After a light crop last year, we were oh so hopeful when the weather and bees cooperated for a good looking crop of Bing cherries this year. But then the rains came. And came again. And came again, along with humid, warm weather between storms. Meanwhile, the fruit was getting red, then turning darker, and then — sacre bleu! — much of the fruit on the lower branches was suddenly covered by white spots of mildew. Even worse, we noticed that some of the fruit was soft, slightly spotty and turning alcoholic. I sent some cherries and strawberries from our garden in my son’s lunch, which headed for the trash after he discovered small white worms in the container. Aughhh! A closer inspection of our prolific  — and now completely ripe — crop revealed the vast majority of cherries were providing home and sustenance for developing maggots of the spotted wing drosophila, Drosophila suzukii.

Drosophilia suzukii

Drosophila suzukii (source: UC Riverside Center for Invasive Species Research)

This fruit pest was first spotted in Santa Cruz County in 2008 and is now widespread in the Pacific coastal areas, where it is causing a great deal of damage to stonefruit and other soft fruit crops. Some researchers have reported it also infesting one of the big exotics we have in our area — Himalaya blackberry (Rubus armeniacus).

Unfortunately, not much is yet known about this species of vinegar fly and research into management methods is still in the early stages. In the meantime, we’ll do our best to keep the cherries cleaned up and not add to the habitat — and we’ll hope for some hot weather above 86 Fahrenheit to kill off the adults.

Our raspberries are the only the fruit crop that is doing reasonably well, followed by our boysenberries, though some of those vines are suffering from some variety of rust. We have a 5-year pluot tree that may give us some fruit and a 2-year old plum that replaced a Santa Rosa plum planted at the same time as the pluot, but which mysteriously died. Both trees have suffered from leaf curl and are showing signs of it this year, too, despite a good dormant spray. Sigh. We may have to give up on the stone fruit entirely.

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