MOFGA Pest Alert
15 July 2004

(View List Of All 2004 Pest Reports)

POTATO LEAF HOPPER HERE IN BIG NUMBERS

This week the potato leaf hopper numbers have really exploded. Check your potatoes, beans, strawberries and eggplants. These are very small insects that are hard to spot until you disturb them. Rub your hand over the top of the plants and look for them flying up and landing. Then you can see the small, wedge shaped bug that sucks juice out of your plants. If you are already seeing "hopper burn" where the edges of the leaves curl and turn brown, it is too late to bother to do anything. But, I think for most of us we have caught it early.

Scout each new bean planting for potato leafhopper by checking the undersides of leaves. Damage is greater in plants that are infested early in their growth. Thresholds are two hoppers per foot of row in seedlings, five per foot of row after seedling stage. Rotenone does not work on leaf hoppers. Concentrated pyrethrum materials are the best thing organic growers have. I think that Pyganic is your best choice.

There are some varieties of potatoes and beans that are more resistant than others. If you find this to be true, please get back to me with your findings.

(About the author: Eric is MOFGA’s Technical Services Director, essentially an organic "extension agent". He can be reached at the MOFGA office to answer your questions about farming and gardening. Link to MOFGA Contact Page, or email Eric directly.)