Mystery photo #3 revealed

The last mystery photo was a close up of a caterpillar covered in parasitoid wasp cocoons! Here's the full size photo.

This is one caterpillar that won't ever be a butterfly (or moth). Why not? And what is a parasitoid wasp? The adult female wasps search for particular species of caterpillars and deposit the eggs inside the caterpillars' body. Then the wasp live inside the caterpillar and slowly eat it from the inside out. When the little buggers are finished, they make cocoons on the caterpillars' back and pupate. Then the next generation of wasps will emerge from the cocoons on the back! The caterpillar will die before it is able to pupate, and so it will never reach adulthood or reproduce.

Some insects like parasitoid wasps can be very beneficial for farmers if they lay eggs on caterpillar species that damage crops. You don't have to go to Africa to see parasitoid wasps! You can find them if you grow tomatoes in Chicago! Large, green caterpillars called tomato hornworms eat tomato plants, but also have their own parasitoid wasp species. The cocoons are very similar to these and will appear on the parasitized caterpillars (from a distance they look like they would be white oblong eggs, but if you look closely you can see the little threads of the cocoon).

One of the reasons I love studying biology is because I get to learn about fascinating relationships between different organisms. Would you ever have guessed that some wasps grow up inside a caterpillar!?

Mystery photo #2 revealed

Last week's mystery photo was a picture of a giant pouched rat. These large rats have cheek pouches like hamsters, which distinguishes them from many other rats (including the rats that are common in cities). The rat in the photo has really stuffed his cheeks full of seeds! Then they hide the seeds somewhere else in the forest (like squirrels with acorns) or bring it back to their burrow.

Here is another photo of a giant rat with his cheek pouches empty. He looks a bit more rat-like in this pose.

These rats are hunted and eaten in many places in Africa, but some people in the U.S. and Europe keep this species as pets. Unfortunately, some have escaped in Florida and they are now an invasive species. But here in Tanzania, they play an important role as seed dispersers.

Mystery photo #1 revealed!

Here's an uncropped version of the same photo:

Can you tell what it is yet?

That's my hand in the background. I'm holding two large seeds that have been chewed on by a rat! You can see the teeth marks on the seeds.

After seeds fall to the ground from the trees, rodents often carry them away. Sometimes they eat them right away, but often they hide them somewhere else to eat later. Many of the seeds will probably get eaten, but the ones that are forgotten can then sprout into seedlings.

Have you seen squirrels hiding acorns in the fall? They're doing the same thing as the rodents here in Tanzania.