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G -- B
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S1996
A bi-weekly newsletter on Landscape IPM for the Green Industry
| Volume 1, Issue 1---------- | Bonnie J. Gonzalez | ---------- April 29 - May 4 , 1996 |
INTRODUCTION
Welcome to the first edition of Bug Bytes, a bi-weekly newsletter on IPM for the Green Industry. Information on what's feeding on what, disease activity, monitoring techniques, indicator plants, use of traps, and other up-to-date landscape control options will be highlighted. Since most of you have little time to read, the format presented here will be in bullet form so that you will know in quick bytes what is going on now and what you can do to control the problem. Your input and suggestions are valuable in the development of this newsletter. Don't be a stranger - phone or fax me with your ideas. If I do not know the answer, I will find it and get back to you.
PHENO: BRIDAL WREATH SPIREA
Spirea X vanhouttei is coming into full bloom this week. This white flowering shrub is often found in older landscapes and its three distinct bloom phases are useful tools for timing certain pest activities. These phases are full bloom (FB), past bloom with some brown blossoms (PB), and finished bloom with most blossoms brown (EB). These phases are easily seen from a distance. The following insects are vulnerable to controls at this time:
Flat-headed and Round-headed Apple Tree Borer (PB) Bronze Birch Borer (PB) Elm Leaf Beetle (FB) Lilac/Ash Borer (PB) Oystershell Scale (EB)Please note that Juniper webworm is no longer vulnerable to control at this time (EB).
EASTERN TENT CATERPILLARS
The tents should be quite visible by this time. ETC hatched out two weeks ago when the Saucer Magnolias were in early bloom. Break open the tents now and manually destroy the caterpillars (using gloves, of course) or spray trees with Bt. If using Bt, make sure to cover the foliage completely. The caterpillars must ingest the treated foliage in order to be affected by the Bt.
AZALEA LACEBUG
Azalea lacebugs have just hatched this week in azalea hosts. Look on the undersides of leaves well inside of the plants to see black specks (fecal matter) and also eggs. The eggs are often laid near the midrib of the leaf. Newly hatched nymphs will feed together at first, causing a concentrated bleached area on the upperside of the leaves. Try to catch them with the first spray before they become adults with wings and can fly to other leaves or plants. Orthene will give the best results. Oil or soap can also be used, but excellent coverage will be necessary, especially to the underside of leaves. One well-timed spray is better than a poorly executed one.
DOGWOOD ANTHRACNOSE
Discula destructiva is the fungus responsible for killing many of our native dogwoods. Management with fungicides begins as buds are breaking. Make applications now at 10-14 day intervals until the leaves have fully expanded and the weather becomes drier. You can use chlorothalonil (Daconil), propiconizol (Banner), Mancozeb, or captan. Prune out any watersprouts that come out on the trunk or main branches. These sprouts are quick entry points for the fungus. Suggest alternative replacements such as Kousa dogwoods and other spring flowering trees.
SPRUCE SPIDER MITES
These cool season mites become active when the Saucer Magnolias begin to bloom. They feed on spruce, juniper, pine, arborvitae, leylands, and other evergreen hosts. Their damage is often noted on the older growth and this is often where they tend to feed. Take a white sheet of paper and place under a branch and tap mites onto the paper. You will see very small dark mites on the paper. A 10X handlens may be necessary to see them. Spruce mites are active for about 6 weeks in the spring and not again until the fall when cool temps return. Manage light populations with oil insuring good coverage - several applications may be necessary. Heavier populations may require a more aggressive material such as Morestan (avoid spraying wet foliage), kelthane, Avid, or Cygon.
APHIDS
OK, so there are aphids of all kinds. They are best managed early in the season with oil or soap for several repeat applications. Early intervention will allow beneficial populations to build up so they can control them later in the season. Some types of aphids are not managed so easily and will be highlighted in upcoming issues. Monitor for ants that often tend colonies of aphids. They protect aphids that produce honeydew which the ants like. You may need to control the ants so that the natural predators can prey on the aphid colonies.
BOXWOOD PSYLLID
Boxwood psyllids are responsible for the cupped leaves on boxwoods. They are active now and can be controlled with oil or soap sprays insuring complete coverage of foliage with spray material.. The young nymphs can be recognized by lokking inside the cupped leaves for small, light greenish white psyllids. They will become adults by June and will be white and fluffy. A residual insecticide will be necessary at that time. You can use acephate (Orthene) for the nymphs. A better kill rate may be achieved if populations are high.
FIREBLIGHT
Warm days and cool nights bring on conditions favorable for this bacterial disease of Hawthorn, Pyracantha, Crabapples, Pears, Cotoneaster, and Amelanchier. Look for a scorched appearance on affected branches and the typical "shepherd's crook" where the terminal shoots bend over. A bacterial ooze can be seen during warm weather and is spread by birds and other hosts. Prune out affected shoots when possible making sure to sterilize your pruning tools between cuts if possible and certainly between plants. Spray at 10-14 day intervals with Agri-strep or copper containing fungicides labeled for fireblight. Continue sprays until weather becomes drier in a few weeks.
LET ME KNOW!
Tell me what you want to hear about. I will report to you on things I come across in the landscape. My goal is to provide you with timely information on diagnosis and remedies for many of the problems that occur on key plants in the landscape. These are plants that either have common problems or are plants found frequently in the landscape. Until next time, this is THE BUG LADY. Have a nice week!
Until next time, keep on scouting!!
Bug Bytes is written, distributed and owned by HORTSERVICES, and produced by Gregg Leonard Graphic Artistry, both of Loudoun County, Virginia. All rights reserved---no part may be reproduced without permission.
Bonnie J. Gonzalez
16 Berkeley Court
Sterling, VA 20165
(703) 430-4545
when your plants need help. She knows her plants as well as her bugs.
Remember, IT’S NOT OVER… UNTIL THE BUG LADY STINGS!