Bean Leaf Beetle Pod Feeding Activity
Bean leaf beetle pod feeding. H. Bohner, OMAFRA
Reports have been coming in about pod feeding from bean leaf beetle (BLB) in IP, food grade and seed soybeans. Pod damage on crush beans typically does not warrant control.
Foliar feeding (defoliation) is rarely the concern this time of year. But BLB can feed on the surface of the pod which exposes the seed inside to pod diseases that can develop. Or they outright clip the pods off the plant, leaving them on the field floor untouched. Rarely is leaf defoliation a concern in the later R stages.
In IP, food grade or seed soybean fields still in the R4 to early R6 stages – if adults are still actively feeding in the field and 10% of the soybean pods inspected have feeding injury, a spray is warranted. If pods are being clipped off the plants and are found on the ground in several areas of the field, a spray is also warranted.
As cooler temps and changes in day length will trigger them to leave fields soon and prepare for winter. Pre-harvest harvest intervals, ranging from 21 to 30 days depending on the product, need to also be considered when determining if spray can still take place. Products registered can be found here: http://www.omafra.gov.on.ca/english/crops/pub812/pub812ch2.pdf