UNCORRECTED PROOF Toxicity of Fipronil to the Predatory Lacewing Chrysoperla carnea (Neuroptera: Chrysopidae) P. MEDINA, F. BUDIA, P. DEL ESTAL, A. ADA ´ N AND E. VIN ˜ UELA Proteccio ´n de Cultivos, Escuela Te ´cnica Superior de Ingenieros Agro ´nomos, Ciudad Universitaria, s/n 28040. Madrid, Spain (Received 1 March 2003; returned 20 May 2003; accepted 20 June 2003) All the developmental stages of Chrysoperla carnea (Stephens) were treated with fipronil using different modes of exposure under laboratory conditions. Eggs were dipped in an aqueous range of concentrations and no effects were recorded, except at the highest concentration. Pupae treated topically on the silk cocoon moulted to healthy adults, without any deleterious effects on their reproduction. In contrast, larvae and adults were killed by the compound, irrespective of the mode of treatment, even at rates below the maximum field recommended rate in Spain (30 g c.p./ha). Sublethal concentrations of fipronil did not affect the fecundityor fertility of survivors. We conclude that fipronil is very toxic under laboratory conditions to this predatory lacewing. Keywords: Chrysoperla carnea, fipronil, side-effects, egg, larva, pupa, adult INTRODUCTION The noxious effects on the environment caused by conventional insecticides might be minimized by the use of new insecticides that require less active ingredient for comparable pest control. This need is met, in part, by fipronil, an insecticide placed on the market in 1993 (Colliot et al ., 1992). This phenyl pyrazole insecticide is a potent blocker of the GABA- regulated choride channels in the neurons of the central nervous system. The GABA- receptor system is responsible for the inhibition of normal neural activity, i.e., preventing nerves from excessive stimulation. When this function is blocked by fipronil, the result is neural excitation and the death of the insect (Cole et al ., 1993). Fipronil kills the insects by contact and ingestion. It is effective against larval and adult stages of both piercing-sucking and chewing insects and can be effectively deliveredvia soil, foliar, bait or seed applications (Burris et al ., 1994). Correspondence to: P. Medina. Phone: /34 91 336 5777. Fax: /34 91 543 48 79. E-mail: pmedina@pvb. etsia.upm.es Biocontrol Science and Technology (Month 2004), Vol. 00, No. 00, 1 /8 ISSN 0958-3157 (print)/ISSN 1360-0478 (online)/04/000001-8 # 2004 Taylor & Francis Ltd DOI: 10.1080/09583150410001665141 Y:/Taylor & Francis/cbst/articles/cbst041001/CBST041001.3d[x] Tuesday, 24th February