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Megacopta cribraria Stone Mountain Park, Dekalb County, Georgia, USA
June 25, 2011Photo#565670 copyright © 2003-2011 Iowa State University |
Soybean aphid, corn earworms, soybean rust, soybean cyst nematode, Sclerotina stem rot and the exotic pathogen, red leaf blotch and now the Kudzu bug
are threatening the US soy bean crop. Soy beans, Glycine max (L.) Merr., are harvested and processed into animal feed and vegetable oil. The oil component of crushed soybeans is bound
for human consumption or biofuel production.
Food uses include tofu, soymilk and soy-based yogurts to name a few. In addition soy ingredients, according to the Soy Facts web page
provided by Soyatech, "...have
become staples in the food manufacturing industry. Soy protein
ingredients play functional roles in baked foods, processed meats and other
products. Soybeans are also processed into many industrial products. The
primary one at this time is biodiesel, or soy methyl esters, which may be used
in any diesel engine."
Finding a
suitable legume for agricultural production in the south eastern US was a major
focus of USDA in the early years of the 20th century. Gibson and Barren (2005)
write that "The soybean was first introduced into the American Colonies in
1765 as "Chinese vetches." According to their web page, "an 1879
report from the Rutgers Agricultural College in New Jersey is the first
reference that soybeans had been tested in a scientific agricultural school in
the United States."[1] In the preface to a 1908 report by Charles V. Piper, agrostologist in charge of forage
crop investigations of the Bureau Of Plant Industry for the United States Department
of Agriculture lays out the importance of new plant species for agriculture:
"Leguminous crops play so important a part in
agriculture that unusual interest attaches to any new ones, especially if
adapted to sections of our country where a satisfactory legume is still a
desideratum. The need of satisfactory legumes is greatest at present in our
semiarid regions, though a good perennial species adapted to the Cotton Belt
would be of incalculable value. If it be true that no system of agriculture can
anywhere be permanent without the use of a leguminous plant in rotation, this
makes imperative the search for such a crop for every part of our country where
agriculture is possible"[2]
Among
the many species that were tested for potential as a food, feed or forage crops
was a close relative of soybean, kudzu, Pueraria
montana (Lour.) Merr. var. lobata
(Willd.) Maesen & S. Almeida.
It should come as no
surprise then that an invasive species, insect native to the same regions of
Asia from which came soybean and kudzu might feed on both species. And given
the general lack of concern on the part of the public and the lack of much support
for invasive species programs such as EDRR (early detection and rapid
response), it was only a matter of time before this new invgasive species reach
the US. Megacopta
cribraria (Fabricius)
was found invading homes in large numbers
in
northern Georgia in late October 2009. The good news is that this pest of
numerous legumes in Asia, has the potential to provide biological control of
kudzu, Pueraria
montana var.
lobata
(Willd.)
Ohwi, (Fabaceae); the bad news is that it islikely to continue to be a
household pest in the vicinity of kudzu fields as well as become a pest of
North American legume crops such as soybean.[3]
To
be very clear, USDA APHIS reports that in China this recent invasive species, the kudzu bug, "...has
caused springtime crop losses of up to 50 percent and summertime losses of up
to 30 percent. Severe infestations on some host plants result in seed yield
losses, improperly developed pods, and undersized seeds. The bean plataspid is
also listed as a harmful pest of Chinese fruit trees. If it moves to other host
plants in the United States, the pest has the potential to cause significant
agricultural damage."[4]
The continual drumbeat of those who claim there is no
problem from invasive species seems at odds with the facts. Part of the problem
is the artificial division of invasive species issues into environmental and
agricultural camps. The very term invasive species was created by naturalists
to address the destructive nature of introduced species on ecosystem services
as if there were no existing category of investigation. At the same time US
agriculture has established a century plus dedication to the research, control
and management of invading species in both USDA ARS and APHIS dating back in to
the late 19th century (and earlier if you take in to account US government
efforts surrounding the Hessian fly - but that is another blog) . Instead of
working together and pooling resources the two stakeholders view each other
warily and lobby their respective federal agencies to adopt policies that occasionally
duplicate efforts in research and control strategies.
As long as we continue to think of managed fields and natural
areas as exclusionary ideas we will not address completely the challenges of
invasive species. All landscapes are managed to some extent; the tools of horticulture
should not be automatically excluded from the needs of ecology. Agriculture
must be sympathetic to the problems of invasion biology. The collision of
desires is highlighted by the positive control of kudzu and the negative impact
on soybean and native legumes. Agricultural pests and ecological invasives are
two sides of the same problem. The destruction of our natural areas and our
managed fields is growing and in growing adding costs (130 billion Pimentel et
al. 2001) which will threaten our collective futures. We must adapt or perish,
we cannot hide.
[1] Lance Gibson and Garren Benson, Revised March 2005. Origin, History, and Uses of Soybean (Glycine max). Iowa State University, Department of Agronomy http://www.agron.iastate.edu/courses/agron212/Readings/Soy_history.htm
[2] USDA
Yearbook - Congressional edition, Volume 5481. 1909
[3] J. E. Eger, Jr., L. M. Ames, D. R. Suiter, T. M.
Jenkins, D. A. Rider, and S. E. Halbert. April 2. 2010. Occurrence of the Old
World bug Megacopta cribraria (Fabricius) (Heteroptera: Plataspidae) in Georgia:
a serious home invader and potential legume pest. Insecta Mundi 0121: 1-11
[4] USDA APHIS Fact Sheet. October 2010. Invasive
Insect (Bean Plataspid) Poses Risk to Soybean Crops and Infests Homes in
Southeastern States
