Weekly News

HUMMINGBIRD MOTHS

            One of the more interesting garden insects is making its appearance at this time of year.  I generally get a couple of live samples brought in to the Extension office as well as some phone calls requesting identification.  Callers usually describe it as humming bird like in its behavior, but too small to be a humming bird.  Upon closer examination, it becomes clear that it is an insect.  This is the hummingbird moth,(Hemaris spp.) and they are a delight to watch as they feed on garden flowers.  Three species of hummingbird moths can be found in Ohio, the most common of which are the hummingbird clearwing, (Hemaris thysbe) and the snowberry clearwing (H. diffinis).  The most seldom seen is the slender clearwing (H. gracilis).
            The hummingbird clearwing has a greenish body and a dark reddish-brown band near the back of the body.  Its wingspan is nearly 2", and the wings are almost devoid of scales, thus the clearwing common name.  The snowberry clearwing is yellow and black striped like a bumblebee with a wingspan of 1- 2".  The least common species is the slender clearwing moth, which is slightly smaller than the hummingbird clearwing.  This moth also has a more yellow body and a gold ring between the yellow portion and the dark band near the abdomen.  A distinction that needs to be made at this point is that although they are called clearwings, they are not the clearwings that produce larvae that are destructive borers such as the banded ash clearwing moth that belong to the Lepidopterous family, Sesiidae.

            The caterpillars of the hummingbird moths are leaf feeders and are called hornworms.  They commonly feed on are honeysuckles and viburnums.  Their feeding may benefit the environment by feeding on the invasive honeysuckles.

INTRODUCTION TO FOREST MANAGEMENT WORKSHOP

            The Ohio Forest Tax Law program provides a 50 percent property tax reduction for landowners with qualifying forestland.  In addition to developing a forest management plan, another requirement of the program says that within the first five years of certification, the forest landowner must attend a minimum of eight hours of forestry training, six hours of which shall be the Ohio State University sponsored workshop entitled “Introduction to Woodland Management and Ohio’s Forest Tax Law".

            On Saturday, August 9, the Ohio Woodlands Stewards program, a part of Ohio State University Extension, is offering an “Introduction to Forest Management” workshop that allows landowners in the Ohio Forest Tax Law program to earn 6 of the needed 8 training hours.  The workshop will run from 8:30 am until 3:30 pm at Room 103 Kottman Hall on the OSU campus in Columbus.

            Some of the topics covered in the workshop include: An Introduction to the Ohio Forest Tax Law, Defining Forest Management, Stand Manipulation to Achieve Management Objectives, Forest Products, Marketing and Harvesting, Creating a Woodland Management Plan and Sources of Information and Assistance.

            The cost of the workshop is $70/person and includes a resource book, lunch and refreshments.  Pre-registration is required and due by August 1.  Registrations are accepted online at: http://woodlandstewards.osu.edu/classes/woodlandmgmt.php or call (614) 688-3421 for more information.  To learn more about the Ohio Tax Law Program go to the following web site: http://www.dnr.state.oh.us/Home/landowner/tax/tabid/5287/Default.aspx or contact the ODNR service forester for the Athens County area at: 589-9909.

WOODLAND INTEREST GROUP MEETING

            The regular monthly meeting of the Southeastern Ohio Woodland Interest Group will be held on Monday, July 21 at 7:00 pm. at the Athens County Extension office.  Pete Woyar, private woodland owner, maple syrup producer, and consulting forester among other things, will present the July program.  Pete has a wealth of forestry experience and knowledge.  Pete will be presenting some of the trends taking place in private woodland ownership along with some management considerations and possibly some recommendations for public policy regarding private woodland ownership.  Anyone with an interest in private woodland management is invited to attend.

JAPANESE BEETLES IN THE LANDSCAPE

            The Japanese beetle has made its annual appearance in the landscape and I have gotten several questions regarding plant damage and control options.  The Japanese beetle is a general leaf feeder and is known to feed on over 400 different plant species. The beetles eat the leaf tissue between the leaf veins but leave the veins behind, a damage referred to as skeletonizing.  I recently received a newsletter from Dr. David Shetlar, a landscape entomologist with Ohio State University Extension that contained some timely information regarding control options for the Japanese beetle.  The following is a re-print of that article:

            With the recent emergence of Japanese beetle adults, the perennial questions about "appropriate" controls have also begun!

            First, do not use the traps! There are several pheromone traps on the market and almost every garden center I've been in is more than willing to sell them to you. These traps generally use two types of pheromones - the floral lure and the female sex pheromone. The floral lure is a mixture of plant oils and perfumes that are like the odors released from a plant that has been skeletonized by the adult beetles. These odors are highly attractive to both female and male beetles. The sex pheromone is attractive to the males and by adding this pheromone to the mix; the trap catches increase more than just having the floral lure alone.

            While it sounds great to be able to lure in hundreds, nay thousands, of beetles to a container, the problem is that the traps are not 100% effective. So, for every 7 to 8 beetles that end up in the trap, 2 to 3 don't get caught! These "escapees" settle on nearby plants and begin feeding. The traps can bring beetles in from a quarter mile radius. If you do the math, a quarter mile radius includes about 5.5 million square feet, and if you only had one grub per square foot in this area, you would need an awful lot of traps to capture this number of beetles! I used to give free traps sent to me by manufacturers to the guy at the end of the block, but even I'm not that mean any more!

            Okay, how about milky disease? This stuff just won't die from the market place. The enticing ads are just too much for folks hoping for a "natural" way to control the grubs that will result from the adult beetles' eggs. Milky disease bacteria that affect Japanese beetles are weak pathogens and, at best, may kill up to 25% of the grubs. In most studies, the infection rate is lower. Here's the kicker! Most of Ohio soils already have the milky disease bacterium and adding more to the top doesn't do anything to increase infection! Save your money for something that WILL work!

            How about natural, botanical oils to repel the adults? I have tried garlic, mint, eucalyptus, and several other oils and combinations of oils and all I can say is that Japanese beetle adults seem to like a little spice in their food! In most of my trials and trials done by fellow entomologists, there is never a reduction in feeding and sometimes the feeding damage is increased! If you want to use a natural botanical product, look at materials that contain azadirachtin. Azadirachtin is the active ingredient produced by the neem tree. Unfortunately, there is crude neem seed extract that usually doesn't have any specific amount of azadirachtin on the label! Only purchase product that has an actual percent of azadirachtins on the label! You may have to make repeat applications every 10 to 14 days, but these products do have activity (both repellency and toxicity).

            Beyond azadirachtin, you can still purchase natural pyrethrum, but you usually need the piperonyl-butoxide adjuvant to be effective. To be really effective at knocking out the beetles, you'll probably have to rely on stronger insecticides! Most of the pyrethroids do a pretty good job, but they also have to be reapplied after rains or every 10 to 14 days. Sevin insecticide is also still available and this insecticide has always been one of the best performers.

            I live in a zone where Japanese beetles have never been overly abundant, so all I normally do is perform a beetle cleaning inspection when I get home from work. I simply knock any beetles I see on the few susceptible plants I have in my landscape into a can of detergent water. After about two weeks of this, I don't see many beetles as I've kept my plants free of damage and the remaining beetles are more inclined to join the feeding frenzies in my neighbors' yards!

            Source: July 7^th edition of The PEST Newsletter, David Shetlar, OSU Extension landscape entomologist

SQUASH VINE BORER

            Each year I receive phone calls from gardeners whose plantings of squash, pumpkins and/or zucchini suddenly wilt and collapse.  In many cases the squash vine borer is responsible for this damage.  It is the larvae of the squash vine borer moth that bores into the stem of the plants and disrupts the flow of nutrients and water.  The point where a borer enters a stem is marked by a hole with yellow granular or sawdust-like frass exuding from it.  If the infestation is small and only a few borers have entered the stem, the plant may survive.  Often though many borers enter the stem and the plants are killed.

            The squash vine borer overwinters as a mature larva in cocoons in the soil, at a depth of from one to six inches. It pupates in the spring and the adult moth emerges sometime in June. Moths are active during the daytime and in the evening they rest on leaves.  The moths fly slowly in zig-zags around plants, and lay eggs singly on stems; eggs are usually found on the main stem near the base, but are also found on leafstalks or on the undersides of leaves. Moths are active for about one month.  Eggs hatch in 9 to 14 days. Larvae enter the stem at the plant base within a few hours after hatching from the eggs. Larvae feed inside the stem for 4 to 6 weeks.

            At this time the moths are active and laying eggs.  Gardeners who have had problems with squash vine borer in the past may want to try some control options.  This pest can be controlled by insecticide if the young larvae encounter a toxic residue before they bore into the stem.  This is the control method that most commercial growers use. Insecticide directed at the base of stems should be applied twice, about 7-10 days apart. The first spray should be applied when eggs are hatching, which is usually in early July.   Most of the synthetic pyrethroids will do a good job of control.

For the average home gardener, other control options are available.  They include:

• Borers can be removed from vines if detected before much damage is done. Examine stems in early summer; once holes are detected, slit the stem longitudinally with a fine sharp knife, remove the borer, then cover the wounded stem with moist soil above the point of injury to promote additional root formation.

• Stems, especially the lower 3 to 4 inches, can be covered with a barrier, such as strips of nylon stockings, to prevent egg laying.

•  Catch and destroy the moths, especially at twilight or in early morning when they are resting on the upper side of leaf bases.

• Hand-pick the eggs before they hatch.

For more information about the squash vine borer and control options, contact the Athens County Extension office at 593-8555.