More black cutworm or soybean aphids this spring?

Weather conditions in April will play a large role in whether Michigan will get an increase in black cutworm and soybean aphid populations.

Chris can’t predict! As discussed in the article “How insects survive cold: The potential effect of a mild winter,” black cutworms don’t overwinter here, and move on weather fronts from south to north. An early warm-up in the south could increase populations in southern states, thus greater numbers of moths might be carried north next month. But that is not for certain, and weather conditions in April will play a big part in determining what moves north, and when. Our mild winter and spring play no role in that. The one way mild temperatures could contribute to black cutworm is through earlier, lusher weed growth, since moths lay eggs in weedy areas before the crop emerges. But again, weeds alone make no difference if no or few moths arrive from the south.

As for aphids, we didn’t find many eggs on buckthorn last fall, and I haven’t seen any soybean aphids yet. But buds on buckthorn were just opening last week. The newly hatched aphids are so small that they are hard to see. We will have a better idea of numbers in the next few weeks.

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