“WHAT’S HAPPENING?”
The University of Tennessee/Agricultural Extension Service
Entomology & Plant Pathology - EPP #60
April 21, 2006
FRUIT AND VEGETABLE SPRAY GUIDES: UPDATES ON AVAILABILITY
by Steve Bost
This is a rundown of the status of the 2006 editions of our fruit and vegetable spray guides:
• Small Fruit - The 2006 Southeast regional integrated pest management guides for blueberries, brambles, bunch grapes, muscadines, and strawberries are available at http://www.smallfruits.org/SmallFruitsRegGuide/index.htm. These guides will only be available in the online form. The decision has been made not to produce print copies because of costs. If you are not equipped to download and print these guides, ask your county extension office to print them for you.
• The 2006 Southeastern Peach, Nectarine and Plum Pest Management and Culture Guide (regional publication) - A very limited supply of print copies are available at county Extension offices. It is available for downloading from http://entomology.ent.uga.edu/Peach/peach_guide.pdf.
Agents, if you run out of print copies, there are few available at the Nashville office.
• The 2006 Integrated Orchard Management Guide for Commercial Apples in the Southeast (regional publication) - A very limited supply of print copies are available at county Extension offices. It is available for downloading from
http://ipm.ncsu.edu/apple/orchardguide/orchard-management-2006.pdf.
Agents, if you run out of print copies, there are few available at the Nashville office.
• The 2006 Commercial Vegetable Disease, Insect and Weed Control (University of Tennessee PB 1282) - Production is being delayed. I will notify you when the print and web versions are available.
• Also, don’t forget our fruit and vegetable IPM newsletter, Fruit Pest News, available only online at http://web.utk.edu/~extepp/fpn/fpn.htm.
TOBACCO DISEASE CONTROL UPDATES
by Steve Bost
Changes made in our tobacco disease control recommendations for this year can be found on the UT tobacco website, http://tobaccoinfo.utk.edu, in a couple of PowerPoint presentations I gave at winter meetings. Both presentations deal with black shank, but a general update is given at the beginning of each. The current status of the Section 18 petition for Quadris for control of frogeye leaf spot and target spot: I have completed the university’s part and submitted it to TDA. They will complete the petition and submit it to EPA. Hopefully, we will have the label in time for use season. The EPA has approved Syngenta’s application for a federal label, but it is uncertain when the new federal label will be completed.
If you are interested in Quadris for black shank control, the PowerPoint on chemical control of black shank contains the results of a trial that Steve Walker and I conducted last year in Macon County.
BEWARE OF TOMATO SPOTTED WILT VIRUS THIS YEAR
by Steve Bost
Tomato growers need to pay attention to spring weather. It can have a bearing on an important summer disease, tomato spotted wilt. If you have the flexibility to choose tomato varieties at this time, it may be wise to order some spotted wilt resistant varieties, at least for part of your acreage. That's because thrips, the insect vector of this virus, proliferate during and after dry weather in the spring, and the disease follows suit. Early spring rainfall amounts have been used as an accurate predictor of spotted wilt severity in peanut crops in Georgia. Despite the recent tornadic weather in Tennessee, rainfall has been below normal since March 1.
Several tomato varieties have been released in recent years that have resistance to spotted wilt. Slicing type varieties with resistance include Amelia, BHN 640, Crista, Debut, and Quincy. Roma types include BHN 685 and Muriel. Since they are new, little is known about them other than the information provided by the companies. Amelia has performed well in Tennessee.
Spotted wilt has shown indications of becoming more problematic in tomato production in Tennessee. It may be prudent to evaluate the resistant varieties now, whether you get the disease or not, so that you will know which ones, if any, fit your system.
DEFOLIATORS
by Frank A. Hale
The new spring foliage is susceptible to many types of defoliators. The small green larvae of the bristly rose sawfly can quickly make rose leaves look like Swiss cheese. These sawflies (Order Hymenoptera which also includes bees, wasps, hornets, and ants) have eight pair of fleshy hind prolegs with no crochets (tiny curved hairs at the end of the prolegs). Remember that BT (Bacillus thuringiensis) insecticides such as Dipel do not control sawflies. BT only is effective on lepidopterous caterpillars (usually 5 pair of prolegs or fewer with crochets).
Also, leaves of rose and other plants with perfectly round bites (the shape reminds you of a person taking a bite out of a piece of bread) are caused by leafcutter bees. These bees use the pieces of leaves to line the cells in which the larvae live and pupate. Dr. John Skinner told me that they provision each cell with food prior to sealing it up. These cells are stacked in small pipes, tubes and other hollow cylindrical places from which the adult leafcutter bees eventually emerge.
Spring and fall cankerworms are also out in large numbers. They hang down on silken threads and they can be blown about on windy days. These inchworms have either two pair of hind prolegs (spring cankerworm) or three pair (fall cankerworms). The eggs started hatching earlier this month and the caterpillars and signs of their feeding can be easily seen in many types of landscape trees. They have the potential to completely defoliate trees. Fortunately, healthy trees will put out new foliage later in May.
With cankerworms, most people think that fall or spring indicates when the caterpillars are active. It actually refers to when the wingless adult female moth is active. The adult female moth is flightless so she has to climb the trunk of trees to lay her egg mass on the branches. The fall cankerworm moth lays her eggs in late fall (November) while the spring cankerworm lays her eggs in late-winter to early spring (March). The eggs of both the spring and fall cankerworm hatch in the spring.
Eastern tent caterpillars feed primarily on wild cherry but can also attack crab apple, apple, and plum. Currently, as they are maturing, they crawl down the tree and disperse. Some are in search of a better source or food but most just crawl around until they are ready to spin a white silken cocoon in which to pupate in leaf duff on the ground. This dispersing behavior has had some bad consequences. Horses feeding on grass in a pasture can accidentally ingest some of these fuzzy caterpillars. The ingestion of Eastern tent caterpillars is thought to be the most probably cause of Mare Reproductive Loss Syndrome (MRLS) which causes the abortion of the fetus in mares.
OTHER UT NEWSLETTERS WITH PEST MANAGEMENT INFORMATION
http://web.utk.edu/~extepp/fpn/fpn.htm
Tennessee Crop and Pest Management Newsletter
http://www.utextension.utk.edu/fieldCrops/cotton/cotton_insects/ipmnewsletters.htm
This and other "What's Happening" issues can be found at http://web.utk.edu/~extepp/whatshap.htm
Disclaimer Statement
Pesticides recommended in this publication were registered for the prescribed uses when printed. Pesticide regulations
are continuously reviewed. Should registration or a recommended pesticide be canceled, it would
no longer be recommended by the University of Tennessee.
Use of trade or brand names in this publication is for clarity and information; it does not imply approval of the
product to the exclusion of others that may be of similar, suitable composition, nor does it guarantee or
warrant the standard of the product.
Precautionary Statement
To protect people and the environment, pesticides should be used safely. This is everyone’s responsibility,
especially the user. Read and follow label directions carefully before you mix, apply store or dispose of a pesticide. According to laws regulating pesticides, they must be used only as directed by the label.
Persons who do not obey the law will be subject to penalties.
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