We investigated the structure of the litter invertebrate community in 141 pine (Pinus sylvestris Linnaeus, 1753) forest sites with five variants of canopy density (30-44, 45-59, 60-74, 75-89 and 90-100%) in the steppe zone of Ukraine. The total number of litter macrofauna specimens collected at each site decreased from an average of 84/100 trap-days in the sparsest stands (30-40% density) to 4-39 specimens/100 trap-days in the forests with a denser canopy. The number of macrofauna species caught in the pitfall traps does not vary significantly with different degrees of canopy density. The Shannon-Weaver and Pielou diversity indexes show increases corresponding to increasing stages of canopy density. The average share of phytophages in the trophic structure of the litter macrofauna does not vary with canopy density. The relative number of saprophages decreases from 54% in the forests with the sparsest canopy to 11-13% in the forests with denser canopies. The relative number of saprophages in pine forests (22%) is lower than that in deciduous forests (40%). The share of zoophages in the trophic structure of the litter macrofauna increases significantly with the increase in the pine forest canopy density (from 21% in the sparsest plots to 59% in the densest). The relative number of polyphages is highest (47-65%) when the canopy density is 45-89%. At canopy densities below or above this range, the share of polyphages in the community decreases to 20 and 24%, respectively. Regardless of canopy density, Formicidae and Lycosidae invariably rank amongst the first three dominant families. Nine families of invertebrates dominate in the pine forest stands with the highest density (90-100%), and 5-7 families dominate in the stands with lower density. For the pine forest litter macrofauna, we have observed an extreme simplification of the community size structure compared with natural and planted deciduous forests of the steppe zone of Ukraine.
Addition of low concentrations of metal ions to the diet of saprophagous insects can impact on their metabolism over a short period of time, causing an increase or decrease in their body mass. This article presents a 14-day laboratory experiment evaluating the changes in the body mass of larval stage 3 of Tenebrio molitor (Linnaeus, 1758) induced by adding different inorganic substances (350 mg kg−1 of dry fodder) to the diet of the larvae. Following the addition of inorganic substances to the fodder, the most marked differences compared to the control were observed in the groups which consumed substrate with lead nitrate (the mass of the larvae increased on average by 102.6% compared to increase in mass in the control variant of the experiments), cobalt nitrate (by 96.9%), calcium chloride (by 89.1%) sodium triphosphate (by 86.0%), zinc chloride (by 83.5%). A nonsignificant effect (a tendency of increase in the body mass) on T. molitor larvae was caused by manganese sulfate (by 57.8%), aluminium nitrate (by 57.3%), iron oxide (by 51.5%), barium nitrate (by 47.9%), orthophosphoric acid (by 47.4%), manganese chloride (by 46.5%), calcium carbonate (by 27.7%), iron sulfate (by 24.2%) and ammonium heptamolybdate (by –7.5%). Therefore, 5 out of the 15 studied inorganic substances significantly stimulated the increase in the body weight of T. molitor larvae, and 7 manifested these capacities at the level of tendency (stimulated an increase in body weight averaging 43–58% over the 14-day experiment). The obtained data indicate a necessity for further study on the impact of inorganic pollutants on different stages of insects.
The laboratory experiment described in this article evaluated the death rate of larvae of Haemonchus contortus (Rudolphi, 1803) nematodes of the Strongylida order and Strongyloides papillosus (Wedl, 1856) of the Rhabditida order under the impact of different concentrations of 8 flavouring acids and source materials approved for use in and on foods and in medicine (formic, wine, benzoic, salicylic, stearic, kojic, aminoacetic, succinic acids). Minimum LD50 for third stage larvae of (L3) S. papillosus was observed with salicylic and wine acids, for L3H. contortus larvae – with formic acid. Minimum impact on all studied stages of development of nematodes was caused by stearic, kojic, aminoacetic and succinic acids: larvae did not die in the course of one day even at 1 % concentration of these substances. The best parameters of LD50 were observed for benzoic and formic acid. Further experiments on flavouring acids and source materials approved for use in and on foods and in medicines, and also their compounds, will contribute to developing preparations with a stronger impact on nematode larvae – parasites of the digestive tract of vertebrate animals and humans.
Modelling the influence of different concentrations of lead and cadmium ions upon a laboratory culture of insects has not been adequately studied. In our research, we assessed the influence of cadmium and lead nitrates at different concentrations (10-2-10-9 М) upon the development of larvae, pupae and imagines of Calliphora vicina Robineau-Desvoidy, 1830 (Diptera: Calliphoridae). We found an acceleration in the development of larvae and an increase in mass of puparia when lead ions were added to the food of the larvae, and decrease in the mass of puparia when cadmium ions were added. We registered nanism and malformation of the fly imagines in experiments with lead and cadmium in the food substrate. We observed that under the influence of the studied heavy metal ions there was a reduced motor activity of the fly larvae at all stages of development, a delay in formation of puparia and a delay in the emergence of imagines in comparison with the control group.
The objective of this study is to evaluate the viability of larval nematodes of ungulates under the infl uence of 14 fl avourings and source materials approved for use in and on foods. Minimum LD50 for L3Strongyloides papillosus (Wedl, 1856) were observed when using Cinnamaldehyde, α-Terpineol and Benzyl alcohol, for L1–2S. papillosus under the infl uence of Benzyl alcohol, Cinnamaldehyde, L-Linalool and Benzyl acetate, for L3Haemonchus contortus (Rudolphi, 1803) under the influence γ-Undecalactone and Cinnamaldehyde. Ethyl acetate, β-Ionone и D-Limonene had the lowest effect on all the studied stages of development of the nematodes: larvae did not die during 24 hours even at 1 % concentration of these substances. Further experiments with usage of mixtures of the substances studied in this article will contribute to the development of preparations with a stronger effect on larvae of nematode parasites of the digestive system of vertebrate animals.
Strongyloides papillosus Wedl, 1856 is one of the most widespread nematodes parasitic in domestic animals. This species has been recorded on almost all continents of the planet. It parasitizes the small intestine of rabbits, sheep and cattle. At laboratory conditions, this species can also infect guinea pigs. Morphological variability of S. papillosus in relation to host species has not yet been studied. Our research showed that L1 and L2 of S. papillosus reached their maximum size in all parameters in guinea pigs: for L1 — length and width of the body, length of esophagus and intestine; for L2 — width of body and length of intestine. L3 of S. papillosus had statistically reliable differences in almost all parameters (except the length of intestine) when parasitizing goats and rabbits. For L3 the width of the body and the length of the tail end, we determined differences between S. papillosus infecting rabbits and guinea pigs, and also goats and guinea pigs. Male S. papillosus were observed to have statistically reliable differences in all morphological parameters for goats and rabbits, and also for rabbits and guinea pigs. Practically all measurements (except the length of the tail) were larger for S. papillosus in guinea pigs and goats than those in rabbits. Free-living females statistically differed by larger size in goats and rabbits. The smallest dimensions were determined for all free-living stages of S. papillosus in goats (except males). The largest size in most cases was determined for larval stages of S. papillosus in guinea pigs.
We analysed the structure of the communities of the ground beetles of the tribe Carabini (Coleoptera, Carabidae) in urban environments on the examples of Kyiv, Kharkiv, Dnipro, Donetsk and Lviv. The ground beetles of this tribe in the five researched megapolises are represented by 24 species of the Calosoma and Carabus genera. The cities each have from 9 (Kharkiv, Donetsk) — 11 (Kyiv) to 14–15 (Dnipro, Lviv) registered species. Only three species (Carabus granulatus, C. cancellatus, C. convexus) turned out to be present in all the studied cities, where they were relatively abundant, and six (Calosoma auropunctatum, C. inquisitor, Carabus coriaceus, C. marginalis, С. nemoralis, C. scabriusculus) were recorded reasonably frequently in most of the cities. In the parks of Kyiv and Lviv (south forest zone), forest (Carabus coriaceus, C. convexus, C. nemoralis) and polytopic species (C. сancellatus) were dominant, while the inhabitants of open biotopes (С. granulatus, C. excellens, C. scabriusculus) were uncommon. In Kharkiv (forest-steppe zone), the common species were both polytopic (Сarabus granulatus, C. cancellatus) and forest (C. marginalis). In Donetsk and Dnipro (steppe zone), some steppe elements (Carabus estreicheri, C. perrini, C. sibiricus) occurred, but the dominant species were habitat generalist (С. granulatus) and certain forest species (C. convexus). At the same time, almost half the recorded species of the tribe were registered as rare or accidental elements in the cities studied, though typical for the natural biocenoses of the geographic region surrounding those cities. A short ecological characteristic of all species of tribe in urbocenoses is given.