When sweep netting for lygus (shown above), it may seem that there are more lygus in the field than end up in the sweep net. This is expected. Sweep net thresholds were establishing knowing that lygus in the sweep nets represented only a certain percentage of lygus in the canopy. Stick to the thresholds, and follow sweep net techniques outlined…
Lygus
-
-
Second generation lygus have arrived. Young nymphs will reach late instar and adult stages in 5 to 14 days. When scouting to see if lygus numbers are near thresholds, include later instars — the ones with black dots on their back — as well as adults in the count. Bertha armyworm larvae are starting to feed in some locations…
-
-
Our current economic threshold tables for lygus in canola may be too low when applied to current canola production systems across the Prairies. If a canola stand is healthy and growing fast, growers are reportedly doubling or tripling thresholds. Say the threshold is 10 per 10 sweeps, some growers are doubling that to 20 per 10 sweeps as the action…
-
-
-
Insecticide control at the bud stage is rarely effective or economical even when counts are 15-20 per 10 sweeps. Under good growing conditions, canola can grow through this early damage without any yield loss. In some cases canola can actually yield more if some early bud feeding occurs. Lygus control at the bud stage may be warranted if all buds…
-
-
Our current economic threshold tables for lygus in canola may be too low when applied to current canola production systems across the Prairies. If the stand is healthy and growing fast, growers are reportedly doubling or tripling thresholds. There is no data to support this, but future research needs to reexamine the thresholds with respect to our newer varieties of…