Vol 96, No 3 (2016)

Four-year monitoring of phenology of the blowfly Caliphora vicina under quasi-natural conditions in the environs of St. Petersburg demonstrated development of two complete generations and overwintering of the third generation. The duration of preimaginal development (from egg laying to adult emergence) of the 1st and 2nd generations varied from 19 to 32 days; the required sum of effective temperatures (SET) was 326 ± 31 degree-days with a threshold of 5°С. Reproductive maturation of females (the period of time from adult emergence to laying of the first eggs) lasted from 15 to 31 days (SET was 262 ± 39 degree-days with a threshold of 5°С). The duration of development of one complete generation (from egg stage to the beginning of oviposition) during the period of observation varied from 34 to 57 days (SET was about 600 degree-days with a threshold of 5°С). The first diapausing larvae hatched from the eggs laid in the middle of August. In September, at shorter day lengths and at a temperature of 10–11°С, 80–100% of the larvae entered diapause. A small fraction of the larvae of the 1st and 2nd generation and most of the larvae of the 3rd generation overwintered. Successful overwintering of adults in the environs of St. Petersburg is hardly possible.

The effects of day length on development and reproductive maturation of zoophytophagous bug Macrolophus pygmaeus (= M. nubilis) were investigated under laboratory conditions using two strains originated from the environs of Rome, Italy (41.75°N, 12.30°E and 41.95°N., 12.80°E) and Sochi, Krasnodar Territory, Russia (43.9°N, 39.3°E). The insects were kept under day length of either 10 or 16 h at a constant temperature of 20°C. Nymphs and adults were fed on the grain moth eggs. Embryonic development lasted 18–20 days, nymphal development, 25–30 days, and reproductive maturation of females, 4–6 days. The short day length (10 h) resulted in 1–2-day prolongation of nymphal development and a longer maturation time in individuals from both strains, whereas the duration of embryo development was independent of photoperiod. Under both photoperiods, males developed faster than females. Under the short day length, females of the Rome strain matured markedly faster than those of the Sochi strain. Faster development under low temperature and stronger tendency to delay the reproductive maturation observed in the Sochi strain could be explained by a relatively fast (when compared with Rome) autumnal decrease in temperature. The mechanism and adaptive value of the long-day acceleration of development are not yet clear.

Attractiveness of methyl salicylate to arthropods in natural populations was studied in a park reserve. During the observation period, representatives of several families of Diptera (the leaf-mining Agromyzidae, the predatory Hybotidae, Dolichopodidae and Empididae), parasitic micro-Hymenoptera (Mymaridae, Pteromalidae, Eulophidae, and Aphelinidae), and phytophagous bugs (Heteroptera) were recorded. Significant attractiveness of methyl salicylate to parasitic micro-Hymenoptera and dance flies (Empididae) was demonstrated. Our data confirm the possibility of attracting beneficial arthropods with methyl salicylate.

Data on the trophic associations of beetles with plants in the east of the Russian Plain are summarized and comparative analysis of host specialization of different groups of phytophagous beetles is performed. In terms of the width of the regional trophic spectrum, monophages and narrow oligophages prevail among the Curculionoidea as a whole and in the families Curculionidae and Apionidae in particular, while moderate and broad oligophages prevail in the Chrysomeloidea and in the family Chrysomelidae. Two-thirds of the regional fauna (66%) of Curculionoidea are closely associated with plants of one genus; by contrast, in Chrysomeloidea almost 40% of the species can develop on plants from different genera of one family, the fraction of the narrowly specialized forms comprising only 43%. The higher level of trophic specialization of weevils (Curculionidae, Apionidae) and seed beetles (Bruchidae), as compared to leaf beetles (Chrysomelidae), is probably due to the larval endophagy of most species of these families. Analysis of the distribution of beetles over host plants has shown that the specialized forms are associated with plants of 65 families (about 60% of the regional flora in the east of the Russian Plain). Distribution of beetles over plant families is very non-uniform. Most of the specialized forms (78%) are associated with plants of 15 families, three of which (Asteraceae, Fabaceae, and Brassicaceae) include hosts of more than onethird of the beetle species (37%). Monophages and narrow oligophages are recorded on 201 genera of plants from 59 families. Polyphagous species are recorded on plants of 58 families. The specific features of the distribution of phytophagous beetles over host plants (as compared to other insects) is a high fraction of species developing on coenophobes (particularly those of the family Brassicaceae) typical of the pioneer stages of successions with sparse herbaceous cover, and a small number of species associated with grasses and sedges. These features are most conspicuous in the fauna of Curculionidae.

Species established outside their native ranges are termed alien. Biological invasions of beetles are poorly studied. Distinguishing between alien and native species is necessary for conservation as well as for taxonomic, zoogeographic, and evolutionary studies. It constitutes a difficult problem, but the experience of botany and some branches of zoology gives reasons to believe that it is not unsolvable. The following criteria for distinguishing alien beetle species from native ones are proposed based on the criteria developed for plants, algae, mammals, and marine invertebrates: (1) detection of an established population of the species which has not been recorded earlier in the region; (2) disjunction of the range which cannot be explained by disjunction of suitable landscapes or host plant ranges; (3) expansion of a part of the range isolated from its main part; (4) highly localized distribution in an area adjacent to a known invasion pathway; (5) establishment in other regions; (6) dependency on another non-native species (feeding on an alien host plant or animal); (7) absence of specific parasites in the given region and their presence in some other region; (8) association with anthropogenic biotopes; (9) sharp fluctuations of abundance; (10) lack of taxonomically close species in the given region and their presence in other regions; (11) detection in the region of two or more taxonomically and/or ecologically close species typical of another region; (12) presence of known vectors of invasion; (13) low genetic diversity; (14) reproduction by parthenogenesis or inbreeding. These criteria are mere indirect evidences of the alien status of a species in the given territory, because numerous exceptions exist. Usually it is impossible to recognize an alien species by a single criterion, but matching several criteria characterizes the species as an alien one with high probability.

Analysis of species of Dromanthomorphus Pic from South-East Asia has shown that the genus is distinguished by the following special male characters: flabellate, serrate, or filiform antennae; one-colored white pubescence of the surface; a swollen metathorax with a gladiate appendage; stout and excavate fore and middle tibiae; elongate and modified fore and middle coxae; apical tergites with a specific slanting and tile-like sculpture at the apex; apical abdominal sternites bilaciniate, with specifically sculptured apices. These characters are completely lacking in the Palaearctic species attributed to Dromanthomorphus, which are characterized by flabellate or serrate antennae, by a simple, not swollen metathorax lacking appendages, double white and black pubescence of the surface, simple, evenly rounded apical abdominal tergites, and evenly narrowed apical abdominal sternites emarginate in the middle and having simple, not sculptured apices. Based on these differences, a new genus, Pectapalochrus gen. n., is described for the Palaearctic species. Keys to Pectapalochrus species and to genera of Apalochrini of Eurasia and also illustrations of the habitus and male structures of the new genus are given.

An illustrated description of a new species, Crobilocerus richterae sp. n., is given. The new species differs from its congeners in coloration and in details of the structure of the male genitalia.