First results concerning the efficacy of entomopathogenic nematodes against Hercinothrips femoralis (Reuter)

Abstract

The efficacy of the entomopathogenic nematodes Steinernema feltiae and Heterorhabditis bacteriophora against larvae and adults of banded greenhouse thrips, Hercinothrips femoralis, was studied under laboratory conditions. The activity of the biological agents under study was determined at three different temperatures (15, 20, and 25°C), with concentration of 200 infective juveniles per individual (larva or adult), a day:night ratio of 4:20 and relative humidity of 95 %. The experiment was conducted in plastic rearing vessels on French bean leaves with a slightly modified version of a method used for studying the bionomics of thrips. The mortality rate of the thrips was determined four days after the application of the nematode suspension. Temperature had significant influence on adult pest mortality, but no significant effects were found with nematode species. Neither temperature nor nematode species had significant effect on larval mortality, which ranged from 23 % (S. feltiae at 25°C) to approximately 50 % (H. bacteriophora at 15 and 25°C). Mortality of adults was significantly influenced only by temperature, with the nematodes being most efficient at 25°C (approximately 30 % mortality by H. bateriophora). The results of our research showed that foliar application of entomopathogenic nematodes might be a relatively efficient way for controlling H. femoralis, but the optimization of environmental factors would likely improve their efficacy further.

Entomopathogenic Nematodes (Nematoda: Rhabditida) in Slovenia: From Tabula Rasa to Implementation into Crop Production Systems

“…At foliar application of the suspension with the concentration 200 IJ/specimen both species were relatively efficient at suppressing larvae and adult specimens of banded greenhouse thrips, though they were markedly more successful in suppressing larvae. Both species of nematodes reached the highest efficiency at 25°C, while independently of temperature and nematodes species the average corrected mortality rates in larvae was 37.7%, in adult specimens only 15.4% (Trdan et al, 2007b). In view of the previous research results (Chyzik et al, 1996;Premachandra et al, 2003) we expected different efficiency of both biological agents in suppression of banded greenhouse thrips.…”

“…The mean number of fruits per plant did not differ significantly between different types of pest suppression. Nine times spraying with nematodes and three times spraying with abamectin showed about the same efficacy against western flower thrips on greenhouse-grown slicer cucumbers (Trdan et al, 2007b).…”

“…In the laboratory experiment we studied the efficiency of Steinernema feltiae and Heterorhabditis bacteriophora for suppressing banded greenhouse thrips -Hercinothrips femoralis (Trdan et al, 2007b). At foliar application of the suspension with the concentration 200 IJ/specimen both species were relatively efficient at suppressing larvae and adult specimens of banded greenhouse thrips, though they were markedly more successful in suppressing larvae.…”

Hercinothrips femoralis (Reuter, 1891) - a new pest thrips (Thysanoptera: Panchaetothripinae) in Slovakia

“…This species is often called a sugarbeet or banded greenhouse thrips. Foliicolous and polyphagous species feed on a variety of ornamental plants with more than 50 host species known to date (Trdan et al 2007). The developmental cycle, from oviposition to adult, takes 19 days under experimental conditions of 27°C (Laughlin 1971).…”

“…Insecticide resistance of this species is relatively low (Scarpelli & Bosio 1999) and chemical control should be efficient, although environmentally acceptable methods of pest control using natural enemies are promising (Trdan et al 2007). In the Czech Republic, this species is listed in the Catalogue of Alien Animal Species (Šefrová & Laštůvka 2005).…”