Spider Mites

Bryan Davis was telling me that he's seeing several fields where spider mites are becoming a problem. One of the fields we had scouted thoroughly in April without finding any mites. I've also seen some spider mite activity in a couple of fields. Though it's been wet and humid, it's also been rather warm (understatement, yes I know!) which makes mites more active. So if you haven't had a chance, now would be a good time to look for spider mites before the shearing season swings into gear and they end up causing damage.

Cryptomeria Scale

Cryptomeria scale (Aspidiotus cryptomeriae) has been a problem on Christmas trees for several years in Pennsylvania and other states, but not in NC until now. Alan Durden found some on Fraser fir in Macon County, which I had the opportunity to visit last week.


The trees were from 4 to close to 12 foot tall, not far out of Franklin. There was a very heavy incidence, but many of the scales didn't look healthy. Some had fungi growing on them. Others appeared to have been feed upon.


For those of you familiar with elongate hemlock scale, the life cycles and control of these two scales are quite similar. The biggest difference is that the cryptomeria scale is more rounded in shape. We found nymphs on the new growth on some of the trees.


We also found a lot of the twice-stabbed lady beetles (genus Chilocorus) -- both adults and nymphs. Richard Cowles and others reports that these are good predators for scales. I have never seen them feeding on elongate hemlock scale, and in fact usually only see about one a year, but there were dozens on these trees.


Because of the predators and because the grower only has a few trees, we decided to wait a month before deciding what to do for control.

Symptoms on the top of the foliage are similar to elongate hemlock scale. They aren't found on all the infested trees just like with EHS. I didn't see any of the white fluff that gets on trees with EHS. That probably doesn't occur.

This is what the scale looks like under the foliage. For a clearer picture, google the scale.

Here is one of the lady beetles. They are real pretty.

Update on Endosulfan

Wayne Buhler, the pesticide coordinator for NCSU sent the following message out this morning. It is from Lee Davis with NCDA&CS about the fate of endosulfan. Nothing has been decided yet about how the product will be phased out, but Lee describes what usually happens. Again, when things have been decided, I'll let you know.

"Yes.  The way I understand it is that the EPA and the registrant are currently working out the details of how to cancel the product.  Usually, the EPA will post to the Federal Register a notice to cancel the product and give a date upon which the product is cancelled.  Usually, the EPA will allow product already in the channels of trade or in the hands of the end user to be used up according to label directions.  This is what usually happens, but each cancellation notice is unique.  So, it is not possible to say exactly what instructions might be in the cancellation notice.

Thanks,

Lee"

Endosulfan (Thionex)

As of June, 2010, EPA has decided that endosulfan, the active ingredient to Thionex, poses too great a risk to workers and wildlife. Therefore EPA is taking action to end all uses of the product. You can read more about it at: http://www.epa.gov/pesticides/reregistration/endosulfan/endosulfan-cancl-fs.html.

According to an EPA news release dated 6/9/2010, "Makhteshim Agan of North America, the manufacturer of endosulfan, is in discussions with EPA to voluntarily terminate all endosulfan uses. EPA is currently working out the details of the decision that will eliminate all endosulfan uses, while incorporating consideration of the needs for growers to timely move to lower-risk pest control practices."

I do not know anything more at this time, but will keep you posted.

Another Scale

In one Christmas tree field near Jefferson, Bryan Davis kept seeing a different kind of scale. We finally sent them in, and they were identified as the hemlock scale (Abgrallaspis ithacae). This scale is native to the US. It is closer to target shaped instead of elongate. It is not reported as being damaging to trees. The following image is from IPM Images. We will be monitoring this site to see if these scales develop into a problem.

Respirators

As more research is being done on the chronic effects of low level exposures to pesticides, it continues to be apparent that pesticide use can adversely affect the health of the pesticide applicator. That's why it's important that people wear the appropriate personal protective equipment, and even use more PPE than is required, especially when treating Christmas trees with a high pressure sprayer.

One of these pieces of equipment is the respirator. In my opinion, anyone treating trees with a high pressure sprayer should use a respirator. This is true whether you are using horticultural oil or a synthetic pesticide. Few materials require the use of a respirator on the label, but since you are continually walking through the spray, that is the best way to reduce exposure.

Some of the commercial applicators have purchased the helmets with motorized forced air which completely cover the head. These offer the most protection, and are the easiest to wear. They keep the worker cool, and don't require a lot of effort to breath through them.

But a lot of people still depend on either the full or 1/2 face respirator with attached cartridges which are certainly less expensive. However, there are several issues with these.

1. They don't cover the entire face, and in fact the ear canal is one area of skin that is particularly thin and will readily absorb pesticides. The rate of absorption is far higher than the skin on your palm or forearm. Using a hood on a spray suit will eliminate this problem.

2. Many people don't fit the respirator closely enough to the face. I've seen several folks wear respirators that just hang on their face. The respirator is supposed to fit snugly so that all air breathed in passes through the cartridges. And yes, when you do this, they will fog up. But, when the fit isn't snug, contaminated air can come in through the sides. If a man has a beard or mustache, this can interfere with the fit. In fact, it is best not to have facial hair when using a respirator.

3. The third issue then becomes one of applicator's health. Some people's lungs just aren't strong enough to pull air through the respirators.We all know how tiring it is to wear a hot spray suit and respirator and walk through trees spraying with a hose. You have to have good heart and lungs to be able to do this demanding work.

In fact, OSHA regulation 1910.134 requires workers be properly trained in using a respirator, that a fit test be conducted, and that the worker is certified by a doctor as being physically fit enough to use the respirator. These requirements have largely been overlooked in agricultural circles, but that may be changing.

So be safe. Check the fit on your respirator, and use it like it was intended.

HWA Control

OK, I know this is a Fraser fir blog, but I had to include a photo of these hemlocks. They are at my office in Mills River. I treated them 2 years ago for hemlock woolly adelgid with Safari using a soil drench, and they are still growing like gangbusters. We'll be looking closer at Safari for the control of balsam woolly adelgid.