Nikolay Simov

Bulgarian Academy of Sciences | BAS · National Museum of Natural History

Recent work at the Upper Cretaceous vertebrate locality near the town of Tran, western Bulgaria, brought to light a diverse assemblage of plant mesofossils and other microfossils of uncertain systematic affinities. Here we briefly report on 18 problematic specimens that share a striking morphological similarity to the Late Cretaceous Knoblochia cre...

Migratory waders use stopover sites to refuel for the next stages of their migration, relying on seasonally abundant prey. Migration success depends on food quality and availability at these key sites. We studied the diet composition and preferences of the Grey Plover (Pluvialis squatarola) at its migration stopover at Pomorie Lake on the South-Wes...

Bats are known to inhabit both caves and open space areas. Bulgaria is among the Еuropean countries with the highest number of bat species. The species found in the country are distributed over a wide area. They range from the Pyrenees and the British Isles to the Pacific region and the Far East. Many bat species are carriers of potential human pat...

Groundwater ecosystems are inhabited by unique assemblages of animals, often with restricted distributions and highly specialized traits. Those assemblages sustain ecosystem functioning and contribute to important ecosystem services. Knowledge of the species occurring in those habitats and the main ecological and historical drivers for their distri...

This study presents novel findings on the Psocoptera (Insecta) fauna of Vietnam, contributing to the understanding of biodiversity in the region. Psocoptera specimens were collected from Tam Dao National Park during October 2023, adding 19 new species to the existing list. These discoveries include species previously unknown to Vietnam and some new...

Two plant bug species, Euryopicoris nitidus (Meyer-Dür, 1843) and Solenoxyphus lepidus (Puton, 1874), are reported for the first time for Bulgaria. Their habitats, host plants, and reasons for the late discovery in the country are briefly discussed. The genera Euryopicoris Reuter, 1875 and Solenoxyphus Reuter, 1875 have not been previously reported...

This study focused on the cave fauna of Costa Rica, which has remained relatively understudied despite the presence of more than 435 recorded natural caves and artificial subterranean sites. We collected and reviewed all available literature data on cave fauna in Costa Rica and created the first comprehensive review of the existing information. In...

Ten specimens of Middle Miocene petrified wood remains collected from the Bulgarian shore of Black Sea, close to Byala locality, were analysed through a microscopic study. The samples originate from the Galata Formation and are of Chokrakian age. Eight of these are taxonomically identified as Populoxylon sp. (cf. Populus tremula L.). This find repr...

Better empirical knowledge of how bat and insect phenology are influenced by seasonal environmental conditions and how this may affect fitness is essential in the face of changing climatic conditions. We examined the winter diet of the Schreibers’ bent-winged bat Miniopterus schreibersii (Kuhl, 1817) from Razhishkata Cave, Balkan Mountains, Bulgari...

During a brief visit of Alonnisos Island in 2022 some insect species (mainly butterflies) were observed and photographed. Three of them are new for the island’s fauna - the giant Asian mantis Hierodula tenuidentata Saussure, 1869, western conifer seed bug Leptoglossus occidentalis Heidemann, 1910, millet skipper Pelopidas thrax (Hübner, [1821]). Th...

The structure of testes and ovaries can be described in its simplest form by the number of follicles and ovarioles they contain. Sixty-five years after the last review of the internal reproductive systems in true bugs (Heteroptera), the data accumulated today on the number of testicular follicles and ovarioles in their gonads are summarized. In add...

The first record of Aradus bimaculatus Reuter, 1872 in Bulgaria and on the Balkan Peninsula is reported with data on the habitats and the true bug assemblage in the region during the collection period (end of February - end of March).

Healthy wing membranes are essential for bats. They are critical for maintaining the water balance and, during hibernation, they protect the bat’s body from dehydration. Assessing the state of the membrane visually is an easy and effective way to monitor a bat’s health and discover abnormal structures and infections in wild bat populations. During...

Antarctica peninsula periphery islands undergo one of the most dramatic ecological changes due to ongoing global warming. The front fields of the Antarctic glaciers are extreme environments and pioneering sites for ecological succession. Rising temperatures lead to deglaciation in the Antarctic habitats, and the new terrain is subjected to the proc...

Data for new local palaeoflora near the village of Bersin (SW Bulgaria) are presented. Eight species of fossil plants have been identified. Eotrigonobalanus furcinervis is dominant over other species. The flora-bearing layers originate from the lower part of the Nevestino Formation, which is formed by alternating sandstone and mudstone sediments. B...

The paper presents results of a brief entomological surveys carried out in the southern parts of Lemnos Island in 2016, 2017 and 2019. It includes a list of 14 recorded species of butterflies, three of which are new for the island.

A study on bat casualties was carried out between 2013 and 2016 on the 16-km road stretch passing through the Kresna Gorge-a European biodiversity hotspot with high conservation value. We found 78 road-killed bats belonging to ten species, adding new data on the bat species composition in the gorge. We identified one road section as a roadkill hots...

Globally, inland waters emit over 2 Pg of carbon per year as carbon dioxide, of which the majority originates from streams and rivers. Despite the global significance of fluvial carbon dioxide emissions, little is known about their diel dynamics. Here we present a large-scale assessment of day- and night-time carbon dioxide fluxes at the water-air...

We present data on the stomach contents and the gross morphology of the fat body in Agile Frogs (Rana dalmatina) from a pond which is an object of a long-termed monitoring. We also provide information on the diet of one female of Lissotriton vulgaris. All of the specimens were found dead during the mating season, when sudden snowfalls and depressio...

The first fossil jewel beetle discovered in Bulgaria is reported from deposits of the Satovcha Basin dated to the Middle Miocene.

The first fossil Diptera of Miocene age and also first fossil Bibionidae discovered in Bulgaria are reported. The presence of relatively many specimens of the genus Plecia without any other Bibionid species is considered to indicate warmer climate than the present in the Rhodope mountains and distinguishes Satovcha Basin from other Middle Miocene-a...

A conference paper reviewing published research and preliminary data on the ongoing studies of a recently discovered late Santonian - early Campanian tetrapod fossil site in Western Bulgaria.

We report the first record for Bulgaria of Campylosteira orientalis Horváth, 1881 and the genus Campylosteira, on the whole, along with data of the habitats and the true bug assemblage in the studied locality.

Heteroptera, or true bugs populate many climate zones, coping with different environmental conditions. The aim of this study was the evaluation of their thermal limits and derived traits, as well as climatological parameters which might influence their distribution. We assessed the thermal limits (critical thermal maxima, CTmax, and minima, CTmin)...

We report the karyotype, some aspects of spermatogenesis, and ovarian trophocytes ploidy in three aquatic bug species: Ilyocoris cimicoides (Linnaeus, 1758), Notonecta glauca Linnaeus, 1758, and Diplonychus rusticus Fabricius, 1871 from previously unexplored regions – South Europe (Bulgaria) and Southeast Asia (Vietnam). Our results add considerabl...

Male karyotype and meiosis in four true bug species belonging to the families Reduviidae, Nabidae, and Miridae (Cimicomorpha) were studied for the first time using Giemsa staining and FISH with 18S ribo-somal DNA and telomeric (TTAGG) n probes. We found that Rhynocoris punctiventris (Herrich-Schäffer, 1846) and R. iracundus (Poda, 1761) (Reduviidae...

The Kresna Gorge is a biodiversity hotspot with high conservation value not only for Bulgaria, but the Balkan Peninsula. In the gorge region, many rare, endemic, and protected species and habitats are found (Hubenov 2012). Since the beginning of the 21 st century, several road and highway projects have threatened the ecological prosperity of this a...

All 100+ bedbug species (Cimicidae) are obligate blood-sucking parasites [1, 2]. In general, blood sucking (hematophagy) is thought to have evolved in generalist feeders adventitiously taking blood meals [3, 4], but those cimicid taxa currently considered ancestral are putative host specialists [1, 5]. Bats are believed to be the ancestral hosts of...

In this paper new data on allochtonous and invasive invertebrate species: Arion (Arion) cf. vulgaris Moquin-Tandon 1855, Cornu aspersum (O.F. Muller, 1774), Harmonia axyridis (Pallas, 1773), Acanthoscelides obtectus (Say, 1831), Trogoderma variabile Ballion, 1878, Stegobium paniceum (Linnaeus, 1758), Oxycarenus (s.str.) lavaterae (Fabricius, 1787),...

The book is written to summarize the results of the WEMA project „Mapping and Assessment of Ecosystem Services of Wetlands in Bulgaria“. The project was implemented by the Institute of Biodiversity and Ecosystem Research at the Bulgarian Academy of Sciences (IBER‐BAS) and was accomplished with the financial support of the BG03 Program „Biodiversity...

Книгата е написана с цел да се обобщят резултатите от проект „Картиране и оценка на екосистемните услуги във влажните зони на България“ (WEMA). Проектът беше изпълнен от Института по биоразнообразие и екосистемни изследвания при БАН (ИБЕИ- БАН) и е осъществен с финансовата подкрепа на Програма BG03 „Биологично разнообразие и екосистеми“, по Финансо...

The paper presents results of an entomological expedition carried out in the southern parts of Kazakhstan in May 2015. This expedition was conducted within a joint team project of the Department of Entomology, Faculty of Biology, Saint Petersburg State University, and the National Museum of Natural History, Bulgarian Academy of Sciences. The paper...

The paper presents results of an entomological expedition carried out in the southern parts of Kazakhstan in May 2015. This expedition was conducted within a joint team project of the Department of Entomology, Faculty of Biology, Saint Petersburg State University, and the National Museum of Natural History, Bulgarian Academy of Sciences. The paper...

Inventory of selected groups of the invertebrate fauna in the EUNIS wetland habitat type D5 “Sedge and reedbeds normally without free-standing water” in Bulgaria was carried out. It included 47 localities throughout the country. The surveyed invertebrate groups included slugs and snails (Gastropoda), dragonflies (Odonata), grasshoppers (Orthoptera)...

The Caucasian subgenus Plumiger Horváth, 1927 of the halticine genus Myrmecophyes Fieber, 1870 is revised. A key, updated diagnoses, and data on distribution are given for the subgenus and its four species, including M.tomisp. n. (Georgia and Dagestan), and the previously unknown male of M.armeniacus Drapolyuk, 1989. Illustrations of the male and f...

Aphelocheirus aestivalis is a stenobiotic species with low dispersion ability. It is the only member of the family Aphelocheiridae found in most of Europe. Hydromorphological changes and water pollution threaten its subpopulations. Considering the vulnerability of the species, more accurate data about its occurrence and geographic distribution are...

All 100+ bedbug species (Cimicidae) are obligate blood-sucking parasites and well-known for their habit of traumatic insemination but the evolutionary trajectory of these characters is unknown. Our new, fossil-dated, molecular phylogeny estimates that ancestral Cimicidae evolved ca. 115MYA as hematophagous specialists on an unidentified host, 50MY...

New records, host associations, damages on oaks and the potential threat of alien oak lace bug (Corythucha arcuata) to native forests in Bulgaria are reported and briefly discussed.

The present paper reports some new records of the species Geranium Bronze (Cacyreus marshalli) from certain localities in the Mediterranean part of the South-East Balkan Peninsula, along with data regarding its biology. The collection of the data was done as a part of field work across Bulgaria, Greece and the Republic of Macedonia, as well as from...

The book is written to summarize the results of the WEMA project „Mapping and Assessment of Ecosystem Services of Wetlands in Bulgaria“. The project was implemented by the Institute of Biodiversity and Ecosystem Research at the Bulgarian Academy of Sciences (IBER‐BAS) and was accomplished with the financial support of the BG03 Program „Biodiversity...

This paper gives records of three assassin bug species (Heteroptera: Reduviiidae) new for the Balkan Peninsula.

We report here the first chromosome numbers for benthic water bugs (Nepomorpha: Aphelocheiridae). All three studied species, Aphelocheirus aestivalis (Fabricius, 1794), A. murcius Nieser and Millán, 1989 and Aphelocheirus sp. from Ebro River (northern Spain), have karyotype 2n = 22 + XX/X(0) and inverted sequence of the X chromosome divisions in ma...

Data on the fossil plants from Tran and Breznik regions (Western Bulgaria) are very scarce. Palamarev (1980) recorded 4 species of Characeae and based on these findings discussed the Еarly Oligocene age of bitominous sediments in Breznik region. Here we present the first data on Oligocene fossil plants from the Erma Gorge and Tran region. The fossi...

The first paleontological data about the Eocene sediments in the studied region of Piyanets were published in the first half of the 20th century when Stefanoff and Dimitrov (1936) mentioned the presence of an insect (Diptera) in Upper Eocene/Lower Oligocene sediments near Rashka Grashtitsa Village. The same specimen was determined by Drensky as Myc...

This article reports new records of the invasive brown marmorated stink bug Halyomorpha halys (Stål, 1855) (Heteroptera: Pentatomidae) in Bulgaria.

New and interesting records of aquatic true bugs species from Bulgaria are reported: Lethocerus patruelis (Stål, 1855); Corixa panzeri Fieber, 1848; Hesperocorixa sahlbergi (Fieber, 1848); Sigara assimilis (Fieber, 1848); Sigara mayri (Fieber, 1860); Cymatia rogenhoferi (Fieber, 1848); Micronecta carpatica Wróblewski, 1958; Anisops sardeus Herrich-...

The digital edition is part of a joint project for a print and digital edition of the Red Data Book of the Republic of Bulgaria. It includes the full information from the print edition (vol 1 Plants and Fungi, vol 2 Animals, vol 3 Natural habitats), enriched with videos, extended photo gallery, higher-resolution drawings, distribution maps with rel...

The first fossil Odonata discovered in Bulgaria are described and illustrated, i.e., the aeshnid Oligaeschna bulgariensis sp. nov., the sieblosiid Stenolestes rhodopensis sp. nov., and the dysagrionid Primorilestes magnificus sp. nov. These genera are present in both Western Europe and Siberia in the Neogene. Their fossil discoveries in Bulgaria pr...

The karyotype and male meiosis, with a particular focus on the presence or absence of chiasmata between the homologs, were studied in the water boatman species Cymatia rogenhoferi (Fieber) and C. coleoptrata (Fabricius) (Corixidae, Cymatiainae). It is shown that the species have 2n = 33 (28A+2m+X1X2Y) and 2n = 24 (20A+2m+XY) respectively, post-redu...

The assessment of the diversity of invertebrates in Macedonia was based on previous assess-ments and analyses of new published data in the period 2003-2013 (after the first country study on biodiversity). The total number of species was estimated at almost 13400 that represents an increase of more than 3700 species. The largest number of species is...

Two cases of fatal myiases on bats are reported, with the first record of myiasis caused by Calliphora vicina on noctule bats in Bulgaria. Myiasis as a factor for increasing mortality of bats are discussed.

The species of the genus Cimex (Heteroptera: Cimicidae) are important ectoparasites of European bats. Unlike other ectoparasites, they are attached to the body of their host only when they need to feed, otherwise they stay in refugia in bat roosts. Consequently, they are often overlooked by bat specialists and in many countries they are either unkn...

The assessment of the diversity of invertebrates in Macedonia was based on previous assessments and analyses of new published data in the period 2003-2013 (after the first country study on biodiversity). The total number of species was estimated at almost 13400 that represents an increase of more than 3700 species. The largest number of species is...

Cleotomiris josifovi is described from the vicinity of Pyong Kang, North Korea. The description of this new species is provided with scanning micrographs of selected structures, and digital microscopic images of habitus and genitalia.

After a in depth study of the legislation of the Republic of Bulgaria, the authors consider that an integrated approach to the protection and management of the cave systems in Bulgaria is only achievable action and should not cause resistance by the state administration, as well as by citizens including representatives of the speleological communit...

In July and September 2012, the invasive alien oak lace bug, Corythucha arcuata (SAY) was established for first time in Bulgaria. It was found on leaves of solitary tree of Quercus robur L. in Plovdiv, and in mixed stands formed by Q. robur and Q. cerris L. in vicinity of Zlati dol vill. near town of Simeonovgrad in South Bulgaria. C. arcuata most...

Since 1998, when the First European Hemiptera Congress (EHC) took place in the small seaside resort Amaliapolis, Greece, the Hemiptera congresses are regularly held every two-three years: EHC 2 in Fiesa, Slovenia (2001), EHC 3 in St. Petersburg, Russia (2004), EHC 4 in Ivrea, Italy (2007) and EHC 5 in Velence, Hungary (2009).

Electronic supplementary material video S1. (doi: 10.3897/zookeys.319.4384.app) File format: MPEG Video File (mpg).

The karyotype and meiosis in males of giant water bug Lethocerus patruelis (Heteroptera: Belostomatidae: Lethocerinae) were studied using standard and fluorochrome (CMA 3 and DAPI) staining of chromosomes. The species was shown to have 2n = 22A + 2m + XY where 2m are a pair of microchromosomes. NORs are located in X and Y chromosomes. Within Belost...