Such defoliation results in a decrease in the quality and quantity of lint. Spider mites usually first occur around field margins next to vegetation, around stumps or ditch banks, etc., where they have overwintered. A good cultural control method is to leave a vegetation-free zone 10 to 20 feet wide between any border vegetation and the cotton field point rows. Any equipment, people or animals moving through a cotton field can spread mites. Mite infestations often occur immediately after mowing border vegetation.
Spot treating border areas can stop an infestation before it spreads throughout the entire field.
Control efforts should begin as soon as mites are evident, or as soon as leaves in an infested area begin to discolor. For effective control with all miticides, it is essential to get good coverage of all foliage, especially the undersides of leaves. Note that spider mite populations may decline suddenly in early August. Therefore, observe fields carefully in August to determine whether mites are present in damaging numbers before applying control measures. Bollworms Cotton bollworm is the same insect as corn earworm, which may be present in large numbers on field and sweet corn.