Mealybug

Did you spot some white and fluffy insects in your crop? That must be mealybugs such as the citrus mealybug Planococcus citri, the obscure mealybug Pseudococcus affinis or the long-tailed mealybug Pseudococcus longispinus. These mealybug species cause damage all over the world in areas with a moist and warm climate. Feeding on plant sap, mealybugs damage a wide range of vegetable crops, fruit crops and ornamentals. Do you also want to take action against these mealybug species with biological control?

What damage can mealybugs cause?

• Mealybugs cover the stems and leaf nodes with white and fluffy wax.
• They suck plant sap and excrete the excess of sugar as honeydew due to which the leaves, stems and fruit become sticky.
• The surface turns black as sooty mould grows on the honeydew, which negatively affects the photosynthesis of the plant.
• Severe infestations reduce the health and growth of the plant resulting in wilting.

How to control mealybugs?

To monitor winged males, you can rely on specific pheromones combined with a trap such as the Delta Trap^® or sticky traps such as Bug-Scan^®.

For biological control of this species, you can introduce:

• The green lacewing Chrysopa-System;
• The ladybird Cryptolaemus-System.

What are the characteristics of mealybugs?

• Eggs are laid in a cotton-like pouch.
• The mobile young nymphs disperse in order to find suitable feeding spots.
• Mealybugs are sexual dimorphic, which means that females look totally different than males.
• Males are tiny wasps that are rarely seen in the crop.
• Females are covered with white, waxy threads. They appear as full-grown nymphs.
• Females and nymphs live in clusters in protected places such as the leaf axils and underneath loose bark.

What about the mealybug’s life cycle?

• Females lay 300 up to 500 eggs, which takes them 5 to 10 days. After laying the eggs, the females die.
• As their life cycle depends on the temperature, it takes them about 90 days to develop from egg to adult at 18 °C/ 64 °F and 30 days at 30 °C/ 86 °F.
• Mealybugs have 3 nymphal stages.
• Only the males undergo a complete transformation to emerge as winged adults. This is called a metamorphosis.