The citrus mealybug Planococcus citri is a major pest species in ornamental crops in greenhouses. This study aimed to enhance the biological control of mealybugs with parasitoids by providing sugars to the parasitoid adults.
A mixture of glucose, fructose and sucrose prolonged the lifetime of the parasitoid Anagyrus pseudococci 5 times.
In cages, it was shown that the control of mealybugs increased when the parasitoids were provided with sugars. These simple sugars apparently had added value to the honeydew that mealybugs secrete. However, providing sugars in a larger greenhouse compartment did not results in enhanced control of mealybugs.
Another way to maintain parasitoids in greenhouses can be achieved through providing alternative hosts. In this study, we evaluated a banker plant system based on Kalanchoe with citrus mealybugs as hosts, surrounded by plexiglass cylinders to prevent escape of mealybugs. These systems were able to produce hundreds of parasitoids for up to 16 weeks. Application in a greenhouse resulted in a faster and more effective control of mealybugs than in a greenhouse with only parasitoids.
Research sponsored by Productschap Tuinbouw