Mealybugs
Pest insect
- Sticky substance on leaves and stems
- Slowed growth
- Cottony substance on the plant
- General weakening of the plant
- Yellowing and leaf drop
- Cottony substance around the plant
- Black mold on leaves and stems
| Difficulty Medium |
| Frquency Very high |
| Reproductive rate Up to 600x |
| Lifecycle Up to 8 weeks |
Mealybugs are polyphagous insects that damage plants by piercing their tissues to feed on their sap.
Host plants
These mealybugs attack most species of succulent and tropical plants, particularly orchids, cacti, and succulents.
Screening
Adult females are relatively easy to detect due to their size of two to five millimeters, white color, and characteristic waxy appearance. Honeydew is a sticky, transparent substance that accumulates on leaves and stems. When honeydew is secreted in sufficient quantities, it can cause a black mold called sooty mold.
Prevention
Mealybug species that attack indoor plants are of tropical origin and are not adapted to the continental climate. Therefore, they are exclusively present in indoor cultivation. Their appearance is always associated with the introduction of infested plants. Hardy mealybug species present in continental climates pose no risk to indoor plants.
Treatment
Mealybugs are relatively easy to eliminate on small to medium-sized plants. Treatment may involve removing visible mealybugs, thorough cleaning, application of contact insecticide, introduction of natural predators, or heat treatment, if the plant variety can tolerate it.
Green lacewings are the most appropriate predators for treating mealybug infestations. Minute pirate bugs and ladybugs can also contribute.
Morphology
Females are oval-shaped, wingless, and their pinkish or yellowish bodies are covered with a waxy white layer. Some species have horizontal lines on their backs as well as longer or shorter antennae or posterior filaments.
Males, much smaller in size, are difficult to observe. They have wings and resemble small white flies.
Behaviour
Depending on the species, mealybugs lay their eggs by the dozens directly on the plant or in egg sacs covered with a white, cottony substance. They can survive for several weeks without food.
Lifecycle
The life cycle of mealybugs consists of 3 stages: egg, nymph, and adult. Females can live for several weeks depending on the species and environmental conditions. Males live for only a few days, just enough for fertilization, and cause no damage to plants. Mealybugs can reproduce in the absence of males.