No. 8/June 11, 2010
Cottony Maple Scale
Cottony maple scale, Pulvinaria innumerabilis, is very common this year in northeastern Illinois. This insect occurs in the northern half of Illinois, as far south as Danville and Lincoln. Cottony maple scale occurs most commonly on silver maple, but is also common on other maples including box elder. It is also common on black walnut, honey locust, linden, black locust, red mulberry, and white ash.
Twicestabbed Lady Beetle
The adult twicestabbed lady beetle is one-eighth inch in diameter and black with two red spots on the back. It overwinters under loose bark as an adult beetle, emerging in the spring to feed on the overwintered cottony maple scales through the spring.
Cottony Maple Scale Management
Control of cottony maple scale can be achieved in several ways. Letting nature take its course and allowing the twicestabbed lady beetles to provide control is one option. Another is to apply a crawler spray after the cottony maple scale crawlers hatch about mid-July. Acephate (Orthene), acetamiprid (TriStar), bifenthrin (Talstar, Onyx), cyfluthrin (Tempo), insecticidal soap, malathion, and summer spray oil are all effective crawler sprays.
Bagworms, earwigs, and grass sawfly are the subject for this week's scouting watch.
Friend or Foe: Giant Hogweed and Its Look-alikes
Giant Hogweed (Heracleum mantegazzianum) is a member of the carrot or parsnip family (Apiaceae). While many members of this family are native to Illinois, Giant hogweed is an invasive species that was brought from Asia in the 1900's. This plant was most likely brought as an ornamental because of its showy white flowers and impressive size. However, it is very aggressive and noxious.
Hemlock Wooly Adelgid: Know This Tree Killer!
The Hemlock Wooly Adelgid (Adelges tsugae) is an invasive species that was brought from Japan to the Western United States in the 1920's. The insect has since moved east and can now be found in Georgia, the Carolinas, through the Appalachian Mountains and in parts of the New England area. The Hemlock Wooly Adelgid is of particular concern because, unlike the Hemlocks in its native range in Japan, American hemlock species have no defenses against it.
Additional notes on NPDES General Permit Comment Period
In last week's issue, notice was given of a NPDES General Permit Comment Period. It seems that this EPA announcement (and the whole concept of requiring NPDES permits) has spurred considerably more questions than answers. We in the Pesticide Safety Education Program are currently unclear about the exact scope of this matter and we encourage all pesticide applicators to participate in these sessions, ask questions, and submit comments.