Saturday, June 27, 2009
Old Field Report (what problems I am seeing in NH, MA and ME)
06/27/09
Winter Moth was huge this year in Massachusetts around Topsfield. I have not seen this pest in NH yet but that does not mean it is not here yet.
Eriophyid mites have been growing in populations on Hemlock and Spruce. These mites do not need the hot dry weather of other mites.
Red Thread seems to be on almost every lawn I see in NH
Black knot on Prunus is heavy.
Note that some diseases such as Red Thread and Black knot can spread with infected tools. Diseases often run through developments as landscapers travel from lawn to lawn and tree to tree without sterilizing equipment.
Apple Scab, Fire blight and Cedar Apple rust are also common this year due to the weather.
Lily leaf beetle were everywhere this year. If you lost your flowers and leaves think about doing something in the spring, its too late to bother this year for the most part. These things are pretty easy to kill with low toxicity products, but hatch for a long period so have to be treated almost weekly. You can soil treat when the lilies first show through the soil and this will control them for a full year.
The usual suspects on the landscape at this time of year regular mites, lacebug, Mealybug are still low in populations due to the cold wet weather.
I am seeing increasingly more scale insects but this is usually on and around customers properties that have been treated with broad spectrum insecticides. Many of these broad spectrum chemicals will kill scale in its vulnerable stage, but that is only about 2-3 weeks long. The rest of the time people are using these to kill scale it is doing nothing but killing all the predators. I can always tell that one product in particular has been used the year before I see a property because of the amount and variety of scale insects.
I am sure we will be seeing a lot more diseases because of the weather. Most of which it will be too late to do anything about for this year.
Thursday, June 25, 2009
Hemlock Woolly Adelgid control
The Hemlock Woolly Adelgid is a sucking insect that is like an aphid. It is introduced and therefore has no natural enemies and left untreated will kill Hemlocks. You can find Hemlock Woolly Adelgid by looking for small cottony masses at the crotch of the needles. The good news is that Hemlock Woolly Adelgid is easily controlled in the landscape and treatment can be applied any time of year. Late winter or very early spring treatments are most effective in New Hampshire and New England. The bad news is that Hemlock Woolly Adelgid is almost impossible to control in a forest situation.
The most common control treatments for Hemlock Woolly Adelgid are Horticultural Oil and Merit (Imidacloprid). Here I discuss the benefits and problems of each.
Horticultural Oil is an ultra refined Oil that is almost non toxic to other organisms and is not hard on insect predators.
Benefits
Horticultural Oil will give you quick results.
Is relatively cheap.
Is available at most stores that sell gardening supplies.
Can be easily applied with hand or backpack sprayer if the plant is not too large.
Problems
As oil works by smothering, any insect not covered with oil will not be killed.
Oil has no residual and must be re-applied if new insects reach the plant.
Can burn if it is used when the weather is hot and sunny, or if sprayed before new growth has hardened.
Can be hard to apply on tall trees, or plants that are not accessible to application equipment.
Imidacloprid is a neonicotinoid, which is a class of neuro-active insecticides modeled after nicotine and acts on the nicotinic acetylcholine receptor. Imidacloprid is notable for its relatively low toxicity to most animals other than insects due to its specificity for this type of receptor.
Benefits
Imidacloprid Is a systemic (a chemical that is taken up by the plant) and will travel within the plants vascular system to all parts of the plant where it will kill all the Hemlock Woolly Adelgid.
Will stay in the plant and kill the pest for two years. (some tests have shown that this can be a lot longer.)
Is usually injected into the soil, or sometimes directly into the tree trunk, reducing the chance of drift to non target areas.
Can be applied by digging small holes around the plant and placing the product in the hole, thus allowing plants to be treated that can not be reached by an oil spray.
Has a low mammalian toxicity, compared to some other common pesticides.
Breaks down quickly when exposed to sunlight
Problems
Imidacloprid is expensive.
Takes time to travel from the roots to the branches, thus Hemlock Woolly Adelgid can feed for several weeks and in a heavy infestation may have time to kill the plant before the chemical can control them.
Under certain conditions has been known to travel through the soil to water sources. ( Before applying, read the label and pay attention to situations where this may happen. )
Will kill benaficial insects including predators of Mites, another common problem on Hemlocks, though these pests rarely will kill Hemlocks.
Breaks down quickly when exposed to sunlight
Conclusion
Wherever possible Oil is my first choice for control of Hemlock Woolly Adelgid because of its ease of use, quick kill and low toxicity to other organisams. I try to reserve the use of Imidacloprid for use where the plant is is hard to treat with oil. One other reason that I tend to restrict my use of imidacloprid is because it is so effective on many hard to kill insects. Indeed for some insects, such as those have become resistant to other chemicals it is about the only product that will affect control. Overuse and or incorrect use of Imidacloprid could lead to resistance, or use restrictions, and this would remove a valuable weapon for the careful applicator. Imidacloprid is also the ingredient in most white grub control products for lawns and is used a lot by home owners.
Xavier
IPM OF New Hampshire
The most common control treatments for Hemlock Woolly Adelgid are Horticultural Oil and Merit (Imidacloprid). Here I discuss the benefits and problems of each.
Horticultural Oil is an ultra refined Oil that is almost non toxic to other organisms and is not hard on insect predators.
Benefits
Horticultural Oil will give you quick results.
Is relatively cheap.
Is available at most stores that sell gardening supplies.
Can be easily applied with hand or backpack sprayer if the plant is not too large.
Problems
As oil works by smothering, any insect not covered with oil will not be killed.
Oil has no residual and must be re-applied if new insects reach the plant.
Can burn if it is used when the weather is hot and sunny, or if sprayed before new growth has hardened.
Can be hard to apply on tall trees, or plants that are not accessible to application equipment.
Imidacloprid is a neonicotinoid, which is a class of neuro-active insecticides modeled after nicotine and acts on the nicotinic acetylcholine receptor. Imidacloprid is notable for its relatively low toxicity to most animals other than insects due to its specificity for this type of receptor.
Benefits
Imidacloprid Is a systemic (a chemical that is taken up by the plant) and will travel within the plants vascular system to all parts of the plant where it will kill all the Hemlock Woolly Adelgid.
Will stay in the plant and kill the pest for two years. (some tests have shown that this can be a lot longer.)
Is usually injected into the soil, or sometimes directly into the tree trunk, reducing the chance of drift to non target areas.
Can be applied by digging small holes around the plant and placing the product in the hole, thus allowing plants to be treated that can not be reached by an oil spray.
Has a low mammalian toxicity, compared to some other common pesticides.
Breaks down quickly when exposed to sunlight
Problems
Imidacloprid is expensive.
Takes time to travel from the roots to the branches, thus Hemlock Woolly Adelgid can feed for several weeks and in a heavy infestation may have time to kill the plant before the chemical can control them.
Under certain conditions has been known to travel through the soil to water sources. ( Before applying, read the label and pay attention to situations where this may happen. )
Will kill benaficial insects including predators of Mites, another common problem on Hemlocks, though these pests rarely will kill Hemlocks.
Breaks down quickly when exposed to sunlight
Conclusion
Wherever possible Oil is my first choice for control of Hemlock Woolly Adelgid because of its ease of use, quick kill and low toxicity to other organisams. I try to reserve the use of Imidacloprid for use where the plant is is hard to treat with oil. One other reason that I tend to restrict my use of imidacloprid is because it is so effective on many hard to kill insects. Indeed for some insects, such as those have become resistant to other chemicals it is about the only product that will affect control. Overuse and or incorrect use of Imidacloprid could lead to resistance, or use restrictions, and this would remove a valuable weapon for the careful applicator. Imidacloprid is also the ingredient in most white grub control products for lawns and is used a lot by home owners.
Xavier
IPM OF New Hampshire
Hemlock Woolly Adelgid
What is that white stuff on my Hemlocks? It could be Woolly Adelgid. This is a fairly easy pest to control on the landscape, though almost impossible to control in the forest. Horticultural Oil easily kills this pest if you can get 100% coverage. Merit (imidicloprid) injected into the soil will also control Hemlock Woolly Adelgid. Imidicloprid can take several weeks to reach the tops of trees depending on hight. Imidicloprid will also kill the predators of mites so should generally be used only if the Woolly Adelgid on your hemlocks can not be controlled by Oil due to tree size or accessibility.
Xavier
IPM OF New Hampshire
www.ipmofnh.com
Posted by IPM Man at 12:44 PM
What is that white stuff on my Hemlocks? It could be Woolly Adelgid. This is a fairly easy pest to control on the landscape, though almost impossible to control in the forest. Horticultural Oil easily kills this pest if you can get 100% coverage. Merit (imidicloprid) injected into the soil will also control Hemlock Woolly Adelgid. Imidicloprid can take several weeks to reach the tops of trees depending on hight. Imidicloprid will also kill the predators of mites so should generally be used only if the Woolly Adelgid on your hemlocks can not be controlled by Oil due to tree size or accessibility.
Xavier
IPM OF New Hampshire
www.ipmofnh.com
Posted by IPM Man at 12:44 PM
Fertilizing Sick Trees
Fertilizing Stressed Trees
For the most part trees, especially older trees, do not need to be fertilized. There are some cases where fertilization can help a tree but these are uncommon. Indeed the careless fertilization of a sick tree can do more harm then good. For instance a Hemlock that is sick because it is infested with Woolly Adelgid is likely to die more quickly if it is fertilized, as the Woolly Adelgid reproduces faster when the tree is fertilized.
Some questions you kneed to ask before fertilizing a stressed tree are:
Is it diseased?
Are pests causing the problem?
Is the tree root bound or does it have girdling roots?
Was this tree planted too deep?
Is there too much mulch and is it touching the tree trunk?
Is the tree suffering from soil compaction?
Is the soil PH right for this tree?
Is this the right tree for its environment?
Has something changed, like sudden exposure to more sun?
Is the tree suffering from drought, or too much water?
Have the roots of the tree been disturbed by construction?
Once you rule out other causes of stress, take a soil sample and have it analyzed.
Only a soil test can tell you if and what your soil is lacking for good tree growth.
Here is more on why we don't just fertilize a sick tree.
For the most part trees, especially older trees, do not need to be fertilized. There are some cases where fertilization can help a tree but these are uncommon. Indeed the careless fertilization of a sick tree can do more harm then good. For instance a Hemlock that is sick because it is infested with Woolly Adelgid is likely to die more quickly if it is fertilized, as the Woolly Adelgid reproduces faster when the tree is fertilized.
Some questions you kneed to ask before fertilizing a stressed tree are:
Is it diseased?
Are pests causing the problem?
Is the tree root bound or does it have girdling roots?
Was this tree planted too deep?
Is there too much mulch and is it touching the tree trunk?
Is the tree suffering from soil compaction?
Is the soil PH right for this tree?
Is this the right tree for its environment?
Has something changed, like sudden exposure to more sun?
Is the tree suffering from drought, or too much water?
Have the roots of the tree been disturbed by construction?
Once you rule out other causes of stress, take a soil sample and have it analyzed.
Only a soil test can tell you if and what your soil is lacking for good tree growth.
Here is more on why we don't just fertilize a sick tree.
Ten fun and easy ways to kill your trees and shrubs.
Sick of all those trees and shrubs cluttering up the yard? Enjoy buying and exterminating expensive plants? Read on my friends and find out how to kill all that pesky vegetation.
1: Plant too deep
Sure fire way to kill a plant. Some plants survive years before succumbing to this method. Eventually they will either grow girdling roots that wrap around the tree and choke it to death, or the deep roots will die due to lack of air. For added fun you can fertilize these trees every year and watch them green up in a hopeless attempt to survive.
2: Mulch deep and up to the trunk
Much the same as #1. You can do this yourself or have your landscaper do it for you. Ah ha you say, but mulch is good is it not? Correct my friend it is, when kept away from the trunk and not more than 3-4” deep, so be sure to get it deep and touching the trunk and the tree will suffer and die just like in method #1.
3: Bury the roots
If you are the unhappy homeowner who inherited properly planted and mulched trees and don’t want to spend the money on mulch. Then just pile up soil around the roots, or if you are lazy you can just let all the grass clippings and stuff collect around the trunk.
(There are some nice pictures and instructions on how to accomplish 1-3 at this site link)
4: Water frequently
After a newly planted tree is established, keep watering it daily so you can rot out the roots. If you like to throw away money you can hire someone to wrap far too many irrigation lines around a plant and set the system to water all the time. Be careful because there are competent people who will install and set irrigation correctly, so make sure you hire someone incompetent and don’t ask any questions.
5: Fertilize randomly
Again you say, but fertilizer is good no? Well yes for the most part but trees seldom if ever need fertilizer, and no plant other than annuals should be fertilized for one full growing season after planting. So if your trees and shrubs look sick go ahead and throw fertilizer at them and if you are lucky they will have been suffering from a condition such as an insect or disease that gets worse if you do. This is a method that can quickly kill a plant so if you are interested in watching your plants die slowly try methods #1-3.
6: Disturb the roots
There are many methods of root disturbance. Laying a driveway, digging a trench, or grading all work well. This death can be slow or fast so if you’re into a little mystery be sure to give this a try. With careful preparation and methods, many construction projects can be done around plants without killing them, so be sure to just wing it. Remember that the majority of a trees feeding roots are shallow and extend to or past the edge of the leaves, so even some light grading in these areas can be all it takes to wipe out a tree.
7: Girdle
This is a very popular and easy method. All you need to do for a newly planted tree that has been staked is nothing. Just sit back and watch as the strapping chokes the life out of your plant when trunk grows. Many landscapers will come and take down the stakes after the tree can support itself so be vigilant and keep an old shoe or something by the window to throw at them to scare them off. You can also tie a dog chain or something around the trunk and wait.
8: Compact the soil
An occasional car parked for a day or two or driven over a trees roots should not bother it at all. To properly compact the soil frequently park or drive equipment on the root areas. Even constant foot traffic can accomplish good soil compaction.
9: Other planting methods
Plants that come in pots are easy to kill, just plant them and the chances of survival are slim. If you break up the roots by cutting down the sides and the bottom, plant them at the right depth, don’t fertilize or pile mulch on top of them most plants quickly become established and get harder to kill. Balled and burlapped plants are much the same. Though they have not grown in pots, the machinery that digs them squashes the roots together and piles soil up around the trunk. So again just plant them and most of the time they will die without any further help. Be careful not to spread out the roots or remove any extra soil from around the trunk. Keep them in the wire basket or burlap and your chances of a good killing are greatly increased. If you screw up and they look like they will live cover them with a big pile of mulch and fertilize them.
10: Weed whack right up to the trunk
Sure, simple and easy especially for smaller plants. Weed whackers quickly girdle trees by cutting through the bark.
Remember most plants left to their own devices will grow and thrive. So unless you do something, before you know it your landscape will be over run with thriving trees and shrubs.
Xavier
IPM OF New Hampshire
www.ipmofnh.com
1: Plant too deep
Sure fire way to kill a plant. Some plants survive years before succumbing to this method. Eventually they will either grow girdling roots that wrap around the tree and choke it to death, or the deep roots will die due to lack of air. For added fun you can fertilize these trees every year and watch them green up in a hopeless attempt to survive.
2: Mulch deep and up to the trunk
Much the same as #1. You can do this yourself or have your landscaper do it for you. Ah ha you say, but mulch is good is it not? Correct my friend it is, when kept away from the trunk and not more than 3-4” deep, so be sure to get it deep and touching the trunk and the tree will suffer and die just like in method #1.
3: Bury the roots
If you are the unhappy homeowner who inherited properly planted and mulched trees and don’t want to spend the money on mulch. Then just pile up soil around the roots, or if you are lazy you can just let all the grass clippings and stuff collect around the trunk.
(There are some nice pictures and instructions on how to accomplish 1-3 at this site link)
4: Water frequently
After a newly planted tree is established, keep watering it daily so you can rot out the roots. If you like to throw away money you can hire someone to wrap far too many irrigation lines around a plant and set the system to water all the time. Be careful because there are competent people who will install and set irrigation correctly, so make sure you hire someone incompetent and don’t ask any questions.
5: Fertilize randomly
Again you say, but fertilizer is good no? Well yes for the most part but trees seldom if ever need fertilizer, and no plant other than annuals should be fertilized for one full growing season after planting. So if your trees and shrubs look sick go ahead and throw fertilizer at them and if you are lucky they will have been suffering from a condition such as an insect or disease that gets worse if you do. This is a method that can quickly kill a plant so if you are interested in watching your plants die slowly try methods #1-3.
6: Disturb the roots
There are many methods of root disturbance. Laying a driveway, digging a trench, or grading all work well. This death can be slow or fast so if you’re into a little mystery be sure to give this a try. With careful preparation and methods, many construction projects can be done around plants without killing them, so be sure to just wing it. Remember that the majority of a trees feeding roots are shallow and extend to or past the edge of the leaves, so even some light grading in these areas can be all it takes to wipe out a tree.
7: Girdle
This is a very popular and easy method. All you need to do for a newly planted tree that has been staked is nothing. Just sit back and watch as the strapping chokes the life out of your plant when trunk grows. Many landscapers will come and take down the stakes after the tree can support itself so be vigilant and keep an old shoe or something by the window to throw at them to scare them off. You can also tie a dog chain or something around the trunk and wait.
8: Compact the soil
An occasional car parked for a day or two or driven over a trees roots should not bother it at all. To properly compact the soil frequently park or drive equipment on the root areas. Even constant foot traffic can accomplish good soil compaction.
9: Other planting methods
Plants that come in pots are easy to kill, just plant them and the chances of survival are slim. If you break up the roots by cutting down the sides and the bottom, plant them at the right depth, don’t fertilize or pile mulch on top of them most plants quickly become established and get harder to kill. Balled and burlapped plants are much the same. Though they have not grown in pots, the machinery that digs them squashes the roots together and piles soil up around the trunk. So again just plant them and most of the time they will die without any further help. Be careful not to spread out the roots or remove any extra soil from around the trunk. Keep them in the wire basket or burlap and your chances of a good killing are greatly increased. If you screw up and they look like they will live cover them with a big pile of mulch and fertilize them.
10: Weed whack right up to the trunk
Sure, simple and easy especially for smaller plants. Weed whackers quickly girdle trees by cutting through the bark.
Remember most plants left to their own devices will grow and thrive. So unless you do something, before you know it your landscape will be over run with thriving trees and shrubs.
Xavier
IPM OF New Hampshire
www.ipmofnh.com
Monday, June 22, 2009
Whats News
Asian Long Horn Beetle is on the move. Now in Worcester this pest is devastating the city trees. Every one needs to be vigilant in looking for and reporting this pest. If Asian Long Horn Beetle escapes in to the Maple syrup production areas we can say good bye to this treat. The Asian Long Horn Beetle is the most serious pest to hit our shores ever. Familiarize yourself with this pest and report sightings immediately.
Some other insects have been brought in to the authorities that people have mistaken for Asian Long Horn Beetle. (The Pine Sawyer is one of these)
Don't worry if you are wrong, not everyone is expected to be an entomologist, or have seen this pest as I have. Better a thousand wrong identifications then to let this pest multiply for years, as it did in Brooklyn NY and Worcester, before any one brought it in.
Xavier
IPM OF New Hampshire
www.ipmofnh.com
Some other insects have been brought in to the authorities that people have mistaken for Asian Long Horn Beetle. (The Pine Sawyer is one of these)
Don't worry if you are wrong, not everyone is expected to be an entomologist, or have seen this pest as I have. Better a thousand wrong identifications then to let this pest multiply for years, as it did in Brooklyn NY and Worcester, before any one brought it in.
Xavier
IPM OF New Hampshire
www.ipmofnh.com
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