black pecan aphid, treatment comparisons

Four collections of leaves lined up next to one another. Each grouping shows different rates of yellowing and browning caused by the black pecan aphid.

These leaves show chlorotic feeding
injury elicited by the black pecan aphid
on pecan when treated with a standard
insecticide treatment, an untreated control
and two different rates of gibberellic
acid. Treatments began in late July and
continued through mid-September.
Foliage shown here was collected in mid-
September. (Photo by Ted Cottrell)