Entomopathogenic nematodes in agricultural areas in Brazil

Abstract

Entomopathogenic nematodes (EPNs) (Steinernematidae and Heterorhabditidae) can control pests due to the mutualistic association with bacteria that kill the host by septicemia and make the environment favorable for EPNs development and reproduction. The diversity of EPNs in Brazilian soils requires further study. The identification of EPNs, adapted to environmental and climatic conditions of cultivated areas is important for sustainable pest suppression in integrated management programs in agricultural areas of Brazil. The objective was to identify EPNs isolated from agricultural soils with annual, fruit and forest crops in Brazil. Soil samples were collected and stored in 250 ml glass vials. The nematodes were isolated from these samples with live bait traps ([Galleria mellonella L. (Lepidoptera: Pyralidae) larvae]. Infective juveniles were collected with White traps and identified by DNA barcoding procedures by sequencing the D2/D3 expansion of the 28S rDNA region by PCR. EPNs identified in agricultural areas in Brazil were Heterorhabditis amazonensis, Metarhabditis rainai, Oscheios tipulae and Steinernema rarum. These species should be considered pest biocontrol agents in Brazilian agricultural areas.

Characterization of the phenotypic and genotypic tolerance to abiotic stresses of natural populations of Heterorhabditis bacteriophora

“…Campos-Herrera et al (2019) recently published a first report of H. indica in a Mediterranean region, in a survey conducted in Portugal. Species variety in the present study was low compared to previous studies of natural populations worldwide 32,34,37,38,43 . This might be due to aggregated spatial distributions of the species, which is a well-known distribution pattern for EPNs 18,33,35 .…”

“…To enrich the genetic pool, natural EPN populations were collected from different habitats across Israel. Abiotic factors are known to have strong effects on EPN occurrence, persistence and species variation [32][33][34] . However, previous studies conducted worldwide have shown varied correlations between effects of habitat parameters and EPN occurrence [35][36][37] .…”

A survey of entomopathogenic nematodes and their symbiotic bacteria in agricultural areas of northern Thailand

“…Also noted in Italy were S. feltiae and H. bacteriophora , which were found to be related with vegetation habitat (Tarasco et al ., 2015). In Brazil, Heterorhabditis amazonensis , Metarhabditis rainai , Oscheius tipulae and Steinernema rarum were isolated from soil in agricultural areas (de Brida et al ., 2017). Oscheius onirici was also isolated from a wild cranberry marsh in Jackson County, Wisconsin, USA (Ye et al ., 2018).…”

Characterization of a new isolate of entomopathogenic nematode, Steinernema sangi (Rhabditida, Steinernematidae), and its symbiotic bacteria Xenorhabdus vietnamensis (γ-Proteobacteria) from Mizoram, northeastern India

“…The relationship between habitat and abundance of entomopathogenic nematodes had been reported by a number of workers. The high rate of occurrence is reported in disturbed habitat with high human impacts like agricultural fields (Campos-Herrera et al 2007;de Brida et al 2017), whereas, it is higher in natural habitats (Stock et al 2008;Valadas et al 2014). It is thus obvious that the occurrence of EPNs relative to the habitat type varied among the species, and also depending on the geographical areas.…”