Impact of soybean injury by Euschistus heros (Fabricius, 1794) (Hemiptera: Pentatomidae) on feeding preference and survival of Lasioderma serricorne (Fabricius, 1792) (Coleoptera: Anobiidae), and on soybean quality maintenance under storage

Abstract

Soybean cultivars tolerant to Euschistus heros injury - known as ‘Block® Technology’ cultivars - were recently released by Embrapa Soja to be cropped in Brazil. Thus, this study aimed to determine feeding preferences and survival rates of Lasioderma serricorne in stored soybean of different cultivars (‘Block® Technology’ and susceptible cultivars), as well as to analyze the grain quality of soybean cultivars after being exposed to two different E. heros outbreak levels (4-5 adults/m and ≤2 adults/m). Two ‘Block® Technology’ soybean cultivars (BRS 543 RR and BRS 1003 IPRO) and four susceptible soybean cultivars (BRS 1010 IPRO, BRS 1061 IPRO, NA 5909 RG and NS 5959 IPRO) were studied. The higher level of E. heros abundance (4-5 adults/m) reduced the nutritional quality of soybean for L. serricorne. It preferred and more severely attacked stored soybean which had been exposed to a lower E. heros level of abundance (≤2 adults/m) in the field. Also, the higher abundance of E. heros in the field triggered higher percentages of fermented grains, which increased with storage time. In conclusion, the studied soybean cultivars tolerant to E. heros in the field were not tolerant to L. serricorne injury under storage conditions. Moreover, despite higher tolerance of ‘Block® Technology’ cultivars to E. heros, our data show that long-lasting outbreaks of 4–5 adult stink bugs/m (R4 and R5 stages) should be avoided in the field since they triggered a higher percentage of fermented grains during storage, mainly in the first 3 months of storage.