Specialty Crop Insects

Spotted Lanternfly and the Potential Impacts on the Maple Syrup Industry

There will be a free webinar on November 16, 2022, at 10:00 AM EST, titled Spotted Lanternfly and the Potential Impacts on the Maple Syrup Industry.

Extension Educator Brian Walsh, Penn State Extension, will discuss what is known about the spotted lanternfly and observations about maple trees that provide insight as to the impact the insect could have on the industry.

Ever since the spotted lanternfly was found in Southeast Pennsylvania, it has been causing damage to agricultural plants as well as non-agricultural plants. As the insect continues to expand its range, more is being learned about the insect’s lifecycle and its feeding habitats. Since the spotted lanternfly can feed very heavily upon certain tree species, the insect can potentially impact the maple syrup industry.

Click this link to register:  https://extension.psu.edu/spotted-lanternfly-and-the-potential-impacts-on-the-maple-syrup-industry

Spotted Wing Drosophila Spotted

Spotted-wing Drosophila (SWD) is one of the major pests of cane berries, blueberries, black berries, strawberries and peaches. Last week it was detected in Greene, Monroe, Geauga and Wayne counties but likely is present and active in most Ohio counties at this point in the season (https://u.osu.edu/jasinski.4/pestvisualization/#linki).

Spotted wing Drosophila male (L) and female (R).

Recall that this pest is relatively new to Ohio, first discovered in 2011, and has the distinction from other drosophila flies of being able to attack whole, healthy fruit as they begin to blush and ripen.

The best way to monitor for this pest on your farm is to use a trap with either a commercial lure or apple cider vinegar as a bait.

Spotted wing drosophila baited Scentry trap.

If you do this, it will be necessary to empty the trap weekly and look through the catch to identify the male (with the spot on its wing) or female (which has an enlarged serrated ovipositor) using a stereoscope. Remember that the threshold for this pest is 1 SWD fly, male or female. Once the threshold is exceeded, trapping can be halted. This can be a fairly intensive endeavor but has been described in detail in various videos posted to the OSU IPM YouTube channel (setting up trap, identification, salt water tests, etc.). https://www.youtube.com/playlist?list=PL0HRPaZDLHyFqKGmNic832l0SWqMO8IQ4

If you choose not to monitor for this pest and have had SWD on your farm before, it is nearly 100% certain they will return once fruit is in the blush or ripe stage, so you should prepare to manage based on their assumed presence. A fact sheet on SWD giving more detail on management and biology with an up to date list of insecticides can be found here: https://cpb-us-w2.wpmucdn.com/u.osu.edu/dist/1/8311/files/2020/11/SWD_Ohio_handout_V20.pdf

Once you decide to stop harvesting in a certain block, insecticide treatment for SWD can be halted. For smaller or organic growers, some cultural methods including use of black mulch, pruning and netting have been shown to reduce and delay infestation.

Medina County grower talking about his exclusion netting project to manage SWD.

Spotted Lanternfly Video – Scouting Tips  

Article contributions by Jim Jasinski, Amy Stone, Thomas Dehaas, Ann Chanon (Dept. of Extension)

While it has generally been a cooler than average spring this year, a few hot days have pushed accumulated degree days past the point where Spotted Lanternfly (SLF) have begun emerging from their overwintering egg masses from known populations in Cleveland. Given the northern emergence location of this pest, it is nearly certain emergence has begun all over the state.

Slf map by degree days

To help scout for early SLF stages, Amy Stone of Ohio State University Extension is featured in a video describing how to locate and identify SLF egg masses and nymphs, both black and red stages (https://youtu.be/jhcURU2yCGE).

In general, the early nymphs are smaller and mostly black with white spots, almost spider or tick like, while the last nymph stage is the largest and mostly red with black and white spots.

Spotted Lanternfly has been detected primarily in the northern and eastern parts of the state but can be easily transported to any corner of the state so we hope the general public and growers remain vigilant in looking for this new pest. If a suspected SLF stage is found, please report to ODA (https://agri.ohio.gov/wps/portal/gov/oda/divisions/plant-health/invasive-pests/slf) or any OSU Extension educator. Take pictures, collect stages and carefully note location as someone will be sent back to confirm detection.

Stink Bugs on My Mind…and Camera

Overwintering BMSB getting active inside house.

While sitting at my home office desk this rainy afternoon, an annoying BMSB adult started buzzing around my head, landed on the window and then flew to the door, a subtle reminder to write this brief article. Earlier this week I was able to get out and shoot a quick video about identifying, monitoring and managing Brown Marmorated Stink Bug (BMSB). If you are interested to learn the current details of how to trap for this pest, take a look at the final video on the OSU IPM YouTube channel (https://youtu.be/PVtY-c92ZdM).

Distribution of BMSB based on trapping network in 2019.

While BMSB has an appetite for most fruit and vegetable crops plus corn, soybean and other hosts, it generally has not developed into a significant pest in Ohio as in states further east and into the mid-Atlantic region.  Our efforts to monitor this pest over the years has evolved with new trap designs and aggregation lures. The results of our monitoring seem to suggest the pest is slowly increasingly in the central, southwest and eastern areas of the state.

Sticky panel trap with pheromone lure.

While BMSB is beginning to become active now, most of the damage can be expected in the summer months on green and ripe fruit. In August and September, BMSB becomes more mobile and is attracted to sticky panel traps baited with pheromone lures. Unfortunately, the only crop with a threshold using the sticky panel traps is apples. For each apple block (ca. 5A) place one baited sticky trap at the edge and one in the interior about 50m away; when either trap catches 4 or more BMSB adults or nymphs, a treatment may be justified. Since BMSB tends to be an edge pest, a perimeter spray may be an effective way to treat this pest instead of the entire orchard.

For other crops, place a trap at the field edge, interior of the field or near a wooded border that is adjacent to a crop field to get an early determination if BMSB is in the area. One of the goals of current BMSB research is to develop more thresholds for other crops to help guide management decisions. Until then growers will have to resort to frequent scouting for nymphs an adults of BMSB and several other pest stink bugs in their crops.

Dr. Celeste Welty has much more information related to identification, biocontrol, damage and treatment of BMSB on her website (https://u.osu.edu/pestmanagement/pests/bmsb/). Additional information can be found at https://www.stopbmsb.org.

Late Season Pumpkin Pest – Aphids

Jim Jasinski, Department of Extension; Celeste Welty, Department of Entomology

Aphids on lower leaf surface.

While most growers have focused on managing cucumber beetles and squash bugs to this point in the season, now it’s time to be vigilant for a common late season pest, aphids. While there can be several species of aphids that invade pumpkin and squash fields in mid to late summer, the melon aphid is likely most common. Regardless of the species in your field, aphid biology and management are similar.

More aphids on a leaf.

Like squash bugs, aphids have sucking mouth parts. Aphids feed on the underside of leaves where tremendously large populations can build up quickly even with natural enemies (ladybugs, green lacewing larvae, parasitoid wasps, syrphid fly larvae, etc.) in the field, especially under hot and dry conditions. A by-product of their feeding is called honeydew, and when high aphid

populations exist, this sticky liquid can drip onto foliage and fruit creating a perfect condition for black sooty mold to grow on the surface of fruit which will need to be washed off prior to sale.

While aphids can create the environment for sooty mold, they can actively vector viruses to pumpkin and squash plants. A survey conducted in the late 1990’s by OSU researchers concluded that Watermelon Mosaic Virus was the most common type of virus found in Ohio pumpkin fields. Viruses in general may not be a serious threat to older plants where the fruit mature, but for younger plants with immature and developing fruit, distorted and strappy leaves, bumpy mosaic colored fruit or no fruit may result. While it is possible to treat pumpkin and squash plants for aphids, if an aphid feeds on a plant for just a second and then picks up a lethal dose of insecticide, the virus may already be vectored to that plant.  As a practical matter, virus transmission cannot be stopped using insecticides alone. Timing of planting is perhaps more effective, with earlier planting leading to potentially less virus incidence because fewer aphids are present as the crop matures.

Pumpkin leaves infected with virus.

Fruit infected with virus.

Sooty mold on pumpkin rind.

Sooty mold on foliage.

If scouting reveals aphid populations building in a field, even in the presence of natural enemies, treatment may be warranted if honeydew and black sooty mold are seen. While pyrethroids are relatively inexpensive to apply, they are devastating against most natural enemies and will likely cause an even more severe outbreak of aphids soon after application. The following products are non-pyrethroid alternatives, and their relative price compared to pyrethroids ($) are listed. Recent systemic materials such as Beleaf ($$$) and Fulfill ($$$) target sucking pests and should be less disruptive to natural enemies.  Other products such as Assail ($$), Sivanto ($$$), Harvanta ($$$$), and Exirel ($$$$$) are also likely to have high efficacy and less disruptive to non-target pests. A full list of recommended insecticides and their PHI’s can be found in the Midwest Vegetable Growers Guide (https://mwveguide.org).  

Insect observations

A few Japanese beetles were sighted today on a peach tree in Columbus. Late June is the usual time that this pest begins to emerge. Beware that large congregations might be seen on their preferred crops over the next few weeks. Japanese beetle is a pest of sweet corn, snap beans, raspberries, grapes, plum, peaches, blueberries, and hops as well as ornamental plants such as roses and linden trees and sassafras, and weeds such as smartweed. This pest can be more readily controlled by insecticides if the spray is made when the congregations are just beginning to form. Insecticides that are very effective for control of Japanese beetle are old ones: carbaryl (Sevin) and pyrethrins plus PBO (EverGreen Pro).

True armyworm is active in corn fields and grassy areas. We previously reported a large surge in the number of armyworm moths caught in our blacklight trap in Columbus between 5/14 and 5/18, with a record of 210 moths in one night on 5/14. We have been seeing increased numbers of moths during the past week, including today when there were 96 armyworm moths in the trap. There have been reports of armyworm larvae being found in field corn fields around Ohio. Daily counts of armyworm and several other common moths in blacklight traps are posted here:  https://docs.google.com/spreadsheets/d/10gh3rHahdxLKkXQapGyEPxWsjHYRmgsezOoFHnwtyEo/edit#gid=1114468121

Squash vine borer is now active, and abundant at our research farm in Columbus. Its adult is a day-flying moth that will be laying eggs on zucchini and other summer squash, winter squash (except butternut), pumpkins, and gourds over the next few weeks. It generally is a severe problem in home gardens and in small plantings, but less severe in large fields. Insecticide can be effective if directed to the base of the main stem before eggs have hatched, usually at least 2 or 3 sprays at 10-day intervals. Insecticides used for its control are pyrethroids such as Asana (esfenvalerate), Pounce (permethrin), Warrior (lambda-cyhalothrin), MustangMaxx (zeta-cypermethrin), or Brigade (bifenthrin); it is usually not well controlled by Sevin (carbaryl). We have found that EverGreen Pro (pyrethrins plus PBO) is effective although squash vine borer is not listed as a target pest on its label. This year we have a field trial in progress to evaluate the non-chemical tactic of a border trap crop of unharvested zucchini.

Corn earworm has been active for the past few weeks but at low numbers, which is typical of this pest in Ohio in early summer in most years. We have not seen the surge in moth activity like we did last year in late May and early June. A pheromone trap is highly effective at detecting the presence of the moth. Farms with early planted sweet corn should have their trap out as soon as tassels are emerging. Information on using traps is available here: https://cpb-us-w2.wpmucdn.com/u.osu.edu/dist/1/8311/files/2014/12/CornTrapInstructions2009-u47rp3.pdf   Information on buying traps to monitor corn earworm is here:  https://cpb-us-w2.wpmucdn.com/u.osu.edu/dist/1/8311/files/2019/07/TrapSpecsAndSources2019.pdf . Trap counts from several Ohio locations are posted here: https://docs.google.com/spreadsheets/d/10gh3rHahdxLKkXQapGyEPxWsjHYRmgsezOoFHnwtyEo/edit#gid=0

Potato leafhopper is active and being reported from beans, potatoes, apples, and hops. The adults and nymphs of this pest are found on leaf undersides where they suck sap. Their feeding results in yellowing then browning along the edge of leaves, a symptom known as ‘hopperburn’. Leafhoppers can be controlled by sprays of a neonicotinoid such as Admire (imidacloprid) or Assail (acetamiprid), or a pyrethroid such as Pounce (permethrin), Warrior (lambda-cyhalothrin), MustangMaxx (zeta-cypermethrin), Brigade (bifenthrin), or by dimethoate.

Brown marmorated stink bug is active now. Our traps are catching only adult stink bugs so far, but a few young nymphs have been seen on host plants. This year we are continuing our investigations of the samurai wasp, which is a tiny parasitoid that specializes in killing the eggs of this stink bug. We have a colony of the samurai wasp at OSU, and we have made releases of it at ten Ohio fruit farms, in comparison with 10 Ohio fruit farms where we did not make a release. We are currently sampling those 20 farms to see if the samurai wasp has become established.

Spotted lanternfly: This invasive exotic pest has NOT yet been found in Ohio, but many people are on the lookout for it, especially in eastern Ohio, because it has been spreading from its initial infestation in eastern Pennsylvania. Its favorite host plant is the tree of heaven but it can cause damage to grapes, hops, blueberries, and other fruit crops, mostly in late summer.

-Celeste Welty, Extension Entomologist

Spotted Lanternfly Slowly Approaching Ohio

The Spotted Lanternfly (SLF) is a newly discovered invasive pest from Asia. It is primarily a pest of trees like apples, cherries, black walnut, poplar, maple, tree of heaven and vines such as grapes and hops but it’s not reported to attack most vegetable crops. This pest was first detected in Berks County, PA in 2014, and has since spread to NJ, DE and VA; it has also been observed in MD, NY, CT and NC. In January 2020, new detections were found in western PA bordering Ohio and in eastern West Virginia (Figure 1).

Figure 1. Current known distribution of Spotted Lanternfly.

Damage is caused by inserting large sucking mouthparts into the trunk of the tree or vine and then siphoning out large amounts of sap. Excess sap from either the trunk injury or the planthopper can drip down the trunk and turn dark if infected with sooty mold. No diseases are known to be spread by this insect at this time, but excessive feeding weakens the tree and causes increased mortality during winter.

This pest is a planthopper and as an adult has red and purple wings and nearly one inch long (Figure 2). The immatures resemble stink bugs, being black with white spots when young, and red with black and white spots when older. The overwintering stage is the egg which is laid in masses of 15-30. At this time of the year, the eggs look like elongated brown seeds which can be attached to just about any surface including wood, stone and metal.

Figure 2. Life cycle of Spotted Lanternfly.

While we have NOT seen this pest in Ohio yet, it is within 15 miles of our eastern border and could very likely hitchhike its way into Ohio on a car, truck, trailer, train or boat. If you have tree of heaven on your property, which is one of its favorite hosts, or a vineyard nearby, check the trunks or vines for eggs now or check for nymphs and adults later in the season. If any questionable insects are seen, mark the location, take pictures, and contact your local Ohio State University Extension office or the Ohio Department of Agriculture, Division of Plant Health at 614-728-6400. Do not collect or transport any suspected SLF eggs, nymphs or adults.

For more information and pictures, see USDA’s Pest Alert on this pest: https://www.aphis.usda.gov/publications/plant_health/alert-spotted-lanternfly.pdf

This article was prepared by Jim Jasinski, Dept. of Extension and Celeste Welty, Dept. of Entomology

Mid-summer insect observations

Corn earworm (CEW) showed a moderate surge of activity during this past week, from 19-22 July when our pheromone trap in Columbus caught 49 moths in a 4-day period. This follows a few weeks of low CEW moth catch, after high CEW moth catch in late June. A pheromone trap near Fremont caught 74 CEW moths this past week. The corn earworm moths will be laying their eggs on silks of sweet corn. Sweet corn can be protected from corn earworm infestation by insecticide sprays during silking. When the number of CEW moths caught in traps is moderate  (1 to 13 moths per day, or 7 to 90 moths per week), then sprays should be applied every 4 days if the daily maximum temperatures is below 80 degrees F, or every 3 days if the daily maximum temperatures is above 80 degrees F. More information about CEW, traps, and trap-based spray schedules is available using this link: http://u.osu.edu/pestmanagement/crops/swcorn/ .

The typical insect pests of mid-summer are currently being found on Ohio farms. Squash bug eggs and young nymphs are being found in squash and pumpkin fields. Cucumber beetles, both striped and spotted, are feeding in flowers of squash and melons. Squash vine borer is past its peak in terms of the number of adult moths caught in pheromone traps, which peaked in early July. The tobacco hornworm is feeding on tomatoes in the field and in high tunnels. Imported cabbageworm is feeding on cabbage and other Brassica crops. Colorado potato beetle adults are on eggplant and potato. Blister beetles are reported on potato. Sap beetles and western corn rootworm beetles are being seen on sweet corn. Japanese beetles are found on sweet corn, asparagus ferns, and various fruit crops, but they seem to be less numerous now than several weeks ago when huge numbers were seen.

The second generation of the European corn borer has not yet been detected, but it should start within the next week or two, and will be important in peppers and sweet corn.

An encouraging note is that many beneficial insects are also active in vegetable crops. Recent sightings include many Orius predatory bugs and the pink lady beetle in sweet corn, lady beetle larvae, lacewing larvae, the spined soldier bug, and damsel bugs in a variety of crops.

-Celeste Welty, Extension Entomologist

They’re back…Japanese beetles on the rise

This article was written to complement Celeste Welty’s blog on Japanese beetle insecticide selection last week (https://u.osu.edu/vegnetnews/2018/06/30/insecticide-notes/).

One of Ohio’s most recognizable leaf feeders, the copper-colored and metallic green Japanese beetle, is on the rise. According to scattered reports across the state, this beetle has been leaving a trail of skeletonized leaves on an array of landscape plants, field crops, vegetable and fruit crops.

 

Japanese beetle adult.

While specific thresholds do not exist for most crops, below are listed a few guidelines that should help growers manage Japanese beetles in general.

Silk clipping.

Sweet Corn – During the early-silking stage, examine 50 ears in small plantings (< 2 acres) or 100 ears in large plantings (> 2 acres). Treat by spraying insecticide directed at the silks to prevent clipping by beetles during the early-silk stage if the average number of beetles is 2 or more per ear.  If pollination has already occurred, silk clipping will not harm kernel development or ear, therefore control is not necessary.

Hops – At this time there is no established treatment threshold for Japanese beetles in hops. Growers should consider that established, unstressed and robust plants can likely tolerate a substantial amount of leaf feeding before any negative effects occur. Those managing hopyards with small, newly established, or stressed plants should take a more aggressive approach to Japanese beetle management, as plants with limited leaf area and those already under stress will be more susceptible to damage. It is also important to carefully observe beetle behavior in the hopyard; if flowers, burrs or cones are present and being damaged, growers should consider more aggressive management as yield and quality are directly affected (excerpted from https://www.canr.msu.edu/uploads/234/71503/Hop_JapaneseBeetle.pdf).

Fruit crops and Grapes – For most fruit crops, there is no economic threshold on the number of beetles or amount of damage that requires treatment. If a susceptible cultivar is being grown and growers previously have experienced high populations of Japanese beetles, an insecticide should be applied when beetles emerge and thereafter as needed.

Feeding damage on raspberry.

A Japanese beetle lure and trap is available for monitoring this pest, however these beetles are easily detected while walking through the planting. If skeletonizing of leaves or feeding on the fruit becomes evident, the plants may need to be protected with an application of insecticide. The usual threshold for making a spray application is about 15% of the leaves damaged with adult beetles still present (excerpted from http://extension.missouri.edu/sare/documents/MidwestSmallFruitPestManagement2012.pdf).

Remember to consult the Midwest Fruit Pest Management Guide 2018 (https://ag.purdue.edu/hla/Hort/Documents/ID-465.pdf) for specific management details about this pest on apples, brambles, peaches, plums, grapes, and blueberries including pesticide recommendations. This resource is rich with details for each crop concerning insecticide group, product selection and efficacy, REI, PHI, and small tips to aid in control.

For help on insecticide selection on vegetable crops, consult the Midwest Vegetable Production Guide 2018 (https://ag.purdue.edu/btny/midwest-vegetable-guide/Pages/default.aspx).

IPM – Insect Pest Scouting and Management – Late May to Early June 2018 – Central Ohio

These insects, some pests, some beneficial, were noted from scouting efforts in central Ohio from mid-May to early June 2018.

Imported Cabbageworm

One of the most common predators of the brassicacea family of vegetables is the larval form of the cabbage white butterfly, called the imported cabbageworm.  The butterfly is a constant presence in Ohio as our most common butterfly species.  It lays eggs on cabbage family plants and the larval forms feed on the foliage.  They can be difficult to spot due to coloration but feeding damage and frass (fecal material) can be observed via scouting.

The focus is on the cabbageworm fecal material, called frass, at the base of the leaf in the bottom of the picture. The cabbageworm can be difficult to locate due to camouflage but the frass and pattern of leaf damage indicates to keep looking to locate the predator.

 

The butterfly lays very tiny eggs a single egg at a time on the leaves using her ovi-positor.

 

Egg size with penny added to picture for reference.

Control is by scouting for eggs, which can be difficult, or for by early recognition of larvae and damage.  Hand removal is very effective for small plantings.   Organic control (check the label carefully) is possible with spinosad products.

Virginia Fact Sheet on Spinosad

Imported Cabbageworm Fact Sheet

 

Cucumber Beetles

Cucumber beetles are a major pest in vegetable plantings. The adults have emerged from their over wintered areas to start feeding on plants and laying eggs in the soil at the base of cucurbit family plants.

 

Feeding damage to the cotyledons and early true leaves of the cucurbit family from over-wintered cucumber beetle adults prior to egg laying.

Cucumber beetles are a serious pest of cucurbit family plants due to feeding on foliage, flowers and fruit.   Control can be difficult.  They also vector a devastating bacterial wilt disease that can quickly kill plants and has no treatment.

Cucumber Beetle Fact Sheet

 

Egg Scouting

A good habit to use when scouting for insect pests on plantings is to look at the underside of the leaves for eggs.  Many of the insect pests lay eggs singly or in clusters on the underside of leaves, where if undetected, will hatch into larvae that will feed on the foliage.  This egg cluster was noted on oregano.  I suspect these eggs to be from Box Elder bugs, which do not normally feed on oregano.  Both a Box Elder and related Sugar Maple are in the vicinity of the oregano planting.

 

Slugs

Slugs will be more numerous in production areas that have high organic matter content. They can feed and damage foliage. Early control is critical to avoid build up and infestation of a production area during a growing season.

Control of slugs can be achieved with organic products containing iron phosphate.  Slug Factsheet from PSU

 

Cutworms

This is the larval form of a night moth.  It curls up around the stem of a plant and feeds until the stem is cut in half and the plant has been killed.  They feed at night commonly so a grower would notice a dead plant that looks cut in half.  Digging around the base of the plant can sometimes find the causative agent.

Dusky Cutworm. Found when digging around base of dead cucurbit plant.

Cutworm Fact Sheet

 

Ground Beetle – Beneficial

Not all insects are pests,  some are beneficial and are feeding on pest and assisting the grower.  Proper identification will allow the backyard grower, community gardener and urban farmer to know what to keep and what to treat.

Ground Beetle Fact Sheet Ohioline

 

If you have questions or concerns about an insect pest located via scouting, contact your Extension office for assistance with identification.