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The components of blackfly (Diptera: Simuliidae) saliva secreted during feeding on humans and animals induce various pathological reactions manifested by skin lesions and systemic symptoms. In this study, we describe 43 cases of severe skin lesions induced by blackfly bites and analyze their potential causes. Based on the results of a survey of 418 patients, we identified periods with risk of blackfly attacks and their environmental determinants in the eastern part of the European Union. Especially strong inflammatory reactions after blackfly bites were reported in patients with concomitant cardiovascular diseases (mainly with venous insufficiency), metabolic diseases, and bacterial infections. Enhanced symptoms of simuliosis were also observed in other patients attacked by these insects only once or repeatedly. The greatest number of blackfly attacks in the study area is recorded from May to July, with a peak in June (38.73%) in the afternoon (37.10%) and evening (33.03%), when patients are in fields, forests, or their households. The case analysis indicates interactions of various factors in the development of severe inflammatory reactions in patients bitten by blackflies. Therefore, it is recommended that subjects exposed to the presence of blackflies during their work or rest should limit the length of their stay in a vulnerable environment during the highest seasonal and daily activity of these insects. It is also necessary to take measures to reduce the number of blackflies and popularize methods for prophylaxis of their attacks.

Tick-borne encephalitis (TBE) is the most common viral neurological disease in Eurasia. It is usually transmitted via tick bites but can also occur through ingestion of TBEV-infected milk and dairy products. The present paper summarises the knowledge of the food-borne TBEV transmission and presents methods for the prevention of its spread. The incidence of milk-borne TBE outbreaks is recorded in central, eastern, and north-eastern Europe, where Ixodes ricinus , Ixodes persulcatus , and/or Dermacentor reticulatus ticks, i.e., the main vectors of TBEV, occur abundantly. The growing occurrence range and population size of these ticks increases the risk of infection of dairy animals, i.e., goats, sheep, and cows, with viruses transmitted by these ticks. Consumers of unpasteurised milk and dairy products purchased from local farms located in TBE endemic areas are the most vulnerable to alimentary TBEV infections. Familial infections with these viruses are frequently recorded, mainly in children. Food-transmitted TBE can be monophasic or biphasic, and some of its neurological and psychiatric symptoms may persist in patients for a long time. Alimentary TBEV infections can be effectively prevented by consumption of pasteurised milk and the use of TBEV vaccines. It is recommended that milk and dairy products should be checked for the presence of TBE viruses prior to distribution. Protection of dairy animals against tick attacks and education of humans regarding the epidemiology and prophylaxis of TBE are equally important.

Rickettsiae from the spotted fever group, i.e. the etiological agents of tick-borne lymphadenopathy/ Dermacentor -borne necrotic erythema and lymphadenopathy (TIBOLA /DEBONEL) syndrome, are associated with ticks, including Dermacentor marginatus and Dermacentor reticulatus. The expansion of these ticks into new areas increases the risk of infection of their hosts with tick-borne pathogens. The study summarises the importance of 2 species from the genus Dermacento r, i.e. D. marginatus and D. reticulatus , in the spread of spotted fever group rickettsiae in various regions of Europe. The study also focuses on the determinants of the presence of vectors and transmission of rickettsiae, as well as the effects of human infections with these pathogens. The climate changes observed nowadays affect vectors and increase the incidence and spread of tick-borne diseases worldwide. Due to the existing risk of exposure to an increasing number of people, knowledge about the course of these serious diseases and their etiological factors should be disseminated among healthcare professionals as well as in society. There is a great challenge for epidemiological services to provide access to medical and veterinary facilities in order to diagnose and treat rickettsioses. Therefore, the development of a strategy for tick control and the popularisation of knowledge concerning prophylaxis of tick-borne diseases is indispensable.

This opinion piece highlights the role of migratory birds in the spread of ticks and their role in the circulation and dissemination of pathogens in Europe. Birds with different lifestyles, i.e., non-migrants residing in a specific area, or short-, medium-, and long-distance migrants, migrating within one or several distant geographical regions are carriers of a number of ticks and tick-borne pathogens. During seasonal migrations, birds that cover long distances over a short time and stay temporarily in different habitats can introduce tick and pathogen species in areas where they have never occurred. An increase in the geographical range of ticks as well as the global climate changes affecting the pathogens, vectors, and their hosts increase the incidence and the spread of emerging tick-borne diseases worldwide. Tick infestations of birds varied between regions depends on the rhythms of tick seasonal activity and the bird migration rhythms determined by for example, climatic and environmental factors. In areas north of latitude ca. 58°N, immature Ixodes ricinus ticks are collected from birds most frequently, whereas ticks from the Hyalomma marginatum group dominate in areas below 42°N. We concluded that the prognosis of hazards posed by tick-borne pathogens should take into account changes in the migration of birds, hosts of many epidemiologically important tick species.

Introduction: This study presents for the first time a case of Hyalomma excavatum hyperparasitism and an analysis of this phenomenon in terms of its potential role in the biology of ticks and epidemiology of tick-borne diseases., Material and Methods: Two partially engorged H. excavatum females, one fully engorged female, and 5 males were collected from a naïve rabbit and placed together in a rearing chamber at a temperature of 25°C and 75% humidity., Results: 3-4 days after tick detachment from the host's skin, one partially engorged H. excavatum female was observed attached to the idiosoma of the fully engorged conspecific female., Conclusions: This study and observations of other authors confirm that partially engorged ixodid ticks can re-infest the host, and even co-feeding fully engorged ticks in order to collect the blood meal that is indispensable for important physiological processes. However, inefficient feeding of a partially engorged female on another conspecific female may reduce its reproductive performance and disturb the development of eggs and larvae. It seems that parasitism of a tick on another conspecific specimen, when at least one of them is infected by a microorganism, may be a yet poorly explored route of transmission of pathogens or symbionts between the ticks. Initiation of feeding by a hungry or partially engorged tick on a fully engorged specimen is an attempt to obtain food in the drastic conditions of the absence of a target host. Tick hyperparasitism with concurrent pathogen transmission can contribute to the genospecific diversity of pathogens in vectors and hosts.

The increasing application of toxic plant substances to deter and fight ticks proves the need for investigations focused on the elucidation of their impact on the developmental stages and populations of these arthropods. We examined the course of embryogenesis and egg hatch in Hyalomma marginatum ticks under the effect of cytotoxic plant substances. The investigations demonstrated that the length of embryonic development of egg batches treated with 20 μL of a 0.1875% colchicine solution did not differ significantly from that in the control group. Colchicine caused the high mortality of eggs (16.3%) and embryos (9.7%), disturbances in larval hatch (8.1%), and lower numbers of normal larval hatches (65.6%). In 0.2% of the larvae, colchicine induced anomalies in the idiosoma (67.6%) and gnathosoma (22.5%) as well as composite anomalies (8.5%). The study demonstrates that cytotoxic compounds with an effect similar to that of colchicine can reduce tick populations and cause teratological changes, which were observed in the specimens found during field studies. Since there are no data on the toxic effects of active plant substances on other organisms and the risk of development of tick resistance, a strategy for the use of such compounds in tick control and the management of plant products should be developed.

Introduction: The three-host Dermacentor reticulatus tick transmits many pathogens, which are introduced into the host with saliva during feeding., Material and Methods: The aim of present study was to analyse the behaviour of males of this species on the host in homogeneous sex groups comprising 15 (group I) and 30 (group II) male specimens and in a mixed group composed of 15 males and 15 females (group III)., Results: Although the dynamics of attachment of the males to host skin slightly differed between these three groups, there was no statistically significant difference in the duration of the attachment process. The duration of host attachment of the males in groups I, II, and III at 18±2°C and 50 ± 2% RH was 2.43 ± 2.46, 7.75 ± 11.85, and 9.07 ± 10.97 days, respectively. After 7-9-day feeding, the male engorgement weight (MEW) was similar, regardless of the size of the group and the presence or absence of females on the host. Tick males ingest a small amount of host blood. The value of MEW in the three groups did not differ statistically from the weight of unengorged specimens., Conclusions: The host feeding behaviour of D. reticulatus males and their effective feeding suggest that they may play a role in transmission of pathogens and non-pathogenic microorganisms with tick saliva during blood meal ingestion. Clinical and laboratory diagnostics of human and animal tick-borne diseases as well as epidemiological studies should consider the possibility of pathogen transmission by males of metastriata ticks, which feed on the host for several days.

Two pyrethroids, deltamethrin (D) and alphacypermethrin (AC), have been used as commercial products for tick control worldwide. However, the effects of sublethal doses of these compounds on various tick species and their developmental stages have not been fully explored yet, although such knowledge could contribute to a more effective application of both pyrethroids and simultaneous reduction of their costs and undesirable side effects, including the harmful impact on other organisms and environmental contamination. This study investigates the effect of sublethal concentrations of D and AC applied to engorged females on the fecundity, development of eggs and larvae, and the number of offspring in the Ixodes ricinus (L.) tick, which is the most important vector of tick-borne diseases of humans in Europe. After detachment from rabbit's skin, fully engorged I. ricinus females were treated with 20 μl of pyrethroid solutions at five concentrations from 0.01562 to 0.25% and kept at 28 °C and 75% relative humidity. The impact of the pyrethroids on maturation and development of eggs as well as development of larvae was assessed based on parameters of the preoviposition and oviposition periods and the course of embryogenesis and egg hatch. The investigations have shown that both tested acaricides reduce the reproductive rate in I. ricinus females by inhibition of egg development and disturb embryonic development and larval hatch. Females did not lay eggs at concentrations higher than 0.0625% AC and 0.125% D. The lower concentrations of both pyrethroids disturbed or inhibited the embryogenesis and egg hatch in I. ricinus.

For the first time in the world literature, the presented study describes oral-anal contact between two sympatric Ixodes ricinus and Dermacentor reticulatus ticks, which are the vectors of many pathogens in Europe. Among the specimens collected in nature, an I. ricinus male was found with the hypostome and chelicerae inserted in the anal aperture of a D. reticulatus female. Given the biological and physiological traits of both species and microorganisms colonising these arthropods, it seems that the interspecific oral-anal contacts between ticks may be an unknown alternative route of transmission of pathogenic and symbiotic microorganisms present in ticks' alimentary tract, faeces, body surface, and in the haemolymph and organs, taking place when the male's mouthparts are inserted into the female's body. The authors suggest that interspecific contacts between ticks in natural conditions can contribute to the spread of some icroorganisms among different tick species and their hosts..

Conformation of N-acetyl-(E)-dehydrophenylalanine N', N'-dimethylamide (Ac-(E)-ΔPhe-NMe(2)) in solution, a member of (E)-α, β-dehydroamino acids, was studied by NMR and infrared spectroscopy and the results were compared with those obtained for (Z) isomer. To support the spectroscopic interpretation, the Φ, Ψ potential energy surfaces were calculated at the MP2/6-31 + G(d,p) level of theory in chloroform solution modeled by the self-consistent reaction field-polarizable continuum model method. All minima were fully optimized by the MP2 method and their relative stabilities were analyzed in terms of π-conjugation, internal H-bonds and dipole interactions between carbonyl groups. The obtained NMR spectral features were compared with theoretical nuclear magnetic shieldings, calculated using Gauge Independent Atomic Orbitals (GIAO) approach and rescaled to theoretical chemical shifts using benzene as reference. The calculated indirect nuclear spin-spin coupling constants were compared with available experimental parameters., (Copyright © 2011 John Wiley & Sons, Ltd.)