University of California IPM Extension Coordinator Pete Goodell doesn't really look like a prophet or poet, but as the rains continue falling this year and are delaying cotton planting, his verse rings more true:
“If green in May, prepare to pay,
If hills are brown, hope abounds.”
There is an array of weeds and grasses in the foothills of the San Joaquin Valley right now. Roadsides and fields also abound in a crop of weeds and grasses not seen in several seasons. Tarweed is one of lygus' favorite host weed and can be a good indicator of what may be at hand with lygus migration.
And with the delay in planting, Goodell can only issue a warning to be aware that a crop of weeds can produce damaging populations of lygus bugs when cotton is squaring.
When the rain stops and the foothills dry down, lygus can flood into the valley. This may be the year when lygus pose a major problem.
Goodell told pest control advisers and growers at the recent Bayer CropScience Cotton Technology seminar that when the foothills dry down early, the lygus are less likely to damage cotton because there is no fruit to feed upon.
The last major lygus loss was probably 1978. This may not be a repeat because temperatures have been cooler this season than then.
Goodell said growers should be concerned about lygus migration from lygus habitat located up to miles away from their cotton.