Pest of the Week - Harlequin Bug

The harlequin bug Murgantia histrionica (Hahn) is also know by other common names such as "Calico Back", "Calico Bug", "Fire Bug".  The harlequin bug injures the host plants by sucking the sap of the plants, causing the plants to wilt, brown and die. Like other stink bugs, they produce odors from their thoracic glands, using them as a defense against predators.  Plants commonly attacked by the harlequin bug include such crucifers as cabbage, cauliflower, collards, mustard, Brussels sprouts, turnip, kohlrabi and radish.

Harlequin bug - Colorado State University

Eggs of the harlequin bug, Murgantia histrionica (Hahn). Photograph by James Castner, University of Florida.

Natural History

Harlequin bug life cycle - UC Davis

Eggs of the harlequin bug resemble tiny white kegs standing on end in a double row. Approximately 12 are laid together, usually on the underside of the leaves of the host plant. Each egg is marked by two broad black "hoops" and a black spot. The eggs hatch in from four to 29 days, the time varying with the temperature.

There are five or six nymphal stages that feed and grow for four to nine weeks before they are capable of mating and laying eggs.  The head coloration of the nymphs ranges from pale orange, darker orange to black in the final nymphal form.

Adult bugs are 3/8-inch long and mottled red, black, and yellow or orange.

Management Strategies

Hand-picking and destruction of the insect pests and egg masses may deter damage where low numbers of insects are found. Hand destruction of the adults in the fall and spring as they emerge from "hibernation" before they lay eggs is an effective control. This may be aided by the use of trap crops of turnip, kale, or mustard in the very early spring or late in the fall after the main crop has been harvested. Once the pests have concentrated in these areas, they can be killed by applying insecticides or by covering the trap crop with straw and burning. Trap crops should never be used unless they can be given careful attention to destroy the bugs attracted to them.   Insecticides are generally not recommended in gardens for stink bugs.

Additional Information

Hemiptera - True Bugs - Colorado State University

True Bug Lifecycle - UC Davis

Harlequin bugs 2013 a growing problem in Pennsylvania? - Penn State University

Harlequin bug - Rutgers University

Notes from September 12, 2013

Weed of the Week: Bedstraw

Pheromone Trap Results

Note: trap collection data is for a two week period.
Trap #1 - Black Cutworm
2 Black Cutworm moths, 1 house fly, 4 spiders

Trap #2 - Corn Earworm
3 Corn Earworm moths, 1 click beetle, 20 noctuid moths

Trap #4 - Fall Army Worm
35 Fall Army Worm moths, 1 bumblebee, 1 spider

Wheat/Soybean Field
Kenny reports that the ladybugs have controlled the soybean aphids – great news.
We observed few active aphids, many ladybugs and ladybug larvae, and many aphid ‘mummies’; i.e. the empty shell of the aphid body.
Found 1 stink bug.

Cover crop Field
The buckwheat is blooming and looks very healthy. It is taller than the soybeans. It is tall enough that this field could be double cropped – that is to set the combine high enough to harvest the buckwheat and then lower it and harvest the soybeans. Interesting concept.

Field Corn
Kenny reports that moisture content is still in the mid 20’s.  Processors prefer moisture to be around 18% so there is still a need for more drying time.  Black tips are visible on kernels, which means the kernels have reached physiological maturity and are in stage R6.

Popcorn Field
Corn Earworm is present. Moisture content is still high. Hull formation is almost complete. Bill has obtained a kernel sheller so we are considering harvesting this crop and selling it.

Soybean Field
This field is beginning to turn. It is in the leaf drop stage. This soybean variety has a shorter photoperiod than our second planting in the wheat field.


Demonstration Plots

Peanuts are continuing to peg.

Cow Peas are still not showing many pods yet continue to flower.
In this plot we broadcast planted Tillage Radish or Daikon Radish/groundhog radish as another type of ground cover that has the additional advantage of holding soil nutrients in the radish tuber over the winter. Optimal planting would have been around August 15th.

Tomatoes – advantages and disadvantages of the different staking methods are becoming very clear. The smaller tomato stakes available to the home gardener are now beginning to break due to the heavy burden of the tomato foliage.
John reports that the Supersonic variety has out produced the Ramapo variety so far.

Peppers – our efforts with the peppers have paid off. Though production is reduced because of the kind of season we had, we are still harvesting peppers from all the varieties. There is a reduced amount of ‘heat’ in the hot peppers due to the amount of moisture and cooler days.

Hops – continue to produce cones near the top of the support system.

Quinoa – the jury is still out on whether we actually have a plant or not. The verdict is in however on whether quinoa is a viable crop for our climate – it is not.

Other notes:
We found a Harlequin Bug in the shed. It is reported that they are in the Community Gardens.  Visit our blog for more an upcoming article on this insect.



Thanks to Roger for compiling this weeks notes. 

Weed of the Week - Smooth Bedstraw

Smooth bedstraw (Galium mollugo ) is a serious weed in pastures, hayfields and field margins.  This plant typically occurs first along roadsides, progressively moving inwards. Its invasive nature allows smooth bedstraw to out - compete forage species, reducing the value of the stand.  Smooth bedstraw is especially problematic within lower input forage areas. This weed contains the toxin anthraquinone that can cause systemic toxicity and skin disorders in mammals. Poor animal performance on high diets of smooth bedstraw has been observed.


Natural History
There are at least 30 different bedstraws in North America, and many are perennials like smooth bedstraw.  Reproduction is by seed and by underground rhizomes.

• Stems - Stems are smooth, wiry, 4-angled, branched, and up to 3 feet long. Stems initially grow upright, but over time they become spreading and matted.

• Leaves - Leaves are 1/3 to 1 inch long, linear, bright green, and whorled (usually, there are 8 leaves per node on main stems and 6 or 7 leaves per node on branches).

• Flowers - Flowers are about 1/6 inch wide, white, and consist of tiny, 4-lobed petals. Flowers form in branched clusters at the ends of stems and branches throughout the plant.

• Fruits & Seeds - Seeds are kidney-shaped, hairless, and dark brown.

Smooth bedstraw ttem - Ontario Ministry of Agriculture and Food

Smooth bedstraw whorls

Smooth bedstraw showing flowers and whorls - Ohio State University

The genus name, 'Galium' is from the Greek word for milk and refers to an old use for the plant to curdle milk in making cheese.  The common name 'bedstraw' has two possible origins: the dried plant was used to stuff mattresses and it is said that bedstraw was placed in the manger at Bethlehem when Jesus was born.


Management Strategies
Manage hayfields by testing the soil and keeping nutrients and pH at levels where grasses and legumes will thrive. Apply nutrients and lime as needed.

Keep bedstraw plants from flowering, setting, and spreading seed, no matter which additional control option you use. In hayfields, try to get the haycrop mowed before bedstraw sets seeds. This will help control the spread, give the grasses a more competitive edge, and also provide you with a better-quality crop. Be aware of a second flowering and seed-production period.

Make sure to control the spread of seed. Mowers, balers, rakes, and tedders can carry substantial amounts of seed from infested fields to clean fields. Remove any source of seed from equipment when moving from field to field. Research is still inconclusive about the spread of bedstraw via manure applications.

Tillage and rotation is very effective in killing perennial crowns and new seedlings that may develop. Consider a weed-controlling cover crop such as buckwheat or sorghum-sudangrass hybrids as part of your reseeding regime. A new seeding will need optimum management to keep smooth bedstraw from reinvading the field.

Additional Information

Smooth Bedstraw -Virginia Tech Weed Guide

Commonly Found Weeds in Vermont Pastures - University of Vermont

Controlling Smooth Bedstraw in Hayfields and Pastures - University of Maine

Ohio Perennial and Biennial Weed Guide - Ohio State University

Pest of the Week - Armyworms

Cutworms and armyworms are the larvae (caterpillars) of several species of night-flying moths in the family Noctuidae.  The armyworm, Pseudaletia unipuncta, and fall armyworm, Spodoptera frugiperda, are generally considered minor pests, but they have the potential for explosive outbreaks in turfgrass.

Natural History

Armyworm Identification - University of Nebraska

Fall Armyworm
The fall armyworm is native to the tropical regions of the western hemisphere from the United States to Argentina. It normally overwinters successfully in the United States only in southern Florida and southern Texas. The fall armyworm is a strong flier, and disperses long distances annually during the summer months. It is recorded from virtually all states east of the Rocky Mountains. However, as a regular and serious pest, its range tends to be mostly the southeastern states.

Typical adult male fall armyworm, Spodoptera frugiperda (J.E. Smith). Photograph by John L. Capinera, University of Florida.

The moths have a wingspan of 32 to 40 mm. In the male moth, the forewing generally is shaded gray and brown, with triangular white spots at the tip and near the center of the wing. The forewings of females are less distinctly marked, ranging from a uniform grayish brown to a fine mottling of gray and brown. The hind wing is iridescent silver-white with a narrow dark border in both sexes. Adults are nocturnal, and are most active during warm, humid evenings. After a preoviposition period of three to four days, the female normally deposits most of her eggs during the first four to five days of life, but some oviposition occurs for up to three weeks. Duration of adult life is estimated to average about 10 days, with a range of about seven to 21 days


Armyworm
Armyworms get their name from their behavior of moving across fields in an army-like fashion. As larvae consume available food sources, they migrate as an army to new host plants. Though they feed primarily on grasses (oats, wheat, fall rye, corn, barley, and forage grasses), they can be a pest of some vegetables (bean, cabbage, carrot, onion, pea, pepper, radish and sweet potato).

The adult moth is uniformly pale brown to grayish brown in color, with a wingspread of about 1 1/2 inches. There is a characteristic small, white spot near the center of each front wing. The eggs are greenish white and spherical and are laid in masses. Mature larvae are about 1 1/2 inches long with a yellowish or grayish ground color, more or less tinged with pink. The dorsum is greenish brown to black with a narrow, broken, light median stripe. A dark stripe on each side includes the black spiracles in its lower edge. The subspiracular stripe is pale orange, mottled, and edged with white. 

Armyworm, Pseudaletia unipuncta or Mythimna unipuncta. (Marlin E. Rice)

Management Strategies

Naturally occurring predators such as ground beetles and rove beetles may be important in keeping armyworm populations low each year. Research conducted by Michigan State University has found over 12 species of parasitic wasps and several flies that commonly attack armyworm larvae.

There are several types of viruses, a microsporidium, and fungi that infect armyworm larvae. A cool and wet spring favors armyworm development while hindering parasite and predator populations.


Additional Information

Noctuidae - Butterflies and Moths of North America

Armyworm Identification - University of Nebraska

Fall Armyworm - University of Florida

The Arthropod Museum - New Mexico State University

Armyworm - University of Illinois - Urbana

True Armyworms - Scout Info Kentucky IPM Pest Information Pages

 Fall Armyworm - Rutgers University

Pest of the Week - Eastern Black Nightshade

Eastern Black Nightshade Seedling

Natural History

Eastern black nightshade (Solanum ptycanthum) is native to the Americas and is commonly found throughout the United States east of the Rocky Mountains. Nightshade begins germinating in May and can continue throughout the growing season. Although it can cause crop yield reductions, more importantly it can interfere with the harvest and lower crop quality.  Eastern black nightshade is a highly branched annual plant that grows 1 to 3 feet tall. Flowers have five reflexed petals and fruits are green berries that turn black at maturity. The plant can be found in cultivated fields, gardens, waste places and overgrazed pastures. Seeds germinate in the spring and early summer and plants flower from July to October with seed maturing in August through October.

Immature eastern black nightshade plants and berries are considered potentially toxic. Rapid ingestion of large quantities of highly toxic fruits of this plants can result in coma and rapid death. The concentration of toxic principle decreases in berries to safe or negligible levels as the plant matures. This alkaloid, solanidine, has been reported to cause nausea, vomiting, bloat, paralysis and even death if the plant is consumed before it has reached maturity. Even though livestock poisonings and deaths have been attributed to nightshade ingestion, species identification in such poisonings is not exact.

Managment Strategies

Mowing, plowing, disking, and cultivating are some of the more commonly used mechanical methods for field crop weed control. Existing nightshade infestations in hay crops or pastures can be controlled by timely mowing or swathing to prevent seed production. Repeated mowings may be necessary, however, due to the sporadic germination of the plant.



Additional Information

Management and Contorl of Nightshade - North Dakota University Extension Service

Eastern black nightshade - Weed Science University of Illinois

How Toxic is Eastern Black Nightshade? - University of Wisconsin Weed Science

Notes from August 29, 2013

Pheromone Trap Results

Trap #1 - Black Cutworm
1 stink bug, 1 leaf beetle, 1 fly (diptera)

Trap #2 - Corn Earworm
10 noctuid moths, 2 leaf beetles

Trap #4 - Fall Armyworm
1 Fall Armyworm moth, 1 True Armyworm moth

Weed of the week: Eastern Black Nightshade
Also looking at the seed head of Fall Panicum

Field Corn
Dent stage with some kernel tips showing black – very close to maturity
Still have approximately 3 weeks to dry to 15% - though if weather remains wet, farmer can choose to harvest at 18% and pay a drying fee rather than lose crop to late fall storms, sprouting, or mycotoxins in mold.

Popcorn Field
Ears appear to be fully fertilized. Hulls are starting to form on the kernels.
Mites are present.

Cover Crop
Buckwheat is blooming.

Wheat/Late Soybean Field
Explosion in the lady bug population in response to the soybean aphid. Scouting threshold is 250 aphids per plant. At this threshold the farmer has about 7 days to the spraying threshold of 1000 aphids per plant. Lady bugs can eat about 180 aphids per day, so we are watching to see if the lady bugs can keep the balance. With all the moisture in the ground, plants are not showing evidence of wilt associated with the aphids feeding.
Still in the reproductive phase with pods just beginning to set.

Sweet Corn Field
Has been mowed down. No decision on what to plant next.

Soybean Field
Nothing noted.

Hay Field
3rd cutting is in.

Demonstration Plots
 
Buckwheat is reseeding with emergence of new plants.

Peanuts are forming underground on end of pegs.

Clustered Mountain Mint is excellent for attracting every kind of pollinator.

Found many Soldier Beetle. These are similar to lightning bugs and feed on pollen or nectar so are found around flowering plants.


Note: next week will meet at RCE for Soil Test Interpretation Class. Potluck to follow.


A special thank you to Roger for compiling the notes for this week.