Entomopathogenic Fungi in Forest Habitats of Ixodes ricinus.

(1) Background: In addition to the microclimate, host availability, and tick microbiota, soil environmental microorganisms can affect tick populations. This study aimed to (1) determine the presence and diversity of entomopathogenic fungi (EF) in forests, where ticks are abundant, and (2) estimate the effectiveness of the isolated EF strains against Ixodes ricinus. (2) Methods: EF were isolated using the trap insect method from soil collected from tick sites. A bioassay was used to estimate the effectiveness of EF against ticks. (3) Results: The presence of EF was found in all tested forest habitat types. A total of 53 strains belonging to the genera Metarhizium, Beauveria, and Isaria were isolated. All the six strains subjected to the bioassay showed potential efficacy against both adult and nymphal stages of I. ricinus; however, the strains differed in their effectiveness. The most effective isolate against I. ricinus was the soil environmental strain of Metarhizium anisopliae. (4) Conclusion: The study indicates that tick habitats can be the source of entomopathogenic fungi, which have a lethal effect on ticks, as demonstrated in preliminary laboratory tests with I. ricinus. However, for practical use, extensive field tests and further research on application methods and long-term effects are necessary to develop effective and sustainable tick management strategies.

First record of Anopheles (Anopheles) hyrcanus (Pallas 1771) (Diptera: Culicidae) in Poland.

The spatial distribution of mosquito species in the course of globalization and climate warming is highly dynamic. Different studies have demonstrated the spread and establishment of thermophilic mosquito species, potentially increasing the prevalence of 'nuisance' mosquitoes and the local transmission of pathogens. Here we report the first recorded sampling of Anopheles hyrcanus in Wroclaw, southwest Poland. This is the most northern detection of this species to date in Europe. Future spread and population development of this potential vector of malaria parasites, viruses or zoonotic helminths, such as Dirofilaria spp., must be monitored carefully. Potential factors underlying the spread of this species are discussed.

The influence of local environmental factors in southwestern Poland on the abundance of Ixodes ricinus and prevalence of infection with Borrelia burgdorferi s.l. and B. miyamotoi.

Ticks are important ectoparasites and vectors of pathogens that cause disease in humans and animals. The natural habitat of Ixodes ricinus ticks is forests, which are convenient habitats to search for hosts, including reservoir hosts, and therefore can be an important habitat source of tick-borne pathogens. The aim of the study was to assess the usefulness of detailed forest habitat-type maps to estimate the tick-borne risk at a local scale (Lower Silesia, SW Poland). For the purposes of estimating tick abundance, we used the land cover maps available from the Forest Data Bank. For I. ricinus collection, nine sites located in three forest habitat types were chosen: broadleaf forest, mixed broadleaf and coniferous forest and coniferous forest. Ticks were collected once a month from April to June 2018 and 2019 using the standard flagging method. At each of the nine sites, ticks were collected in four plots, of 100 m2 each. Tick abundance was analysed using general linear mixed models (GLMM). A total of 2196 (10.1/100 m2) ticks were collected, including 2093 Ixodes ricinus (95.3%; 9.6/100 m2), 46 Dermacentor reticulatus (2.1%; 0.2/100 m2) and 57 Haemaphysalis concinna (2.6%; 0.3/100 m2). Among the collected I. ricinus were 589 larvae (28.1%; 2.7/100 m2), 1261 nymphs (60.3%; 5.8/100 m2), 128 females (6.1%; 0.6/100 m2) and 115 males (5.5%; 0.5/100 m2). We found a highly significant effect of forest habitat type on the density of ticks for broadleaf forest (coefficient = 1.87267, p-value = 2.79e - 07). Additionally, a significant influence of air temperature and relative humidity on the abundance of ticks was observed. During spring, the peak activity of I. ricinus was recorded in May and June. For DNA amplification of Borrelia burgdorferi s.l., a nested PCR method was used. Out of 494 I. ricinus, 83 (16.8%) were positive for Borrelia spp. The RFLP method showed the occurrence of five species including four belonging to the B. burgdorferi s.l. complex: B. afzelii (30.1%), B. garinii (38.6%), B. valaisiana (2.4%) and B. lusitaniae (18.1%). Furthermore, B. miyamotoi (9.6%), a species belonging to bacteria that cause relapsing fever as well as co-infection of B. miyamotoi/B.lusitaniae (1.2%) were found. The differences in the infection level of Borrelia spp. between broadleaf forest and mixed broadleaf and coniferous forest were statistically significant.

Sensitivity of Ixodes ricinus (L., 1758) and Dermacentor reticulatus (Fabr., 1794) ticks to entomopathogenic fungi isolates: preliminary study.

Entomopathogenic fungi of the genus Beauveria and Metarhizium play an important role in controlling the population of arthropods. However, the data on their effectiveness against ticks focus mainly on species that do not occur in Europe. The aim of the study was to assess the effectiveness of entomopathogenic fungi against two of the most important tick species in Europe: Ixodes ricinus and Dermacentor reticulatus. In our study, the majority of tested entomopathogenic fungi strains showed potential efficacy against both tick species; however, D. reticulatus was less susceptible in comparison to I. ricinus. The observed mortality of ticks was up to 100% by using all commercial strains as well as three out of nine of the environmental strains. Among all tested fungi, the most effective against both tick species was environmental strain Metarhizium anisopliae LO4(1) with LC50 values: 2.6 × 103 cfu/ml-5.7 × 105 cfu/ml. Botanigard proved to be more effective than MET52 with LC50 values: 6.8 × 103 cfu/ml-3.3 × 106 cfu/ml. The conducted bioassays indicate the potential possibility of using the environmental isolates of entomopathogenic fungi, as well as commercial strains in control of local populations of I. ricinus and D. reticulatus; however, the possibility of using them in vivo requires more research.

First record of Haemaphysalis concinna (Acari: Ixodidae) in Lower Silesia, SW Poland.

Haemaphysalis concinna Koch is one of 19 species of the genus Haemaphysalis which has been reported in the Palearctic region. In Europe, the presence of H. concinna ticks has been reported in numerous countries. In Poland, to date, the precise occurrence of H. concinna was known only from one site in the north-western region. This paper shows that H. concinna ticks can be considered a typical example of the tick fauna occurring in Lower Silesia, SW Poland. Tick monitoring was conducted using a standard flagging method in 24 sites in the various forest types of Lower Silesia. Among 1622 host-seeking ticks collected, H. concinna accounted for 2.7%. From the collected H. concinna there were: 25 (58.1%) larvae, 15 (34.9%) nymphs, 1 (2.3%) female, and 2 (4.7%) males. The presence of H. concinna was confirmed in 6 out of 24 tested sites in fresh mixed broadleaf forests, fresh mixed coniferous forests and in pastures.