The mutualistic interspecific relationships of trophobiosis between trophobiont planthoppers (Hemiptera, Fulgoromorpha) providing food to the host called xenobiont, are reviewed. The degree of interspecific relationships between these symbionts varies from occasional or short time duration (a few hours to a few days) to longer ones, with trophobionts left free to escape (optobiotic type) by the xenobiont, or maintained enclosed in nests or ant shelters (cryptobiotic type). Of 267 collected cases, 126 are new illustrated observations. Occasional trophobiosis is documented in 13 families of planthoppers and appears to be quite general in Fulgoromorpha, although it is reported for the first time for Dictyopharidae, Eurybrachidae, and Nogodinidae. Xenobionts associated with planthoppers are reported from ants and other Hymenoptera, Lepidoptera, and Blattodea, but also from Mollusca and even small gekkonid vertebrates. Tettigometridae appear to be exclusively tended by ants, while Fulgoridae significantly more often by cockroaches (40%) than by ants (27%). Long-time trophobiosis occurs always with ants, cryptobiotic ones reported in Cixiidae, Delphacidae, Tettigometridae, Meenoplidae, Flatidae and Hypochthonellidae, while optobiotic ones remain restricted to tettigometrids. A particular focus on Tettigometridae attended by ants is provided with new etho-ecological observations of 92 currently described tettigometrids species, 32 different species (35%) are now known to be able to be ant-attended. In Bulgaria, where fourteen species occur, trophobiosis occurs with at least five species of them (36%). In tettigometrids, subsociality, sessility, and underground life appear to be key factors allowing more complex relationships with ants. However, the planthopper size and thus the amount of food (drops of honeydew) is probably also an important factor. This might explain many new observations in large-sized and often isolated fulgorids with cockroaches. Tapping of trophobiont forewings by cockroaches, moths, or of the bark subtrate by geckos has been observed, but antennal palpation behaviours by ants are the most commonly observed with tettigometrids, although not with larger planthoppers. In tettigometrids, specific tegumentary glands secretions (allomones) of the abdomen pleurites might also mediate their long-term mutualistic associations, even possibly completing honeydew kairomones actions mediating planthopper trophobiosis in general.

This study presents a new design of sensor tool to record substrate-borne vibrations produced by insects. We applied a piezo element acting as a contact microphone connected to a digital recorder to detect the signals emitted by insects. A suitable 3D printed microphone box with a mechanism of connection to the substrate or to soft tweezers holding the insect is created. We found that the recordings of the low-frequency signals (up to 20 кHz) were sufficiently good for analysis and, at the same time, a much faster and easier method than the common ones of detecting micro-vibrations using a piezoelectric sensor and, importantly, is incomparably cheaper than using a laser vibrometer. This setup is suitable for the detection and structural description of signals emitted by insects and other arthropods. Oscillograms, spectrograms and audio files of the recorded signals of selected ants (Manica rubida, Latreille, 1802, Messor wasmanni Krausse, 1910, Myrmica ravasinii Finzi, 1923) and Ponera coarctata (Latreille, 1802)), an ant nest beetle (Paussus turcicus I. Frivaldszky von Frivald, 1835), a planthopper (Orosanga japonica (Melichar, 1898)) and a jumping plant louse (Bactericera perrisii Puton, 1876) are provided to demonstrate the effectiveness of the created equipment. The recordings from stridulation in Myrmica ravasinii, Manica rubida, Ponera coarctata and Paussus turcicus and the male call song of Orosanga japonica represent the very first documented signal production for these species. A scheme of the contact microphone and its mode of connection is shown. The research presented will democratise biotremological methods for the needs of integrative taxonomy and behavioural ecology, providing a broader understanding of vibrational signals through an efficient, accessible and operational method for both professional and citizen scientists.

Psyllids (Hemiptera: Psylloidea) are plant sap-sucking insects whose identification is often difficult for non-experts. Despite the rapid development of DNA barcoding techniques and their widespread use, only a limited number of sequences of psyllids are available in the public databases, and those that are available are often misidentified. Here, we provide 80 sequences of two mitochondrial genes, cytochrome c oxidase I (COI) and cytochrome b (Cytb), for 25 species of Aphalaridae, mainly from Bulgaria. The DNA barcodes for 15 of these species are published for the first time. In cases where standard primers failed to amplify the target gene fragment, we designed new primers that can be used in future studies. The distance-based thresholds for the analysed species were between 0.0015 and 0.3415 for COI and 0.0771 and 0.4721 for Cytb, indicating that the Cytb gene has a higher interspecific divergence, compared to COI, and therefore allows for more accurate species identification. The species delimitation based on DNA barcodes is largely consistent with the differences resulting from morphological and host plant data, demonstrating that the use of DNA barcodes is suitable for successful identification of most aphalarid species studied. The phylogenetic reconstruction based on maximum likelihood and Bayesian inference analyses, while showing similar results at high taxonomic levels to previously published phylogenies, provides additional information on the placement of aphalarids at the species level. The following five species represent new records for Bulgaria: Agonoscena targionii, Aphalara affinis, Colposcenia aliena, Co. bidentata, and Craspedolepta malachitica. Craspedolepta conspersa is reported for the first time from the Czech Republic, while Agonoscena cisti is reported for the first time from Albania.

The singing cicadas (Hemiptera: Cicadidae) of Bulgaria were poorly known. There are published records for 14 species:Cicada orni,Lyristes plebejus,Cicadatra atra,Cicadatra hyalina,Cicadatra persica,Cicadetta montana,Cicadetta mediterranea,Dimissalna dimissa,Oligoglena tibialis,Tympanistalna gastrica,Pagiphora annulata,Saticula coriaria,Tibicina haematodesandTibicina steveni.Two species from this list were doubtful in the beginning of our study, sinceTympanistalna gastricais distributed in central and southern Portugal andSaticula coriariais a north African species.We checked three major institutional collections housed in Sofia, Bulgaria: the National Museum of Natural History (SOFM), the Institute of Zoology (ZISB) and the Biology Faculty of Sofia University "St. Kliment Ohridski" (BFUS). We confirmed 11 of the species mentioned in literature, exceptCicadetta mediterraneaand found two additional species:Cicadatra platypteraandCicadetta macedonica(the specimens in BFUS were bioacoustically confirmed).Based on this knowledge, we further investigated the singing cicadas of Bulgaria with the use of morphological and bioacoustic methods in the years 2008, 2009, 2010, 2012, 2016, 2018 and 2019. We were not able to confirm the presence ofCicadatra persicaandCicadetta mediterranea, but found three additional species:Cicadetta brevipenniss. lat.,Cicadetta cantilatrixandTettigettula pygmea. Using the bioacoustic methods, we also detected unknown singing patterns, which could belong to three or four additional taxa, which need to be described.The Bulgarian fauna of singing cicadas at the moment consists of 16 confirmed and 3-4 potential species.

Historia naturalis bulgarica -- Volume 46 (2024) -- Damage caused by singing cicadas (Hemiptera: Cicadidae) in the field protective forest belts in South Dobrudzha, Bulgaria -- Article synopsis

Knowledge of the fauna of jumping plant lice or psyllids in Bulgaria is rather scattered. So far, 113 species of psyllids have been recorded from Bulgaria in 51 publications. The aim of this study is to provide an up-to-date checklist of the Psylloidea species from Bulgaria, based on extensive fieldwork by the authors and examination of specimens mainly from the Zoological Collection of Sofia University (BFUS) and the Moravian Museum in Brno (MMBC). In addition, a thorough review of all relevant literature was undertaken to consolidate the existing records. Twenty-five species of jumping plant lice are recorded here from Bulgaria for the first time. Of these, two species represent new records for Europe: Dyspersa kantshavelii (Gegechkori, 1977) and Heterotrioza kochiae (Gegechkori, 1975); and three additional species represent new records for the Balkan Peninsula: Arytainilla spartiicola (Šulc, 1912), Craspedolepta araneosa Loginova, 1962 and Eryngiofaga babugani (Loginova, 1964). A new synonymy is proposed: Colposcenia osmanica Vondráček, 1953 = Colposcenia kiritshenkoi Loginova, 1960, syn. nov. A lectotype is designated for C. osmanica to stabilise the nomenclature. Original drawings or photographs of diagnostic characters on male and female terminalia are provided for C. osmanica, D. kantshavelii, Heterotrioza eurotiae (Loginova, 1960) and H. kochiae. Distributional maps summarising all known records from Bulgaria are provided for each species. Where available, photographs of live or mounted specimens and information on host plants are also provided, including new host plant records for 10 species. The previously published records of Aphalara sauteri Burckhardt, 1983, Bactericera acutipennis (Zetterstedt, 1828), B. reuteri (Šulc, 1913), Dyspersa apicalis (Foerster, 1848), D. viridula (Zetterstedt, 1828), Eryngiofaga mesomela (Flor, 1861) and Trioza dispar Löw, 1878 from Bulgaria are considered doubtful and these species are deleted from the list of the Bulgarian fauna, which now comprises 130 species from 33 genera and six families of jumping plant lice. This diversity is compared with the known data on Psylloidea in other countries of the Balkan Peninsula and Turkey and the Bulgarian psyllid fauna is discussed from the perspective of biogeography.