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| Updated:
April, 2008 |
The Grapevine
Here Comes the Bugs!!!!!
Time
to Check for Spruce Spider Mits
The mite spends the summer and winter months in the egg stage. As temperatures
cool in the fall, or warm in the spring, the eggs hatch, making this a "cool-season"
mite. Overwintered eggs will hatch when we reach a GDD of 162, which
is also when the full bloom of 'Bradford' callery pears. Both of these predictors
should be met later this week with the predicted warm temperatures.
Some of you have had problems with this pest in the past, so beware!
Hosts include spruce, arborvitae, juniper, hemlock, pine, Douglas-fir, true firs, and sometimes other conifers. The mites feed by rupturing individual cells of the host's foliage, producing characteristic tiny yellow spots, or "stippling." As the stippling coalesces, foliage becomes bleached and eventually bronze-colored. Inner foliage is generally affected first.
A "beating tray" is the most effective tool for discovering and assessing spruce spider mite populations. Simply us an 8.5" x 11" tablet of white paper. Hold the white target beneath the conifer foliage and shake the foliage several times causing the mites to drop onto the white target. Next, tilt and lightly tap the collection paper or tray to allow plant debris to fall off.
Look closely for small, slow-moving dots, not much bigger than the period at the end of this sentence. These are the spider mites. The faster moving dots are likely to be predaceous mites; the good guys that feed on the spider mites. A finger can be used to "mash and smear" the mites to further distinguish the good mites from the bad. Greenish-brown streaks are "pate de spider mite."
Effective management efforts include washing (syringing) mites from the foliage using a heavy stream of water, applications of soaps and oils, or applications of traditional miticides. Syringing will conserve predaceous mites, but may be difficult on large trees or large numbers of trees. Soaps and oils are also kind to predators, but oils will wash away the blue color on Colorado blue spruce. Give us a call if you need insecticide recommendations.
Source– Buckeye Yard & Garden Line (BYG)
The mite spends the summer and winter months in the egg stage. As temperatures
cool in the fall, or warm in the spring, the eggs hatch, making this a "cool-season"
mite. Overwintered eggs will hatch when we reach a GDD of 162, which
is also when the full bloom of 'Bradford' callery pears. Both of these predictors
should be met later this week with the predicted warm temperatures.
Some of you have had problems with this pest in the past, so beware! Hosts include spruce, arborvitae, juniper, hemlock, pine, Douglas-fir, true firs, and sometimes other conifers. The mites feed by rupturing individual cells of the host's foliage, producing characteristic tiny yellow spots, or "stippling." As the stippling coalesces, foliage becomes bleached and eventually bronze-colored. Inner foliage is generally affected first.
A "beating tray" is the most effective tool for discovering and assessing spruce spider mite populations. Simply us an 8.5" x 11" tablet of white paper. Hold the white target beneath the conifer foliage and shake the foliage several times causing the mites to drop onto the white target. Next, tilt and lightly tap the collection paper or tray to allow plant debris to fall off.
Look closely for small, slow-moving dots, not much bigger than the period at the end of this sentence. These are the spider mites. The faster moving dots are likely to be predaceous mites; the good guys that feed on the spider mites. A finger can be used to "mash and smear" the mites to further distinguish the good mites from the bad. Greenish-brown streaks are "pate de spider mite."
Effective management efforts include washing (syringing) mites from the foliage using a heavy stream of water, applications of soaps and oils, or applications of traditional miticides. Syringing will conserve predaceous mites, but may be difficult on large trees or large numbers of trees. Soaps and oils are also kind to predators, but oils will wash away the blue color on Colorado blue spruce. Give us a call if you need insecticide recommendations.
Source– Buckeye Yard & Garden Line (BYG)
Eastern Tent Caterpillars
Coming Soon!!!!
The Eastern tent caterpillars (ETC) are covered in short, grayish-white hairs
and have a distinct, unbroken white stripe down their backs. ETC is an accomplished
and prolific tent-maker producing highly visible silk nests in the forks
of branches. The tents are only about 1-2" across and difficult to spot.
The caterpillars hatched when we reached 92 GGD (from earlier
article) The caterpillars prefer to feed on trees in the family Rosaceae,
particularly those in the genus Prunus, such as cherries. They also occasionally
feed on ash, birch, maple, and oaks.
These general defoliating caterpillars are capable of causing serious stress to their host trees. Leaves lost to caterpillar feeding this spring must be replaced using energy stored from last season. Small ETC nests can be eliminated digitally using five-fingered "smash and/or smear" techniques.
Less hands-on methods include applications of the naturally occurring Bacillus thuringiensis (Bt), applied to early instar stages, as well as other insecticides listed for general caterpillar control in the OSU Extension Bulletin 504, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials" [http://ohioline.osu.edu/b504/index.html].
Another pest to watch out for are European pine sawflies, which hatch at about 144 GGD, which we should reach this week. So be on the lookout for these caterpillars in the next few weeks as well.
Coming Soon!!!!
The Eastern tent caterpillars (ETC) are covered in short, grayish-white hairs
and have a distinct, unbroken white stripe down their backs. ETC is an accomplished
and prolific tent-maker producing highly visible silk nests in the forks
of branches. The tents are only about 1-2" across and difficult to spot.
The caterpillars hatched when we reached 92 GGD (from earlier
article) The caterpillars prefer to feed on trees in the family Rosaceae,
particularly those in the genus Prunus, such as cherries. They also occasionally
feed on ash, birch, maple, and oaks.These general defoliating caterpillars are capable of causing serious stress to their host trees. Leaves lost to caterpillar feeding this spring must be replaced using energy stored from last season. Small ETC nests can be eliminated digitally using five-fingered "smash and/or smear" techniques.
Less hands-on methods include applications of the naturally occurring Bacillus thuringiensis (Bt), applied to early instar stages, as well as other insecticides listed for general caterpillar control in the OSU Extension Bulletin 504, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials" [http://ohioline.osu.edu/b504/index.html].
Another pest to watch out for are European pine sawflies, which hatch at about 144 GGD, which we should reach this week. So be on the lookout for these caterpillars in the next few weeks as well.
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OSU Extension Office - Union
County
18000 State Route 4, Suite E
Marysville, OH 43040-8390
Phone:800/589-8584, 937/644-8117
Fax: 937/644-3062
Email:unio@cfaes.osu.edu
Ohio State University Extension embraces human
diversity and is committed to ensuring that all research and related
educational programs are available to clientele on a nondiscriminatory
basis without regard to race, color, religion, sex, age, national origin,
sexual orientation, gender identity or expression, disability, or veteran
status. This statement is in accordance with United States Civil
Rights Laws and the USDA.
Keith L. Smith, Ph.D., Associate Vice President for Agricultural Administration and Director, Ohio State University Extension TDD No. 800-589-8292 (Ohio only) or 614-292-1868
Keith L. Smith, Ph.D., Associate Vice President for Agricultural Administration and Director, Ohio State University Extension TDD No. 800-589-8292 (Ohio only) or 614-292-1868
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Revised April, 2008