Red Rubin Basil leaves have holes - Plant 2

Asked June 30, 2020, 11:39 AM EDT

This is a second red rubin basil plant and it is also being eaten by something. (I sent a separate message about the first basil plant) It's planted next to a tomato plant, which has aphids crawling underneath, and a zucchini plant that has yellowing leaves (I sent another email about the zucchini). I haven't seen evidence of aphids on the basil plant.

Prince George's County Maryland

1 Response

[repeating the prior answer here as our impression of this damage is the same]

Aphids do not cause chewing injury, so these holes were likely caused by a different pest - or possibly even physical damage from elements in its environment. Leaf-feeding beetles, slugs and snails, and a few other chewing insects could be to blame. A number of these shelter elsewhere during the day and come out at night, so you could examine the plants with a flashlight after dark or before dawn (especially in dewy or damp conditions) if you want to try to catch the culprits in the act.

For now, we do not recommend treatments until a culprit is identified. It does not appear to be causing significant damage thus far and the plants otherwise appear healthy. If damage continues and becomes more prominent, you could try treating them with spinosad (verify the product label lists vegetables/herbs as plants that can be sprayed). This insecticide can kill chewing insect pests a couple of days after they ingest it and is derived from a naturally-occurring soil microbe. Because it needs to be ingested by the pest in order to work, re-application after copious new growth and heavy rains may be needed if the pests are persistent. If slugs or snails are the pests here, a different pesticide would be required.