Advances in Entomology, 2018, 6, 134-147 http://www.scirp.org/journal/ae ISSN Online: 2331-2017 ISSN Print: 2331-1991 DOI: 10.4236/ae.2018.62010 Apr. 25, 2018 134 Advances in Entomology Predatory Potential of Phytoseiulus macropilis (Banks) Preying on Tetranychus urticae Koch (Acari: Phytoseiidae, Tetranychidae) Giselle Christiane Souza-Pimentel 1 , Paulo Rebelles Reis 2 , Gilberto Rodrigues Liska 3 , Marcelo Ângelo Cirillo 4 1 Postgraduate Program, Universidade Federal de Lavras-UFLA, Lavras, Brazil 2 Empresa de Pesquisa Agropecuária de Minas Gerais-EPAMIG Sul/EcoCentro, Lavras, Brazil 3 Universidade Federal do Pampa-UNIPAMPA, Rio Grande do Sul, Brazil 4 Departamento de Ciências Exatas, Universidade Federal de Lavras-UFLA, Lavras, Brazil Abstract The two-spotted spider mite, Tetranychus urticae Koch (Tetranychidae), is considered one of the most important species of pest-mites because it is cos- mopolite and polyphagous. This species has been described as attacking over 1,100 plant species in 140 families of economic importance. On the other hand, Phytoseiulus macropilis (Banks) (Phytoseiidae) is a predatory mite of group I, specialist as predatory mite from the Tetranychus genus. Thus, the objective of this work was to evaluate predatory potential of P. macropilis in its different stages—nymphs, female and male adults—preying on T. urticae also in different stages—eggs, larvae, nymphs, and adults—and to know the functional and numerical responses in lab studies. Both the experiments were carried out on arenas made of Jack-bean leaflets’ discs [Canavalia ensiformis (L.)—Fabaceae] with 3 cm in diameter over agar-water at 3% inside 5 cm in diameter uncapped Petri dishes. To know the predatory activity, forty T. urti- cae and one predatory mite were placed in each arena with the respective phases of the developmental life cycle to be evaluated. To know the potential of predation, the no killed mites were counted after 24 hours. To know the functional and numerical responses, immature T. urticae in densities of 1 to 300/arena were offered for P. macropilis. The results for the predatory poten- tial showed that larvae and male adult of T. urticae were the most killed stag- es, and the female predatory mites were the one that consumed most prey. The functional response showed a positive and significant correlation, sug- gesting a type II functional response (convex), a cyrtoid curve rising at a de- creasing rate to a plateau, where the consumption remains constant regardless How to cite this paper: Souza-Pimentel, G.C., Reis, P.R., Liska, G.R. and Cirillo, M.Â. (2018) Predatory Potential of Phyto- seiulus macropilis (Banks) Preying on Tetranychus urticae Koch (Acari: Phyto- seiidae, Tetranychidae). Advances in En- tomology, 6, 134-147. https://doi.org/10.4236/ae.2018.62010 Received: January 25, 2018 Accepted: April 22, 2018 Published: April 25, 2018 Copyright © 2018 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access