Well this is new to me: Saskatoon fruit worms

As I was inspecting my saskatoon and noticing fruit drop I saw they had a small dot injury. upon carefully slicing one open with a razor blade I found these worms inside of them.

About half of the crop seems to be with them :\ What are they?

I am seeing this on a wild tree this year as well. I have not been able to figure out which species it is via web search to date.

I’m wondering if it may be apple maggot. They have been noted in the literature as utilizing a number of alternate hosts…I also have a blueberry maggot in my area that does the same…

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Observe the true leg and protoleg counts on the worm; that can help ID the type of insect.


None of my apples are affected. Plum maggots maybe.

What’s the usual protocol for these?


These all look pretty similar- any culprits?

I saw that.

I’m guessing plum. I’m going to manually engage in a murdering spree and then spray some Permethrin in the event that these are the sort that crawl out of the fruit in search for fresh fruit to continue their damage.

I hate spraying unnecessarily but it sounds to me that moving forward (next year) I will need to spray after petal fall, once the pollinators have moved on.

Is there value in spraying the soil after the plant goes dormant? It sounds like these overwinter in the soil.

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I swear every year it is something new. These a* pretty much obliterated all the fruit and it seems they are still at it; pristine fruit is showing the little egg deposit marks. Then there is the ant/aphid combo that infected the singular apple tree; it was covered on them. Also the carpenter ants that ate the rhubarb bush, that was new as well.

I guess moving forward I will need to start spraying saskatoons once the pollinators move on after petal fall.