Bimodality of auditory receptors in bush-crickets. Сontinued discussion. It's time to experiment.

Continuation of the discussion on the sensitivity of the chordotonal sensilla of the tympanal organ of bush-crickets to vibratory stimuli. We have previously shown that individual receptors registered directly in the tympanal organ perceive vibrations along with sound stimuli. In addition, scolopidia of the crista acustica possess mixed sensitivity, too, as well as receptors of the intermediate organ. The authors of the comment offered their opinion concerning our applied methods as well as our obtained results. In particular, they noted the dissimilarity of our data from the previously obtained data (the 1970s-1990s), mainly in the laboratory of Prof. K. Kalmring, who assumed that only low-frequency receptors, in particular receptors of the intermediate organ, possess mixed sensitivity. At the same time, receptor activity was recorded in the tympanal nerve without morphological identification of receptors (with the exception of one stained neuron in the prothoracic ganglion). We carried out a series of experiments using the method of K. Kalmring and found that it is possible to register several receptors in the tympanal nerve with different reactions during one experiment: to sound only, also both to vibration stimuli and sound. In the latter case, we dealt with low-threshold receptors, which responded to ultrasound, and this with high probability belonged to the crista acustica. Similar data were previously obtained on the bush-cricket Decticus verrucivorus. In this publication, we explain the methodological features of our work and suggest that the loss of sensitivity to vibrations at the level of the tympanal nerve by some auditory receptors may be due to the ephaptic and/or chemical interaction of the tympanal organ receptors with vibroreceptors of the subgenual or other organs. To verify this hypothesis, it is necessary to conduct additional studies, such as physiological, morphological, and immunohistochemical, along the entire vibroacoustic afferent tract, that is, from the peripheral part to the first switches to the corresponding interneurons.

Acoustic and vibrational signaling in true katydid Nesoecia nigrispina: three means of sound production in one species.

The males of Mexican katydids Nesoecia nigrispina (Stal, 1873) produce calling songs and protest sounds using the typical stridulatory apparatus, situated, as in most of the other Ensifera, at the bases of the tegmina. It includes a stridulatory file on the upper tegmen and a plectrum on the lower one. The calling sounds, which are of two types (fast and slow), are two-syllabic series, with a repetition rate fluctuate within 3-4.5 s-1 (fast) and 1.2-2 s-1 (slow). After tactile stimulation, males produce protest signals in the form of short trills of uniform syllable duration. The syllable repetition rate is higher than that of the calling sounds: 7.7 s-1. The frequency spectra of these signals have maxima in the band of 14-15 kHz. However, in addition to the sounds described, both males and females are capable of producing protest signals of the second type, with the help of another sound apparatus, namely the hind wings. Apparently, the sound is produced by the friction of the hind wings on the lower tegmen. The dominant frequencies in the frequency spectra of these sounds are 40-60 kHz. In adults of both sexes and older nymphs, in response mainly to tactile stimulation, short clicks are recorded, which they produce, apparently, by the mandibles. Thus, N. nigrispina seems to have the most extensive acoustic repertoire among pseudophyllines and three means of emitting sound signals. Tremulatory substrate-borne vibrations are produced by individuals of both sexes during courtship and by males completing the calling signal cycle and after copulation. It is possible that vibrational signals are an additional factor in the reproductive isolation of sympatric species, since the calling sound signals in representatives of the genus Nesoecia are similar and exhibit considerable variability. The type and parameters of the calling signal used by the female during recognizing a conspecific mate remain unclear.

Biology, sounds and vibratory signals of hooded katydids (Orthoptera: Tettigoniidae: Phyllophorinae).

The tettigoniid subfamily Phyllophorinae, distributed in Southeast Asia and Australia, is poorly known. Our study of the biology of Giant Katydid Siliquofera grandis (Blanchard, 1853) from a laboratory culture has shown that these insects mate more than once, the females lay a total of up to 400 eggs during their life, and these hatch after 2-2.5 months. The life cycle from egg to death takes longer than one year. In the laboratory, the insects fed mainly on leaves of various Rosaceae, Ficus, and lettuce, and on fruits.                It is known that the males of hooded katydids lack the tegminal stridulatory apparatus typical for Tettigoniidae, but are capable of producing protest sounds using their coxosternal sound-producing organs for stridulation. Here, protest stridulation of the males and females and the sound-producing organs used to produce it have been analyzed in Phyllophorina kotoshoensis Shiraki, 1930 and S. grandis. In addition, nymphal protest sounds produced by friction of the metafemur against the edge of the pronotum and adult protest signals produced with the wings are described. In S. grandis, vibratory signals have been described and studied for the first time: territorial, protest, drumming and rhythmic low-amplitude vibrations emitted by adults and nymphs and pre- and postcopulatory vibrations of the males and females. The territorial signals not accompanied with visible movements of the body may be produced by contracting the antagonist muscles of the thorax and possibly of the legs. Using their coxosternal sound-producing organs males of S. grandis produced also an audible courtship song lasting for several seconds. Acoustic signals may thus both regulate intrapopulation relations and serve for interspecific communication (protest signals). The acoustic communication in Phyllophorinae is probably especially important during mating behavior.

Unusual mechanism of emission of vibratory signals in pygmy grasshoppers Tetrix tenuicornis (Sahlberg, 1891) (Orthoptera: Tetrigidae).

Acoustic communication plays an important role in the life of insects and especially in representatives of the order Orthoptera. Their vibrational signalling, unlike signalling by sound, is poorly studied. The pygmy grasshoppers Tetrix tenuicornis (Sahlberg, 1891) belonging to the ancestral family Tetrigidae (Orthoptera) can produce several types of substrate-borne vibratory signals using their mid-legs. The emission of these signals is not accompanied by visible movements of any parts of the body. The goal of our study was to elucidate the mechanism of production of these vibrations. For this, we synchronously recorded the vibratory signals and the muscle activity in various regions of the legs and thorax in freely moving males. The obtained results revealed an unusual mechanism for the emission of acoustic signals. We found that the strongest muscle activity during the emission of the vibratory signals was recorded in the mesofemur and mesotibia. According to the position of the electrode, these muscles are the flexor and extensor of the tibia, levators and depressors of the tarsus, and probably pretarsus. The motor system employed during the emission of vibratory signals was most similar to that of the jump of locusts and probably is performed as a result of co-contraction of antagonistic muscles of the tibia, tarsus, and pretarsus. The data obtained make significant additions to the presentation of a variety of insect acoustic communication systems.

Fauna Europaea: Coleoptera 2 (excl. series Elateriformia, Scarabaeiformia, Staphyliniformia and superfamily Curculionoidea).

Fauna Europaea provides a public web-service with an index of scientific names (including synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. Coleoptera represent a huge assemblage of holometabolous insects, including as a whole more than 200 recognized families and some 400,000 described species worldwide. Basic information is summarized on their biology, ecology, economic relevance, and estimated number of undescribed species worldwide. Little less than 30,000 species are listed from Europe. The Coleoptera 2 section of the Fauna Europaea database (Archostemata, Myxophaga, Adephaga and Polyphaga excl. the series Elateriformia, Scarabaeiformia, Staphyliniformia and the superfamily Curculionoidea) encompasses 80 families (according to the previously accepted family-level systematic framework) and approximately 13,000 species. Tabulations included a complete list of the families dealt with, the number of species in each, the names of all involved specialists, and, when possible, an estimate of the gaps in terms of total number of species at an European level. A list of some recent useful references is appended. Most families included in the Coleoptera 2 Section have been updated in the most recent release of the Fauna Europaea index, or are ready to be updated as soon as the FaEu data management environment completes its migration from Zoological Museum Amsterdam to Berlin Museum für Naturkunde.

Novel cathepsin L-like protease from dermestid beetle Dermestes frischii maggot.

A novel cathepsin L-like protease from dermestid beetle Dermestes frischii maggot guts was obtained and investigated. The protease was isolated through affinity chromatography at arginine-diasorb followed by FPLC gel-filtration at Superdex 75. Protease is active against chromogenic peptide substrates, containing Arg or Leu in P1 position and a hydrophobic residue in P2 position. PH optimum is about 4,5 and temperature optimum at 40°C. Enzyme is inhibited completely by HgCl(2) and leupeptin that prove it's belonging to cysteine proteases of papain family. cDNA analysis of cathepsin L-like protease showed that protein sequence consists of 339 amino acid residues. Mature cysteine protease contains 219 amino acid residues corresponding to molecular mass 24027.20Da. Residues of the active site were identified: Gln(140), Cys(146), His(285), Asn(306) and Trp(308). Calculated pI is 4,73. The amino acid sequence of the cystein protease from dermestid beetle displays high structural homology with cathepsin L of other insects.