A Raspberry’s Worst Nightmare

With all the beautiful berries available now, I’ve been seeing more fruit flies hanging around the kitchen. Annoying? Yes. Ruining my strawberries? Nope. Fruit flies lay their eggs on damaged or rotting fruit. So they’re only interested in the pieces that are going bad. I’m ok with that.

But consider a fruit fly who lays her eggs on fresh fruit. She’d have the agricultural community freaking out. Just imagine the risk to berry crops. Actually, you don’t have to imagine because scientists have already done the calculations for you: it’s potentially $2.6 billion of risk (1).

Evolution has already dealt this stunning set of cards to Drosophila suzukii, the spotted-wing drosophila (2). The females have an ovipositor (the anatomical structure that deposits eggs) that looks like a serrated knife. Unlike the common fruit fly in your house, this species’ egg-laying parts can cut through the skins of raspberries, strawberries, blueberries, cherries, and grapes.

Want to learn more about the spotted-wing drosophila? IFAS at the University of Florida has a great info page on the little beastie (with horrifically gorgeous pictures, by Martin Hauser, of that ovipositor – if you haven’t seen fruit fly genitalia yet, you are missing out).

p.s. Thanks to Dr. Nadia Singh for introducing me to Drosophila suzukii.

1. Walsh, Douglas, M. Bolda, R. Goodhue, A. Dreves, J. Lee, D. Bruck, V. Walton, S. O’Neal, F. Zalom. 2011. Drosophila suzukii (Diptera: Drosophilidae): Invasive Pest of Ripening Soft Fruit Expanding its Geographic Range and Damage Potential. Journal of Integrated Pest Management. 2(1): G1-7.

2. Atallah, L. Teixeira, R. Salazar, G. Zaragoza, A. Kopp. 2014. The making of a pest: the evolution of a fruit-penetrating ovipositor in Drosophila suzukii and related species. Proceedings of the Royal Society B: Biological Sciences, 281 (1781)

Invasion of the House Finch

Once upon a time, House Finches (Haemorhous mexicanus) only lived west of the Rocky Mountains. Then, in 1940, a group of captive birds flew to freedom from their New York cages. Their numbers slowly grew until… BOOM… population explosion. Today, House Finches reside throughout the U.S. and Mexico.

There’s a downside to dense populations though – disease. In the 1990s, a bacterium (Mycoplasma gallisepticum) started swirling among groups of House Finches. The infection causes conjunctivitis (like “pinkeye”) in the birds. If you’re a bird with swollen eyelids and crusty build up, you’re not going to be very good at flying or avoiding the neighbor’s cat.

Today, roughly half as many House Finches live in the East compared to 20 years ago.

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If you’d like to learn more about House Finch diseases (with gross pictures), visit http://www.birds.cornell.edu/hofi/abtdisease.html.

And if you’d like to see the growth and decline of House Finch populations in your state, check out www.pwrc.usgs.gov/BBS/RawData/ (1)- fun with data!.

1. Pardieck, K.L., D.J. Ziolkowski Jr., M.-A.R. Hudson. 2014. North American Breeding Bird Survey Dataset 1966 – 2013, version 2013.0. U.S. Geological Survey, Patuxent Wildlife Research Center.

Hemlock or Hemlock??

I have never poisoned anyone. I’ve just learned that if I were to try, I would be very bad at it. The hemlock I thought was poisonous turns out to just have an unfortunate common name. And rather than brewing up a batch of tainted tonic, I would apparently make my intended victim an aromatic cup of tea loaded in Vitamin C.

While hiking around the Appalachians this weekend, I spied tons of hemlock trees. “What a great post for October… Hemlock!” I thought and pulled out my sketchbook.

Sketch done, I hopped online to find out just how the poisoner killed Socrates. Uh oh, wait… it’s a different Hemlock?

Evidently, the poisonous hemlock is a small plant related to a carrot. Not THIS hemlock (the Eastern Hemlock, Tsuga canadensis) which is a tree known for its wonderful aroma – a sweet, fruity pine-like scent. Oils from the leaves and twigs are condensed and sold for home sprays, perfumes and some homeopathic uses (often listed under a non-Hemlock name though).

Perhaps the Eastern Hemlock would benefit if it produced a little poison though. Small insects called Wooly Adelgids are munching their way through every Eastern Hemlock in the southern Appalachians. Researchers are concerned that, if a solution is not found, most of the Eastern Hemlocks in this region could be gone in the next decade.