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Monday, December 30, 2013

Cold weather-loving cockroach discovered in U.S.

Jeffrey Hahn, Extension Entomologist

Lyle Buss, University of Florida

Photo 1: Japanese cockroach, male (left) and female (right)
Earlier this month, the Japanese cockroach, Periplaneta japonica, was confirmed for
the first time in the U.S. in New York City. This cockroach is originally from Japan and other parts of Asia.  Although it is not known how this cockroach arrived in the U.S., it is possible that it may have been transported in the soil of ornamental plants.  

This cockroach is fairly large, growing up to 1 3/8th inch long.  It is generally brownish black to black in color.  The male has wings which just extend past the end of its abdomen while the wings of the female cover only about half of its body.  The Japanese cockroach is closely related to the American cockroach, P. americana, a long time pest of the U.S.

The Japanese cockroach can live inside buildings like other pest cockroaches.  What is unusual about this species is that it is tolerant of cold weather; they have been observed outdoors in below freezing temperatures and on snow.  The pest cockroaches that live in the U.S. generally remain indoors in the northern U.S. and are normally not seen outdoors.

What does this mean for the U.S. and Minnesota?  It is not clear how well the Japanese cockroach can spread in here; it has similar habits to other structure-infesting cockroaches and it will probably be challenging for it to become too abundant as it competes for favorable harborages and food.  However, it would not be unexpected for New Yorkers to see this species occasionally outdoors this winter.  Like other cockroaches, the Japanese cockroach is a good hitchhiker so it is possible that it could one day be found in Minnesota.

Monday, December 2, 2013

December 1 Issue of Yard and Garden News

In this issue:

Do-it-yourself bed bug control: What does and doesn't work

Extension Publications: New and Revised

Minnesota's Native Holly

EPA Pesticide Labeling Changes to Protect Pollinators

Protect Your Young Trees from Rabbits

Good Question: Do you really need to rake those leaves?

Take a Survey and Win an iPad Mini

Do-it-yourself bed bug control: What does and doesn't work

Jeffrey Hahn, Extension Entomologist

Jeff Hahn, University of Minnesota

Photo 1: Bed bugs are a serious insect problem today.

After an absence that lasted for decades, bed bugs have become a significant pest problem in our lives again. Unfortunately, they are usually very challenging and costly to control. Still, the most effective solution to eliminate them is hiring a pest management company to treat them; they have the experience and understanding of bed bugs to effectively control them.

However, residents can become frustrated with controlling bed bugs (and its cost) and may resort to a variety of do-it-yourself solutions. Unfortunately, many of these methods are not only ineffective but can make the problem worse and be potentially harmful to people and pets.

The following is a list of what research has shown to be effective and ineffective in bed bugs control.

What does not work?
  • Insecticides purchased in hardware stores, retail variety stores, grocery stores,
    pharmacies, and other places that sell insecticides to the public.  The active ingredients in the products are not effective against bed bugs. This can lead people to use insecticides excessively and even apply insecticides that are not labeled for indoor use, such as landscape and garden insecticides which can be harmful to people and pets. Using ineffective insecticides can also cause bed bugs to disperse, making them more difficult to eliminate. 
  • Bug bombs or foggers (also called total release insecticides).  These products contain ineffective insecticides which does not reach bed bug hiding places when they are
    activated. Excessive use of bug bombs can potentially cause explosions and fires and cause severe damage to buildings. See also the December 2012 Yard and Garden News for more information.
  • Moth balls.  They have very little effect, if any, on bed bugs. They can be irritating to people's eyes and noses.
  • House cleaning products.  These chemicals are not effective in eliminating a bed bug infestation. They can cause bed bugs to disperse, making the problem harder to control.
  • Isopropyl alcohol.  A very labor intensive method that can kill some bed bugs but the alcohol has to come in direct contact with them. The majority of bed bugs will be unaffected. 
  • Ultra sonic repelling devices. The sound these devices emit does not kill or deter bed bugs. 

While working with a pest management service is the most effective means of eliminating bed bugs from a home, there are some effective steps that people can use to help in their battle against bed bugs. 
  • Heat treatment. Clothes laundered in hot water and/or dried in temperatures hotter than 122° F for 20 minutes will kill all stages of bed bugs. This is typically the medium-high setting. You can also heat treat curtains and other fabrics, rugs, shoes, backpacks, stuffed animals, toys, and similar objects by drying them for about 30 minutes (for a full load).
  • Cold treatment. All stages of bed bugs will be killed when infested objects are placed in a freezer at 0oF for four days.
  • Mattress encasements.  They protect mattresses that are bed bug free from becoming re-infested. Encasements on infested mattresses and box springs trap bed bugs inside them and allowing you to continue to use them.
  • Interceptors. Bed bug interceptors are placed under bed legs and captures bed bugs that try to climb up or down beds.  It is used primarily as a monitoring tool to help determine whether bed bugs are present (if that is an issue).
For more information, see Let's Beat the Bed Bugs web page.

Sunday, December 1, 2013

Minnesota's Native Holly

K. Zuzek, UMN Extension

Photo 1: Winterberry, November 11, 2013

Mention holly during the month of December and we all think of cut holly branches adorning homes during Christmas season. But our native holly, called winterberry or Ilex verticillata, is just as ornamental outdoors in our early winter landscapes because of its colorful and abundant fruit (Photo 1).

Winterberry is native throughout the eastern United State (Photo 2) and in Minnesota it is usually found growing in forested wetlands in the eastern half of the state along with larch, willows, and speckled alder. You may also see it growing along lakeshores and ponds or in acidic sandy soils with high water tables.

USDA Natural Resources Conservation Service Plants Database

Photo 2: Native range of Ilex verticillata

Although there are over 400 species of holly (Ilex spp.) worldwide, less than a dozen species are commonly used as landscape plants. Winterberry is one of these species. Approximately 35 cultivars have been selected within the species for fruit color (red, orange, and gold), fruit size and abundance, and compact plant size.

Winterberry cultivars range in size from 4-10 feet in the landscape. Small, inconspicuous flowers are produced from mid-June to early July. Winterberry's dark green foliage provides a beautiful backdrop to the brightly colored fruit that become showy in September. After leaves drop, the fruit will continue to light up a winter garden until birds find and eat it.

Winterberry is an easy plant to grow in light or heavy soils. Because it is native to swampy areas, it does well in wet conditions. It does prefer acidic soils with a pH between 4.5 and 6.5; chlorosis will develop in high pH soils. The other important fact to remember is that winterberry is dioecious, meaning male and female flowers are produced on separate plants. Besides planting a female cultivar that will produce the showy fruit, you must also plant a male plant whose pollen will be produced at the appropriate time to pollinate the flowers on your female cultivar that will later develop into the fruit. Two male cultivars are available at garden centers: the early blooming 'Jim Dandy' and the later blooming 'Southern Gentleman'. Plant labels and garden center staff can help you select the appropriate male cultivar for your fruiting female cultivar.

EPA Pesticide Labeling Changes to Protect Pollinators

Karl Foord - Extension Educator, Horticulture

The United States Environmental Protection Agency (EPA) has instructed the manufacturers to change the labels on those chemicals that have been designated as Pollinator Toxic Pesticides (PTP). One educational piece that has been released describes the changes (Exhibit 1). The label will contain a Bee Hazard Icon to alert users that this is a PTP (Exhibit 2).

The old label language for pesticides toxic to bees was as follows:

"For crops in bloom, do not apply this product to target crops or weeds in bloom."

The new language is as follows:

"Do not apply (product) while bees are foraging. Do not apply (product) to plants that are flowering. Only apply after all flower petals have fallen off."

The language is more extensive for commercial users and lists conditions under which one might apply chemicals even though bees are present. The main difference between old and new labels appears to be the last sentence stating that the product cannot be applied until all of the petals have fallen off the plant.


Exhibit 1:EPA Advisory Box


Exhibit 2: Bee Hazard Icon

At least one significant factor motivating the label changes by the EPA was the move by the European Commission to restrict the use of three neonicotinoids (clothianidin, imidacloprid and thiamethoxam) within the European Union. This would be for purposes of seed treatment, soil application and foliar treatment on bee attractive plants and cereals. The member states failed to generate a majority either for or against this proposal and so the decision went to the Commission.

As you might expect, there are those who felt that the move by the EPA fell significantly short of what was required to protect pollinators. The science behind this controversy is no doubt complicated. Traditional experimentation involves setting up experiments where all factors but the one under interest are controlled permitting a clear picture of the effects of this one factor. However, under field conditions it is difficult if not impossible to control all factors in this way and one is left to entangle interactions. For example, there is research demonstrating that the interaction between the neonicotinoid imidacloprid and Nosema (a gut fungus causing dysentery) hampered bees ability to sterilize colony and brood food (Alaus et. al. 2010). This effect was not seen in the control or the single imidacloprid or Nosema treatments.

Even though European Union members failed to achieve a majority vote, the commission still chose to restrict use. On the other hand the U.S. EPA chose to modify labeling language and revisit the issue in 2018 when the registration of these chemicals is subject to review.

Both entities had access to the same research findings. The difference in reaction may be a philosophical one. The European Commission took the position of, given the facts the safety of these chemicals needs to be demonstrated before their use will be reinstated. The U.S. EPA took the position perhaps of, given the facts the damage of these materials must be more definitively demonstrated before their use will be restricted.

Given that we live in the U.S. we have inherited the latter philosophy. However, as a gardener I will be keenly aware of the potential impact of neonicotinoids and only use them on non-flowering plants and only under extreme circumstances, if even that.

C. Alaus et. al. Interactions between Nosema microspores and a neonicotinoid weaken honeybees (Apis mellifera). Environmental Microbiology (2010) 12(3), 774-782.

Protect Your Young Trees from Rabbits

Karl Foord - Extension Educator, Horticulture

I noticed rabbit damage on my Frosty Canadian Hemlock (Tsuga canadensis 'Frosty') (photo 1). I was again reminded of the fact that I did not wrap or protect my young apple trees last winter (photos 2 & 3). Remedy (photo 4).

Karl Foord

Photo 1: BEFORE - Frosty Canadian Hemlock (Tsuga canadensis 'Frosty')

Karl Foord

Photo 2: Zestar! Apple (Malus domestica Zestar!)

Karl Foord

Photo 3: Chestnut Crabapple(Malus 'Chestnut')

Karl Foord

Photo 4: AFTER - Frosty Canadian Hemlock (Tsuga canadensis 'Frosty')

If you have young trees don't forget to protect them from rabbits. Two articles have been previously published on this topic.

Rabbits and trees and shrubs

and Trees - Protecting from Rodent Damage
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