Alfalfa looper (Autographa californica)
Cabbage looper (Trichoplusia ni)
Pest description and crop damage This is a minor leaf-feeding pest of sugar beets that is most commonly seen late in the season in sugar beets that border alfalfa fields. Mature larvae are up to 1.5 inches long and light to dark green with a thin white stripe along each side. Loopers differ from all other sugar beet caterpillars in that they have only three pairs of fleshy prolegs-on abdominal segments 5, 6, and 10-and crawl in a characteristic looping motion; all other sugar beet caterpillars have five pairs of prolegs-on abdominal segments 3, 4, 5, 6, and 10.
Scouting and thresholds No formal economic thresholds exist for looper insecticide treatment decisions in sugar beets.
Management-biological control
Many microbial pathogen-derived products are available as commercial sprays (Table 3).
Management-chemical control
Many post-emergence insecticides are available (Tables 2-3).