Name: Phenacoccus spp.

Alias: The mealybug is often difficult to see or detect. They are usually less than an eighth-inch long and appear to be covered in a light dusty wax. They appear like small scales or bumps on the outside of plants. It has a quick lifecycle, being able to transform from egg to adult in about two months.

Mealybug

Mealybug.

Crimes: Mealybugs use their piercing, sucking mouthparts to feed on plant sap, stressing the plant. The excess sugars are excreted as sticky honeydew, which can cause fungus and disease to thrive. Large populations can kill plants. They are a significant problem in greenhouses but also pose a threat to agricultural crops and home landscapes.

Redeeming Qualities: None known.

Sentence: There are a few insecticides that are labeled for mealybugs, such as Warrior and Besiege. Unfortunately, most insecticides have a hard time controlling mealybugs because they have a waxy outer shell, including the larval stages. Chemical applications are really more of a suppressant when no other options are available. Instead, it is best not to discourage predators that may feed on mealybugs from feeding in the desired area. Oftentimes a chemical may wipe out the beneficial predators and leave nothing between the mealybugs and their plants of choice. In small infestations, they can simply be scraped off of the plant with a razor blade or gardening tool. Always remember to read and follow label instructions whenever using a pesticide.

For more information on dangerous and beneficial bugs, call UI Extension educator Joseph Sagers at 208-745-6685 or email jsagers@uidaho.edu.