My parents are coming to visit from Michigan in a couple days and as soon as they get here we are heading up to Napa for a little wine tasting getaway. I feel fortunate that I have lived within 2 hours of some of the best wineries in the world for the last seven years. Spending a little bit of time up in wine country, I couldn’t help but learn about the great soil and perfect weather coastal California harbors for wine grape growing (and for people!). I’ve learned that Pinot Noir grapes (my favorite) grow better in cooler areas, like the foggy Mendocino coast and, in contrast, Zinfandel grapes prefer that hotter, drier weather of inland Napa and even into the central valley of California. However, while wine making is interesting, I, of course, wanted to learn about the bugs! Luckily one of my former lab mates, Julie Jedlicka, was conducting her dissertation in wineries on insects and the birds that eat them.
As great as some insects can be for agriculture (i.e. lacewings, lady bugs, and parasitoid wasps, oh my!), many can be very detrimental to crops, some people may call them “pests”. I prefer not to use that word, as one could argue that they are only in abundance because of the way we grow our food…but enough about that, whatever you call them, they eat our crops and that is a problem. They even eat our wine grape vines. And that is a big problem! One major player is the Glassy Winged Sharpshooter- a leafhopper would a cool name and a cool look. This leafhopper is like a plant mosquito- it sucks the sap out of grape vines and in the process transmits diseases from plant to plant. One disease is known as Pierce’s Disease, caused by the transmission of bacteria that essentially clogs a plant’s arteries- it forms a gel that blocks water from traveling up the vine from its roots. This causes leaves to die, shoots to die, and eventual total plant death after a few years.
So how do we save our wine? Fortunately for us, Julie is a bird person into insects and agroecology! She decided that it would be a good idea if we had more birds in the vineyards to eat up those little leafhoppers. For her dissertation at UC Santa Cruz, Julie tested the effect of adding bird nest boxes to vineyards to see if more birds would come and, thus, if more sharpshooters would get eaten. She found that significantly more insect-eating birds came to vineyards where she placed nest boxes than in vineyards that didn’t have nest boxes. Insect-eating Western Bluebirds were by far the most abundant birds in the vineyards with nest boxes.
Julie also collected a bunch of insects from vineyards to see if those vineyards with nest boxes had less insects than those without nest boxes. I am a part of this part of her project, as I identified all her insects (to the family level!) and measured all their lengths to see if the type and size of insect changed between vineyard treatments. We are still analyzing the data, but I will write about the paper once we get it published! Julie is now a NSF Postdoc at UC berkeley and she continues with this project using molecular methods to see what the birds actually eat! Yes, she is collecting bird poop and analyzing it for insect DNA fragments. Pretty Sweet.
If you enjoy some wine this week, thank a bird and put up a nest box! 🙂