A Tiny Black Wasp is an Effective Alternative to Pesticides

By Earl Hunsinger

Do you remember DDT? DDT or Dichloro-Diphenyl-Trichloroethane was first synthesized in 1874, but its insecticidal properties weren't discovered until 1939. Ironically, given its later history, the scientist that made this discovery won the 1948 Nobel Prize in Physiology and Medicine for doing so. Although DDT was used extensively in the 1940s and 1950s, after discovering the devastating effect it had on wild birds and fish, its use was banned in the U.S. in 1972. Similar bans have also been imposed in most other countries.

Of course, other pesticides continue to be used. Until recently, it seemed to be an accepted fact that farmers had to use pesticides. Although pesticides are very effective at safeguarding crops and increasing productivity, there is now a growing concern over the effect that pesticides in general have on the ecosystem. This concern includes the danger that they pose to wild birds and animals, as well as to household pets. Millions of humans are sensitive to pesticides. In addition, they have been linked to a wide range of serious and often fatal conditions, including cancer, leukemia, miscarriages, decreased fertility, genetic damage, liver damage, thyroid disorders, neuropathy, diabetes, still births, asthma, and various auto-immune disorders. Add to this the fact that some studies show that only about 5% of the pesticides sprayed ever reach their target and you may wonder if their use is even worthwhile from an economic standpoint. Of course, the other 95% isn't just wasted; it ends up in our water or the air that we breathe. Studies have also shown that pesticides have a negative effect on the microorganisms that live in the soil, the same soil that farmers are relying on to grow their crops. This can have a negative effect on soil productivity. Still, if you're a farmer you have to use pesticides. Right?

Organic farmers say no, you don't have to use chemical pesticides. In fact, they refuse to even use artificial fertilizers. Are natural methods effective? Many seem to think so; according to a report by CNBC, as of 2004, organic food sales at the retail level totaled 10.4 billion dollars, with increases of 17 to 20 percent per year. Of course, organic growers face some of the same challenges and pests as conventional farmers. How do they cope with these? There are many methods. For example, more information recently became available about an interesting tool for dealing in a natural way with bothersome insects.

According to the website Science Daily, "A commonly used parasitoid, or parasitic insect that kills its host, has proven to be quite effective in the control of fruit flies in vineyards. " Dr. Jean Pierre Kapongo, an entomologist with the University of Guelph, in Ontario, Canada just concluded a study that investigated the effectiveness of using a minute, black wasp called Muscidifurax raptor to control fruit flies. The adult parasitoid stings the fly pupae, thus killing them. The adults then feed on these fly pupae. The female wasp will often lay an egg in a pupal case. When the egg hatches, the wasp larva will then feed on the dead fly pupa.

In addition to fruit flies, these tiny wasps, which are only 1 to 2mm long, also feed on houseflies, stable flies, and other kinds of flies. It seems to be especially effective on farms in the northeastern United States. In addition to vineyards, these parasitoids can be used to control flies that threaten animals in confined environment, such as poultry houses, dairy barns, and horse stables. Insectaries, where parasitic insects are commercially produced and sold, are ready to increase production of the Muscidifurax raptor based on demand. So if you're a farmer or vineyard owner, why not consider this natural alternative to an old problem?

Of course, this is just one example of an alternative to commercial pesticides. Still, it demonstrates the point that pesticides are not always necessary. There may be more natural and environmentally friendly alternatives. This is one aspect of what has been labeled sustainable agriculture. It also illustrates that is possible to think about both the environment and making a profit, that they are not mutually exclusive goals. That's good. After all, we live here, and most of us would like to for some time to come. But if we don't take care of our environment, that may not be possible.