Mealybugs
Mealybugs Facts
Common name: Mealybugs
Scientific name: Planococcus citri, Pseudococcus longispinus, P. calceolariae and more.
Mealybugs feed on many greenhouse and indoor plants.
Mealybugs are active all year round.
Typically covered in a white, waxy material mealybugs are sap sucking true bugs (Hemiptera) closely related to scale insects.
Symptoms include:
- A fluffy white waxy residue left on leaf axils and hidden spots on the plant
- Black sooty mould
- Sticky honeydew residue
- Stunted growth and loss of leaves prematurely
Glasshouse Mealybugs are common insects that tend to live together in clusters in inaccessible parts of plants, such as leaf axils, leaf sheaths, between twining stems and under loose bark. There are also some mealybug species found on plant roots.
Non-Chemical Treatments include:
- Dispose of fallen leaves that may have eggs on
- Attract predators to the plants
- Dispose of heavily infested plants
- Spray plants with soapy water
About Mealybugs
Mealybugs Lifecycle
Mealybugs lay eggs (except for the long-tailed Mealybug that births live young), 3 (sometimes 4) nymph stages and adult. Immature crawlers mature in about 6 weeks to 2 months depending on temperature, humidity and species. Mature females die after laying eggs. Reproduction is greatly influenced by nitrogen contents of the host plant, being more rapid when nitrogen content is high. Males are winged and do not cause plant damage.
The adult females have flattened oval-shaped soft bodies up to 4mm in length; they are sometimes pink in colour but appear whitish due to the white, waxy powder that covers their bodies. Waxy filaments project from the edges of their bodies. Some species are all female; others have small winged males, but the latter are infrequently seen.
Female Mealybugs lay eggs under a white, waxy coating. Mealybug nymphs resemble the adult insects and can complete their development in about a month in mid-summer. Breeding continues throughout the year in greenhouses, but takes place at a slower rate in winter.
In warm greenhouses, or in the house, Mealybugs can feed and reproduce all year round. Females lay batches of 100-150 eggs, protected by wax. These hatch out in a few weeks and the nymphs crawl around on the plant for a few hours before they settle to feed. Once they become adults, they can still move but rarely do. Colonies of mealybugs tend to congregate in leaf axils, at the base of cactus spines or underneath leaves.
An infestation of Mealybug is often mistaken for a fungus, but if you squash a colony, it will be wet and sticky. Woolly aphids, which also hide under fluffy white protective wax, look similar but attack a different range of plants. They are hardy and most commonly found outdoors on apples.
