100 Species #87: brown and white striped leaf beetle
This brown and white striped leaf beetle (either Calligrapha bidenticola or Zygogramma suturalis) was found on a weed (I think devil's beggartick, definitely not ragweed) along the fence between the side yard and the big yard.
EDITED TO ADD: See below for revised identification
Calligrapha bidenticola is a leaf beetle that feeds on many species of plants, and is native to eastern North America. Zygogramma suturalis is a leaf beetle native to Russia, introduced to North America in an apparently inadequate attempt to control ragweed. Both species are reported to occur in eastern Massachusetts, and both are virtually identical. My picture matches more of the pictures of Calligrapha but that doesn't even meet my meager standards for rigor for identification to species. The teeny tiny claws at the end of the feet, the "tarsal claws," are the best clue: in Zygogramma they are parallel; in Calligrapha they are "divaricate." Hope that clears it up for you.
EDITED TO ADD: The previous text was written before I got identification assistance from Jenn Forman Orth. Jenn orchestrated our participation in the Dedham BioBlitz Nocturnal Insect event, and we found this beetle that night, feeding on beggarticks (Bidens sp.). The beetle Calligrapha bidenticola feeds on this plant, making identification through examination of the tarsal claws a bit more rigorous than we need for our purposes.
All around the perimeter of the yard I left some rangy tall weeds because I knew they would turn into asters in late summer and fall. Asters are a taxonomic headache to identify (worse than beetles?) so I left this one off the list of 100 for now.