Some consider insects the most important of all life forms on the Earth. Life as we know it would certainly be nearly impossible without insects. But the costs some insects impose on human life are nearly intolerable. Science has been at war with those insects for many years. Modifed fruit flies are the latest salvo in the ongoing battle.
A lot is at stake. Pests cause billions of dollars damage. Other costs include veterinary bills for sick animals and direct costs to human health. Pests also cause environmental harm. Some produce requires lots of water to raise. Throwing out large amounts due to insect damage therefore wastes water.
According to YahooNews researchers at North Carolina State University have succeeded in creating modified fruit flies. They modify female fruit flies. The females lay sterile eggs, which is expected to lower the population dramatically.
“Previously, scientists have experimented with moths only capable of producing male offspring to limit population and avoid crop loss. Others have modified mosquitos to have deformed mouths, rendering them unable to bite people to slow the spread of malaria.However, Luciano Matzkin, a professor of entomology, said this new method of sterilizing female fruit flies is very hopeful because it avoids the issue of offspring who evade the desired gene mutation.” links in original.
Researchers said the sterilization method is still years from implementation but is very promising. They did not say how the insects were sterilized.
Starting in the 1930’s scientists Edward F Knipling and Raymond C. Bushland investigated ways to control the screw worm fly, which lays eggs in the flesh of living animals. The eggs are usually laid near an open wound or cut and the eggs hatch quickly and the larvae exploit the wound. The animals suffer enormously and can die if not treated. Treatment involved cleaning the wound, removing larvae with tweezers and continuing to treat the wound. The two men realized controlling the insects was the best strategy.
After World War Two the scientists found ways to use radiation to sterilize the flies without killing them or otherwise changing their behavior. Millions of sterile flies were captive raised and then released. They mated with regular females who did not lay fertile eggs. Since the females only mated once, the number of fertile eggs laid eventually reached near zero. The method was tested in Florida and brought to Texas. Screwworms were eradicated in Texas by 1966 and have been eradicated in Mexico and several Central and South American countries since then. Their work has been hailed as one of the greatest success stories in insect control. But nothing is perfect and veterinarians remain alert for screwworm outbreaks the world over.
The use of genetic modification to control pests is not limited to insects. Australia is plagued by millions of feral housecats and rabbit and is looking into genetic control of these and other creatures. Genetic control is complicated. As control effort moves further up the food chain the issues become more complex. People probably do not mind controlling fruit flies, but genetically modifying housecats to be sterile?
Meanwhile, researchers have found a way past tick defenses and may be closer to controlling these blood thirsty disease carriers.