Flatbacked Millipedes from British Columbia

Subject: Is this a Sawfly larva?
Location: South Surrey, BC, Canada
July 24, 2016 12:18 pm
Hi Bugman,
I came upon several of these in my garden in South Surrey, BC, Canada in June, 2016. South Surrey is south of Vancouver, BC, near White Rock, just north of the USA border (WA State) — just in case your readers aren’t familiar with the local geography.
I had no idea what they are, but I think they look like your photo of a Sawfly larva. Are they harmful to plants or beneficial insects?
Thanks for your help.
Signature: Jerry Steinberg

Flatbacked Millipedes

Dear Jerry,
These are NOT Sawfly larvae.  They are Flatbacked Millipedes,
Harpaphe haydeniana, and according to BugGuide:  “This particular millipede secretes a dark fluid that has an odor similar to the almond extract used in cooking. Apparently this is a defensive manuveur. Millipedes also curl up in tight coils when threatened.  Caution: Many millipedes with bright color patterns secrete a compound containing cyanide. Wash your hands after handling them and do not allow children to pick them up.”  According to Island Nature:  “the millipede can perform its duty as a ‘macroshredder,’ breaking up plant material and initiating the process of nutrient recyclying [sic] in the soil ecosystem … . In fact, it plays such an important role in the process that it can be considered to be a “keystone” species.”

Thanks so much!
Keep up the GREAT work!

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