Abstract. Biological activity and morphometric characteristics of entomopathogenic nematodes, Steinernema kraussei, isolated from the Świętokrzyski National Park were studied. The results have shown that S. kraussei has slower, but more efficient invasiveness than nematodes originated from the bio-pesticide. Morphometric comparative analysis did not show any significant differences between nematodes isolated from natural environment and those from control sample. It was also shown that the reproduction rate of isolates collected from the soil was 45% higher than the reproduction rate of nematodes originated from the commercial pesticide.

Insect trap studies were carried out to determine the presence of entomopathogenic nematodes (EPN) from the family Steinernematidae in the soils of Poland and to compare the biological activities of field nematode isolates with nematodes from commercial biopesticide. The fauna of these organisms in central Poland is poorly studied in both taxonomic and biological terms. Tilled soils representative of this region were sampled from cultivated fields. EPN were isolated from soil samples under laboratory conditions and identified using a key for species identification and molecular analysis. Basic morphometric parameters of infective juveniles and adult males of the first generation were determined. The research showed that males and infective juveniles Steinernema feltiae from Łoniów were the largest. The smallest infective juveniles were found in the isolate from Oblasy, and the smallest males in the isolate from Danków. In Poland, new field isolates showed close genetic similarity to other S. feltiae isolates. The research showed that the field isolates from Poland had greater infectivity and rate of reproduction compared with nematodes from the commercial biopesticide. The findings indicate the potential use of field S. feltiae isolates from Poland (iso1Lon, iso1Dan and iso1Obl) to develop new biopesticide products.

One of the pests of white chestnut (Aesculus hippocastanum L.) is a horse-chestnut leaf miner (Cameraria ohridella). Effective methods of reducing the population of this butterfly are still under investigation. One of them is the use of insecticidal nematodes that occur naturally in the environment. This paper presents the results of the susceptibility of horse-chestnut leaf miner larvae on entomopathogenic nematodes of the genus Steinernema. The experiment was conducted at a temperature of 20ºC and a dose initialized to 100 nematodes/insect. Applied nematodes were harvested from the greenery of Swietokrzyskie Province. The results of the analysis showed that the larvae Cameraria ohridella are susceptible to insecticide nematode invasion isolated from different sources. It was also shown that the efficiency of killing an insect by nematodes (extensiveness of invasion) is not correlated with the ability to reproduce or the viability of successive generations of insecticidal nematodes.

Abstract. Pest control in urban green areas is particularly difficult due to the limitation of pesticide use. Using efficient methods for biological control of herbivores there may be a good solution. Planting plants growing in the forest container breeding have a better growth and better root system comparing to the seedlings produced in traditional forest nurseries. Such plants are not subject to significant shock when replanted, however, they are still exposed to pests living near plantings. Our research assessed using entomopathogenic nematodes to be introduced into the soil used for plantings in order early protect seedlings against their pests. Nematodes isolated from the natural environment as well as, for control samples, from biopreparations were used in the study. The research was conducted on the soil substrate in containers with seedlings. During the experiment were taken the following parameters: insect mortality, nematode invasion extensity, migration time of invasive larvae, number of migrating larvae, and their survival.The results showed that entomopathogenic nematodes isolated from various provinces in Poland were effective, but characterized by a diverse insecticidal activity in a peat substrate.

The pathogenicity of entomopathogenic nematodes (EPNs) depends directly on the presence of bacteria in the nematode digestive tracts. Based on 16S rRNA and MALDI-TOF analyses 20 isolated bacteria were assigned to 10 species with 10 isolates classified as Pseudomonas ssp. Six strains (30%) show ureolytic activity on Christensen medium. Spectroscopic analysis of the strains showed that the ureolytic activity is strongly correlated with the following wavenumbers: 935 cm(-1) in window W4, which carries information about the bacterial cell wall construction and 1158 cm(-1) in window W3 which corresponds to proteins in bacterial cell. A logistic regression model designed on the basis of the selected wavenumbers differentiates ureolytic from non-ureolytic bacterial strains with an accuracy of 100%. Spectroscopic studies and mathematical analyses made it possible to differentiate EPN-associated Pseudomonas sp. strains from clinical Pseudomonas aeruginosa PAO1. These results suggest, that infrared spectra of EPN-associated Pseudomonas sp. strains may reflect its adaptation to the host.