A +/- 10 yr old potted rosemary spent the winter in a sunny W window. After an uneventful winter, today I noticed a serious problem. All the tips (.5-2") were light, frosty colored with stippling characteristic of lace bug. But there was no black frass on underside of any leaves. The bugs I saw were cigar shaped, about 1/16th long, with some brown and white mottling. When some moved I could not tell whether flew or jumped, but think the latter. Did see one with wings but it was also real skinny, nothing like lace bug pix online. I sprayed over and under with insec soap this morn but 6 hrs later still had bugs. Could it be lace bug? Are they ever inside? Other suspects? Since first spray not consequential, can hort oil be used on edibles? tnx
Anne Arundel County Maryland
Rosemary do not have a lot of insect pests. We're not sure from your description just what you have. They do get aphids and white flies. (Look at Google images.)
Since they move readily, we'd recommend that you take the rosemary outside (or into a shower) and hit it with a strong jet of water to knock off all insects.
Please send us a photo of the leaf damage and the insects if you can, then we can give you a more definitive answer.
Yes, horticultural oil an be used on edibles.