Search

A reliable determination of Hydrotaea borussica females, and of females in closely related species, has so far not been possible as a range of criteria, some contradictory, has been ascribed to their identification. The DNA sequence of H. borussica is identified to enable the assignment of females to males. In addition, the DNA sequence of H. meridionalis is identified for comparison with H. borussica, and the DNA sequence of H. pandellei determined for intraspecific comparisons. The yellow colour of the abdomen, regardless of its extent, and the two dark shiny dorsolateral third tergite patches reported from various females have little or no taxonomic significance in these flies. Existing identification keys are inadequate for distinction between H. borussica and H. meridionalis females; a considerable number of Hydrotaea females may have been incorrectly assigned to species in collections. Identification criteria for females of Hydrotaea borussica and similar species are re-evaluated and a revised evidenced-based key to these species (albeit based on a limited number of specimens) is proposed.

Black bullhead Ameiurus melas (Actinopterygii: Siluriformes) is an alien fish species of North American origin, which has expanded its invasive geographical range in Europe. In 2017–2019, 32 black bullhead specimens from the Lake Srebarna Biosphere Reserve, Bulgaria, were examined for monogenean parasites. Two species of monogeneans were recorded and identified on the basis of morphological and molecular data: Ligictaluridus pricei (Ancyrocephalidae), with prevalence 100% and intensity 2–32 (mean 13.3 ± 6.8), and Gyrodactylus nebulosus (Gyrodactylidae), with prevalence 72.0% and intensity 1–15 (mean 7.4 ± 4.3). Partial 18S rDNA and the ITS1 region of L. pricei were sequenced. For G. nebulosus, sequenced genes included the partial 18S rDNA and the entire ITS1–5.8S rDNA–ITS2 region as well as the mitochondrial COI gene. Both recorded monogenean species are specific parasites of North American ictalurid fishes and alien to Europe. The present study is the first record of L. pricei from Bulgaria and the first record of G. nebulosus from Europe and the Palaearctic Region.

Immune response to pathogens such as avian malaria (Plasmodium spp.) and related haemosporidian parasites (Haemoproteus spp. and Leucocytozoon spp.) can lead to increases in energy demands of birds. Migrations are energetically costly for birds and require resources that could be otherwise invested in immune defence against pathogens. Here, we examined the prevalence and intensity of haemosporidian parasites (Apicomplexa, Haemosporida) in rosy starlings (Pastor roseus), an irruptive migrant on the Balkans, during their pre-migratory period. We further evaluated if these infections affected the stress levels of birds brought into overnight captivity, using leukocyte profiles (ratios of heterophils to lymphocytes, or H/L ratios). Haemosporidian parasites were detected based on microscopic examination, PCR and sequencing. We found high prevalence of haemosporidian parasites (83.9%) in rosy starlings (n=31), with predominant infections of Haemoproteus pastoris (cytochrome b lineage LAMPUR01) (80.1%). All birds had high heterophil/lymphocyte ratios (mean = 3.86), indicating the transition to captivity was stressful. However, there was no added stress from blood parasite infection during captivity, since infected birds did not have significantly higher heterophil/lymphocyte ratios than uninfected birds, despite all birds facing the same stress conditions. There was a negative correlation between intensity of H. pastoris and monocyte proportions, which may indicate an association with infection, or an artefact of the stress-induced shift in leukocyte profile following captivity. Our findings suggest that blood parasites have minimal additional impact on rosy starlings during an acute stress scenario (overnight captivity), arguing that they carry little cost to the energetically challenging migratory flight.

Haemosporidians (protozoan blood parasites) are known to modify avian hosts’ behaviour in the acute phase but not much is known about the chronic phase. We identified blood parasites by microscopy and a polymerase chain reaction (PCR)-based method in a sample of 22 wild-caught nightingales (Luscinia megarhynchos) in northeast Bulgaria. We compared non-infected and infected birds in single behavioural traits under the hypothesis that infected birds should show more risk-taking behaviours and quicker exploration. Infected nightingales were more prone to risk-taking and this behavioural trait was significantly correlated with the intensity of infection. However, no differences were found in exploration speed or body condition and reactions to a stressful situation (weight change in captivity, handling), which might be due to either a lack of differences or the limited sample size.

Many biting midges of the genus Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) are competent vectors of a diverse number of pathogens. The identification of their feeding behaviour and of vector–host associations is essential for understanding their transmission capacity. By applying two different nested polymerase chain reaction (PCR) assays, of which one targeted the avian cyt b gene and the other targeted the COI gene of a wide range of vertebrates, we identified the blood hosts of six biting midge species including Culicoides circumscriptus, Culicoides festivipennis, Culicoides punctatus, Culicoides pictipennis, Culicoides alazanicus and Culicoides cf. griseidorsum, the latter two of which are reported in Bulgaria for the first time. Bird DNA was found in 50.6% of 95 investigated bloodmeals, whereas mammalian DNA was identified in 13.7%. Two Culicoides species were found to feed on both birds and mammals. There was remarkable diversity in the range of avian hosts: 23 species from four orders were identified in the abdomens of four Culicoides species. The most common bird species identified was the magpie, Pica pica (n = 7), which was registered in all four ornithophilic biting midge species. Six bloodmeals from the great tit, Parus major, were recorded only in C. alazanicus. None of the studied species of Culicoides appeared to be restricted to a single avian host.

DNA barcoding (molecular characterisation) is a useful tool for describing the taxonomy and systematics of organisms. Over 250 species of avian haemosporidian parasites have been described using morphological characters, yet molecular techniques based on polymerase chain reaction (PCR) suggest this diversity is underestimated. Moreover, molecular techniques are particularly useful for the detection of chronic infections and tissue stages of these parasites. Species delimitation is problematic among haemosporidians, and many questions about the mechanisms and patterns of speciation, host specificity and pathogenicity are still unresolved. Accumulation of additional genetic and morphological information is needed to approach these questions. Here, we combine microscopic examination with PCR-based methods to develop molecular characterisation of Haemoproteus (Parahaemoproteus) manwelli Bennett, 1978 and Haemoproteus (Parahaemoproteus) gavrilovi Valkiūnas & Iezhova, 1990, both of which parasitise the bee-eater Merops apiaster L. We also describe a new species, Haemoproteus (Parahaemoproteus) palloris n. sp., from the blood of the willow warbler Phylloscopus trochilus (L.). We performed phylogenetic analyses with a set of mitochondrial cytochrome b (cyt b) gene lineages, which have been linked to parasite morphospecies and are available in the MalAvi database. Our findings show that morphological characters, which have been traditionally used in the description of haemosporidians, exhibit phylogenetic congruence. This study contributes to a better understanding of avian haemosporidian diversity and provides new molecular markers (cyt b and apicoplast gene sequences) for the diagnostics of inadequately investigated haemosporidian infections.

The occurrence of haemosporidians in biting midges of the genus Culicoides is examined in North-East Bulgaria in order to reveal their potential role for parasite transmission. A PCR-based technique amplifying part of the mitochondrial cytochrome b gene of the parasite is applied on naturally infected biting midges. Totally, 640 parous individuals of four species and 95 blood-fed individuals of six species of Culicoides are examined for the presence of DNA of haemosporidians. Haemosporidian genetic lineages are identified in individuals of three insect species: Culicoides alazanicus (12 lineages, nine lineages of Haemoproteus and three lineages of Plasmodium), Culicoides festivipennis and Culicoides circumscriptus (with two and one lineages of Haemoproteus, respectively). Two genetic lineages of Haemoproteus are recorded in more than one vector species. These results demonstrate variations in the specificity of Haemoproteus genetic lineages to their potential vectors, since some lineages are recorded in a single vector species and others occur in two or more vector species.

This study presents data from a molecular survey of the species of the genus Culicoides from the region of Kalimok Field Station (NE Bulgaria) and haemosporidian parasites occurring in them in order to investigate the host-parasite specificity of haemosporidians to their dipteran vectors. The identification of Culicoides spp. was carried out by morphological and molecular-genetic methods. We collected and analysed 230 individuals of the genus Culicoides. Nine species were found. Eight species were identified morphologically; Culicoides obsoletus, C. riethi, C. newsteadi, C. circumscriptus, C. festivipennis, C. punctatus, C. pictipennis and C. puncticollis. The ninth species might be classified as either of C. nubeculosus or C. riethi and its identification needs additional investigations. The total prevalence of Haemoproteus in the examined biting midges was 2.17%. Three individuals of C. pictipennis were infected with the Haemoproteus lineage TURDUS2 (prevalence 16.67%), a common parasite of thrushes (Turdidae). Two individuals of C. circumscriptus contained Haemoproteus lineages (prevalence 2.78%); these were the lineage HAWF2 (previously reported from Coccothraustes coccothraustes) and a new lineage CULCIR1 not previously reported in the literature.

Егейският район се характеризира със засилена геотектонска активност и голямо климатично разнообразие. Районът е ключов за двупосочното разселване на сухоземна фауна между Европа и Азия. Представеното изследване се концентрира върху две моделни видови групи микроптерни, растителноядни скакалци от род Poecilimon Fischer, 1853 - P. jonicus и подрод Hamatopoecilimon Heller, 2011, които имат разпокъсано разпространение западно и източно от Средно-егейската падина, на остров Крит и на архипелазите Циклади и Южни Споради. Цел на изследването е да се проучи филогеографията на скакалците от избраните групи и да се направят изводи за техните темпове на еволюция и еволюционни стратегии, както и пътищата и времето на разселване на филогенетичните линии. Приложен е интегративен подход, включващ молекулярно-генетични, акустични методи и моделиране на екологичните ниши. Предложена е таксономична ревизия на групата P. jonicus на основата на молекулярна филогения и биоакустика. Представени са добре подкрепени филогенетични реконструкции, базирани на митохондриални и ядрени маркери. Приложени и сравнени са различни методи за датиране на филогенетичните линии и стратегии за калибриране. Изготвени са модели на климатичните ниши на избрани видове и са извършени тестове за припокриване на нишите между близкородствени таксони. Анализирана е времевата рамка за еволюционните процеси в моделните групи и са изказани филогеографски хипотези относно видообразуването и разселването в Егейския регион. The Eastern Mediterranean is characterized with high geotectonic activity, and high climatic diversity. The region has a major role for exchange of terrestrial fauna between Europe and Asia. The present study concentrates on the species group Poecilimon jonicus and subgenus Hamatopoecilimon, which have disjunct distribution on both sides of the Mid-Aegean Trench. The aim of the present study is to explore the phylogeography and systematics of the Poecilimon jonicus species group and subgenus Hamatopoecilimon, and to draw conclusions about their evolution at a temporal and spatial scale. We apply integrative approach, including molecular, acoustic and ecological methods. Comparisons of acoustic communication between closely related taxa of doubtful status is performed. Different methods for molecular dating and alternative molecular clock calibration strategies are compared. Ecological niche models are created, based on bioclimatic variables. Ecological niche overlap between closely related taxa is measured to study the ecological divergence in the P. jonicus species group. Data are compared and discussed in an evolutionary and systematic context. The major role of Messinian terrestrial corridors for dispersal of terrestrial fauna, the importance of subsequent re-flooding as a factor for explosive vicariant speciation, and the role of the Plio-Pleistocene climatic cycles for lineage diversification at a species and subspecies level in the region is confirmed.