Stung my granddaughter yesterday
Hi, I think this might be a sawfly, which is a type of wasp. The larvae are plant pests. Here are some photos: http://bugguide.net/node/view/33234/bgimage
I couldn't locate an image that's exactly the same as what you shared, but the wide waist is characteristic of sawflies. Mason and potter wasps have very narrow waists (petioles).
I hope this helps!