Earwigs

Joel Grossman (0003216125@mcimail.com)
Sat, 15 Jul 95 14:03 EST

Earwigs are both scavengers and predators. In Germany, organic apple
growers use earwigs for biological control of aphids, spider mites, fruit
worms and other orchard pests. Earwigs tend to be nocturnal, and hide
during the day -- i.e. the split peaches probably make a good hiding place.
I have a few suggestions:

1.) Find alternative controls for other insect pests, so that earwigs do
not buildup their numbers. Likewise, check the debris situation, like
rotted peaches etc. that could also be an earwig food source.

2.) From what I understand, split peaches are a physiological disorder from
an imbalance of minerals like calcium. Eliminate the splits as a hiding
place.

3.) A German Company, G.E. Bartz [Potthaus, D-4178 Kevelaer 2] makes a
plastic earwig trap that is hung in trees by some orchardists in Germany.
Since the German growers are trying to conserve earwigs as natural enemies
for biological control of orchard pests, they have to eliminate spider
nests from near the earwig traps. The spiders, which eat earwigs, set up
shop outside earwig traps, which would be a good thing if you are looking
to eliminate earwigs.

4.) There are also Tachinid fly natural enemies of earwigs being
investigated in Germany and at the International Institute of Biological
Control in Switzerland by U. Kuhlmann [See J. Appl. Entomol.
117(1994):262-7]. One Tachinid fly, Ocytata pallipes, was released in
Oregon in the 1930s, but seems not to have persisted. Perhaps you could
develop a cooperative program.

5) There has been some work with earwig aggregation pheromones by Karen
Walker et al. at Virginia Tech Univ. in Blacksburg, VA, written up in the
Journal of Chemical Ecology, v. 19, n.9, 1993. I don't know if anything
practical has yet been developed, but you might be able to set up some
cooperative research projects for next season.

6) If you have retail outlets where you market the peaches directly to
consumers, like farmer's markets, you could do an educational spiel and
market the earwigs in splits as a sign of biocontrol -- though I suspect
that fear of bugs is too high in much of the population to tolerate
anything more than a lady beetle or two, if that.

Good luck,

Joel Grossman
3216125@mcimail.com

Bryan Butler wrote:
<We are experiencing a tremendous problem with earwigs getting to split pit
<peaches. Peaches are being harvested for fresh market and consumers are
<finding the earwigs when they eat the peaches at home.