Contents lists available at ScienceDirect Biological Control journal homepage: www.elsevier.com/locate/ybcon A fuzzy-based index to identify suitable areas for host-parasitoid interactions: Case study of the Asian citrus psyllid Diaphorina citri and its natural enemy Tamarixia radiata Adriano Gomes Garcia ⁎ , Alexandre José Ferreira Diniz, José Roberto Postali Parra Department of Entomology and Acarology, University of São Paulo, ESALQ – 11, Pádua Dias avenue, 13418-900 Piracicaba, SP, Brazil GRAPHICAL ABSTRACT ARTICLE INFO Keywords: Ecological zoning HLB Fuzzy Theory Computational tools GIS Citrus ABSTRACT We developed a computational index to identify suitable areas for biological control using the interaction be- tween an insect pest and its natural enemy. The index considers that environmental conditions should be suitable for the development of both insects and that the plants participating in the tritrophic system should be in the appropriate stage of development. In order to represent the uncertainty associated with empirical information and lack of data, we decided to use fuzzy sets theory to develop the index. We ran simulations for a specific case study and then validated them, classifying 54 locations in the state of São Paulo, Brazil, as areas of “high suitabillity” and “low suitability” for biological control of the Asian citrus psyllid, Diaphorina citri, using the wasp Tamarixia radiata. We constructed maps to provide a visual description of the interpolated data, using GIS (Geographic Information System). The index satisfactorily classified the areas, as confirmed by field data. The results suggest that in this state, the most effective period to use the parasitoid is September to March. The index can be easily used for different locations and species and has the potential to support biological control pro- grams, helping entomologists and farmers to define the best period to use biological control. 1. Introduction One of the main concerns of entomologists is identifying areas with suitable conditions for the development of insect species. For instance, abiotic factors may influence the presence or absence of insects and have been used to determine the spatial occurrence of some species (Kutywayo et al., 2013), combining biological studies and GIS (Geo- graphic Information System). This is particularly important in agri- culture because it helps to develop Integrated Pest Management plans by providing information about hot spots and areas susceptible to insect https://doi.org/10.1016/j.biocontrol.2019.05.001 Received 3 December 2018; Received in revised form 25 April 2019; Accepted 1 May 2019 ⁎ Corresponding author. E-mail address: adrianogomesgarcia@usp.br (A.G. Garcia). Biological Control xxx (xxxx) xxx–xxx 1049-9644/ © 2019 Elsevier Inc. All rights reserved. Please cite this article as: Adriano Gomes Garcia, Alexandre José Ferreira Diniz and José Roberto Postali Parra, Biological Control, https://doi.org/10.1016/j.biocontrol.2019.05.001