Pecan Varietal Differences in Hemipteran Kernel Damage

Abstract

Pecan, Carya illinoensis Wangenh. (K. Koch), is susceptible to feeding by leaffooted bugs (Hemiptera: Coriedae) and stink bugs (Hemiptera: Pentatomidae) from fruit set to post harvest. These hemipterans are difficult to control with insecticide sprays. We found that 33 pecan varieties had consistent and significant differences in the incidence of hemipteran kernel damage indicating that host plant resistance may help solve this problem. The rank of varieties for average incidence of damage over 4 yrs, from highest to lowest was: ‘USDA 53-11-139’, ‘USDA 57-7-22’, ‘Shawnee’, ‘Moreland’, ‘USDA 40-9-266’, ‘USDA 49-20-112’, ‘Linberger’, ‘Cape Fear’, ‘Robinson’, ‘Shoshoni’, ‘USDA 64-11-17’, ‘USDA 55-12-17’, ‘Caddo’, ‘USDA 62-5-8’, ‘Sioux’, ‘Melrose’, ‘Tejas’, ‘Pawnee’, ‘Forkert’, ‘Kiowa’, ‘Owens’, ‘Candy’, ‘Gloria Grande’, ‘USDA 49-1-182’, ‘Western Schley’, ‘Creek’, ‘USDA 53-3-36’, ‘USDA 41-19-20’, ‘Maramec’, ‘Sumner’, ‘GraBohls’, ‘Kanza’, and ‘USDA 53-9-1’. Many of the more tolerant varieties have desirable kernel quality and often have good production characteristics, while many of the more susceptible varieties are also not horticulturally desirable. Adults of the southern green stinkbug, Nezara viridula (L.), and the leaffootted bug, Leptoglossus phyllopus (L), when placed in cages on pecan nut clusters by sex, differed in their ability to cause damage to ‘Cape Fear’, ‘Creek’, ‘USDA 64-11-17’, ‘Melrose’, and ‘Shoshoni’. Males of both species caused less damage than females, and N. viridula generally caused more damage than L. phyllopus.