Rearing of Leptomastix dactylopii for pest control in organic citrus orchards (BIOFRUITNET Practice Abstract)

Summary in the original language of the document

Farmers can promptly react to mealybug infestations and perform multiple releases of parasitoids in a short time, bypassing the high delivery cost.
Practical recommendation
• Wash ripe pumpkins in a bleach solution (5%) for 10 minutes, then thoroughly rinse with tap water and dry in the open air.
• Field-collect a colony of mealybugs and rear on pumpkins held on stands inside a room (Picture 1, 26 ± 2°C, 45 ± 5% humidity). Either gravid females, eggs, or crawlers may be used as inoculum.
• Once pumpkins are infested, obtain/ purchase a colony of L. dactylopii (Picture 2) and rear inside cages placed in another room (45 ± 5% humidity). The temperature must not exceed 28°C.
• Cages (Picture 3) may be homemade (i.e., following online DIY tutorials) or be bought (i.e., online stores).
• Place pumpkins infested by 2nd-3rd instar mealybugs (15-20 days after egg hatching) inside the cages.
• New parasitoids emerge 12-16 days after a pumpkin is placed into the cage (Picture 2).
• Fill a plastic tube with water, plug it with cotton, and place it in the cage as a water source. Apply little drops of pure honey in the cage to feed adult parasitoids. Renew the tube and the honey once a week.
• Collect adult parasitoids from the rearing with an aspirator (Picture 4) and release them into the infested orchards. Alternatively, open the entire cage in the field after removing the infested pumpkins.
• It is important to preserve a colony of parasitoids for further releases. The time between releases (i.e., two weeks) allows the insects to thrive and reach numbers compatible with pest control action.
• It is important to keep the mealybugs rearing and the parasitoids in two different rooms. Operators should never enter the mealybug room after being in the parasitoid room.