Assessing resistance to southern green stink bug in five okra varieties

The southern green stinkbug (SGSB), Nezara viridula (L.), is an important pest of okra, Abelmoschus esculentus (L.).  Stink bug feeding can cause fruit to become warty and parrot beaked, reducing quality, and can introduce pathogens.  Control of this pest is with insecticides and currently there are very few products labeled for stink bugs in okra.  An alternative method of control is host plant resistance.  Low levels of host plant resistance can effectively lessen pest pressure by increasing developmental duration and reducing fecundity, and thus favor population regulation by natural enemies.  Experiments were conducted on five okra cultivars: Burgundy, Clemson Spineless, Hill Country Red, Silver Queen, and Star of David.  Arena choice studies and life table parameters were investigated in the laboratory.  Silver Queen was chosen the least often (6%) while Hill Country Red was chosen the most often (35%).  Survival from immature to adult (59%), net reproductive rate (240.5) and intrinsic rate of increase (0.079) was highest on Star of David and lowest on Silver Queen (33%, 8.9 and 0.022 respectively).  The five cultivars differed in their susceptibility to SGSB and Silver Queen appears to contain both antixenosis and antibiosis.