Olivero, J., & García, S. Wong, E., Márquez, A.L., & García, S. 2003 Defining a method to determine the release dose of Cryptolaemus montrouzieri Muls. based on the incidence of Planococcus citri Risso in citrus orchards.. Bulletin OILB/SROP (Sect. Reg. Ouest Palearctique) 26(6): 163-168.
Notes: [Integrated control in citrus fruit crops. Proceedings of the IOBC/WPRS Working Group, Valencia, Spain, 6-8 November, 2002. Garcia-Marí, F. (Ed.) Publisher: International Organization for Biological and Integrated Control of Noxious Animals and Plants (OIBC/OILB), West Palaearctic Regional Section (WPRS/SROP).] The use of C. montrouzieri as an exotic predator for the biological control of P. citri (citrus mealybug) dates back to 1892 in California (USA), and from then on, many countries have adopted this method for controlling the pest. Despite the long history behind its use in citrus crops, there is still no consensus about the suitable dose to be applied for a successful control of the mealybug. In this work, we designed a mathematical model to estimate the release doses of C. montrouzieri needed to ensure an effective control of the pest, based on a statistical procedure. In three spring seasons (1998, 1999 and 2002), we noted down the amounts of adult C. montrouzieri released per hectare in many citrus orchards in Malaga, Spain. The initial incidence of citrus mealybug was known in all these orchards, and we monitored the incidence of the pest in a sample of fruits weekly. Finally, we considered that the biological control had been successful if the fruit percentage with citrus mealybug became lower than 5% at least two months after the predator release. With the data collected, we designed a probability model based on the logistic regression method, which allows us to define the release doses suitable for every initial incidence level of P. citri. For this, we assumed different risk margins about the probability of a control success being reached.