Vol 97, No 4 (2017)

Preimaginal development and maturation of females of two laboratory strains originated from two populations of the multicolored Asian ladybird Harmonia axyridis were investigated under laboratory conditions. Females of the autochthonous population from Irkutsk (Siberia) enter diapause under the short day conditions, whereas in females of the invasive population from Sochi (the Caucasus) photoperiodic induction of diapause is weak. The two populations also differ in the proportions of morphs: the population from Sochi is represented only by the morph succinea, whereas the population from Irkutsk is represented by the morphs succinea и axyridis with the predominance of the last one, which in our study was separated into two phenotypes, differed in the degree of melanization. Rearing of adults under the short day (12 h) conditions induced reproductive diapause in females of all the studied morphs and phenotypes of the Irkutsk population, whereas under the long day (18 h) conditions females of the morph succinea showed a slightly lower tendency to diapause. Evidently, the interpopulation differences in the responses regulating the seasonal cycle of the multicolored Asian ladybird are determined by genes that are not involved (or almost not involved) in the determination of the color polymorphism. The interpopulation differences in size and weight were quite substantial, whereas the differences between morphs and phenotypes were statistically significant in only some of our experiments. In combination with the literature data, these results suggest that the genes determining the color polymorphism in H. axyridis may have a pleiotropic effect on other traits including important eco-physiological parameters but this effect is relatively weak and manifests itself only against a particular genetic background and / or under particular environmental conditions.

The aftereffects of the Russian wheat aphid (RWA) Diuraphis noxia on sowing and productive qualities of barley and spring bread wheat grain were assessed. Seeds of 4 cultivars of barley (Volgar, Povolzhsky 65, Kazak, and Povolzhsky 16) and 4 cultivars of spring wheat (Kinelskaya 59, Kinelskaya Otrada, Kinelskaya Niva, and Kinelskaya 2010) from spikes infested and uninfested with RWA in 2007 and in 2014 were sown in the subsequent years, using 0.5 m² experimental plots in four replications, at a seeding rate of 300 grains/m². The least significant difference (LSD_0.5) was used to compare the mean ± standard deviation (SD) values. The field germination rate of seeds from spring wheat spikes damaged by RWA was reduced by 15%. Of the components of grain yield, barley and spring wheat grown from seeds from the infested spikes showed a 23-31% smaller number of productive tillers before harvesting, a 16% smaller number of grains per spike, a 13-16% lower grain weight per spike, and a total yield loss of 33-42%. In hulless bread wheat RWA fed on the developing kernels inflicting greater damage, whereas the hulled barley seeds were practically not damaged. The mean yield loss of the barley and spring wheat spikes infested with RWA was 24-32% and 50-66%, respectively. Due to the greater tillering capacity and formation of secondary productive tillers in barley, about 52% of the productive barley tillers and 37-39% of spring wheat ones were infested with RWA, which resulted in a comparable yield loss (20-25% in barley and 19-23% in spring wheat). Resistance to RWA was higher in spring wheat and barley cultivars with a shorter vegetation period, looser spikes, and thinner culm walls. The length of productive tillers damaged by RWA was reduced by 21-28%, which determined a lower incidence of leaf diseases.

Beetles of the family Buprestidae from the salt deposits of the surf zone of Lake Eroyulanduz (Badkhyz Nature Reserve, Turkmenistan) were studied. More than 48% species of the regional fauna were revealed, two of which, Sphenoptera chalybaea and S. repetekensis, were recorded for Badkhyz for the first time. Several rare species were found, known previously from a few specimens only. The possible dates of adult flight can be inferred from records in the salt deposits.

Variation of the fore and hind wing lengths and the diameters of wing eyespots in two subspecies of Coenonympha hero (L.) from the central part of the species range was analyzed. Clinal variation was revealed, manifested in a gradual increase of the wing size and eyespot diameters from west to east in the Urals. Both in C. h. hero in the Urals and in C. h. perseis in Siberia, the northern peripheral populations had a specific wing pattern with eyespots smaller than in more southern parts of the corresponding ranges. In most cases, such climatic factors as the mean annual air temperature, precipitation, duration of the frost-free period, and humidity were shown to affect significantly the variation of morphological traits of C. hero. Chrono-geographical analysis of variation showed that in some cases the differences between the samples collected in the same locality in different years were comparable to or greater than geographic variation within the subspecies range. Thus, the population as a whole is influenced by climatic factors and weather conditions in a particular part of the range during a particular season; C. hero may therefore be a suitable object for monitoring the impact of environmental changes on insects.

New records of plant bug species are given for selected regions of European Russia based on the extensive collections of the Zoological Institute, Russian Academy of Sciences (St. Petersburg). The locality data and general distribution are given for all the 71 species included.

Philbyella aculeata sp. n. is described from Fujairah Emirate (UAE) in the northeastern Arabian Peninsula. This species differs from the other members of the genus Philbyella China in the presence of a pair of spiniform triangular processes on the posterior margin of the male pygofer and in the style with a massive capitulum without the neck.

Originally described as a monotypical genus with unclear taxonomic position from Sudan, Meroctenus Gemminger et Harold, 1868 is treated as a polytypical genus of the Selenophori genus group with two subgenera: Meroctenus s. str. and Xenodochus Andrewes, 1941, stat. n. (the latter was previously considered a distinct genus). Within Meroctenus, two species are recognized: M. (Meroctenus) crenulatus Chaudoir, 1843 (type species) and M. (M.) mediocris (Andrewes, 1936), comb, n., transferred to Meroctenus s. str. from Xenodochus. A new subspecies M. (M.) crenulatus orientalissubsp. n. is described from Pakistan. Diagnoses of the genus Meroctenus in new interpretation as well as of its two subgenera are discussed, and a taxonomic review of the subgenus Meroctenus s. str. with a key to the species and subspecies is provided. The following synonymy is proposed: Meroctenus Gemminger et Harold, 1868 = Paregaploa Müller, 1947, syn. n.; Meroctenus crenulatus (Chaudoir, 1843) = Egaploa (Paregaploa) conviva Müller, 1947, syn. n. Lectotypes are designated for Ctenomerus crenulatus Chaudoir, 1843 and Xenodus mediocris Andrewes, 1936.

The biological diversity of the ixodid tick fauna of the North Caucasus is analyzed. On the whole, 38 tick species are recorded in the fauna of the North Caucasus. Their distribution within the region, biotopic associations, and host-parasite relationships at different stages of development are considered.