A couple of days ago I showed you pictures of where we can find Drosophila in the Southwestern United States. Today, I’ll show you some pictures of those flies. Below the fold are flies with racing stripes and others with fancy colored testicles. That’s right: fly balls only a click away. You know you want it.
Before we get to the red and yellow testicles, I’ve got some striped flies to show you. Now, these guys aren’t Drosophila, but they are members of a closely related genus. Well, closely related as far as insects go. The two genera diverged at least 50 million years ago. Here is a dorsal view of a Zaprionus fly:
And here is a side view:
Now for the terrific testicles. These two flies are from the repleta group. In this picture you can see the pigmentation in the testicles of these two males:
The boy on the left has yellow testes, and the one on the right has red testes. If you can’t see them, you probably should reconsider that career in entomology. The coloration of the testes can be used to identify different species, but only if you have males (if you don’t know why, you should apply for a job at the Department of Health and Human Services). When you don’t have males handy (or are trying to identify a female) you can use the characteristic banding pattern on the fly’s abdomen.
Those are the same two males from the previous picture, but the same banding patterns are observed in both males and females. If you don’t know where to look, check out the area around the colorful testes. These patterns are the most used markers for distinguishing repleta species.
But not all flies are as happy and healthy (and sexually expressive) as those shown above. Here’s a fly with a few hangers on:
The dark red critters hanging on to the abdomen are mites. Those of you who have worked in a Drosophila lab may have encountered mites; they are the scourge of fly pushers and require special care to remove from your laboratory stocks. But these mites aren’t the type that parasitizes your lab’s fly room. They’re much bigger. Imagine having a parasite nearly as big as your head sucking on your abdomen. Yummy!