Elongate Hemlock Scale

Elongate Hemlock Scale seems to be exploding this year over most Christmas tree farms in Mitchell County. The treatment window for this summer is getting close to closing so now if the time to be out scouting and evaluating the amount of infestation you have from Elongate Hemlock Scale.

The elongate hemlock scale, sometimes known as the fiorinia scale, is a serious armored scale insect pest of hemlock and Fraser fir. It is believed that this armored scale insect was unintentionally introduced into the United States from Japan.

The EHS is found almost exclusively on the underside of needles and will be found on multiple years of growth. On infested branches, scale numbers average 10 per needle and there can be as many as 30 on a single needle with scales sometimes found on top of each other.

When infestations are heavy, trees may have yellow blotches or patches on the needles and growth will be stunted. However, such symptoms are not commonly seen on Fraser fir in western North Carolina. More commonly what is seen are the white, waxy excretions of the male scales found on the upper surface of needles especially during summer months when males are maturing. Infestations that do not reduce tree growth can still make trees un-saleable because of this white covering to the needles.

The EHS has two, overlapping generations in the southern Appalachians. Because of this overlap, all life stages can be found almost any time of year, though proportions of one stage to another will vary. Crawlers emerge throughout the growing season and even in winter months, but peak crawler emergence is in May into June and again in late October into November.

The crawlers must find an appropriate feeding site. Crawlers may move somewhere else on the same needle, crawl onto the new growth, or move passively through wind or bird movement onto other trees or fields. Once a feeding site is found they molt, never moving again.

Immature scales appear to burrow under the waxy layer produced by the needle, making them even more protected against pesticide applications and predators. As the scale matures, it forms behind the original yellow immature, making it look as if a smaller scale is attached to a larger. The feeding tube of the immatures is as long as it is, appearing as a tiny coppery wire. The scales feed in epidermal cells.

Immature female scales go through three stages of development while males have additional prepupal and pupal stages. Males emerge as a tiny winged insect with large black eyes and long antennas. Before they emerge, they can sometimes be found under the white cotton of the pupal stage. They have no mouth-parts and live only a few days, mating with females. Eggs are produced six to eight weeks after mating. Each female produces 12 to 16 eggs at a time, which hatch within a month. Mature females may live for more than one year.

Emerald Ash Borer

This week the Tennessee Department of Agriculture announced that emerald ash borer has been found in Knox and Loudon counties. This places it very close to Swain and Graham counties in North Carolina. The Tennessee Department of Agriculture and USDA’s Animal Plant Health Inspection Service are expected to issue quarantine measures on the movement of firewood, ash nursery stock and ash timber.

Emerald ash borer beetles can kill an ash tree within three years of the initial infestation. Adults are dark green, one-half inch in length and one-eighth inch wide, and fly from April until September, depending on the climate of the area (probably more like May to August in North Carolina). Larvae spend the rest of the year beneath the bark of ash trees. When they emerge as adults, they leave D-shaped holes in the bark about one-eighth inch wide.

For more information, see the USDA Forest Service’s Pest Alert on the emerald ash borer at http://www.na.fs.fed.us/spfo/pubs/pest_al/eab/eab.pdf. If you want help identifying an ash tree, go to http://www.anr.msu.edu/robertsd/ash/ashtree_id.html.

From: Steve Bambara and Steve Frank, Extension Entomologists

2010 Marketing Season

The 2010 marketing season is fast approaching. Below are three tips to get you thinking about the upcoming season.

1.Begin making contact with the customers that you had last year. Make phone calls or personnel visits to discuss this years plans.

2.Look for ways to get your business name out to more potential customers. Design a website if you don't have one, join a growers association that can help market for you, buy adds in papers, magazines or journals that may target the area you want to market in.

3.Deliver great customer service. I read an article recently that discussed the importance of customer service. It stated that customer service was more important than quality when it came down to a determining factor of whether a customer was going to purchase from you or someone else.

Chemical Mowing Rates

I have had a few calls about rates for chemical mowing applications. Even though the new growth of Fraser fir is out and seems to be hardening up, I would caution going back up to a full 8 oz. per acre rate of RoundUp at this time. You may want to stick to the 4 oz. per acre rate for another couple of weeks if you have fields that need spraying right now.

Summer Pest

Now is a good time to be scouting for a couple of pest. We are seeing some spruce spider mite activity with this hot, dry weather. Be on the lookout for spruce spider mites, especially in fields with little groundcover or along dusty roadways. Also, last week I looked at some trees with Elongated Hemlock Scale and they are producing the white covering right now and are easy to spot. Look on the underside of branches and make plans to treat in late July or early August if you find them.

Rust Mites

Hemlock Rust Mites are continuing to cause problems, especially in fields that were treated last fall and have not had a treatment for mites this spring. The weather conditions have been good for rust mite development, so you will want to get out and do some scouting even in fields you have treated for twig aphids this spring.

RoundUp Timing

Christmas tree and ornamental conifer growers that are using the chemical mowing practice with RoundUp should begin wrapping up their applications. When the new growth gets out to around 2" then you should stop applying the RoundUp directly to the foliage or cut your rate to the 4 oz. per acre rate instead of the 8 oz. per acre rate. For help with calibrating spray equipment, please contact your local Extension Agent.