Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, June 11, 1995 TAG: 9506130009
SECTION: HOMES PAGE: E-1 EDITION: METRO
SOURCE: JOHN ARBOGAST
DATELINE: LENGTH: Medium
This name has been given to the worm that is enclosed in a cone-shaped bag that hangs from branches and consumes foliage. These bags are easily mistaken in mid- to late summer for pine-cone-like structures that belong on the plant.
Unfortunately, folks who call the extension office at the time they see the bags will be out of luck, because larger larvae are not as easily killed as they could be now.
Overwintering bagworm eggs normally begin hatching in early June. However, this year they likely are ahead of schedule thanks to our mild winter. The tiny larva (worm in this case) immediately begins to construct a tiny silken bag around itself and starts feeding. Larvae and bags remain small, less than 1/4-inch long, for a few weeks and thus are not easily discovered. This is why we need to inspect plants now, especially those that had bagworms last summer, to look for those small bagworms while they are more susceptible to insecticides. There is just one generation of bagworms per year.
``Bags'' increase to 11/2 inches by late summer. Bits of leaves and twigs from the host plant are used in constructing the bag, thus helping it to blend in with the host plant.
Control of bagworms with organic or synthetic pesticides must be done by mid-June while the worms are still rather young and small.
Recommended control products include: the organic Bacillus thuringiensis, also known as Bt and sold under many trade names; Orthene, Dursban or Cygon.
Q: Please tell me what to do about my beautiful iris. They have been in the ground for about five or six years. Last year they had a few blooms; this year there were even fewer blooms. Before then the iris blooms were beautiful. Should I dig them up and separate them? Fertilize? Cut the leaves back? I have heard that a lot of people have had the same problem. The iris leaves look good. E.H., Roanoke
A: Crowded iris tubers, increasing shade, any adverse conditions in the iris bed such as excessive weed or grass competition, and a shortened life of the iris leaves the preceding summer all can cause poor iris blooming. Five or six years probably is not enough time for an iris planting to become crowded with the result of declining blooms as yours did in the last two years unless you planted the iris at close spacing to begin with.
However, digging your iris to separate and promptly replant them as you suggested would be a good idea any time now that the blooming is completed. This will give you an opportunity to inspect the tubers, looking for signs of deterioration, decay or iris borer damage. Cut out bad tuber parts if found and replant only those healthy ones.
Fertilizer is optional for irises unless a soil test reveals very poor soil. You wrote that your iris's leaves look good, so don't expect results from fertilizing. You can scatter a light amount of 10-10-10 over an iris planting immediately after they bloom.
Iris foliage needs a long healthy growing season in order to produce food for the next growing season. So, don't cut the iris foliage as long as it is still green.
Send short questions about your lawn, garden, plants, or insects to Dear John, c/o the Roanoke Times & World-News, P.O. Box 2491, Roanoke 24010-2491. We need your mail, but this column can't reply to all letters. Those of wide appeal will be answered each week. Personal replies cannot be given. Please don't send stamps, stamped envelopes, samples, or pictures.
by CNB