ISSUE 5 June 1, 2000
CUTWORMS, APPLE MAGGOTS, AND SEED HEAD FORMATION
Have you just finished planting your flower or vegetable garden to come out the next morning to find ½ of what you planted cut off at the ground? Check carefully around the fallen victims and you will likely discover a plump larvae laying in a ½ circle sleeping off the previous nights gorging! I have found a couple in my garden and IDd them as black cutworm (Agrotis ipsilon). Immediately dispatch every one you find, and spread diatomaceous earth, broken egg shells, very sharp sand, or hydrated lime around each plant remaining. If you have acres to cover, then an appropriate soil insecticide for the crop in question should be used.
Apple maggots are going to become active now. The adults emerge from overwintering pupae in mid-June to early July and lay eggs in punctures in fruit skin; the eggs then hatch in about a week, and the larvae tunnel in the fruit until it drops, then leave to pupate in the soil for the winter. To control, collect and destroy dropped fruit daily until September, twice a month in the fall. Hang apple maggot traps in trees from mid-June until harvest - with 2-3 traps being average for good control. A planting of clover as a ground cover will attract beetles that prey on the pupae. Growing late maturing cultivars will help in control, as they prefer the earlier maturing fruit.
Seed head formation on bluegrass lawns is taking place now as well. This is in response of some cultivars to the lengthening daylight hours. Continue to mow your lawn at 2 ½ - 3 inches, and if you have not yet fertilized, make an application now. By the time we get into early July, the seedheads will have disappeared, and most lawngrass species will be in their vegetative stage. Some ask if they should delay mowing their lawns at this time to allow the seed to mature and drop, thinking this will thicken up their lawns. This is not true, of course, and in spite of your mowing height, the seedheads will still form below the last cut made.
NDSU Extension Horticulturist and Turfgrass Specialist
Department of Plant Sciences