Lygus spp.
Pest description and crop damage Pale green to red-brown sap-sucking bugs, 0.25 inch long when mature; the wings of adults fold flat over the back producing a yellowish, V-shaped mark behind the thorax. Lygus bugs are primarily seed feeders, so usually they are inconsequential pests except in sugar beet seed fields. Lygus bug damage may be observed as chlorosis and slight curling of the distal end of leaves; close inspection may reveal black "stings" from lygus bug feeding on the main leaf vein, just below where chlorosis begins.
Scouting and thresholds No formal economic thresholds exist for lygus bug insecticide treatment decisions in sugar beets.
Management-biological control
The insect-killing fungus, Beauveria bassiana, is available in commercial formulations.
Management-chemical control
Few conventional insecticide options are available as post-emergence sprays (Table 2), but several biorationale insecticides are registered (Table 3).