Vol 8, No 2 (2017)

The population density and distribution of copepod Pseudodiaptomus inopinus Burckhardt, 1913 were studied in Peter the Great Bay (the mouth of the Razdolnaya River of Amur Bay and Posyet Bay). This species is new in the fauna of this part of the Sea of Japan. The first record of the species with density of 225 ind./m³ was reported in the mouth of the Razdolnaya River in August 2005. The highest density of this species (up to 354 ind./m³) was reported in the mouth of the Razdolnaya River in August 2015. This species was likely brought with the ballast water of commercial vessels. The increase in the share of P. inopinus in the total zooplankton abundance from 3 to 7% in the period of 2005–2015 indicated its gradual naturalization in the ecosystem.

The analysis of my own and published data has made it possible to reveal the main trends of invasions in coleopterans of European Russia. On the whole, 168 alien species of beetles from 30 families have been recorded in the region; 102 of them are pests. The following biotopes are typical for alien beetles of European Russia: houses, agrocenoses, biocenoses of human settlements, and ruderal biotopes. However, more than 50% of species occur in their native biotopes: forests, animal shelters, etc. No species has drastically changed native communities, but species of tree pests, which penetrated recently from East Asia, can potentially inflict serious damage to the forests of European Russia: Agrilus planipennis (Buprestidae), Trichoferus campestris (Cerambycidae), Anisandrus maiche (Curculionidae, Scolytinae), Xyleborinus attenuatus (Curculionidae, Scolytinae), and Xylosandrus germanus (Curculionidae, Scolytinae). About half of these species were accidentally introduced with products of either animal or plant origin, about 25% of them were transported with plant substrates (straw, compost), about 10% came with wood, about came 14% with living plants, and less than 5% of species were introduced intentionally. The native ranges of alien beetles of European Russia are situated in the Mediterranean region, East and Southeast Asia, Central Asia, Africa, South and North America, Western Europe, and Australia. The highest number of species (about 20%) originate from East Asia. Most alien beetles were introduced to European Russia not directly, but rather from Western Europe (invasion in stages). In the last 20 years, the number of new alien species originating from East Asia has increased. The regions in which the majority of new beetle species alien to European Russia have been found over the last 20 years are Krasnodar krai and Adygea (14 species) and Moscow oblast (8 species). The process of invasion of beetles into European Russia is accelerating. More alien beetles have penetrated into European Russia during the last 20 years than in the same periods in the past: 42 new alien species, including 23 pest species. The percentage of new alien species associated with living plants has been constantly increasing since the middle of the 20th century and has reached more than 50% in the last 20 years. Alien beetles typically have wide ranges. About 80% of alien beetle species of European Russia have adapted not only in Europe but also in other parts of the world; more than 50% of them have become cosmopolitan. The distribution of an alien species is usually fast: such a species spreads thousands of kilometers in several decades.

The structure of a fragment (523 nucleotide pairs) of the 1st subunit of mitochondrial cytochrome oxidase (COI) gene has been studied in the populations of alien crab Rhithropanopeus harrisii (family Panopeidae) that established in the basins of the Azov-Black and Caspian Seas in 1930–1950s. In the samples of 6 populations from this region, 4 haplotypes (A, B, T, Lerm1) have been found. One of them has been unique (Lerm1) to the northern part of the Black Sea. Haplotype T has only been found in the Black and Caspian seas region, while haplotype A is common in almost all European populations. Only 4 substitutions have been observed in the sampled sequence, one of which is non-synonymous and there have been 3 polymorphic sites. The diversity of haplotypes (h) of the Black Sea–Caspian region populations (from 0.181 ± 0.143 to 0.475 ± 0.098) is significantly lower than this in the other European populations, where the value of h ranged from 0.563 ± 0.063 to 0.795 ± 0.065, and in North American populations (from 0.725 ± 0.083 to 1 ± 0). Harris crab populations of the Black Sea–Caspian region have a common origin, and differ in their genetic structure from populations of the rest of introduction area in Europe. The population of the Caspian Sea originates directly from the Sea of Azov populations and, possibly, there have been numerously repeated exchange events due to shipping vector. The populations in the estuaries of rivers Shapsuho and Vulan in the northeastern Black Sea might be partly isolated since their haplotype composition is slightly different from other populations in the region.

Two species of dodder are widespread in the Russian Far East—alien species Cuscuta campestris Yunck and native C. japonica Choisy (Cuscutaceae Dum.). For the first time we have identified individual species of Smicronyx genus in relation to specific dodder species as there was no such a research done in the Far East before. Smicronyx rubricatus Kono, 1930 was found on Cuscuta japonica Choisy, but plant galls were not detected. The insects fed on dodder sap and mate during the flower bud formation and flowering stages. Smicronyx madaranus Kono, 1930 was found to affect Cuscuta campestris Yunck.; its larvae form stem galls.

The history, rates, and factors of the invasion of lime leafminer Phyllonorycter issikii Kumata, 1963 (Lepidoptera, Gracillariidae) in Eurasia are studied. In 27 years (from 1985 to 2011), the leafminer range in Europe and Western Siberia reached 4086000 km² or 60.4% of the total range of the indigenous species of the Tilia genus. It is reported that the leafminer undergoes three stages of invasion (arrival, establishment, and spread) over a period three years. The maximum invasion rates (from 80 to 85 km per year) of westward and eastward spread from the recipient range were measured. It is shown that the rate of invasion slows down on the boundary of a host-plant range. The high rate of invasion of the lime leafminer Ph. issikii is associated with the conditions as follows: a wide range of host trees, a lack of any regulation effects of the third trophic level representatives, and no direct rival of the leafminer. In addition, the high reproductive potential of the species, the pattern of its dispersal (anemochory), and the possibility to transform the ratio between the intrapopulation forms under the impact of population density can contribute to this process.