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Updated: Jun 25, 2026
Soil Sampling and Isolation of Entomopathogenic Nematodes (Steinernematidae, Heterorhabditidae)
Published on: July 11, 2014
Target Host Finding by Steinernema feltiae and Heterorhabditis bacteriophora in the Presence of a Non-Target Insect
Abstract:
The ability of Steinernema feltiae or Heterorhabditis bacteriophora infective juveniles (IJ), when applied to the soil surface, to infect a Galleria mellonella larva at the base of a soil-filled cup (276 cm(3)) was evaluated in the presence and absence of 100 larvae of a non-target insect, the aphid midge Aphidoletes aphidimyza, near the soil surface. In all four trials with either S. feltiae or H. bacteriophora, A. aphidimyza presence did not affect the number of IJ finding and infecting a G. mellonella larva. Steinernema feltiae and H. bacteriophora IJ movement (as measured by the percentage of IJ aggregating on either side of an experimental arena) in the presence of one or many A. aphidimyza larvae was evaluated in agar- and soil-filled petri dishes, respectively. Infective juvenile movement in the presence of A. aphidimyza did not differ from random, indicating that IJ were not attracted to A. aphidimyza. It is suggested, therefore, that A. aphidimyza does not reduce IJ efficacy when these two forms of biological control agent are present together in a field situation even though it is known that A. aphidimyza is susceptible to IJ of these species.
Insights
Steinernema feltiae and Heterorhabditis bacteriophora infective juveniles (IJ) effectively infect target pests. The presence of non-target aphid midge larvae does not impact IJ efficacy or movement, ensuring successful biological control.
Area of Science:
- Agricultural Entomology
- Nematology
- Biological Control
Background:
- Steinernema feltiae and Heterorhabditis bacteriophora are entomopathogenic nematodes used for insect pest control.
- Aphidoletes aphidimyza is a non-target insect that may co-exist with entomopathogenic nematodes in field applications.
- Understanding potential interactions is crucial for optimizing biological control strategies.
Purpose of the Study:
- To evaluate the impact of the non-target aphid midge, Aphidoletes aphidimyza, on the efficacy of Steinernema feltiae and Heterorhabditis bacteriophora infective juveniles (IJ).
- To determine if the presence of A. aphidimyza affects the ability of IJ to locate and infect target prey.
- To assess the movement patterns of IJ in the presence of A. aphidimyza.
Main Methods:
- Infective juveniles (IJ) of S. feltiae or H. bacteriophora were applied to soil surfaces with Galleria mellonella larvae as prey.
- Experiments were conducted in the presence and absence of A. aphidimyza larvae near the soil surface.
- IJ movement was quantified in agar and soil arenas with and without A. aphidimyza.
Main Results:
- The presence of A. aphidimyza did not significantly affect the number of G. mellonella larvae infected by S. feltiae or H. bacteriophora IJ.
- IJ movement in the presence of A. aphidimyza was not significantly different from random movement.
- IJ were not attracted to A. aphidimyza larvae.
Conclusions:
- Aphidoletes aphidimyza does not reduce the efficacy of Steinernema feltiae or Heterorhabditis bacteriophora infective juveniles.
- Co-application of these biological control agents is likely compatible in field settings.
- This finding supports the integrated use of entomopathogenic nematodes and beneficial insects in pest management programs.
