David Owens, Extension Entomologist, owensd@udel.edu
Small Grains
Aphid populations are spotty in small grains. Some barley fields have very high populations, with reports up to 70 per foot in some spots. The good news is that parasitoid and lady beetle activity is much greater this spring than last year. Fungal infected aphids have also been detected. The natural enemies should keep aphids from taking off this year. Malting barley seems to be more susceptible to aphids than wheat or feed barley, but there is very little research on the matter. Last year we had little parasitoid activity in March and early April when aphid populations really took off. In a small plot malt trial, we did not see any quality loss due to aphid numbers, but possible yield loss with a population that was at or above our typical small grain threshold for 3 weeks. Wheat yields did not appear to be affected by the enormous but brief 2019 aphid outbreak.
Alfalfa
Sometime during the week of March 30 southern Delaware will have accumulated enough degree days for alfalfa weevil eggs to start hatching. Be on the lookout for them. We will be posting updated alfalfa insect control recommendations on our website soon.