- MeSH
- Neoplasms, Experimental MeSH
- Immunization MeSH
- Rats MeSH
- Radiation Effects MeSH
- Check Tag
- Rats MeSH
In addition to their active ingredients, pesticides contain also additives - surfactants. Use of surfactants has been increasing over the past decade, but their effects on non-target organisms, especially natural enemies of pests, have been studied only very rarely. The effect of three common agrochemical surfactants on the foraging behavior of the wolf spider Pardosa agrestis was studied in the laboratory. Differences in short-term, long-term, and overall cumulative predatory activities were investigated. We found that surfactant treatment significantly affected short-term predatory activity but had no effect on long-term predatory activity. The surfactants also significantly influenced the cumulative number of killed prey. We also found the sex-specific increase in cumulative kills after surfactants treatment. This is the first study showing that pesticide additives have a sublethal effect that can weaken the predatory activity of a potential biological control agent. More studies on the effects of surfactants are needed to understand how they affect beneficial organisms in agroecosystems.
- MeSH
- Agrochemicals chemistry toxicity MeSH
- Spiders drug effects MeSH
- Pesticides chemistry MeSH
- Surface-Active Agents toxicity MeSH
- Predatory Behavior drug effects MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Parasitoids acting as biocontrol agents provide farmers with valuable ecosystem services, but are sensitive to insecticides applied against pests. Besides lethal effects of insecticides, sublethal effects observed among survivors may further influence parasitoids' performance. However, information on sublethal effects is scattered across case studies, without a quantitative synthesis and evaluation of generality of respective data. We conducted an analysis of 85 primary empirical datasets to quantify sublethal effects of insecticide application on two key parameters of parasitoid fitness, offspring production and proportion of females among offspring (i.e. sex ratio). To create a direct link to existing agricultural practices, we primarily focused on studies in which parasitoids were exposed to field-recommended concentrations of insecticides. Insecticide-exposed females produced substantially fewer and more male-biased offspring, accounting for an average of about 28% cumulative loss in parasitoid reproductive capacity per generation. The magnitude of sublethal effects was significantly affected by insecticide mode of action, with broad-spectrum insecticides being particularly harmful to parasitoid reproductive performance. Transgenic crops and toxins derived from such plants were generally associated with weaker sublethal effects than majority of synthetic insecticides. Nevertheless, species responses, even to the same insecticides and transgenic crops, showed high variability, cautioning against extrapolating results from individual studies to a wider range of species. Overall, our results indicate that sublethal side-effects on parasitoid reproductive performance represent a significant and widespread cost of insecticides that should explicitly be taken into account when evaluating their harmfulness. Linking laboratory results to field situations remains a key challenge for future research.
- MeSH
- Plants, Genetically Modified drug effects growth & development parasitology MeSH
- Hymenoptera drug effects growth & development MeSH
- Insecticides toxicity MeSH
- Host-Parasite Interactions drug effects MeSH
- Lethal Dose 50 MeSH
- Reproduction * MeSH
- Sex Factors MeSH
- Crops, Agricultural drug effects growth & development parasitology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
