Crawling with Scale

The first generation of Euonymus scale (Unaspis euonymi) crawlers are quite active in container grown Euonymus and also in the landscape.  Euonymus scale look like tiny white flecks (males) and tiny brown sea shells (females) along twigs and the undersides of leaves.  Look for TINY, bright, orange crawlers amongst the adult scale shells on leaves and twigs.  (click on the image to enlarge)


Click here for video of Euonymus scale crawlers.  Where insecticide applications are warranted, multiple applications may be required to get good knockdown since crawler emergence is staggered over a few weeks.  Try insecticidal soap and the summer rate of horticultural oil in the landscape.  In the nursery, Kontos is now registered to manage container grown Euonymus scale as a media drench application.

Where Fletcher scale (taxus scale, Parthenolecanium fletcheri) has been a problem in the past, monitor for dark brown “bumps” on twigs and needles of Eastern white cedar (Thuja occidentalis) or yews (Taxus spp.).


Pick off the brown bumps and look for white grain-like eggs.  Fletchers scale (2)

Some of those eggs will have legs (click here for video) and will be crawling looking for tender new growth to feed on.

Several insecticides are registered for management of Taxus scale crawlers in the nursery.  Try insecticidal soap in the landscape.    The summer rate of horticultural oil may be phytotoxic on some hosts, especially when temperatures are > 26C.


About Jen Llewellyn

OMAFRA Nursery and Landscape Specialist @onnurserycrops
This entry was posted in Insects, Uncategorized and tagged , , . Bookmark the permalink.

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