Crop Protection 27 (2008) 869–872 Short communication Acaricidal efficacy of neem against Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) Madelaine Venzon a,Ã , Maria Consolac - a˜o Rosado b , Adria´n Jose´ Molina-Rugama b , Vanessa Silveira Duarte b , Rondinelli Dias b , Angelo Pallini b a Agriculture and Livestock Research Enterprise of Minas Gerais (EPAMIG), Vila Gianetti 46, 36570-000 Vic - osa, Minas Gerais, Brazil b Department of Animal Biology/Entomology, Federal University of Vic - osa, Vic - osa, Minas Gerais, Brazil Received 30 May 2007; received in revised form 1 October 2007; accepted 1 October 2007 Abstract The broad mite, Polyphagotarsonemus latus, is one of the most serious pests attacking chilli pepper in Brazil. Aiming to offer an additional tool to be used for its control, we tested the acaricidal effect of neem, Azadirachta indica, on P. latus. Chilli pepper seedlings were sprayed with neem seed extract (NeemAzal T/S, 1% of azadiractin) at concentrations of 0.05, 0.10, 0.15 and 0.20 g a.i./l, with abamectin 1.8% (Vertimec 18 CE) and with water. Adult females of P. latus were transferred to each treated plant and after 6 d, the instantaneous rate of increase (r i ) was calculated. All mites on plants treated with abamectin died without ovipositing before the end of the experiment. The r i for P. latus decreased linearly with increasing neem concentration, with the population growth rate becoming negative when mites were exposed to plants treated with neem at concentrations higher than 0.13 g a.i/l. r 2007 Elsevier Ltd. All rights reserved. Keywords: Broad mite; Capsicum frutescens; Azadirachta indica; Instantaneous rate of increase 1. Introduction The broad mite, Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae), is a polyphagous pest that attacks several important crops worldwide (Flechtmann, 1989; Gerson, 1992; Pen˜a and Bullock, 1994). This minute mite (0.1–0.3 mm in length), also known as the white mite, is found in the apical portion of plants, especially in shoot structures (Flechtmann, 1989). Its damage usually begins in small clumps in the field, but infestations can spread rapidly. Leaves damaged by P. latus curl downward and the flowers become distorted and fail to open normally. Also, in most attacked hosts the internodes are greatly shortened and fruit drop may occur under severe infesta- tions (Pen˜a and Bullock, 1994). In Brazil, P. latus is one of the most important pests attacking chilli pepper, Capsicum frutescens L. (Venzon et al., 2006). Because of their small size, broad mites are not initially noticeable in fields, being detected only when they have increased in number and already caused serious damage to plants. In addition, their short generation time, high fecundity, and tendency to live in protected habitats make control very difficult, resulting in preventive or excessive use of pesticides by chilli pepper growers. Indeed, most of the chilli pepper growers in Brazil use a calendar- based approach for pest control despite the lack of success for P. latus control (Venzon et al., 2006). Less toxic and efficient alternatives to conventional pesticides are sought by producers, particularly by organic farmers, because no pesticides are allowed in this produc- tion system. Among several alternative strategies, the use of botanical products is considered a suitable pest manage- ment practice. Products derived from the neem tree, Azadirachta indica A. Juss (Meliaceae), have been used against many pest arthropods (Schmutterer, 1997; Gahu- kar, 2000; Isman, 2006). Azadirachtin, the primary active compound, acts primarily as a feeding deterrent and as a growth retardant of more than 200 pests (Ascher, 1993; Mordue et al., 1998; Isman, 2006). ARTICLE IN PRESS www.elsevier.com/locate/cropro 0261-2194/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.cropro.2007.10.001 Ã Corresponding author. Tel.: +55 31 3891 2646; fax: +55 31 3899 5224. E-mail address: venzon@epamig.ufv.br (M. Venzon).