Infected cherry laurel
Something has attacked one of our cherry laurels which is in the middle of about 9 other cherry laurels. Please see the attached pictures. Can you tell me what it is and how to treat it? My husband has sprayed it with Sevin twice and we don't know if it's working or not and are concerned about it spreading to the other bushes. Thanks for any help you can give us in advance.
Howard County Maryland
This cherry laurel has prunicola scale, a type of sucking insect. Here is information on scales and their control: http://extension.umd.edu/hgic/plants/armored-hard-scale-trees-and-shrubs
When you have an infestation like your plants do, you can also scrub the larger trunks with a stiff bristled brush (not wire) before you spray. This knocks the covers off the adults so more pesticide gets in.
Here is a calendar for when to spray the crawler stage (the only time they are vulnerable to pesticide sprays): http://extension.umd.edu/ipm/landscape-management-nursery-production/monitoring-scale-insects-focusi...
When landscaping, it is always dicey to have a row of any plant or try to establish a perfect symmetry because it is so easy to lose one or a few. It's easier to have a more diverse look. It makes it harder for diseases to get established and beneficial insects are also more likely to more in to combat pest insects.