COLUMN

Fall lawn care, syrphid flies

By John Fulton

[September 12, 2013]  The time of year has arrived to put that final push on to prepare your lawn for the upcoming winter months. What you do now will have a big impact on how your lawn will look next spring.

Grub problems have traditionally been found first along walks, driveways or patios. The current list of products includes imidacloprid and trichlorfon as the active chemical ingredients. Sevin may also be used, but it is specific for Japanese beetle grubs. Sevin also will have an effect on earthworms, which is good and bad. It is good if you have mole problems and bad if you don’t. If label directions are followed, these should provide adequate control of grubs. The insecticide must get to where the grubs are, so make sure to water the liquid formulations in as soon as they are applied.

Seeding of grass is normally accomplished by Sept. 10. This is a tried-and-true date, but the end of the world won't come about if you are a week later. The goal is to give the seed enough time to germinate and become established before bad weather arrives. The dry weather again this year means seed sown in mid-August would still be lying there (if birds haven’t found it). Seed at the rate of 4 pounds of seed per 1,000 square feet on bare spots, or half that rate on overseedings.

If you have a compacted yard or a deep thatch layer, now is also an ideal time to dethatch or aerate. Thatch layers should not be over 1/2-inch deep for optimum growing conditions. When aerating, make sure you use a core-type aerator.

Fall fertilization is also a good practice. If you haven't fertilized in the last month, consider applying a fertilizer treatment now. Use about 8 pounds of 13-13-13 fertilizer per 1,000 square feet of lawn. Try to avoid the high-nitrogen fertilizers this late in the year. It's hard enough to keep up with the mowing as it is, and nitrogen promotes top growth. The even-analysis fertilizers will also promote root growth, which is what we want, going into the late fall and winter.

Crabgrass and other annual grass weeds can be seen about everywhere, but they have been affected by the hot, dry weather that has sent many lawns into dormancy. The annual weeds surviving the weather thus far will die with the first frost, so treatment is not available or recommended in the fall. Make a note of where these grasses are, and an overseeding to thicken up the grasses you want there may help crowd out the annuals.

What most people call sweat bees are actually syrphid flies. Many people are commenting about the yellow and black "sweat bees" flying around everywhere the last week. If you have several in an area, you can hear the drone as the wings vibrate. Syrphid fly is a generic name given to an entire group of flies. There are some differences in appearance and color, but the yellow and black color is the major one in our area. The other names for syrphid flies are hover flies or flower flies. They tend to hover around your arms and face when you have been perspiring, and they land to lap up the sweat. They are also commonly found on flowers, hence the flower fly name, and they do a good job of pollinating.

Syrphid flies are actually beneficial insects. They help pollinate; larvae feed on dead organic matter; and the larvae are predators of aphids. Syrphid flies cannot sting, but their mouthparts can usually be felt when lapping up sweat from sensitive areas. You may feel a slight pinch.

[By JOHN FULTON, University of Illinois Extension]