Re: Can insects detect magnetic forces?

Hi Ian-

The answer to your first question is yes: it does appear that insects are able to detect a magnetic field. Many migratory animals are believed to use the magnetic field lines of the earth to navigate. There is evidence for this in birds, sea turtles and whales, as well as insects. Of the insects, monarch butterflies, which migrate thousands of kilometers, have been suggested to use the earth's magnetic field; it has also been suggested that ants and bees use magnetic fields to orient themselves. A good place to start would be a 1991 article in National Geographic Magazine:

It appears that insects (at least ants and bees) use small amounts of a compound called magnetite to orient themselves to magnetic field lines. An article by S. Darcy and others appeared earlier this year in a Brazilian Journal, and presents the latest work on ants and bees- you can view a summary of the article that appeared in the the June 2000 issue of the APIS newsletter by clicking here. There is a link there to the original article, but that may not be of much use to you, unless you happen to speak Spanish! I would, however, suggest that you check out their list of references- there are several citations, in english, on orientation to magnetic fields, particularly in ants.

I also found an article on the effect of magnetic fields on the singing behaviour of common house crickets:

I'm not quite sure I understand what you mean by your second question about the "choice of container". If you have chambers set up in a magnetic field, it is possible that insects would preferentially go to one chamber over another (i.e. choose one branch of a T-maze). The results of such an experiment would depend on both the insect in question and the magnetic field. If you check out the papers cited by Darcy et al.(the article in Spanish) and the Shaw et al. (1995) paper you should find answers to questions of methodology.

Hope that helps!
Rob Campbell, MAD Scientist