Occurrence of Entomopathogenic Nematodes (Rhabditida: Steienernematidae, Heterorhabditidae) from Agricultural Ecosystems in Forest (Polissya) and Forest-Steppe Natural Zones of Ukraine

Abstract

A survey for entomopathogenic nematodes (EPNs) of the Steienernematidae and Heterorhabditidae in soils of different crop types of agricultural lands (household plots, commercial fields) in the forest (Polissya) and forest-steppe (Lisostep) zones of Ukraine was carried out in spring, summer and autumn months from 2016 to 2018. In total, 205 soil samples and 92 live-traps were processed. In addition, 98 samples of soil-living larvae and adults of insect crop pests, including cockchafer beetles, click beetle larvae, darkling beetle larvae, caterpillars of the scoops were collected. It is shown that the EPNs distribution and frequency of occurrence depends on the natural geographical features (regional characteristics) and habitat types. EPNs were found in 46 (15.4 %) out 297 samples. The incidence (% of samples) of the entomopathogenic nematodes, and their diversity varied depending on the location-based sampling, the type of agrocenosis, and the predominant agricultural plant species or typical species-edificators. The proportion of entomopathogenic nematodes (Steinernema spp., Heterorhabditis spp.) recovery from regions of Lisostep zone was 16.9 %, and 13.6 % from regions of Polissya zone. The highest number among all positive samples was recorded from the apple trees, Malus domestica Borkh., 1803 (10 samples). The least number of positive samples (one sample) was obtained from sweet cherry trees, Prúnus cérasus L., 1753, junipers, Juniperus communis L., 1753, alfalfa, Medicago sativa L., 1753, common beans, Phaseolus vulgaris L., 1753, and common pumpkin, Cucurbita pepo L., 1753. The steinernematid nematodes were noticeably dominant over heterorhabditid nematodes: 60.8 % vs 39.2 % respectively. Steinernema spp. is widespread in different regions and plots, whereas Heterorhabditis spp. are common in fruit orchards and coniferous decorative perennial plantings.

Plant protection consequences in Hungary of the withdrawal of systemic active substances from sugar beet seed treatment

“…Scarabaeidae larvae, cause damage by chewing roots, destroying the root surface, manifesting in early wilting symptoms (Lange, 1987). Tenebrionidaesuch as Opatrum sabulosum L. and Omophlus proteus Kirschlarvae, cause damage by chewing the underground organs, may result in wilting and subsequent death especially in drought (Sigareva et al, 2019). Elateridae larvae cause the death of young plants by masticating their immediate underground parts, such as Agriotes sputator L., Agriotes lineatus L., Agriotes obscurus L. and Agriotes ustulatus Schaller (Furlan et al, 2021).…”

Frequency of occurrence and identification of nematodes among entomopathogenic organisms in agrocoenoses of Ukraine

“…So far, four species of entomopathogenic nematodes (Steienernematidae and Heterorhabditidae) have been recorded in Ukraine: Steinernema carpocapsae (Weiser, 1955) Wouts et al 1982, Steinernema feltiae (Filipjev, 1934) Wouts et al 1982, Steinernema arenarium (Artyukhovsky, 1967) Wouts et al 1982, and Heterorhabditis bacteriophora Poinar, 1976[Stefanovska 2007Anonymous 2012;Yakovlev et al 2014;Sigareva et al 2019]. All findings of entomopathogenic nematodes were associated with the analysis of soil samples collected in different biocoenoses in Ukraine.…”