update 12/18/2010
by Melanie Bondera
Thank you for all your feedback and input! We’ve sent the fungus off to several labs for identification. Farmers should go out and collect any b. bassiana fungus from their own farms before the harvest season ends and there are no more coffee cherries. Here’s my suggested collection procedure.
- Find coffee cherries with CBB, which is mainly identified by a small hole at the blossom end of the coffee cherry (green or red).
- Look for a bit of white fungus coming out the hole (works best in high humidity, where you have soil, shade, or moisture on your farm). I also find multiple on one lateral. (I needed my reading glasses to see this)
- Collect in a clean ziplock or tupperware. Take inside and work on a clean cutting surface. Cut the cherry in half across the beans (the difficult direction); I use my clippers. You’ll see the remains of the CBB life cycle inside.
- Find a dead CBB stuck in the exit hole with white stuff coming out of its body. This is your most likely source of B. bassiana. Use a clean tweezers (I sterilized with flame) to remove it from the cherry. Place in a sterilized canning jar or similar container (running thru a dishwasher counts as sterilizing) with a cotton ball or wad of clean paper towel.
- I was getting about 5 dead beetles with white fungus in the entry hole out of every 30 cherries I picked with white coming out the exit hole. So, be patient. Take the leftover cherries, beans, live beetles and other mess and keep it in a ziplock for 3 weeks or bury it one foot down or boil it.
- Let jar with beetles sit open in a clean, dry, protected area for 3-4 days to dry. In my coffee shack, I put a bit of mesh screen over it. Then put the lid on and store, until we have a protocol to spread on your farm.
We’re working on a farm-scale protocol for farmers to expand it on their own farms, but it’s trickier than we originally thought, so stay tuned.
Get on Google and start educating yourself about B. bassiana and CBB. There is a lot of information out there from the 70 coffee growing countries that have this beetle. B. bassiana is a naturally occurring soil fungus that is drawn into the coffee trees’ tissue by the presence of the CBB. The fungus is not a silver bullet, but an important part of the ongoing control practices including sanitation and trapping. This pest is very resistant to chemical pesticides, so most growing areas have abandoned them. We’ll never be rid of CBB, but we can get it down to a manageable threshold of 5-10%.
Remember as you start your pruning, do a clean-up round of picking the cherry, so none of them can be hosts to the next round of beetles. Bury them one foot under or store in plastic bags for 3 weeks in the sun to kill the CBB, then compost.