Damage by redbanded stink bug (Hemiptera: Pentatomidae) in R2-R6 growth stage soybeans

The redbanded stink bug (RBSB), Piezodorus guildinii Westwood, (Hemiptera: Pentatomidae) is an emerging pest of soybeans in the southern states of the US.  It has become the most abundant stink bugs species in Texas soybeans. Field cage studies were conducted to determine the damage potential of RBSB during R2-R6 growth stages of soybeans. Soybeans at respective growth stages were infested with varying densities (0, 1, 2 and 4 RBSB adults/cage) of field collected RBSB adults. At each growth stage four adjacent plants were randomly selected and cylindrical wire mesh cages were installed to confine RBSBs on the plants. RBSB infestation was maintained for 10 days after which cages were removed and plants were repeatedly sprayed with acephate. Plant responses were measured in terms of leaf chlorophyll content, rate of photosynthesis, number of flat pods, seed yield, and number of green leaves at maturity. RBSB infestation during R4-R6 growth stages significantly increased the number of flat pods. Yield responses were also significantly different among treatments. Highest seed yield was recorded in control plants (50 gm/plant) while the least (21 gm/plant) was recorded when soybeans at R6 stage were infested with 4 RBSBs/cage. RBSB infestations at R4 stage significantly increased the leaf chlorophyll content and number of green leaves per plant at maturity indicating the potential role in delayed maturity syndrome of soybeans.