Vol 99, No 4 (2019)

Long-term observations have revealed the factors responsible for periodic rises in abundance of the European corn borer Ostrinia nubilalis Hb. in the Central Chernozem Region of Russia. These factors are sufficient precipitation during several consecutive years and the current decline in agrotechnical soil treatment. The host specialization, biology, and phenology of the corn borer in the region have been clarified. Corn is damaged most intensely among the cultivated plants, and the yellow foxtail Setaria glauca, among the weeds. The effects of precipitation on seasonal development and harmfulness of the corn borer have been demonstrated. Low precipitation during the pest pupation period leads to mass pupal mortality, a shift of the seasonal development onto later dates, and a lower proportion of damaged stems in the crops. Insufficient precipitation during the larval feeding period enhances the effect of pest damage on the plant productivity and results in heavier yield loss. During the corn borer outbreaks the yield loss reached 15% in corn and 11.4% in millet. Depending on the weather conditions, the loss of millet yield due to this pest may be as great as 39% or as low as 3%.

Many Bruchidae species are quarantine pests and are widely used as model species. However, as far as we know, acoustic communication has never been studied in detail in this group. Below we present the first data on the repertoire and emission mechanisms of acoustic communication in the bean weevil Acanthoscelides obtectus. Three types of signal emission were recorded in A. obtectus: striking the head and abdomen against the substrate, abdominal tremulations, and wing vibrations. Two types of signals were recorded in males, and one type, in females. All the acoustic signals recorded in A. obtectus contained both stable (pulse duration, pulse period: CV = 5–12%) and variable (duration of the pulse series: CV = 50%) signal elements. The frequency parameters showed low variation in all the signals (CV = 5–11%). Moreover, the dominant frequencies were similar in all the signal types (889–1158 Hz).

An insect complex decomposing large animal carcasses was studied in two habitat types in northern European Russia (the Republic of Karelia), with the domestic pig Sus scrofa domesticus L. used as a model. Altogether, 100 species of insects belonging to 25 families and 6 orders were revealed on or in the carcasses. The two biotopes differed in the species composition and relative abundance of necrobionts. The structure and succession of the insect complex in the process of carcass decomposition are analyzed.

The assemblage of hymenopteran parasitoids associated with the leafminer Phyllonorycter apparella (Lepidoptera: Gracillariidae) developing on the aspen Populus tremula L. was studied near Izhevsk in Udmurtia in 2014–2016. Eighteen species (Hymenoptera: Eulophidae and Braconidae) were reared from Ph. apparella, four of them (Pnigalio mediterraneus, Sympiesis dolichogaster, Chrysocharis phryne, and Neochrysocharis formosus) representing the first records as parasitoids of this pest. Monitoring a steady outbreak site of Ph. apparella revealed an annual increase in the number of species in the parasitoid complex: 6 species in 2014, 9 in 2015, and 16 in 2016. Accordingly, the rate of infestation of the leafminer larvae and pupae increased from 7.4 ± 1.4% in 2014 to 19.6 ± 1.6% in 2016. The dominant parasitoid species changed annually. In 2014 there was only one dominant species, P. circumscriptus (92.4%); in 2015, two dominants: M. frontalis + C. trifasciatus (65.6%); in 2016, three species: C. trifasciatus + C. pictus + M. frontalis (59.5%). The percentage of each species declined in subsequent years. The ratio of ecto- to endoparasitoid species was similar in the three years of research: 1: 1 in 2014, 1: 1.25 in 2015, and 1.29: 1 in 2016. The shares of endoparasitoids in 2014, 2015, and 2016 were 95.1, 50.3, and 56.9%, respectively. The role of endoparasitoids in controlling the leafminer was slightly greater than that of ectoparasitoids.

Sticky traps and an aspirator were used to assess the species composition and abundance of sand flies (Phlebotominae) in 14 coastal localities and their environs on the Crimean Peninsula. Sand flies were found only in four localities: Parkovoe, Gurzuf, Sudak, and Kurortnoe. Altogether, 942 specimens of 5 species were collected: Phlebotomus papatasi (0.7%), P. similis (0.1%), P. neglectus (64.7%), P. perfiliewi (33.1%), and P. longiductus (1.4%). The highest species diversity of sand flies was observed in Kurortnoe locality where 4 species were trapped (P. similis, P. neglectus, P. perfiliewi, and P. longiductus) and also in Parkovoe locality where 3 species were trapped (P. neglectus, P. perfiliewi, and P. longiductus). Phlebotomus perfiliewi and P. neglectus were the prevalent species on the southeast and south coasts of the peninsula (94.7 and 95.8%, respectively). PCR methods are recommended for more accurate identification of sand flies from the subgenera Larroussius and Adlerius, since they are rather similar in morphological characters.

An exceptionally large-scale attack of mosquitoes (Diptera, Culicidae) on people and domestic animals was observed in May 2018 in the southern areas of Voronezh Province (Russia). Aedes sticticus (Meigen, 1838) was the absolute dominant in the collections although it had been previously considered a rare mosquito species in the region. Abiotic factors, the frequency of mass attacks of bloodsucking dipterans under the regional conditions, and the possibility of their prediction are discussed.

The formation of Hypothenemus eruditus foci is described on a tree of Buxus sempervirens ssp. colchica which died as the result of damage caused by larvae of Neoglyphodes perspectalis. This is the first record of H. eruditus on boxwood and the first discovery of its foci in Russia.

A new subspecies, Melitaea tangigharuensis nambi ssp. n., is described from eastern Iran. The external features and the male and female genital morphology of the new subspecies are compared to those of the nominate one. A description of the female of the latter subspecies is given for the first time. The taxonomic position of the species in question within the genus Melitaea is discussed.

Two new oribatid mite species collected in the park zone of Yuzhno-Sakhalinsk (Sakhalin Island, Russia) are described. Xenillus similis sp. n. is a large pale brown mite with lamellae covering the major part of the proterosoma. Its cusps are separate, large, and blade-shaped with sharpened diverging medial teeth. The translamella is narrow with a tiny tooth between the cusps. Sensilli are fusiform. The new species differs from the closely related X. sculptrus Kulijev, 1963 in the finer rostral and lamellar setae, long interlamellar setae, and different shape of sensilli (fusiform vs. clavate), lamellae (in X. sculptrus they are broadened towards the anterior end), and cusps. The new species differs from X. tegeocranus (Hermann, 1904) in the presence of fine and poorly pubescent dorsal and ventral setae, shorter lamellar setae, longer and sparsely pubescent interlamellar setae, the fusiform sensilli (vs. clavate), and the shape of cusps with more elongated internal teeth. Lasiobelba (Lasiobelba) sakhalinensis sp. n. is a middle-sized mite with slightly projecting and rounded rostrum. Costulae are absent, prodorsal setae are smooth. Sensilli are fusiform without apical spine. Ten pairs of notogastral setae are long and smooth (except for setae c which are represented by alveoli); p₁–p₃ are shorter than other setae. The anogenital setae are fine and smooth. The discidium is pointed. Leg claws are fine. The new species differs from morphologically similar L. (L.) remota Aoki, 1959 and L. (L.) insulata Ohkubo, 2001 in the smaller size, fusiform sensilli without apical spine (both L. (L.) remota and L. (L.) insulata possess long sensilli widened in the middle part and with the apical spine), shorter interlamellar setae (in compared species, they nearly reach bases of lamellar setae), and in the smooth prodorsal and notogastral setae.