High Levels of Potato Leafhopper Already Present in Virginia Alfalfa
Crop and Soil Environmental News, June 1998
Curt Laub, research associate
and Rod Youngman, Extension specialist
Potato leafhopper populations are weeks ahead of their normal levels, and are already at threshold levels in some fields. Leafhopper populations were slightly above threshold in fields sampled in Augusta County on June 3 and Montgomery County on June 4. The two fields sampled had been cut a few weeks ago and alfalfa regrowth was about 10 inches tall.
All the leafhoppers counted were adults, which tells us that high numbers of eggs are being deposited. These eggs will be hatching in the next few weeks and we expect very high numbers of nymphs to start feeding. Damage to alfalfa may be severe, especially to fields that are just now being harvested. Growers are advised to monitor all alfalfa fields for potato leafhopper, especially those fields that have recently been cut. Procedures for monitoring potato leafhopper are described on pages 126-127 of the 1998 Virginia Pest Management Guide for Field Crops (Extension Publication no. 456-016).
Virginia Cooperative Extension's potato leafhopper scouting program, in which trained field scouts monitor alfalfa between June and August, is available in many counties in the northern Piedmont and Western part of the state. With this year shaping up to be particularly severe for potato leafhopper, the sign-up period has been extended - growers may still enroll fields in this program. Please encourage your growers to consider enrolling their alfalfa in the scouting program this year.