Spotted Lanternfly – Be on the Lookout

The Spotted Lanternfly (SLF) is an invasive bug, not a fly, from Southeast Asia that was first observed in Pennsylvania in 2014.  This pest has sucking mouthparts and is known to feed on the stems, vines, and trunks of many crops grown in Ohio such as grapes, hops, apples, plums, cherries, peaches, and nectarines where it produces sap weeping wounds in the plant.

Sap weeping from spotted lanternfly wounds.

The host range extends to many tree species such as maple and willow, but this bug is especially fond of the Tree of Heaven, which can be found all across the state.  If you aren’t familiar with how to identify this tree, here is a nice factsheet (

Mature stand of Tree of Heaven.

This pest has spread from Pennsylvania to New Jersey, Delaware, New York, and Virginia in the past few years. To be clear, this pest has NOT been found in Ohio yet, but we want growers to remain vigilant while out on their farms and surrounding property. Fortunately, in some respects, this insect is rather large as an adult, about an inch long and brightly colored, which should aid in its detection.

Adult spotted lanternfly.

If you see one of these pests, please take a few pictures and try to collect a specimen in a container, then report it to your local Extension educator or the Ohio Department of Agriculture (614-728-6400 or

At this time of year, late instar nymphs (which resemble black or red stink bugs) or early adults might be seen, especially on the Tree of Heaven.

Spotted lanternfly nymphs; dark nymphs are younger than red nymph.

Many articles have been written about this pest insect which are listed below in case you want more information about hosts, identification, biology, etc.

BYGL article

Penn State University

Penn Dept. of Agriculture

General information

Many thanks, credit, and acknowledgements to those authors whose pictures and websites were used for this article.




Managing Cucurbit Powdery Mildew

Powdery mildew arrived this week on squash, pumpkins and other cucurbits throughout Ohio. It is a little late – we often see it by early- to mid-July.  The fungus that causes cucurbit powdery mildew does not overwinter in Ohio, so the disease does not appear until spores arrive on wind currents from warmer growing areas.  This fungus is an unusual plant pathogen in that it is inhibited by free water – so frequent rains may delay powdery mildew’s appearance, at least to a notable level.  Signs of infection are small circular powdery growths (mycelium and spores of the pathogen) on either side of the leaf. These spots enlarge and can eventually cover most of the leaf surface and kill the leaves.  Stems and leaf petioles are also susceptible, but the disease is not observed on fruit.  In pumpkins, powdery mildew may also attack the “handles”, which can be further damaged by secondary pathogens.

Powdery mildew is managed using powdery mildew-resistant varieties and fungicides.  Development of insensitivity to overused fungicides is common in populations of the fungus that causes this disease, so it is important that a fungicide resistance management program is followed. Remember to alternate fungicides in different FRAC (Fungicide Resistance Action Committee) groups, indicating different modes of action against the fungus. It is important to apply fungicides when the disease first appears and incidence is low. Fungicides that are effective against cucurbit powdery mildew can be found in the Midwest Vegetable Production Guide for Commercial Growers; product ratings and FRAC codes are on page 125.  Our evaluations of efficacy of powdery mildew fungicides at three locations (Wooster, Columbus, South Charleston) in Ohio in 2017 indicated that Procure, Quintec, and Rally consistently provided very good control of powdery mildew on pumpkins in all three locations (see table).  Approvia Top and Inspire Super were very good in two locations but fair in a third; and Merivon Xemium, Fontelis and Torino were very good in one location and fair in two. Both Bravo and Pristine performed poorly in all three locations.

Spotted Wing Drosophila Update

The summer is approaching half over at this point and spotted wing Drosophila (SWD) populations should be steadily increasing across the state, including most berry farms, peach orchards, day neutral strawberry plantings, vineyards and wild host areas (mulberry, elderberry, pokeweed, etc.). For those operations not actively managing their crop with insecticides or other means, the SWD adult numbers can be very high resulting in severe fruit damage.

If you have soft berries or berries that appear to be “leaking” juice and aren’t sure what might be causing the damage, try picking some healthy ripe berries and give them the salt water test to see if any SWD larvae are inside.  Here’s how:

If you are looking for insecticide options to treat your berries, take a look at the chart on this factsheet:

Starting in June, SWD monitoring sites were established in 25 counties.  For those sites reporting their trap activity, the approximate trends over the past month (July) are listed below:

Spotted wing Drosophila trends across the state.




2nd Annual Midwest Mechanical Weed Control Field Day comes to Central Illinois!

A full day of exhibitors, in-row demonstrations, farmers and industry experts!

The Midwest Mechanical Weed Control Field Day is the Midwest’s largest field day devoted to vegetable growers and mechanical weed control.

This year’s Midwest Mechanical Weed Control Field Day takes place on Wednesday, September 26 at PrairiErth Farm in Atlanta, IL. Hans Bishop, co-owner of PrairiErth Farm, will be hosting the event in the farm’s new packing shed, which also serves as a local Food Hub and Educational Center. The event is being planned by Sam Hitchcock Tilton, an organizer of last year’s event and Midwest representative for KULT-Kress precision weeding tools, and The Land Connection, an Illinois non-profit organization that promotes farmer training and land stewardship.

The field day is an ideal opportunity for farmers to learn about weeding tools and techniques. In the morning soil health expert Alan Philo (formerly the specialty crop specialist for Midwestern BioAg) will give a presentation on cultivation methods that preserve soil health and soil-building techniques that allow for subsequent precision cultivation. The exhibition period that follows is an opportunity for growers to see weeding tools from more than 10 companies and speak with representatives. University weed scientists from surrounding states will share their research, Midwest farmers will exhibit their favorite weeding tools, and

‘Walk-Behind Alley’ tent will feature two-wheeled walk-behind tractors and implements. In the afternoon, Myriad cultivators and cultivating tractors will be demonstrated in the field on direct-seeded beets and transplanted lettuce. These demonstrations will show how the machines should be mounted and properly adjusted, and will help farmers visualize how the implements can work on their own farms to increase efficiency and productivity.

All currently-manufactured cultivating tractors will be attending (Tilmor, Oggun, and Tuff-Bilt) as well as many others (IH-274, Hefty G, IH Super C, and modified Allis G’s). Field demonstrations will include a tine-weeder, belly-mounted finger-weeders, rear-mounted steerable toolbar, basket weeder, a mechanical transplanter, and a camera-guided in-row robotic cultivator. Numerous additional tools will be in the exhibition area, such as a Lilliston rolling cultivator, William’s toolbar system, Reigi/Eco weeder, and propane flame weeder.

The field day costs $20 and includes breakfast, lunch, and root beer floats at the end of the day. Register online:

If you would like more information please contact Mallory Krieger at mallory@thelandconnection.orgor by phone (312) 840-2128.

Field day news release.

Notes from the Pumpkin Patch in South Charleston

Summer is in full swing, and the pests are no exception.  This past week saw an escalation of many of our common insect pests. For control of any of the pests mentioned below, please consult the Cucurbit chapter of the Midwest Vegetable Production Guide for our most up to date recommendations.

Striped cucumber beetles– The summer generation has emerged and an uptick of beetles can be found on the lower stem and leaves of plants, and particularly in flowers. While the beetles pose no immediate threat to larger plants, keep an eye on the sizing green fruit which can be susceptible to feeding and eventually scarring, potentially affecting marketability.

Wilting plants– For those areas of the state where it has been hot and dry, pumpkin and squash plants may naturally wilt a bit during the day but then recover in the evening when temperatures cool off.  If the plant stays wilted and shows any symptoms of leaf yellowing or even necrotic or brown tissue between the veins, it might be bacterial wiltor squash vineborer.

Severely wilted plant…is it bacterial wilt or squash vine borer? Can’t reliably tell just by looking at the plant.

To check for bacterial wilt, cut the plant stem and press the two ends together, then slowly pull them apart.  If strings of syrupy liquid can be seen between the pieces (cut ends), it is likely the plant is infected.  This test is usually fairly reliable but if no strings are seen, the plant may still be infected.  Unfortunately, for plants that are infected, there is no remediation and should be rogued out.

Before you cut the stem and look for bacterial wilt, look closely near the base of the plant for evidence of squash vine borer (SVB) entering the stem. If there hasn’t been a significant rain event recently, look for brownish wet sawdust material (insect frass or excrement) which is strong evidence for this pest.  If you decide to sacrifice the plant, slice down the stem and you may find more frass and up to several white grub like insects tunneling through the stem.  As the immature SVB chew through the water conducting tissue of the vines (xylem), wilting results.  Once the borers are in the vines, there is no treatment. It is possible that plants can have both bacterial wilt and SVB, for a double whammy of wilting.

Squash vine borer frass at the tip of the blade.

Slice the base of the plant open to find squash vine borer larvae (at tip of blade).













To round out the insects increasing on squash and pumpkin crops, keep an eye on Squash Bug populations. Whitle these insects can vector Yellow Vine Decline, it has not been a huge economic concern in Ohio so far.  Heavy numbers of bugs feeding on plants can cause them to collapse.

Squash bug eggs.

A squash bug adult.

An emerging disease in the state with several names (Plectosporium, Microdochium, and White speck) can now be readily seen affecting foliage, petioles, and the veins on the backs of leaves.  As this disease progresses, it will eventually bleach and kill the vines, ruin the handles and mar the fruit, giving them a white blotchy appearance. Dr. Sally Miller will be writing a more detailed article on this disease and its management in an upcoming veg blog post.

Plectorsporium symptoms on pumpkin leaves.

Plectorsporium on leaf petiole. Note the diamond or spindle shaped lesions on the petiole and major leaf veins.

Be on the look out for powdery mildewin the next week or two, as it has been arriving in Ohio anytime from the middle of July through the first week of August. As of this blog post, no powdery mildew or downy mildew has been reported in the state.

Lastly, mark your calendar for the annual Pumpkin Field Dayto be held at the Western Ag Research Station in South Charleston on August 23 from 6-8 pm.  More details will be forth coming.



Be on the lookout for spider mites

Now that the weather has turned hot and dry, it is likely that spider mite infestations will be found in various crops. In some fields, the mite infestation is worst on a field edge by a dusty road. Because mites are tiny, they are often overlooked or misdiagnosed as a disease. Infested leaves have fine webbing on the leaf undersides. Tomato leaves damaged by spider mites usually have yellow blotches, while bean leaves show white stipples or pin-prick markings from mite feeding. Pumpkins can tolerate moderate levels of mites, but watermelons are more sensitive to injury from mite feeding. A simple method of diagnosing spider mites is to shake leaves over a piece of paper and look for moving specks that are visible to the naked eye. A closer look with a magnifier can show the tiny mites that are white, marked with two large dark spots on the middle of the body.

Mites can be suppressed by overhead irrigation. Mites have many natural enemies that kill them, such as specialized predatory mites or generalist lacewings, ladybugs, and pirate bugs, but these helpful predators are often killed by pesticides. Chemical intervention can be needed to keep the crop alive if spider mites are abundant. When a mite infestation is limited to field edges, infested fields should be scouted, and a miticide applied as a spot treatment to isolated infestations. Mite control is better when higher volumes of water are used; 25 gallons of water per acre is better than 10 gal/A. Several pesticides are registered for spider mite control; some are restricted use and some are for general use, as shown for vegetable crops in Table 1 and for hops and fruit crops in Table 2. At some locations, organophosphates are still effective for mite control, with Dimethoate being the best bet and MSR (Metasystox-R) as another choice. Dimethoate is an option for melons but is not allowed on squash or cucumbers; it has been a preferred product for mite control on soybeans. Dimethoate is prohibited from use on ornamental crops in high tunnels and greenhouses but is not prohibited from vegetable crops in high tunnels and greenhouses. Where organophosphates are not effective, Agri-Mek (abamectin) is generally the most effective product for mite control but it is a restricted-use product, while Acramite (bifenazate) and Oberon (spiromesifen) are nearly as good but are not restricted-use products. Although Brigade (bifenthrin) and Danitol (fenpropathrin) are labeled for spider mite control when used at the high end of the rate range, they are generally not as effective as the true miticides. Dicofol is an old miticide that is still effective at some sites, but does not perform well at sites where resistant populations have developed. Vydate (oxamyl) is a restricted-use product that is registered for use on eggplant for mite control. On organic farms, insecticidal soap can be used for mite control but thorough coverage of the undersides of leaves is needed for good control.

-Celeste Welty, Extension Entomologist

No Cucurbit Downy Mildew Reported Yet in Ohio, but be Prepared

Cucurbit downy mildew reports as of July 12, 2018.

Cucurbit downy mildew is marching up the U.S. eastern seaboard from Florida to central Pennsylvania, but has not been reported in Ohio, Michigan or Ontario as of July 12.  This is later than normal for Ohio – last year our first cucumber downy mildew report was on June 28. Excessive heat followed by sunny days have likely contributed to the delay.  However, cucurbit growers should be vigilant and scout their fields regularly for downy mildew.  These crops should be protected now with an effective protectant fungicide such as chlorothalanil (Bravo, Echo, Equus, Initiate versions), which will also help manage anthracnose and Alternaria leaf spot – we have seen an unusually large amount of Alternaria leaf spots in various crops this summer. When we start experiencing cooler, rainier weather with high humidity and overcast skies, the downy mildew risk will increase.  We evaluated numerous fungicides for efficacy against cucumber downy mildew in 2017 (see chart below).  Ranman 400SC, Orondis Opti, Omega 500F and Gavel 75 DF performed best in these tests.  Bravo Weather Stik 6F, Zampro 52SSC, Tanos 50DF, Presidio 4SC and Curzate 60DF were intermediate in efficacy and can be used as rotational partners in a fungicide program, particularly under low to moderate disease pressure.  The poorly-performing fungicides are not recommended for downy mildew management.  Always rotate fungicides with different modes of action and follow label instructions. Remember that Orondis Opti applications are restricted to 1/3 of the total fungicide applications. Under highly conducive environmental conditions, apply fungicides on a 5-7 day schedule.  When the risk is lower due to hot, dry, sunny weather, or downy mildew has not been reported in the area, the schedule may be stretched to 7-10 days. Cucumber and cantaloupe downy mildew risk is much higher in northern than in central and southern Ohio at this time.

Information on fungicides for vegetables, including Fungicide Resistance Action Committee (FRAC) code and greenhouse use can be found in a table beginning on page 79 of the 2018 Midwest Vegetable Production Guide for Commercial Growers. Pre-harvest intervals are shown for each crop/fungicide combination throughout the guide.

Hardin County – Fruit and Vegetable Crop Walk

Hardin County Extension News Release
For Further Information Contact:
Mark Badertscher
Agriculture and Natural Resources Extension Educator
Phone – 419-674-2297
E-Mail –
For Immediate Release – July 10, 2018

Fruit and Vegetable Crop Walk

Hardin County– Are you a commercial fruit and vegetable grower who is looking for ways to manage pest issues in your produce?  Maybe you raise vegetables in your home garden and have spots on the leaves.  Do you have berries growing on your property or fruit trees in your yard that are not producing like they should?  Hardin County OSU Extension has planned a fruit and vegetable Crop Walk program on Wednesday, July 18 from 6:00-8:00 pm to help answer these concerns.  This program will include an emphasis on fruit and vegetable production.  The location of the program will be 2355 Codding Road, LaRue.

OSU Extension entomologist Dr. Celeste Welty and OSU Extension Horticulture field specialist Jim Jasinski will be providing presenting information about insect identification and recommendations, along with Integrated Pest Management (IPM) techniques for fruit and vegetable production.  OSU plant pathologist Dr. Sally Miller will provide information on managing plant diseases on produce.  Dr. Doug Doohan, OSU Horticulture and Crop Science weed specialist will provide instruction on how to better control weeds in fruit and vegetable production, using both conventional and organic methods.

The program will be held outside so bring your lawn chair and umbrella in case of rain.  There will be a diagnostic table so be sure to bring along any weeds, plant nutrition problems, plant diseases, and insect specimens in a sealed plastic bag for questions and answers.  The program will conclude with a walk through a produce patch and high tunnel greenhouse, pointing out fruit and vegetable issues and steps to properly manage them.

Western bean cutworm in sweet corn

The first reports of the adult moth of western bean cutworm being active this year were last week in Sandusky County and this week in Clark and Franklin Counties. This new pest was found in much larger numbers than ever in some parts of northern Ohio last year, so sweet corn growers should be on the lookout for it this year. The western bean cutworm has slowly but steadily been advancing into Ohio from the western USA over the past 12 years. It was found first in northwestern Ohio but has moved into north central and northeastern Ohio. It has not yet been detected at some southern Ohio sites. This pest is a caterpillar feeds on kernels of ears in both sweet corn and field corn. Feeding damage is usually at the tip end, but can be in the middle or butt end of the ear. There are often several western bean cutworm larvae in one ear, because this species is not cannibalistic; this makes it different than the corn earworm, which also feeds on kernels at the tip of the ear, but which typically is found as a single larva per ear because it cannibalizes its fellow corn earworm larvae.

Monitoring of western bean cutworm can be done in two ways. The adult moths can be monitored with a pheromone trap using a commercially available lure that lasts for 4 weeks. A bucket type of universal moth trap can be used, or a trap can be made from a one-gallon plastic milk jug with part of the sides removed, with an inch of dilute antifreeze solution in the bottom as a drowning and preserving agent. This pest has one generation per year, with adults usually first detected in late June, peak activity in late July, and moth activity ending by late August. Trap reports on western bean cutworm from several Ohio locations can be found using this link: The second way of monitoring is scouting. This is particularly important on any farm where the moth of western bean cutworm is detected in traps. Scouting should be done to monitor eggs and hatching larvae. Scouting should concentrate on plantings in the emerging-tassel stage. Look at 20 consecutive plants in each of 5 random locations per field. Examine the flag leaf (the leaf below the tassel), where eggs are usually laid. Eggs are laid in masses. Eggs are white when fresh, then they darken to purple when ready to hatch. Hatch will occur within 24-48 hours once eggs turn purple. Our tentative threshold for sweet corn is to consider treatment if eggs or larvae are found on more than 1% of plants for fresh-market or on more than 4% of plants for the processing market. Insecticide applications must occur after egg hatch, or after tassel emergence, but before larvae enter the ear.

The newer BT sweet corn hybrids in the Attribute II series (from Syngenta) provide genetic control of the western bean cutworm, but BT sweet corn hybrids in the Performance series (from Seminis) and the older Attribute series (from Syngenta) do not control this pest.

Pictures and additional details on western bean cutworm can be found in our OSU fact sheet:

-Celeste Welty, Extension Entomologist, OSU, Columbus OH

Common stalk borer

There have been several reports of common stalk borer (Papaipema nebris) in tomatoes and peppers in the past week. It can also attack potatoes and corn. This is an occasional pest that typically affects only a few plants in a field but which can sometimes cause economic damage. An early symptom is a drooping branch. If the affected stem is cut open, a caterpillar can be found inside. The stalk borer has a distinctive appearance, with long stripes on the back half of its body, and solid coloring on the front half of its body (see picture below). This insect takes 2 to 4 months to develop, which is much longer than most other caterpillars; it has up to 14 larval instars or sub-stages. As it grows, it tends to out-grow the stem that it is in, and it moves to a larger stem. By late summer, it prefers large-stemmed plants such as giant ragweed. Like with most borers, any stalk borer that is inside a stem is protected from insecticides. However due to its habit of moving from one stem to a larger stem, insecticide residues can kill a stalk borer when it moves out of a stem in search of a larger stem. Pyrethroid insecticides, which have long residual activity, are suitable for this purpose; these include Asana, Baythroid, Brigade, Hero, Mustang Maxx, permethrin, and Warrior.

Larva of common stalk borer in a maple stem. Photo by James Solomon, USDA Forest Service,

-Celeste Welty, Extension Entomologist, OSU, Columbus OH