola infests cavity-nesting birds, its entire life cycle is restricted to natural and man-made cavities (Walter et al 1979;Heylen et al 2014), where it detaches after feeding (Heylen and Matthysen 2010;White et al 2012;Heylen et al 2014). There, immature ticks (larvae and nymphs) moult to the next developmental stage (nymph or adult, respectively), and adult female ticks lay eggs after their meal and die.…”

“…Endophilic ticks typically have a smaller host range than exophilic ticks, which are not associated with nests and encounter many different host species (Hoogstraal and Aeschlimann 1982;Salman and Tarrés-Call 2012). Indeed, I. arboricola chiefly infests cavity-nesting birds, with great and blue tits (Parus major, Cyanistes caeruleus) as its principal host (Walter et al 1979;Hudde and Walter 1988;Heylen et al 2014). It is unknown to what extent feeding performance differs among different cavity-nesting birds, thus to what extent I. arboricola can be considered a specialist or generalist parasite.…”