Insects on bark of dwarf hemlock

Asked September 8, 2019, 11:07 AM EDT

There are small white insects on the stems of a dwarf hemlock; I have tried to remove them by hand. Can help identify them? Any suggestions on how to deal with them? Or on how they spread? I have a bunch of dwarf conifers and hope they won’t get harmed.

Baltimore Maryland pest insects and mites

1 Response

Hi -- This looks like Indian wax scale. They are insects that feed on the sap of many different host plants. https://extension.umd.edu/hgic/topics/soft-scales-trees-and-shrubs. Generally, the best thing to do is to pick them off by hand, as you have been trying to do. The next step would be to apply the dormant rate of horticultural oil during the winter. The juvenile insects (called "crawlers") emerge typically in June, at which time you can apply horticultural oil. There is more information here, https://content.ces.ncsu.edu/soft-scale-identification-and-management-on-ornamental-plants.

Christa