Lygus has moved to the front of the line as one the most troublesome cotton pest in the United States. It is a promotion by default, according to University Arizona entomologist Peter Ellsworth, based at the Maricopa Ag Center in Central Arizona.

The bollworm/budworm complex continues to rank as the No. 1 cotton pest Beltwide, reducing yields by 1.5 percent, but lygus is a close second with 0.95 percent loss. In some areas lygus losses are much higher than that with the plant bug as the No. 1 pest.

According to Michael Williams, Extension entomologist at Mississippi State University, lygus is emerging as a sectionalized pest, with Lygus lineolaris infesting the Mid-South and Lygus hesperus infesting the western United States. Cost of control for this pest Beltwide was $10.49 per acre in 2005.

Ellsworth, was on a panel of entomologists with Williams reporting on cotton yield losses to insects at the recent Beltwide Cotton Conference in San Antonio, Texas. He said lygus have long been part of the insect pest complex that threatens U.S. cotton. For years, however, lygus has taken a back seat to boll weevil, pink bollworm and other lepidopterous pest. Now that the weevil has been all but eradicated and worm pests have been brought to their tiny knees with Bt cotton, lygus has become the bad boy down the cotton rows.

Lygus is not taking a significantly larger share of cotton yield losses, but it is taking a bigger percentage of growers' pest control costs, said Ellsworth. In Arizona it accounts for 40 percent of a grower's pest control cost. Beltwide it is 20 percent.

The UA entomologist disagrees with those who say lygus represent the next generation of cotton pests.

“Lygus is not really a new pest, just a bad actor that we have not had to deal with for some time. Its prevalence and promi-