A True Fruit Fly - Tephritidae

Fruit flies are a family, Tephritidae, containing about 5,000 species of often strikingly colored insects.  As the name implies, these flies are frugivores.  Many, such as the mediterranean fruit fly, are agricultural pests.

Drosophila melanogaster, the insect that has been so important in genetic research, is not a true fruit fly.  Drosophila is a member of the Drosophilidae, the vinegar or pomace flies.  They are mostly fungivores, and their association with fruit is indirect: they eat the fungus that lives in rotting fruit.  Some pointy-headed geneticist started using the wrong common name for them a century ago, and legions of geneticists unfortunately followed suit. Now when someone says “fruit fly” we have no way of knowing what sort of insect it is without additional context.

I bring this up because the confusion between fruit flies and vinegar flies entered into U.S. presidential politics this week when Sarah Palin attacked Fruit Fly spending as wasteful:

Where does a lot of that earmark money end up anyway? […] You’ve heard about some of these pet projects they really don’t make a whole lot of sense and sometimes these dollars go to projects that have little or nothing to do with the public good. Things like fruit fly research in Paris, France. I kid you not.

Palin was referring to a project to fund studies of the olive fruit fly, a true tephritid and a major threat to California’s olive industry.  Popular biology blogger PZ Myers made the common lab scientist mistake of thinking fruit fly meant Drosophila, and was off and running with political commentary:

This idiot woman, this blind, shortsighted ignoramus, this pretentious clod, mocks basic research and the international research community….Yes, scientists work on fruit flies. Some of the most powerful tools in genetics and molecular biology are available in fruit flies, and these are animals that are particularly amenable to experimentation.

Myers’ rant was picked up across the progressive blogosphere, hammering on Palin’s inconsistency of appearing to support programs to understand childhood autism yet cutting funding for the very basic science that would underpin the research.

The issue of whether spending in support of agricultural industry is sound policy is beyond our expertise here at myrmecos blog.  I would like to point out, however, that the debate is best served if all sides were at least talking about the same thing.

Drosophila - A Vinegar Fly, not a Fruit Fly

Drosophila - A Vinegar Fly, not a Fruit Fly