Ever see a white, cottony looking, waxy mess on the trunk of your grapevines? And other locations? No, it's not candle wax.
This sticky, cottony mess is the secretion of a waxy material by vine mealybugs. These vine mealybugs are similar to the mealybugs that sometimes affect your indoor and outdoor house plants. Mealybugs belong to the Class Insecta, Family Pseudcoccidae. The species scientific name for the vine mealybug is Planococcus ficus.
When you look closely at the above photo, you will see several white/gray wax-covered adult mealybugs along with the wax they leave on themselves, leaves, stems, trunks and fruit on grapevines. The mealybugs also excrete a sticky honeydew which sometimes causes black sooty mold to grow on top of the honey dew. This honeydew will attract ants. In the pictures above and below, the mealybugs were on the trunk of a grape vine with honeydew dripping onto the surrounding iris and hollyhock garden.
Here are three resources that will provide you with guidance on dealing with mealybugs:
Vine Mealybug / Grape / Agriculture for the various biological and cultural control methods to reduce the problems the vine mealybugs will cause.
Mealybugs Management Guidelines--UC IPM and Identifying Mealybugs - Grape to help identify different species of mealybugs and see their life cycles.
Mealybugs--UC IPM for further information about pests in gardens and landscapes and how to control them. Additional species of mealybugs will infest other plants and can include your outdoor and/or indoor plants.
