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It is cold and windy this morning. The only insects that are still active are the fruit flies in the compost heap.

Why are they still active?  Probably because the rotting compost gives off heat. It is the warmest place in the yard.

Fruit flies of the genus Drosophila are easy to identify because of their bright red eyes.

You might also recognize that the white crawly things are the fruit fly larvae. (Photo by RickP at Wikimedia)

What are not so easy to identify are these funny little brown objects.

Those are the fruit fly pupae. The larvae change into pupae, usually after crawling out of the food to a drier location. Adults emerge from the pupae.

It is appropriate to honor the fruit fly here at Growing With Science. The humble fruit fly have been been the backbone of scientific work on genetics and developmental biology for over a century. Way to go, fruit flies!

Have you ever used fruit flies for a science project?

Ever wondered where something like “Bug of the Week” might lead? Sure it is fun, but can anything really useful come out of checking the insects in your back yard once a week? It turns out some very cool things can result from regular bug watching.

A few weeks ago when I was looking at the fruit flies in my yard, I found something I didn’t recognize. I sent it to a friend of mine at the University of Arizona to identify.
Take a look:

zaprionus fruit fly
When I looked through my camera lens I saw this fruit fly with incredible white stripes that almost glow florescent, they are so bright.

My friend identified it as Zaprionus indianus, a fruit fly native to Africa, the Middle East, southern Europe and southern Asia.  This species was first found in the Americas in 1998 when it was reported from São Paulo, Brazil. It just arrived in Arizona within the last year or so. I call it “Z” because of the genus name and its fancy zebra stripes.

zaprionus fruit fly

Here is a photo of Z under a powerful microscope:

zaprionus fruit fly

I’ll be keeping a good eye on Z to find out what it likes to eat and how many are around. Right now it hangs out with the other fruit flies in the compost heap.

You never know when you might meet some new insect neighbors, if you just go out and look.

Carrying along the theme of insects that have changed the course of human history, let’s look at another species with humble beginnings and a big role. Here is a celebrity that can be found in the fallen, rotting grapefruit in my backyard.

fruit fly

This photograph is of a male fruit fly, Drosophila melanogaster. Notice the bright red eyes. I can tell the one in the middle is a male because the end of the abdomen is dark. You might recognize these little flies if you have ever taken a genetics class or left a banana out on the counter too long.

fruit fly

These are female fruit flies. Their abdomen lack the black block at the end.

Also called vinegar flies or pomace flies, these tiny creatures don’t actually feed on fruit, but their larvae feed on the fungi associated with decay. A sound, healthy fruit is of no interest to a fruit fly.

As for their benefit to humans, fruit flies have been the staples of biology labs for over a century. Much of what we know about genetics and developmental biology came from studies of fruit flies.

Drosophila melanogaster was not native to North America, but is now almost a domesticated species. It is found wherever people are found. In the western United States we have a few native species, including another fruit fly used in biology labs called Drosophilia pseudoobscura.

If you are interested in learning more about fruit flies, try the quirky adult nonfiction
book Fly: The Unsung Hero of Twentieth Century Science by Martin Brookes (Be aware that this book contains what would be considered adult themes.)

For kids, you might try a cute fiction picture book about flies, called
Diary of a Fly by Doreen Cronin, Harry Bliss (Illustrator). My son got to meet the author and illustrator of this book at a local indie bookstore, and they were a wonderful team. The illustrator had a big impact on my son, who loves to draw.