Control of Mediterranean fruit flies in organic citrus orchards (BIOFRUITNET Practice Abstract)

Summary

Traps allow the detection of the medfly and the reduction of damages. Functional biodiversity (i.e., predators in the ground cover) decreases the emergence of medfly adults.
Practical recommendation
• Apply control strategies accordingly to the life cycle of the medfly (Picture 1).
• Use traps composed of (i) a parapherormone (i.e., trimedlure) or food attractants; (i.e., hydrolysed pro-teins); and (ii) a pyrethroid (e.g., deltamethrin) or Spinosad (Picture 2A).
• Make your trap! Fill a transparent bottle with a 9% water solution of protein hydrolysate (or the fertiliser sulfur ammonium) and 2% borax (Picture 2B). As an alternative, attach a vial with food attractant to a ply-wood panel soaked in deltamethrin (2.8%) (Picture 2C).
• Place 50-75 traps/ha, from late August (before fruits change colour) in orchards with a minimum extension of 2-3 ha or isolated ones.
• Check available biocontrol agents (Table 1) and consider the agent biology before applying (e.g., nema-todes require the presence of pupating larvae in the soil).
• Apply cultural control methods: eliminate infestation sites and destroy infested fruits.
• Promote biodiversity (e.g., plant combinations, ground cover management, etc.) to increase predation on medfly pupae and parasitisation of larvae.
• If infestations are too high to be managed with mass trapping alone, treat with clays (kaolin at 4% concen-tration) before fruits change colour in plots below 3 ha. Treat plot perimeters and repeat in case of intense rainfalls.