The Japanese beetles and earwigs are gone, you heave a sigh of relief. But don't relax - just when you thought the garden was safe, here come the cucumber beetles to eat virtually any yellow flower. They migrate from the South, arriving in the Northern States in midsummer. These nasty little pests resemble slim, yellow lady bugs with their small, spotted bodies. I don't grow cucumbers, but that hasn't stopped hordes of them from descending on the Solidago 'Fireworks' (goldenrod). They're also feasting on the big ex-asters, Symphyotrichum novae-angliae (pictured above), Symphyotrichum oblongifolius 'October Skies', and Symphyotrichum laeve 'Bluebird' (smooth blue aster). What's curious is that they don't seem interested in a seedling of 'Bluebird' with slightly smaller flowers. They also don't bother Solidago 'Dansolitlem' (Little Lemon™), Symphyotrichum ericoides 'Snowflurry', or the wildings out back, all of which have small flowers.
Take a good look at your larger flowered asters. If the ray petals are missing or mangled, you probably have an infestation of cucumber beetles. I've been hand-catching and squishing the little buggers, but there has to be a better way, short of growing only small flowered ex-asters and goldenrods. The only suggestions for organic controls I've come across are floating row covers (not going to work for ornamental plants), and yellow sticky traps, which I fear might trap bees.