Haven’t seen this mentioned on here yet, may be of interest to some members growing figs in the area in question, e.g., @Richard:
https://academic.oup.com/jipm/article/13/1/12/6576130
The abstract and map of known infestations:
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It was imported by a FigBid seller who obtained cuttings from overseas. It is generally not a problem in the commercial setting because we annually treat our soils in the winter for the larvae of a number of pests (e.g. Japanese beetles). Gnatrol WDG is the most common control.
Active infestations on leaves or fruit can be effectively treated with the commercial product Evergreen or the consumer product Ortho Fruit Tree Spray.
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Here’s what that paper says about chemical control measures:
Chemical control recommendations are rather limited as well. Silba adipata larvae in infested fruit are protected from pesticide sprays and there are no effective soil drenches for pupal control. Katsoyannos (2008) recommended the use of proteinaceous bait sprays (such as GF-120, Corteva Agriscience, Wilmington, DE) and, more recently, Ismail et al. (2016) reported some efficacy of plant extracts and entomopathogenic fungi. Two different bait sprays are registered in California for use on figs against flies, one utilizes spinosad (GF-120 Fruit Fly Bait, Corteva Agriscience) and the other spinetoram (Delegate 250 WG, Corteva Agriscience). Data on the efficacy of these products against S. adipata specifically are sorely needed.
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Gnatrol WDG is a known biological control. The article list of chemical controls only includes those with Ficus carica on the label, omitting those with the more general label of “fruit trees”. Both the Evergreen and the Ortho Fruit Tree Spray contain PBO at a concentration that is lethal to BFF.
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With this new pest being the case I would highly suggest any fig cuttings coming from CA be treated to kill any potential eggs. They likely only reproduce in the fruit, but precautions are good. Also I would not buy any fig plants grown in CA. Why risk it? However, so few figs are grown in most other parts of the USA it’s likely not a huge threat outside the West Coast, but could be a localized headache like fig bud mites in a greenhouse, etc.
I soak all my fig cuttings coming from elsewhere in a solution of soap and Zero Tolerance, one of my favorite organic pesticides that kills mites, eggs, aphids, scales, etc.
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The BFF was detected in Spring 2021 but the fig collectors/sellers community did not take heed even though I notified them of the treatment protocol. Now last year’s soil larvae have morphed into adults and are a problem in large, licensed and unlicensed collections in TX, FL, PN, MN, and other states.
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None of the listed ingredients in Dr. Rosenthal’s Zero Tolerance products are effective against mediterranean fly larvae. Consider Gnatrol WDG, it’s NOP listed.
@Richard
I thought as of right now it’s in California are you saying it in other states too? I think I’m done with figs anyways but wow this just stinks. If they ever get to my yard I might just cull my figs last thing I need is more spraying at different times and different products.
You expected something different from unlicensed plant sellers?
Here was my schedule for 2021:
Annual Fertilizer & Pesticide Calendar.pdf (136.7 KB)
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Hi Richard,
So I only purchase fig cuttings and pretty much nothing from CA in order to reduce chances of disease and pests coming in, especially in soil. Is there any risk of this new pest arriving on cuttings or only in soil? Another strong point in favor of bare-root plant exchanges.
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It’s entirely supplier dependent. There are licensed and unlicensed suppliers who are too cheap to treat their plants with any effective product and so you can end up with mites, scale, spores etc. on or embedded in cuttings.
I understand you’d like to maintain your organic brand. I have the CA agricultural pesticide applicator license and previously held the advisors license as well. I sympathize with the many challenges you have.
The greatest risk is in media - and not just from California. Keep in mind that the infestation started in a plant nursery, then spread to other nurseries, and then into suburbs when the larvae emerged from soil at the various sites.
I don’t know if the larvae can survive hard freezes, such as those in your location. In the eastern hemisphere it is confined to the mediterranean and other semi-tropical regions. In fact it might have arrived from the latter.
Your point about BFF on cuttings is good. I believe it is an extremely unlikely occurrence. Bareroot though … now we’re back to the supplier. A licensed commercial wholesale propagation nursery in CA will have treated the plants and soil with effective pesticides. Others - both inside and outside CA are a concern. I treat all plants as they come out of the box.
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ortho- I have this for other fruits, didn’t even think of using it for the figs. it’ll kill these if any show up? I plan to get one or two figs to add this year and am concerned. would I need to spray twice
Depending on how much you heat the hoop house, they probably wouldn’t survive the winter there.
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35-45° F usually. they go dormant but it’s not freezing
It will kill adults that it comes in contact with either while you spray or within a few hours afterwards. That is true for all pests listed on the label.
Coincidentally, I was reading the label of the systemic “Marathon II” which I have for another purpose and I noticed it can be used as a soil drench to kill gnat and fly larvae in the ground under and around fruit trees. The dosage instructions seem easy to follow.
Marathon II Label
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I guess we’ll find out as they spread northward what temperatures they can handle, but as @Richard mentioned above, this fly’s native range is in warmer areas than most of the U.S. If you did get them in the hoop house, one treatment might be turning the heat way down for awhile over the winter.
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Is there more to the story? Did anything happen to the person who imported it?
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So far, no.
@Richard - Out of curiosity, how do you know that it came from a buyer of overseas cuttings? While cuttings can be the vehicle for various pests, BFF eggs are laid on the fruit, larva drop to the ground and pupate there. I would think basic precautions with cuttings would prevent BFF transmission. Soil and fruit should never be moved around.
I believe there are known BFF infections in various areas in Mexico that supply fresh figs to the US. I’ll need to hunt down that source, but IMO that is probably how BFF was imported into California.
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I’d be happy to tell you next time we meet.