ECOTOX, THE INRA'S NETWORK OF ECOTOXICOLOGISTS Side effects of Bacillus thuringiensis var. kurstaki on the hymenopterous parasitic wasp Trichogramma chilonis Marcel Amichot 1 & Christine Curty 1 & Olivia Benguettat-Magliano 1 & Armel Gallet 1 & Eric Wajnberg 1 Received: 3 June 2015 /Accepted: 17 November 2015 /Published online: 21 November 2015 # Springer-Verlag Berlin Heidelberg 2015 Abstract Most of the detrimental effects of using conven- tional insecticides to control crop pests are now well identified and are nowadays major arguments for replacing such com- pounds by the use of biological control agents. In this respect, the bacterium Bacillus thuringiensis var. kurstaki and Trichogramma (Hymenoptera: Trichogrammatidae) parasitic wasp species are both effective against lepidopterous pests and can actually be used concomitantly. In this work, we stud- ied the potential side effects of B. thuringiensis var. kurstaki on Trichogramma chilonis females. We first evidenced an acute toxicity of B. thuringiensis on T. chilonis. Then, after ingestion of B. thuringiensis at sublethal doses, we focused on life history traits of T. chilonis such as longevity, reproductive success and the time spent on host eggs patches. The repro- ductive success of T. chilonis was not modified by B. thuringiensis while a significant effect was observed on longevity and the time spent on host eggs patches. The phys- iological and ecological meanings of the results obtained are discussed. Keywords Bacillus thuringiensis . Trichogramma chilonis . Life history traits . Interaction . Biological control . Bioinsecticide Introduction Conventional chemical pesticides used to control crop pests are the object of numerous studies demonstrating their impact on the environment and human health. This includes, for in- stance, the induction of resistance in the targeted pest species, disruption in the endocrine system of several non-target spe- cies or reduction of their life span (more information can be found herein: http://toxnet.nlm.nih.gov/ ; http://www. pesticideinfo.org/). To overcome these problems, the use of natural products or beneficial organisms through biological control programs is promoted as an alternative pest control strategy. In this respect, projections of the phytoprotection market predict that biological control will account for 15 % of the sales in the 2015–2020 period (The world of organic agriculture–Statistics and emerging trends 2015, FiBL and IFOAM). Biological control can rely on either micro- or macroorganisms. Among microorganisms, bacteria are widely used and many species present a good potential to be used as bioinsecticide (Ruiu 2015). Among the microorganisms, the bacterium Bacillus thuringiensis (Bt) is the major bioinsecticide used in biological control programs (50 % of the biopesticide market, (Consultants 2010)) and was the first organism used at a large scale to control different lepidopter- ous pests (for a review about bioinsecticides based on bacteria, see (Ruiu 2015)). Bt is a Gram-positive bacterium naturally found in the soil, at the surface of leaves (Raymond et al. 2010), or even within the plant (Monnerat et al. 2009), that sporulates under stressful conditions. Interestingly, during the process of sporulation, the bacterium yields toxins that aggre- gate in a crystal, thereby the toxins are called Cry toxins. The Cry toxins differ by their primary sequence and their acute toxicity covers a wide range of animal species, although each single Cry toxin has a limited number of target species (van Responsible editor: Philippe Garrigues * Marcel Amichot marcel.amichot@sophia.inra.fr * Eric Wajnberg eric.wajnberg@sophia.inra.fr 1 INRA, Univ. Nice Sophia Antipolis, CNRS, UMR 1355-7254, Institut Sophia Agrobiotech, 06900 Sophia Antipolis, France Environ Sci Pollut Res (2016) 23:3097–3103 DOI 10.1007/s11356-015-5830-7