False oleander scales reproducing

False oleander scales. Photo: SD Frank

False oleander scale, Pseudaulacaspis cockerelli, is a tropical and subtropical pest originally from China. False oleander scale is common throughout many southern states but just reaches the very warmest parts of North Carolina. This means the southeastern part of the state around Wilmington where the scales are very common. By the time you travel just 2 hours north to Raleigh, false oleander scale is nowhere to be found. Presumably this is due to lower minimum temperatures in winter. However, everyone might as well get familiar with this pest because it will creep north gradually as the climate warms.

False oleander scales on Magnolia grandiflora. Photo: SD Frank.

False oleander scale feeds on the leaves of hundreds of plant species. In areas where it is abundant, false oleander scale is a major pest of ornamental plants in nurseries and landscapes. It is very common on Magnolia grandiflora in southeastern North Carolina. It is very easy to see on M. grandiflora so maybe that is why it seems so common. False oleander scales are also common pests of plants like aucuba, boxwoods, oleander, Hedera spp., and many others.

False oleander scale feeding produces chlorotic spots on leaves and can stunt leaf growth. Heavy infestations can cause leaf loss and general decline of the infested plant. These symptoms are similar to other armored scales that feed on evergreen leaves like euonymus scales on euonymus and tea scales on camellia.

False oleander scale eggs and crawlers underneath an adult test. Photo: SD Frank

False oleander scales are white and oyster shell shaped armored scales. They are similar to white peach scales. Underneath the cover (called a test) you will find a yellow insect. Right now they are producing yellow eggs that hatch into crawlers. These crawlers will find a new spot to feed and soon begin constructing their own test. There are several generations of false oleander scale each year and during summer you can generally find all life stages at the same time. This complicates management because it is impossible to target a whole generation of crawlers. You are always treating some crawlers, some adults, and some nymphs, which vary in their susceptibility.

Many products are available to help manage armored scales and scales in general. A good place to start is with horticultural oil or insecticidal soaps.  You can read about scale management with oils and soaps in a recent article. Other products are listed in the 2017 Southeastern US Pest Control Guide for Nursery Crops and Landscape Plantings.

2019-03-06T12:05:05-05:00 March 6th, 2019|Categories: Landscape IPM|Tags: , , , |

About the Author:

Steve Frank
I am broadly interested in the ecology and management of arthropod pests. Herbivorous arthropods cause extraordinary damage to plants in agricultural, urban, and natural ecosystems. Understanding interactions between pests and their environment, plant hosts, and natural enemies can improve management practices and reduce pesticide applications.