So begins a quote at the end of the movie, “The Mission”
which takes place in South America, but explains the death and slavery of a native
population due to geo-political conniving in Europe. While there is few harms greater than murder
and enslavement, the world is caught in a web complexities brought about by
ease of trade and travel. We all enjoy
cheap products made in China, many want that Japanese car, and still others
desire an exotic pet or plant. Humans,
for the most part, are social creatures, and travel and exploration are ways to
satisfy our curiosity. The world trade
in food, lumber, and other organic resources also brings about the transfer of
pests. To think that such freedom in
trade and travel has few negative consequences to native species and
populations is to show a lack of understanding of history.
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| Rose with a Japanese beetle inside its petals |
Over 40 years ago the
street on which I grew up was canopied by a number of stately elm trees. A tall magnificent street tree, which my
children have not had the benefit to enjoy.
Most of those trees were removed forty years ago as they died due to
Dutch elm disease. I recall Mr. Loney,
who seemed to be the tree remover of choice, roping up high to bring a tree and
its dead branches back to earth, limb by limb until only a stump remained. I also recall my Dad, working with my older
brother’s, using my grandfather’s heavy old McCulloch chainsaw, a beast of a
machine, to remove a dead elm near the corner of our property. Dutch elm disease made its way to the US in
1928 from a ship carrying logs to be turned into veneer in the furniture
factories of Ohio. It did not take long
for the elm bark beetle and the fungus it carried to wreak havoc on the streets
of the nation. A decade after its debut
in the US, scientists were hard at work attempting to find disease resistant
cultivar’s which are now in use.
Although, I suppose the jury is still out on their level of
resistance. The building in which I work
had planted some disease resistant elms on its lawn a decade ago, and are still
seemingly healthy, but the trees are still very young.
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| Closeup of invasive beetle in the above rose |
Of course, disease affecting
the human population is another issue. A
large Ebola virus outbreak in Africa claimed its first US citizen this
week. The man had been attending to his
ill sister in Africa, who unknown to him apparently had the Ebola virus. Prior to making his way back to Minnesota, he
stopped at a conference in Lagos, Nigeria.
Had he not stopped at the conference, where he would collapse and be
hospitalized, he could well have made it to the US, and collapsed at the
Minneapolis airport. The Peace Corps has
pulled out of some African countries due to the Ebola epidemic. As we know from high school history, native
populations in the US were decimated many years ago by diseases brought over by
Europeans for which the native populations had little or no resistance. These European diseases still wreak havoc
today on indigenous populations in New Guinea, and the jungles of South
America. Today, every flu virus begins
in China, and teams of experts attempt to find the virus that will be next
winters dread, and to create a vaccine that many of us will receive in the
fall. Most of the time, they get it
right, but sometimes a different strain develops that is resistant to the
created vaccine.
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| Raspberry leaves eaten by Japanese beetles. |
Vaccines may help
with some disease, but plants and animals are a different story. Sometimes an
invasive plant, animal, or insect is introduced to assist with some issue. Kudzu, while unknown in Wisconsin and the
Midwest, is a rampant plant originally from Japan that was brought to the US
for the in 1876 at the Philadelphia Centennial Exposition. This fast growing vine is estimated to
consume upwards of 150,000 acres annually in the southern states. That is 234 square miles. Its original purpose to control soil erosion
has well gotten out of hand. Crown vetch
was used in WIDOT seed mixes, but is now an invasive. African bees were introduced into Brazil in
the 1950’s to breed with local bees and increase honey production, but this
Frankenstein type experiment went horribly wrong and the killer bees have now
made their way into the United States.
Some speculate they will make their way north and develop a resistance
to the subzero temperatures we experience in the north.
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| Japanese beetle on a Raspberry leaf |
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| No words needed |
Personally, I see
first-hand the devastation caused by the invasive Japanese beetle. The beetle is thought to have first entered
the US even before Dutch elm disease, arriving in 1912 in a container of bulbs,
but not being discovered until 1916 in a nursery in New Jersey. One only needs to look at my raspberry
plants, and roses to see their negative effect.
In the first years they were noticed in my yard, they left my pole beans
but a skeleton of leaves, with no discernable crop. They did not eat, and so far have not eaten
the bush beans I plant. They now make
green bean production to forever be horizontal and not vertical. They even can host on elm, maple, arborvitae,
and perhaps 70 other types of host plants.
While they host on tomatoes, peppers and many other garden plants, so
far they best enjoy the raspberry plants.
If they want to host on a plant, why cannot it not be creeping Charlie?
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| Another view of the pest |
One other example is
the Emerald Ash Borer (EAB). Another
import from the Far East, where it has natural predators, but where such
predators are lacking the in US. I have
been treating my Purple Autumn Ash, a cultivar of the white ash developed at UW
Madison, for two years as I now head into year three. The EAB has gradually made its way into
Wisconsin from Michigan. It devastates
whole forests of ash, and is not particular.
The problem is the chemical treatment, at least those non-injected, I
recently found out, may be partially attributed to the decline of the bee
population. Although the decline of the
bee population is more likely due to mono-culture and wide spread use of
agricultural chemicals. Foresters in
Minneapolis have noted that the cold severe winter likely affected the EAB
population, at least in their area, perhaps by as much as a reduction of over
50%, but this was dependent upon the micro-climate situation. Mother Nature may have been giving us some
moderation for the pesky EAB. There is
talk of importing a wasp from China which is a predator, but if that is done,
hopefully it will not have the negative detriments that other well intended
efforts created in regard to invasive species.
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| Several Japanese beetles have destroyed a rose |
Travel and trade have
given, and continue to give many benefits.
Yet there are negative effects.
We now see Asian Carp are flying out of the water in the Mississippi
River basin, and probably making their way to the Great Lakes via our friendly
Illinois brethren having changed the course and flow of the Chicago River, or
the small broken shells of zebra mussels originally from Russia (by way of ship
ballast) are now scattered over the beaches of Lake Michigan, and of course,
the ill health caused by exotic and tropical diseases. Our children will not have known the majestic
elms, and perhaps their grandchildren will not know an ash tree (and what will
baseball do). The invasive problem is
rampant and costs the economy billions each year. I do not mean to say travel and trade should
end, but more care needs to be utilized to avoid what could be costly invasion
of the species. In “The Mission” the second to last exchange
is relevant to us today, albeit, in a different way:
Senor Hontar: “We must
work in the world.
The world is
thus.”
Papal envoy: “No
Senor Hontar
…thus have we made the world.
Thus have I made it.
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