Sigh...bugs? Or something?

Asked June 25, 2016, 1:21 PM EDT

Something is eating my beet leaves. I think they're leaf miners, but am not sure, as the disease/eating pattern looks different than I thought for leaf miners. Neem and other organic sprays have no impact on whatever the heck is slowly destroying these leaves. Can you wonderful folks tell by the attached pics? Please let me know!

Multnomah County Oregon

4 Responses

You’re an excellent diagnostician because yes, the damage is from leafminers. They are very common pests of leafy greens (beets; spinach, and chard) here in the northwest. If you hold the damaged leaf up to the light, you may see the quite small larvae (youngsters) lined up at the edge of the fresh tissue where they are feeding.

Least toxic management includes regular search-and-destroy missions to get rid of the eggs which are laid in small groups of up to 4 elongated, and set side-by-side. At the same time, keep an eye out for heavily infested leaves to remove and discard before the larvae drop to the ground where they’ll complete their life cycle. And whenever you see small whitish areas of new damage, stop the larvae in their tracks by squishing that area between two fingers.

To avoid the problem next year, plant your beets in a new site and immediately cover the planting with row cover to exclude the adults. To do so, loosely blouse row cover over the planting, and then secure the edges. Row cover is a filmy white, non-woven fabric available in most garden centers but you can substitute bridal tulle. See “How to Install a Floating Row Cover”

Thank you so much, Jean! They are sooo hard to stop and they take over in a flash! If all of a beets leaves are infested, can I pick them off and expect the beet to live, or does that mean game over?

The plants must have leaves to form the beet roots. But, by squishing the larvae inside the leaves as soon as you see damage, you would preserve considerable live leaf tissue.

Perfect! Thank u so much for the speedy and thorough responses:). Have a great afternoon!