Distribution Of Ixodes Ricinus Research Articles

Distribution of Ixodes ricinus (Arachnida, Ixodidae) in Ukraine in the Context of Tick Hazard, and Factors Favoring its Persistence in Conditions of Fast-Going Environmental Change

Habitat conditions and factors were studied contributing to the spread of I. ricinus over vast territories. There are excellent conditions for the existence of hard ticks in the settlement agglomerations throughout Ukraine: suitable biotopes with expedient litter and a large number of hosts for all stages of development of ticks. The castor bean tick lives in all of Ukraine, adapting its size of idiosome and diapause to changing environmental conditions, and using the ability to parasitize on animals well adapted to urban conditions. I. ricinus prefers urban landscapes in areas with unfavorable environmental conditions. The hiatus in the range of the castor bean tick between the southern mainland of Ukraine and the steppe regions of Crimea may be restored due to global climatic changes.

Heterogeneity in the abundance and distribution of Ixodes ricinus and Borrelia burgdorferi (sensu lato) in Scotland: implications for risk prediction.

BackgroundCases of Lyme borreliosis, a vector-borne zoonosis caused by bacteria in the Borrelia burgdorferi (sensu lato) species group, have increased in recent years in Europe. Knowledge of environmental factors associated with abundance of the tick vector Ixodes ricinus and the pathogen B. burgdorferi (s.l.) is of interest to understand responses to environmental changes, predict variation in risk and to inform management interventions.MethodsNineteen woodland sites across Scotland were surveyed in 2012 for B. burgdorferi (s.l.) infection in questing I. ricinus nymphs (n = 200 per site), deer abundance and vegetation. Climatic factors were extracted for each site. Six additional sites were surveyed for questing nymphs in both 2012 and 2013 (n = 200 per site and year) to test for variation in B. burgdorferi (s.l.) prevalence between years.ResultsThe mean prevalence of B. burgdorferi (s.l.) across 19 sites was 1.7% (95% CI: 1.4–2.2%; range 0–6%), all four genospecies known to be present in the UK were detected: B. garinii, B. afzelii, B. burgdorferi (sensu stricto) and B. valaisiana. A higher prevalence of B. burgdorferi (s.l.), higher densities of nymphs and higher densities of infected nymphs were found at sites with warmer climates, estimated with growing degree-days. No association between infection prevalence in nymphs and woodland type (semi-natural mixed vs coniferous) or deer density was found. At six sites sampled in 2012 and 2013, there was a significant increase in B. afzelli prevalence at two sites and a decrease in B. garinii prevalence at one site.ConclusionsThis study highlights challenges for the prediction of risk of Lyme borreliosis, reflecting the sensitivity of both pathogen and vector ecology to habitat, host and climatic factors. Significant changes in the prevalence of individual genospecies at sites monitored across time are likely to be due to variability in the host community composition between years. Our results indicate the importance of monitoring dynamic variables such as reservoir host populations as well as climate and habitat factors over multiple years, to identify environmental factors associated with Lyme borreliosis risk.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1875-9) contains supplementary material, which is available to authorized users.

Distribution of Ixodes ricinus and I. persulcatus ticks in southern Karelia (Russia)

The northern boundary of the sympatric zone of Ixodes persulcatus and I. ricinus (Acari: Ixodidae) passes through Karelia. Studies carried out in the 1950s showed that these Ixodes species were mostly found in southern Karelia. I. ricinus inhabited the west of the region, I. persulcatus the east, with a zone of sympatry in the centre. Here, we describe the present distribution of these species in southern Karelia and provide a retrospective assessment of potential changes in the sympatric zone. Tick distribution and abundance were investigated during transect samplings, conducted in May–June 2006–2010. Additional information was obtained during examination of pet dogs and cats. Overall, 4561 adult ticks were collected. Since the 1950s, there has been a significant increase in the abundance of I. persulcatus, and a decrease in I. ricinus. Currently, southern Karelia can be considered as a zone of sympatry for I. ricinus and I. persulcatus, without a clear geographic boundary between the 2 species. In most areas, except to the west of Lake Ladoga, I. persulcatus is more abundant. Possible reasons for this trend are discussed.

Aggregation in the Tick Ixodes ricinus (Acari: Ixodidae): Use and Reuse of Questing Vantage Points

Ongoing work in oak woods in Killarney National Park in southwestern Ireland is focusing on the factors influencing the fine-scale aggregated distribution of Ixodes ricinus L. (Acari: Ixodidae) on the ground. The extent of reuse of stems of vegetation as questing points by adult ticks was determined by paint-marking stems on which ticks were found, counting and removing these ticks, and subsequently reexamining the same stems for ticks on two further occasions. Overall, an estimated 2,967 stems in 123 separate rush plants (Juncus effusus L.) were examined. Statistical analysis of the data demonstrated a highly significant reoccupancy by ticks of stems previously and recently used. Furthermore, it is shown that the extent of stem reuse by ticks is significantly and positively correlated with the numbers of ticks originally observed on those stems. Although other factors may be involved in generating clumping of ticks, the results are compatible with the proposition that aggregation of I. ricinus on the ground is pheromone-mediated. The findings are discussed in relation to what is known about the powers of lateral movement of I. ricinus on the ground and the possible implications for the performance of tick traps.