Biological control in the national campaign against fruit flies in Mexico

The use of Augmentative Biological Control (ABC) against fruit flies (Diptera: Tephritidae) through the releases of Diachasmimorpha longicaudata (Hymenoptera: Braconidae), have been periodically conducted in some specific areas of Mexico, in order to contribute in the control of fruit fly populations of Anastrepha spp. Previous studies have reported that the mass release of D. longicaudata could successful contribute to suppress fruit fly populations with levels of parasitism around 50% on Anastrepha larvae. According to a national plan, 25 million pupae are produced weekly and released on marginal areas and/or backyard orchards identified as fruit fly reservoirs, in order to minimize later the presence of these pests in commercial orchards. The application of this strategy is conducted under an Integrated Pest Management frame, in conjunction with other techniques as the Sterile Insect Technique and / or the aspersion of toxic baits (among others). These actions have allowed to obtain some low prevalence areas, or even, some fruit fly free zones, which implies a great advantage for the fruit marketing of these regions. To reinforce the use of parasitoids, in the Mexican campaign there are plans to integrate the pupa fruit fly parasitoid Coptera haywardi (Hymenoptera: Diapriidae), which has shown to be specific for Anastrepha flies, and to have a good capacity of discrimination to pupa previously parasitized by D. longicaudata. The objective is to complement the action of the first parasitoid, in those cases (e.g., larger fruits) were a high proportion of larvae could escape to the parasitoid attack. The use of the ABC also demands the continue improvement of the parasitoids mass rearing, and the reinforcement of its quality control. The final intention is to apply a strategy either using the optimal natural enemies or multiple species to achieve a better control of the fruit fly populations.