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In anticipation of the 31st
Annual Insect Fear Film Festival, which they will host Saturday on the UI
campus, this week’s Environmental Almanac is written by two members of the
Entomology Graduate Student Association: Michelle Duennes and Todd Johnson.
The theme of this year’s Insect Fear
Film Festival is “PESTICIDE FEAR!” In one of our two feature films, "Riders
of the Whistling Pines," Dichlorodiphenyltrichloroethane (aka
DDT) plays a prominent role. As the story opens, an outbreak of tussock
moths is threatening the health of the trees in the North Woods. Government
foresters want to spray DDT to eliminate the pests and keep the forest healthy.
Here’s the plot twist—a bunch of greedy loggers want the trees to be damaged, so they can cut and sell the wood.
Enter the singing cowboy Gene Autry wearing a white hat. Exciting action
follows, but we won’t spoil the plot for you.
Whereas 65 years ago, pesticides were
portrayed as heroes, today you would be hard-pressed to find anything in praise of them. As
entomologists, we’re concerned about the health of insects but we also
recognize that pesticides can be really useful. Without them, many farmers
simply would not be able to grow or sell crops damaged by insect pests. Take
California, for example, where almonds are king. Over half-a-million acres of
orchards contribute approximately 80 percent of worldwide almond production. A
pest of almonds is the navel orangeworm. During its immature stage, the
caterpillar feeds on the developing almond. Without effective control measures,
this insect could severely damage the 4.3 billion dollar industry.
That’s where pesticides like the
pyrethroids come into play. Pyrethroids act on the nervous system of an insect,
causing paralysis and death, and they’re very effective against navel
orangeworms. There is a catch, though--pesticides are great at what they do,
but they should not be the major focus of an insect pest management program. (Entomologists
generally favor a system known as Integrated Pest Management, or IPM, which uses
chemical, biological, and cultural controls synergistically to control pests
and reduce inputs of pesticides into the environment.)
The problem with pyrethroids is that they aren’t very specific. In addition to
killing the navel orangeworm, they also kill the honey bee pollinators of the
crop, as well as beneficial predatory mites. Growers are now advised to not
apply these pesticides right before or during flower bloom and avoid their use
if possible.
Our second feature film emphasizes (in
a sensationalized and exaggerated fashion) the tradeoffs to pesticide
application. “Locusts: The 8th Plague” is a 2005 Syfy original about a swarm of
genetically engineered, flesh-eating locusts. When the locusts escape from a
government research facility in Idaho, the military wants to eradicate them
with chemical weapons. Colt Denton, local entomologist, also wants to save the
local human population. But instead of chemical weapons, he proposes using
“organic pesticides.” Here, the movie mixes things up a bit. The characters use
“organic” to mean non-toxic and safe for the environment. In reality, the term
“organic insecticides” as used today refers to insecticides that are not
synthesized in a laboratory. (In the 1940s and 1950s, “organic insecticide”
meant any pesticide synthesized in the laboratory that did not contain heavy
metals such as copper and arsenic—those insecticides were called “inorganic.”)
An example of an “organic” pesticide
would be nicotine, a familiar toxin from tobacco plants that acts on the
nervous systems of animals and can be very deadly at low doses. Synthetic
analogues of nicotine, the neonicotinoids, have recently gained infamy because
of their potential effects on honey bees; a severe mishap with a pesticide
applied inappropriately in Oregon caused the mass
death of over 50,000 bumble bees.
To reduce their negative effects of
pesticides, it’s important to understand the biology of the target insect(s)
and how they will affect the environmental as a whole. Additionally, pesticides
should be used only when necessary, and in conjunction with other management
tools. We hope you learned a little bit about pesticides and will join us as we
suspend our disbelief (briefly) and enjoy some great pesticide fear-related
movies.
Doors to Foellinger Auditorium open at
6pm with an insect petting zoo, face-painting, BugScope, art contest display,
and our first ever “Pesticide Petting Zoo.” An introduction by Entomology Department
chair, May Berenbaum, will be given at 7:00 and the films start at 7:30.
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