Efficacy of commercial formulations of entomopathogenic nematodes against tropical sod webworm, Herpetogramma phaeopteralis (Lepidoptera: Crambidae)

Abstract

Large quantities of insecticides are used on warm season turfgrasses to combat pest infestations. To investigate the potential for microbial control, we screened commercially available entomopathogenic nematode products against Herpetogramma phaeopteralis Guen ee, an economically injurious pest in the south-eastern United States and Caribbean islands. All tested products, based on Steinernema carpocapsae, S. feltiae, Heterorhabditis bacteriophora, H. megidis and H. indica, were pathogenic to H. phaeopteralis larvae in the laboratory, but S. carpocapsae caused the highest mortality. Amongst nematode species, median lethal concentration (LC 50 ) was not different for three different larval sizes (based on 95% CL) with the exception of H. indica, which had higher LC 50 for small larvae. The number of infective juvenile stages (IJs) produced per White trap was significantly greater from larvae infected by H. bacteriophora and least for those infected by H. indica. A proprietary formulation of S. carpocapsae 'Millenium â ' was chosen for further greenhouse experiments. Overall, the neonicotinoid insecticide clothianidin provided the best control, but greenhouse experiments also revealed that the label rate of Millenium (10 6 IJ/l at 2500 l/ha) reduced webworm populations by 83-93% and was as effective as clothianidin against larger-size larvae. Our data suggest that commercial formulations of S. carpocapsae can be a good option for H. phaeopteralis biocontrol, but further field studies are warranted to confirm effectiveness under different environmental scenarios.

Encapsulamiento de nematodos entomopatógenos en materiales basados en biopolímeros y su efecto sobre Galleria mellonella

“…Por su parte, Tofangsazi et al (2014) reportan que la DL50 de Heterorhabditis indica, H. bacteriophora y H. megidis en suspensión para el control de larvas pequeñas de Herpetogramma phaeopteralis fue de 387, 270 y 554 (JI.ml -1 ) por larva. Mahmoud (2014) reportaron que la DL50 de H. bacteriophora sobre larvas de los olivos Palpita unionalis a 25°C fue de 38,2 (30,9-47,2) JI.larva -1 .…”

Variability in foraging behaviour, thermal requirement and virulence of entomopathogenic nematodes against sod webworm, Herpetogramma phaeopteralis Guene� (Lepidoptera: Crambidae)

“…These observations indicated two types of variability related to virulence of EPNs viz., variability among EPN species and variability due to insect host. Earlier Tofangsazi et al, (2014) studied the effect of commercial formulations of five EPN species against TSW and reported variability in virulence among five EPN species against TSW.…”

“…Previously, Tofangsazi et al, (2014) demonstrated that S. carpocapsae caused the highest mortality in comparison to S. feltiae, H. bacteriophora, H. megidis and H. indica against TSW, using their commercial formulations. Studies have also established the efficacy and applicability of EPNs against other insect pests of turfgrass.…”

“…Entomopathogenic nematodes are natural enemies of soil insect pests, and naturally harbor monoxenic bacterial symbionts. Together they cause insect mortality in 24 to 72h depending on inset host, foraging strategies, exposure time and IJs concentration, soil type, etc., Tofangsazi et al, (2014) demonstrated that TBW could be controlled by using EPN formulations, with variability in virulence among species of EPN.…”

Formulation of entomopathogenic nematodes for crop pest control - a review

“…Therefore, it is necessary to develop environmentally friendly alternatives to control soil pests, such as entomopathogenic nematodes (EPNs). The EPNs of the families Heterorhabditidae and Steinernematidae are obligate parasites of insects and have demonstrated to pose a high potential for the agricultural pest control (Ehlers 1996;Georgis et al 2006;Lacey & Shapiro-Ilan 2008;San-Blas 2013;Tofangsazi et al 2014;van Zyl & Malan 2014;Půža 2015). Also, they have been exempted from registration in the USA, are compatible with many chemical pesticides and amenable to genetic selection (Kaya & Gaugler 1993).…”