Harlequin Stinkbugs in the Garden

The following information was suggested by Elizabeth Beggins whose bed (#29) in the St. Michaels Community Garden has been overrun by Harlequin bugs. The information below can be found in its entirety at http://www.toxicfreenc.org/organicgardening/stink_bugs.html. The photos are also from that website. The photo of the eggs is helpful. Barrel shaped and distinctive. One more thing to look for.

Harlequin stinkbugadult  Adult Harlequin Harlequin nymphs Harlequin nymphs

About Harlequin Bugs and Stink Bugs

The Harlequin bug is a type of stink bug that causes trouble for many gardeners in the Southeast. Other stink bug pests in North Carolina include the Green stink bug, Brown stink bug, and Southern green stink bug.

All are pests of many crops, but they especially love plants of the brassica family. The brassicas include cabbage, collards, broccoli, mustard, turnips, and kale. During heavy outbreaks, or when all their favorites are gone, Harlequin bugs will eat other garden plants such as squash, okra, tomatoes, corn, beans, and tree fruits.

Both adults and  nymphs cause damage. They eat all parts of the plants, including stems, leaves, fruits, and seeds. They use piercing mouth parts to suck out plant juices. Damage on leaves and stems looks like uneven discolored spots around a hole. Young plants may wilt, turn brown, and die. Mature plants may survive but growth is slowed. Damage on fruits such as squash, tomatoes and okra appears as dark holes surrounded by bumps, pits, or white-yellowish spots. The lighter spots do not ripen to the same color as the rest of the fruit. Fruits may also dimple or grow in strange shapes.

The tips below are designed to help you control stink bug damage in your garden. Sustainable pest management strategies usually work best when used together. Think about your garden, your resources, and your time, and put several of these tips together into a plan that works for you.

Identifying  Harlequin Bugs and Stink Bugs

Adult stink bugs are about half an inch long and shield-shaped. Their colors range from dark brown, tan, to green. The Harlequin bug is black with orange, yellow and red markings (see picture above).

Nymphs are similar to adults but smaller and with a more rounded shape. Eggs are barrel-shaped. They are laid in groups on stems and the undersides of leaves, and may be yellow, green, pink,  gray, or striped. (see picture above)

Harlequin eggs Stink bug eggs

It is important to note that not all stink bugs are pests. Some predatory stink bugs, such as the spined soldier bug, actually attack other garden pests. They should be encouraged in the garden. The spined soldier bug looks similar to the brown stink bug, but has spikes standing out on its shoulders.

Stink bug good spinedsoldierbug Good guy!

Life Cycle

Stink bug adults spend the winter in old plants and other garden litter. They come out in the early spring to begin laying eggs. In early spring eggs take up to 20 days to hatch, but as the weather warms they may hatch in as few as 5 days.  Nymphs mature into adults in 5 – 8 weeks. Populations tend to grow through the season, getting heaviest during early to mid fall.

Prevention

1) Grow healthy organic plants. Strong plants can handle some damage from stink bugs better than weak, struggling plants. Make sure that your crops are getting enough sunlight and water. Ensure that the soil is well-drained, and rich in nutrients and organic matter.

2) Grow resistant varieties. Some types of brassica plants are naturally resistant to Harlequin bugs. NC Cooperative Extension recommends the following varieties: Cabbage: Copenhagen Market 86, Headstart, Savoy Perfect Drumhead, Stein’s Flat Dutch, Early Jersey Wakefield. Collards: Green Glaze. Cauliflower: Early Snowball X, Snowball Y. Radishes: Red Devil, White Icicle, Globemaster, Cherry Belle, Champion, Red Prince.

3) Till in late fall. Tilling crop leftovers into the soil once cold weather has arrived can reduce the number of adult stink bugs who survive the winter. Then fewer come back out the following spring.

4) Control weeds in the garden area. Stink bugs are attracted by weedy areas in or near the garden. Weeds should not be allowed to spread in the garden. Weedy areas around the garden should be mowed before spring planting and regularly after that to keep stink bugs from hanging around.

5) Use row covers. Keep stink bugs from finding your crop by covering your brassica plants with a lightweight “floating” row cover such as Reemay. These materials (as opposed to plastic or heavier fabrics) let water and air through and do not block very much sunlight. They can be found at garden supply stores or ordered from seed catalogs. The covers can lie directly on the plants (the plants will lift the cover as they grow), or you can support the covers with wire hoops. The trick is to keep the edges of the covers tightly buried or weighted so that the stink bugs cannot get in.

Getting Rid of  Harlequin Bugs and Stink Bugs  Without Toxic Chemicals

6) Scout and hand pick. Hand picking stink bug adults, nymphs and eggs early in the season can really help you control them later in the year. Likewise, hand picking in the fall can cut down the number of adult stink bugs that come back the following season. Scout the garden often throughout the year. When you find stink bug adults, nymphs, or egg clusters, crush them with your fingers. Or, since stink bugs really do stink when you squish them, it might be less smelly to drop them into a pail of soapy water.

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Garden Maintenance

Garden maintenance can be one of the more annoying things about gardening. Weeds are inevitable in the garden, but some are more noxious than others. I blogged previously about poison ivy. Another weed, wire grass (Bermuda grass), is even more troublesome.

Wire grass is a noxious weed that is hard to control.

Wire grass is a noxious weed that is hard to control.

It grows by rooting runners and underground rhizomes and is almost impossible to get rid of. It has very long roots so no matter how deep you dig, you never seem to get it all. If you’ve ever tried to pull it, it just breaks off and the plant takes that as a green light to grow more.

Wire grass is the one reason we occasionally use Round-up on the mulched paths. It’s the only thing I know of that will kill the roots. You don’t want Round-up sprayed in your garden bed because it is a dangerous chemical and will kill anything green it comes in contact with.Last year when I noticed wire grass coming up in my bed, I used a Q-tip to put Round-up on the sprouting weed. One of the issues in community gardens is that not everyone keeps their gardens weeded. Weeds get tall, seeds are blown into neighboring beds and wire grass creeps. Good bed maintenance makes good neighbors.

Our Watering System

On a recent visit to the garden I noticed the spigot on the hose near my bed had been left open. (See the wire grass creeping out of a neighboring bed. That bed was weeded after I took this photo, but it’s almost impossible to get it all. You can see how it creeps out into the path.)

open spigot

Below is the way the spigot should be left. Note the closed handle. This will extend the life of our hoses and eliminate leaks so thanks for closing the water spigots.

closed spigot

The recent rains have perked up our veggies, but also the weeds. Please be a good neighbor and keep your bed tidy. Pulling any weeds in the mulched paths will also reduce the need for Round-up.

Poison Oak – In Our Neighborhood?

poison oak

After I posted about finding poison ivy in my garden bed, Master Gardener Lin Clineburg (bed  #10) sent me this photo of poison oak. I’ve lived in Maryland for more years than I’d like to admit and have never seen it. The leaves do look like oak leaves. People tell us it’s around on the Eastern Shore. Have any of you seen poison oak in our area?

This photo is poison oak in the fall. Gorgeous color, but I don’t want it in my yard.

Poison Oak up close

Poison Oak up close (Photo credit: Wikipedia)

How NOT To Cook Spaghetti Squash

Apparently I didn’t put enough steam holes in this spaghetti squash. I heard a bang from another room and when I investigated (thinking home invasion…should I call 911) I found the microwave door blown open and an exploded squash inside. The squash blew right off the plate it was on. Fortunately most of the squash was still inside the rind and the microwave still worked. Clean up just took a few minutes and the squash was delicious at dinner served with a bison red sauce.

spaghetti-squash exploded

A learning experience. Microwaving (for me) is the easiest/quickest way to cook hard skinned squash, but if you are cooking them whole, make sure to make adequate holes for the steam to escape.

Basil Downy Mildew In The Garden

Elizabeth Beggins alerted me to this problem which she is seeing in a number of beds in the community garden. The following information is from Johnny’s Seeds. Diseased plants should be pulled and put in the trash. Do not put diseased plants in the compost bins.

Basil Downy Mildew is a new disease to North America and Europe. It was first reported in Europe in 2001 and was identified in the U.S. in Oct. 2007. In 2008, downy mildew was confirmed in both field-grown and greenhouse-grown basil in many states including FL, NC, PA, NJ, NY, MA, KS, and MO. Prior to these outbreaks it was only known to occur in Uganda back in the 1930’s. To date the pathogen has been reported in 38 states throughout the U.S., including Hawaii, with devastating results.

DESCRIPTION: The pathogen (Peronospora belbahrii) is a water-mold (oomycete) that can be spread by contaminated seed, by infected basil leaves, and as wind-dispersed spores. Spores of the pathogen are capable of being dispersed long distances. Infected basil leaves produce an abundance of spores. Thus the pathogen can spread widely once introduced to an area. The optimum environmental conditions for disease development occur at high humidity levels with extended periods of leaf wetness.

 basil downy mildew 2

SYMPTOMS: Basil Downy Mildew can easily be mistaken for a nutritional deficiency. The infected leaves develop a diffuse yellowing on the top of the leaf separated by veins. On the underside of the leaves, distinctly vein-bounded patches appear. When spores are produced, a characteristic purplish gray, fuzzy growth on the underside of the leaves is evident.

basil downy mildew

For a gallery of photos see link below. http://www.longislandhort.cornell.edu/vegpath/photos/downymildew_basil.htm

PREVENTION: At this time no commercially viable tests are available for the detection of infested seed. Prevention is the best course of action in all cases. Foliage should be kept dry. Use drip irrigation or bottom-watering wherever possible. Set up plantings to ensure good airflow within and between rows. Harvest the crop early if the disease is present or the risk of infection is high due to disease presence in the area. Carefully remove and destroy any infected plants. Fungicide applications need to begin before the disease is present to obtain effective control. Few products are labeled for this use. Additionally the post-harvest interval and label restrictions limit the use of many fungicide materials. Actinovate AG®, MilStop®, and Oxidate® are all OMRI-approved materials labeled for use on herbs to suppress foliar diseases including Downy Mildew.

 

 

Get Rid of Poison Ivy Without Getting It On You

Poison ivy hides among other weeds and a chance encounter can make you miserable. I was weeding the other day in my community garden bed and reached for something green. Fortunately I stopped myself before grabbing a very unwelcome “weed.”

poison-ivy-

This shiny three-leafed plant is distinctive and it was growing right in a row of sun scorched beets that are begging to be pulled out. Birds eat the seeds and that’s probably how this was planted.

I have had horrific bouts of poison ivy in the past and am very careful around it. Here is my solution to the occasional plant I find. Our local newspaper is delivered on rainy days in a long plastic bag. I save these for all sorts of gardening chores. For poison ivy I slip my arm into the bag, pull the ivy, and turn the bag inside out over my hand. My skin never gets close to the oils on the plant which cause the oozing blisters.

using newspaper bag

Use throw-away protection on your hands or over your gloves. The oils from the plant can get on your garden gloves and be transferred to your face. That observation is from personal experience. If you reach for something that even remotely looks like poison ivy, protect your hands and arms when pulling it.