While you enjoy your cup of coffee this morning, take a moment between sips to thank the birds and the ants that made it beetle-free. You might wonder why I, a self proclaimed beetle lover, want a beetle-free anything ? Well, even I understand that there is a time and place for beetles…which, while that includes most times and places, does not include my coffee mug in the morning (ok, I’m lying, I’d love that…but I’m trying to relate…).
The tiny coffee-loving beetle I am referring to is known as the coffee berry borer (CBB). I didn’t know the CBB existed until Stacy Philpott and her lab joined my department at UC Santa Cruz a couple years ago. Coincidentally, the CBB showed up in my life again- twice- last week, so I saw it as a sign to share it with you all. The CBB has quickly become a big issue for coffee growers- and drinkers- everywhere as it spreads from its native Africa to Central and South America and, as of 2010, it is even in Hawaii.
The CBB. Photo L. Shyamal wikicommons.org
Exit hole of female CBB in a coffee fruit. Photo by L. Shyamal wikicommons.org
The CBB is a tiny beetle in the weevil family that burrows into coffee beans when it is developing into a fruit. Specifically, the female enters the bean and lays her eggs. Once the larvae have eaten enough, they molt into adults and mate. There are 13 females to every 1 male and males never leave the bean and cannot fly. Because of this, female eyes are adapted differently to actually see the berries in the environment, while the males eyes are greatly reduced. Check out this blog post for more info and a cool pic of CBB eyes (the first place I saw the CBB this week).
Once the coffee bean becomes the CBB nursery, it is no longer good for consumption. Thus, the CBB can greatly reduce coffee yields, reducing farmer’s profits and making your coffee more expensive. So, how do we get rid of this CBB?
Stacy and her lab study the insect predators of CBB in Mexican coffee farms, specifically the ants. Here are some cool videos showing what the ants do to the CBB on the coffee (videos by Stacy’s graduate student Esteli Jimenez-Soto):
BUT it isn’t just ANTS taking care of the CBB for us, BIRDS are effective predators too!
Last week for the “bio lunch” at work (when we get together to geek out on a paper- ecologist style) we read “Forest bolsters bird abundance, pest control and coffee yield” by Karp et al. The researchers showed that birds reduced CBB infestation by 50% in Costa Rica coffee farms! They then figured out which birds eat the CBB by checking the bird’s poop for CBB DNA! (Like Julie Jedlicka is doing in CA vineyards)
The best part about this study is where these CBB-eating birds are coming from. It turns out that patches of forest within and between coffee plantations provide habitat for CBB-loving birds. Specifically, with increasing forest cover, both the number of birds and their predation on CBB increased, causing a reduction in CBB infestation. The study also showed that not just the large, protected patches of forest provide bird habitat- but that small patches throughout the coffee farms work just as well.
In other words, farms that maintain at least some forest get more beneficial free CBB control services- conservation agriculture works! More forest means more birds and ants, increasing coffee yield, farmer profits, and savings for us. Which also means more coffee for you and me. Win!