Soybean seed damage by different species of stink bugs

1 Damage caused by the three main species of stink bugs occurring on soybean Nezara viridula (Linnaeus), Piezodorus guildinii (Westwood) and Eusehistus heros (Fabricius) was compared in field cages and in greenhouses. Infestation levels of 4 stink bugs/m row of plants (field cages) and 2 stink bug/plant (greenhouse) for 15 days during the pod filling stage are reported. At harvest, the yield and seed quality were evaluated. 2 In the field, there was no difference in yield between infested and insect-free plants, but damage to seed quality varied with stink bug species. Plants damaged by P. guildinii had the lowest quality seeds. From 50 g seed samples harvested in the field, the mean weight of seeds classified as 'good' was 37.3 g in plants infested with P. guildinii, compared to 41.8, 44.2 and 46.6g in plants infested with E. heros, N. viridula and the control, respectively. 3 Plants infested with P. guildinii showed the highest number of seeds damaged by stink bugs, whereas those infested with E. heros showed the lowest damage. 4 Plants infested with P. guildinii had 18.5% damaged seeds, higher than the 3.6% and 3.4% damaged seeds from plants infested with the two other species and 0.1% in control plants. The percentage of non-viable seeds due to stink bug damage was 5.7% for P. guildinii but lower for the other two species.