Integrated Pest Management

Wayne County IPM Scouting Notes from June 15 – June 19

Wayne County IPM Notes

(From the Week of June 15 – June 19)

Frank Becker, IPM Program Coordinator

OSU Extension Wayne County

Vegetable Pests

Japanese Beetle on corn, F. Becker photo

This week I began seeing Japanese Beetles, specifically in sweet corn. These beetles are generalist feeders and will do damage to most any crop. Keep an eye out for the beetles and the defoliation that they can cause. More Info

Flea Beetles are doing damage to a lot of younger transplants. Flea Beetles will utilize weeds as host plants. Keeping your fields free from weeds will help to reduce the populations of flea beetles.

Cucumber Beetles are high in numbers right now. Cucumber Beetles vector the Bacterial Wilt disease so early season control of the beetles is vital to the long-term health of the plant. Also note that as your plants are blooming, the beetles may be in the blossoms. In small enough numbers, they are not detrimental, but they can also damage the fruit from feeding on the blossom and interfering with pollination. Consider the pollinators when planning out treatment options for cucumber beetle.

European Corn Borer moths are out. A trap this week in Wayne County picked up 14 moths. ECB will do damage to both peppers and sweet corn.

Onions are at a point where thrips populations could begin to increase. Consistent rains and small plants had kept the thrips population down, but with onions increasing in size and putting on more leaves, this will be a pest to watch in the next few weeks.

The Imported Cabbageworm larvae, among other worm pests of brassicas, are feeding on cole crops and leafy greens such as kale. Severe foliar feeding could stunt the plant growth or significantly reduce yield.

Vegetable Diseases

            Timber rot is still being found, mostly in high tunnel tomatoes. Botrytis is still being seen too, as is blossom end rot. To manage blossom end rot, it is important to limit moisture stress on a plant, from either too much or not enough moisture. Being consistent in watering and monitoring soil moisture conditions will help to prevent exposing the plant to moisture stress. Proper moisture will also provide conducive conditions for adequate nutrient uptake, given that the nutrients are present at appropriate levels in the soil.

Botrytis is also being seen in onions. This disease is primarily affecting the foliage but can impact the integrity of the bulb if left uncontrolled. Find out more about management of onion diseases here: Growing Onions

Some of the field peppers I am scouting showed signs of damping off. Damping off is caused by soil borne fungi such as Rhizoctonia, Pythium, Fusarium and Phytophthora.

Fruit Pests

Japanese Beetles, left untreated, feeding on young apples, F. Becker photo

With finding Japanese Beetles this week, I would encourage fruit growers to keep a close eye on their trees and small fruit plants. Grapes especially can be a target of the Japanese Beetle and can be defoliated very rapidly. This kind of damage can be detrimental to the yield of the crop. Japanese Beetles will also do damage to the fruit, as seen in the photo to the right, taken in 2019.

SWD traps are out and we will start getting an idea of population numbers within the next week.

Codling Moth and Oriental Fruit Moth traps counts were low but starting to tick up. This week will be an important week in determining the next generation of moths. More on Codling Moth management and additional information from Celeste Welty: Codling Moth

Fruit Diseases

            Now is the time to be managing early season diseases in apples. Scab, rust and powdery mildew are the three main diseases of concern at this point in the season. It may also be appropriate to start considering managing summer diseases such as flyspeck, sooty blotch, and fruit rots.

Strawberry leaf diseases may appear unsightly right now, however, now is not the time to be managing these leaf diseases. Once harvest is done and during patch renovation it is recommended that you address these concerns, either with a fungicide or with resistant plant varieties. This is also a critical time to be watching for fruit rots such as Botrytis.

 

Wayne County Scouting Notes, June 8 – June 12

Wayne County IPM Notes

(From the Week of June 8 – June 12)

Frank Becker, OSU Extension Wayne County

Vegetable Pests

Young Colorado Potato Beetle larva (F. Becker photo)

The Colorado Potato Beetle is still feeding heavily, especially on potato. The larvae are out in large numbers and many egg clusters are hatching or will soon be. They are most effectively controlled in the larval stage. It is best to coordinate insecticide applications in line with when the egg masses are hatching, and young larva are starting to feed on the foliage.

Flea Beetles are still prevalent and doing damage. Flea Beetles will also utilize weeds as host plants. Keeping your fields free from weeds will help to reduce the populations of flea beetles.

Cucumber Beetles are out in force right now. For growers who use a seed treatment on cucurbit crops, keep in mind that the treatment is typically effective up to the 2-leaf stage, at which point the efficacy starts to decline. Cucumber Beetles vector the Bacterial Wilt disease so early season control of the beetles is vital to the long-term health of the plant.

In sweet corn, cut worm damage has started popping up along with some more significant European corn borer damage.

Onions are at a point where thrips populations could begin to increase. Consistent rains and small plants had kept the thrips population down, but with some drier weather in the forecast and onions increasing in size and putting on more leaves, this will be a pest to keep an eye on.

Imported Cabbage Worm Larva (F. Becker photo)

The Imported Cabbageworm larvae, among other worm pests of brassicas, are feeding on cole crops and leafy greens such as kale. Severe foliar feeding could stunt the plant growth or significantly reduce yield.

Vegetable Diseases

Timber Rot on a high tunnel tomato (F. Becker photo)

Timber rot of tomato is being found, especially in high tunnel tomatoes. This disease will take down a plant very rapidly. The survival structure, called a sclerotia, can survive in the soil for several years. It is important to allow for good airflow to avoid excess moisture in the tunnel. Additionally, it is recommended that if you are pruning to sanitize the tools between each cut. Diseased plants may also be removed and disposed of to prevent further spread of the pathogen.  Find more details about timber rot and management options in this article by Sally Miller: https://u.osu.edu/miller.769/2016/06/22/white-moldtimber-rot-management-in-tomato-high-tunnels/

Botrytis is still being seen, as is blossom end rot. To manage blossom end rot, it is important to limit moisture stress on a plant, from either too much or not enough moisture. Being consistent in watering and monitoring soil moisture conditions will help to prevent exposing the plant to moisture stress. Proper moisture will also provide conducive conditions for adequate nutrient uptake, given that the nutrients are present at appropriate levels in the soil.

 

Fruit Pests

Strawberry producers typically are facing several insect pests this time of year. One of these pests is the eastern flower thrips. This small insect feeds on and damages the strawberry blossom. As the berry begins to develop, this damage results in cat-facing on the berry or a russeting/bronzed appearance. When you notice these symptoms on the developing berry, the damage has already been done and there are no treatment options. To look for thrips in the blossoms, take a white piece of paper or a plate and shake the blossoms onto the plate and watch for any small, slender yellow thrips to be moving around. Once you have reached 2 or more thrips per blossom, you should move forward with a treatment. Consider the pollinators before applying an insecticide, considering the target of your application is primarily associated with the blossoms. Preventative sprays can also be used in successive plantings. See more on Thrips in this post by Celeste Welty: Beware of thrips on strawberries

Another pest of strawberries and small fruits is the spotted wing Drosophila. The SWD is a small fruit fly that can lay its eggs in ripening fruit while it is still on the plant. As you are picking, do not discard unwanted fruit on the ground right next to the plant. The rotting fruit on the ground will attract SWD. Instead bring a bucket to discard unwanted fruit in and either bury it a foot or so deep in soil or seal the fruit in a clear plastic bag exposed to the sun for about a week to kill any larvae. If culls are discarded in the trash or compost pile, they might attract SWD flies and allow for more generations to be produced. This is also the time to put traps out in your bramble and blueberry patch but if you have June bearing strawberries, they likely won’t be affected by this pest. More details about how to set up traps can be in the  OSU IPM YouTube page under the SWD playlist at https://www.youtube.com/channel/UCzcWaLH3mx7HUKh4OF7bYPA and on Celeste Welty’s page here: https://u.osu.edu/pestmanagement/

Codling Moth and Oriental Fruit Moth traps are showing low numbers right now.

Fruit Diseases

            Now is the time to be managing early season diseases in apples. Scab, rust and powdery mildew are the three main diseases of concern at this point in the season. It may also be appropriate to consider looking at managing summer diseases such as flyspeck, sooty blotch, and fruit rots.

Strawberry leaf diseases may appear unsightly right now, however, now is not the time to be managing these leaf diseases. Once harvest is done and during patch renovation it is recommended that you address these concerns, either with a fungicide or with resistant plant varieties. This is also a critical time to be watching for fruit rots such as Botrytis.

Grapes are currently either at pre-bloom or blooming. This stage is the most critical stage of development for controlling diseases. Fungicide applications for black rot, powdery mildew and downy mildew are highly recommended during this time. See more details about grape black rot here.

 

Wayne County IPM Notes (Week of June 1- June 5)

These observations are from Frank Becker, Dept. of Extension Wayne County.

Vegetable Pests

The Colorado Potato Beetle is being seen feeding in both potato and eggplant. When approaching plants to look for them, be cautious. When the beetle is startled, they drop to the ground and may be difficult to see. They do significant damage to the foliage and can cause significant reduction in yield. The Colorado Potato Beetle also has a history of developing resistance to insecticides being used as control measures. This has limited our choices for treatment options. The best way to prevent further resistance is to avoid using the same insecticide repeatedly. At the current plant stage for potato, the threshold is approximately 1 beetle per plant. For eggplant, it is 25 beetles per 50 plants.

Another pesky insect this time of year is the flea beetle. Their damage may seem insignificant at first, however, their populations can rapidly increase and can quickly overwhelm young plants. Flea beetle damage is occurring primarily on potato, eggplant, cole crops and sweet corn. Sweet corn is of particular concern due to Stewart’s Wilt disease which is vectored by the flea beetle. Susceptible sweet corn varieties have a threshold of 6 beetles per 100 plants, while tolerant varieties have a threshold of 2 beetles per plant. On cole crops, the threshold is 5 or more beetles per plant. For potato, you will need to count the “shot holes” in the leaves caused by the beetle. The threshold is 15 shot holes per leaflet. Eggplants have a threshold of 8 beetles per plant.

In sweet corn, there is light slug damage occurring as well as some light damage being done by the European corn borer larva. Young sweet corn is also a target of black cutworm. The cutworm will cut plants at the soil line. If you find a cut plant, dig up some soil around the plant to see if you can find the cutworm.

Vegetable Diseases

In high humidity this time of year, greenhouse tomato crops become especially susceptible to infection from Botrytis. This can initially present itself on the fruit as “ghost spot” which appear as pale or white rings on the fruit. It can then progress into Botrytis gray mold and the fruit will begin to rot. It is important to increase airflow in the tunnel as well as between plants. It would also be beneficial to reduce the humidity within the tunnel.

Blossom end rot is also prevalent this time of year in crops such squash and tomatoes. Although this is not necessarily a pathogen, secondary infections commonly compound the issue. To manage blossom end rot, it is important to limit moisture stress on a plant, from either too much or not enough moisture. Being consistent in watering and monitoring soil moisture conditions will help to prevent exposing the plant to moisture stress. Proper moisture will also provide conducive conditions for adequate nutrient uptake, given that the nutrients are present at appropriate levels in the soil.

Fruit Pests

Strawberry producers typically are facing several insect pests this time of year. One of these pests is the eastern flower thrips. This small insect feeds on and damages the strawberry blossom. As the berry begins to develop, this damage results in cat-facing on the berry or a russeting/bronzed appearance. When you notice these symptoms on the developing berry, the damage has already been done and there are no treatment options. To look for thrips in the blossoms, take a white piece of paper or a plate and shake the blossoms onto the plate and watch for any small, slender yellow thrips to be moving around. Once you have reached 2 or more thrips per blossom, you should move forward with a treatment. Consider the pollinators before applying an insecticide, considering the target of your application is primarily associated with the blossoms. Preventative sprays can also be used in successive plantings.

Another pest of strawberries and small fruits is the spotted wing Drosophila. The SWD is a small fruit fly that can lay its eggs in ripening fruit while it is still on the plant. As you are picking, do not discard unwanted fruit on the ground right next to the plant. The rotting fruit on the ground will attract SWD. Instead bring a bucket to discard unwanted fruit in and either bury it a foot or so deep in soil or seal the fruit in a clear plastic bag exposed to the sun for about a week to kill any larvae. If culls are discarded in the trash or compost pile, they might attract SWD flies and allow for more generations to be produced. This is also the time to put traps out in your bramble and blueberry patch but if you have June bearing strawberries, they likely won’t be affected by this pest. More details about how to set up traps can be in the  OSU IPM YouTube page under the SWD playlist at https://www.youtube.com/channel/UCzcWaLH3mx7HUKh4OF7bYPA and on Celeste Welty’s https://u.osu.edu/pestmanagement/ page.

Orchard traps are now out in Wayne County and we will be monitoring Codling Moth and Oriental Fruit Moth numbers closely.

Fruit Diseases

Now is the time to be managing early season diseases in apples. Scab, rust and powdery mildew are the three main diseases of concern at this point in the season.

Strawberry leaf diseases may appear unsightly right now, however, now is not the time to be managing these leaf diseases. Once harvest is done and during patch renovation it is recommended that you address these concerns, either with a fungicide or with resistant plant varieties. This is also a critical time to be watching for fruit rots such as Botrytis.

Grapes are currently around the pre-bloom stage. This stage is the most critical stage of development for controlling diseases. Fungicide applications for black rot, powdery mildew and downy mildew are highly recommended during this time.

Pumpkin & Squash Growers Wanted for On-Farm Mustard Biofumigation Trial

Plectosporium blight on fruit and handle.

Plectosporium blight on petioles and leaf veins.

In 2019, research was conducted into the use of mustard cover crops as a biofumigant to reduce a specific soil borne disease in pumpkins, Plectosporium blight, also known as white speck or Microdochium. The signs of this disease start out as spindle shaped lesions on the petioles, vines and back of leaf veins potentially killing the plant. If the disease progress, it can infect the handles and turn immature and mature fruit white.

Although our trial in 2019 was planted in a Plectosporium infested field, very little disease developed due to the near drought like conditions at the research station in South Charleston. In wetter locations around Ohio this disease was seen last year and we still think there is potential for this cultural technique to reduce disease in pumpkin and squash fields. To accomplish this on a wider scale in 2020, we plan to replicate and expand our mustard cover crop (MCC) biofumigation study to include on-farm trials with growers.

We are looking to recruit 4-6 growers preferably in the central or southern part of the state to put out a mustard cover crop biofumigation trial to reduce soil borne disease pressure with the following guidelines and conditions.

Growers requirements and general protocol:
-Growers must plant in field known to have a Plectosporium blight infestation. Growers with fields infested with Fusarium or Phytophthora will also be considered.

Equipment needed to successfully manage a mustard cover crop.

-Growers need to have equipment to seed the cover crop, chop (bush hog or flail), incorporate (rototill), pack the soil (culti-mulcher) and possibly seal the soil using a sprayer or irrigation system. These steps will be done in rapid succession so 3-4 tractors are ideally needed, each hooked to an implement.

-Growers will put out 4 strips of MCC and 4 strips without a MCC.

-Strip sizes will be up to 0.1A for a maximum of 0.8A needed for the entire on-farm study.

-Growers will plant Caliente Rojo, currently the highest yielding glucosinolate mustard cover crop available.

OSU will provide:
-The MCC seed, the fertilizer (urea + granular ammonium sulfate) and 1K seeds of the pumpkin hybrid Solid Gold (Rupp).

-Also evaluate each grower site for disease incidence on foliage three times during the season, plus a harvest where mature fruit are weighed and graded for disease.

Study Timeline:
-The MCC strip plots fertilizer will be disked into the soil prior to seeding to ensure high biomass production.

-The MCC planting date will be between March 30 and April 30 based on soil conditions and weather forecasts.

Mustard cover crop at full bloom.

-Approximately 50-60 days later, the MCC will be at peak flowering and will be chopped, rototill incorporated into the soil and then packed using culti-mulcher. If irrigation is available, water will be applied to help seal the soil and create a better environment for biofumigation.

-Within 10-14 days of incorporation, Solid Gold pumpkins will be transplanted into those strips at roughly 4ft spacing between plants. Note that transplants are preferred at each site instead of direct seeding, but if this is not possible, we can discuss options. Transplants will lead to an earlier harvest.

Plot Care:
Each farm will follow their own standard weed, insect and disease control and fertility practices on the 8 strips. The fungicides used on the crop will need to be discussed ahead of time so we can limit the use of fungicides that might help control Plectosporium blight. These fungicides are Flint, Cabrio, Quadris, Inspire Super and Merivon.

Disease ratings of incidence on vines, foliage and fruit will be taken at 14-21 day intervals from vining until fruit maturity. Sections of all strips will be harvested and fruit will be weighed and graded for disease.

The Big Picture:
By expanding the number of sites for this research through on-farm trials, we expect to see the potential MCC may have to reduce the soil borne disease complex affecting cucurbits. By recruiting growers into this process at a small scale, we hope to gain their valuable feedback as to the feasibility and challenges of using MCC on their farm. If successful, growers will spread the news to other growers who might be willing to try MCC on their farm. In addition to the potential biofumigation benefit, growers will be enhancing their soil organic matter levels and provide premium although brief pollinator habitat during flowering.

If growers want to see a video detailing the steps and processes involved with planting MCC as a biofumigant, check out the work we did in 2019 at https://youtu.be/Taz-PhDphhA.

Sign up:
If interested in participating in this project or have questions, please contact me at 937-484-1526 or jasinski.4@osu.edu by March 14.

This project is being funded by the Ohio Vegetable and Small Fruit Research and Development Program and the IPM Program.

Practical Skills for Managing Invasive Insects Workshop

Adult spotted lanternfly. Photo by Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org

Join members of the OSU Department of Entomology and the OSU IPM Program for a workshop that highlights recent research results and reviews the latest recommendations for key practices in monitoring, identifying, and managing the spotted-wing Drosophila and Brown Marmorated Stink Bug on fruit and vegetable crops. Although the spotted lanternfly has not yet been found in Ohio, this invasive pest has been detected in nearby states, so we’ll provide some tips to remain vigilant for this potentially new pest.

The workshop will be held Tuesday, March 26 at OSU’s Waterman Farm (2490 Carmack Road Columbus, OH 43210) in the Wittmeyer Conference Room in the Headquarters Building, from 9 AM – noon. The agenda is not yet finalized but will be modeled after the following outline:

Brown marmorated stink bug on apple.  

Spotted-Wing Drosophila, on berry crops
-Overview of distribution and biology
-Key advances in monitoring, identification & management
-New streamlined approach to monitoring in 2019
-Additional Resources

Brown Marmorated Stink Bug, on fruit & vegetable crops
-Overview of distribution and biology
-Key advances in monitoring & management
-Biological control update
-Additional Resources

 

Spotted Lanternfly, potentially on tree fruit & hop crops

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

-Overview of distribution and biology
-Monitoring techniques
-Management decisions / options
-Additional Resources

Coffee and light snacks will be served. Registration will cost $5 per person and be limited to only 35 attendees due to room constraints. All participants must pre-register using this link (https://www.surveymonkey.com/r/OSUinvasive). Registration will end March 22nd.  Payment, cash or check, will be accepted at the door.

If you have any difficulties registering or have other questions, please contact Jim Jasinski, jasinski.4@osu.eduor 937-484-1526, or Celeste Welty, welty.1@osu.edu, 614-292-2803.

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.

 

Hopeful news about stink bug biocontrol

The news about the brown marmorated stink bug (BMSB) has generally been bad over the past few years, as this new invasive pest has continued to expand its range within the USA, causing increasing problems as a pest of fruit, vegetable, and field crops. We know that our native natural enemies have not been able to provide much biological control of BMSB, but there has been hope about potential biological control of BMSB by a tiny wasp that parasitized BMSB eggs in China. The wasp is Trissolcus japonicus, nicknamed the samurai wasp.

USDA entomologists at Newark, Delaware, have been conducting intensive studies of the samurai wasp over the past 10 years with the hope that it could be introduced into the USA for control of BMSB, but thus far its introduction has not been approved. However a significant event occurred in 2014, when the samurai wasp was detected outdoors in Maryland, where it apparently showed up on its own, probably via a parasitized BMSB egg mass present in cargo shipped from Asia. In 2015, the samurai wasp was also detected in Virginia, Delaware, and Washington State. In 2016, it was detected in New Jersey, New York, and Oregon. In 2017, it was detected in Pennsylvania. Once an exotic species like this has been detected, it can be studied and intentionally spread within any State, but it is not allowed to be transported across State lines.

In Ohio, as part of our involvement in a multi-State project on BMSB management, we surveyed for the possible presence of the samurai wasp within Ohio in 2017. To do this, we collected fresh egg masses from our lab colony of BMSB; we deployed the egg masses in the field by clipping them to the underside of leaves, mostly on plants in wooded edges adjacent to fruit and vegetable crops. The egg masses were left outside for 3 days, then brought back to the lab where we observed whether they eventually hatched into stink bugs or if they were parasitized. We deployed 544 egg masses between May and September at several Ohio locations. Over the winter, we have been working our way through these samples, and identifying wasps that emerged from parasitized eggs. This past week, we found that wasps that emerged from two egg masses were identified as the samurai wasp. The two egg masses were deployed in Columbus in early August 2017. This finding that the samurai wasp has spread to Ohio is quite exciting. We plan to do additional surveys in 2018 to determine whether it is present at additional locations within Ohio.

 

by Celeste Welty, Extension Entomologist

Scouting – Harlequin bugs on broccoli

Hocking County had a serious problem last growing season with Harlequin bug damage on crucifers.  Any plant that was not monitored with hand picking or treated with insecticide was severely damaged up to complete loss of product.

Scouting started in mid-May with the first bugs noted at The Urban Farm on June 13th.

Feeding damage from the bugs is noted on the leaf in the form of white stippling. Large holes were caused by feeding of Cabbage White larvae

Hand picking was used to remove the several bugs noted instead of insecticide to allow harvest of the remaining broccoli.  The planting beds will be rotated out of broccoli within the next couple weeks and no other cruciferous vegetables will be planted until August, but scouting will continue.

Harlequin bug (Murgantia histrionica) –>  Profile: Journal of Integrated Pest Management

Factsheet: University of Maryland

OSU Vegnet photo identification