Chapter member (and SD organic commercial farmer) Ellen Maisen found an interesting article from the UC Division of Agriculture and Natural Resources. It was aimed at olive growers who are battling the olive fruit fly but the traps seem identical to what are being proposed for Silba Adipata McAlpine (the Black Fig Fruit Fly).
These are the instructions in the article for an easy DIY trap. In the absence of torula yeast, I have found that Marmite and other yeast products work pretty well also as attractants.
Olipe traps are made with 1.5 to 2 liter plastic non-food bottles, with several 4 to 5 mm sized holes drilled or melted at the top, and baited with 3 to 4 torula yeast tablets per liter of water. Pheromones may or may not increase trap catches.
- Place two traps for each 5 to 10 acre block for monitoring and one trap per tree for mass trapping control. Mass trapping usually does not work as a stand-alone treatment, but can supplement the efficacy of other treatments or reduce the number of treatments by reducing the overall number of flies in the orchard. Flies attracted to the bait, crawl into the bottle through the holes at top, and drown.