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The use of genetically modified crops was intended
to reduce the need for herbicides to control weeds and insecticides to control
pest insects. However, The New York Times
reports that instead herbicide use increased over 16 years, while insecticide use
decreased somewhat. The widespread use of a single herbicide glyphosate, sold
under Monsanto’s brand name Roundup, has resulted in the evolution of a number
of glyphosate-resistant weeds. The Times piece, http://green.blogs.nytimes.com/2012/10/05/the-legacy-of-pesticides-superweeds-and-superpests/?src=rechp,
describes different approaches to the use of these genetically modified
organisms. “Roundup Ready” corn, soybeans, and cotton seeds were planted on
1.37 billion acres from 1996 to 2011. The GMO plants, tolerant of the herbicide
glyphosate, were supposed to reduce or eliminate the need to till fields and
reduce the need for harsher chemicals. The use of these GMOs was supposed to
also save money and be less stressful on the environment. As
glyphosate-resistant weeds increased, increases in the use of glyphosate
slowed; and in 2010 the National Research Council warned that, “Eventually,
repeated use will render glyphosate ineffective.”
Those deploying the genetically modified seed containing
the Bt gene producing toxins from the soil bacterium Bacillus thuringiensis
recognized the potential for evolving resistant insects, and they took precautions.
They required that a percentage of non-Bt seed be planted with Bt crops to
ensure that some insects susceptible to the Bt toxin survive to mate with
survivors of the Bt crops. Otherwise, surviving pest insect populations could
become increasingly resistant to the Bt toxin with each generation. The
mechanism for ecological harm from chemical pesticides was described by Rachel
Carson in Silent Spring 50 years ago:
“First, many of these chemicals are indiscriminate, killing not only pest but
also the predators and parasites that help to keep them at bay. Second,
surviving pest populations become increasingly resistant to the applied toxins
with each generation, as those most susceptible to the toxins die off. It’s
natural selection in overdrive.” Today’s photo: applying herbicide to control
grasses in GMO soybeans.
Three types of bee hives are used in Ethiopia.
Ninety-seven percent of the hives are traditional hives, long baskets built at
no expense of cane and banana leaves. These hives are usually hung high in
trees, but they are also attached to the outside walls of houses. Some
traditional hives are placed inside houses under beds. Modern bee hives similar
in design to the Langstroth bee hive comprise two percent of Ethiopia’s bees.
The remaining one percent of Ethiopian bee hives is top bar hives, described as
“transitional hives.” These simple boxes are also built from locally available
materials at no expense. Transitional hives provide an economical method of
managing honey bees that allows for the benefits of modern beekeeping: ease of
hive inspection, ability to combine and divide colonies, move brood between
hives, requeen, and improve genetics. Most importantly, transitional hives
allow for the non-destructive harvesting of high quality honey. Beeswax is
harvested by crushing honeycombs. Hive products are collected without killing or
losing the honey bee colony. Today’s photo from Ethiopia shows one of Teshome’s
transitional bee hives mounted in a tree. This top bar hive is covered in plastic
and foliage as is the custom in Ethiopia. I recommended that Teshome consider
removing the foliage to improve air circulation. Chalkbrood, a honey bee fungal
infection, is a major hive problem in Ethiopia’s rainy season.
Many transitions are occurring on Ethiopian farms.
Beekeepers earn additional income with transitional and modern bee hives. Using
standardized sized hives, beekeepers can move combs from one hive to another.
Teshome recognizes the benefits of improving queen bee genetics; he uses
similar techniques in cattle breeding. He foresees the ability to produce gentler
bees by selecting queen stock from his best hives. His farm is steadily
transitioning to a broader based economy. Teshome eagerly traces the design of
my hive tool so that he can have the local blacksmith produce tools for area
beekeepers to take a more hands-on approach to beekeeping.
Before embarking on my latest beekeeping trip to
Africa, I checked the hive that I was using to transfer a colony of feral honey
bees from a hollow tree. All was progressing well, the capture hive was full of
bees; the bees even filled two honey supers with summer honey. When I returned
a few weeks later, the hive was completely “slimed” by small hive beetle
larvae; the bees had abandoned the hive; and the honey was fermented. The hive
was overtaken by small hive beetles. Bees and beekeepers find invasive small
hive beetles difficult to control. Currently, chemical and cultural controls
are used to reduce small hive beetle populations.
Researchers at the University of Arkansas asked a
question: Could the small hive beetles have brought their own parasites with
them when they entered the US? The presence of such a parasite of the small
hive beetle could possibly lead to a biological control for these bee hive
scavengers. To investigate the possibility that there may be a not-yet-discovered
parasite, Natasha Wright collected small hive beetle adults and larvae and
samples of soil from bee yards in Arkansas and adjacent states. She dissected
749 adult beetles and 230 larvae from 13 counties in Arkansas and one county
each in Oklahoma and Missouri. Natasha found no microbial pathogens in the SHB
larvae, but she did find a protozoan pathogen in adult SHBs from three Arkansas
counties. Most of the infected beetles were from a single apiary in nearby St.
Francis County, Arkansas. One infected beetle was found in a Peace Bee Farm
apiary in Crittenden County, Arkansas. In total, 5.3 percent of the adult
beetles sampled were infected with the protozoan pathogen, which forms cysts in
the beetles’ Malpighian tubules. The heavily infected beetles detected in St. Francis
County were described as having an “impaired function in life.” Hopefully,
research will find safe and effective controls for small hive beetles. For
published results: www.springerlink.com/content/b103041x41163216/.
Today’s photo: SHB larvae slime a hive.