REVIEW ARTICLE Is the Naturally Derived Insecticide Spinosad † Compatible with Insect Natural Enemies? TREVOR WILLIAMS 1,2 , JAVIER VALLE 2 AND ELISA VIN ˜ UELA 3 1 Depto. Produccio ´n Agraria, Universidad Pu ´blica de Navarra, Pamplona 31006, Spain; 2 ECOSUR, Apdo. Postal 36, Tapachula 30700, Chiapas, Mexico; 3 Unidad de Proteccio ´n de Cultivos, E.T.S.I. Agro ´nomos, Madrid E-28040, Spain (Received 12 November 2002; returned 2 January 2003; accepted 15 January 2003) Spinosad † (Dow Agrosciences) is a neurotoxic insecticide produced by fermentation of an actinomycete. Spinosad is classified as an environmentally and toxicologically reduced risk material and has been embraced by IPM practitioners as a biorational pesticide. We examined the available information on the impact of spinosad on natural enemies and classified mortality responses to spinosad using the IOBC laboratory and field scales that run from 1 (harmless) to 4 (harmful). In total, there were 228 observations on 52 species of natural enemies, of which 162 involved predators (27 species) and 66 involved parasitoids (25 species). Overall, 71% (42/ 59) of laboratory studies and 79% (81/103) of field-type studies on predators gave a class 1 result (not harmful). Hymenopteran parasitoids are significantly more susceptible to spinosad than predatory insects with 78% (35/45) of laboratory studies and 86% (18/21) of field-type studies returning a moderately harmful or harmful result. Predators generally suffer insignificant sub-lethal effects following exposure to spinosad, whereas parasitoids often show sub-lethal effects including loss of reproductive capacity, reduced longevity, etc. All studies agree that spinosad residues degrade quickly in the field, with little residual toxicity at 3 /7 days post- application. We also examined the importance of route of exposure, species-specific and stage- specific susceptibility and we make recommendations for future studies. We conclude that for conservation of predator populations, spinosad represents one of the most judicious insecticides available but the use of this product should be evaluated carefully in situations where conservation of parasitoid populations is of prime concern. Keywords: Spinosad, biorational insecticide, toxicity, insect predators, parasitoids, integrated pest management Correspondence to: Trevor Williams. Tel:  / 34-948-169-663; Fax:  / 34-948-169-732; E-mail: trevor.williams@unavarra.es Biocontrol Science and Technology (August 2003), Vol. 13, No. 5, 459 /475 ISSN 0958-3157 (print)/ISSN 1360-0478 (online)/03/050459-17 # 2003 Taylor & Francis Ltd DOI: 10.1080/0958315031000140956