Spotted Cucumber Beetle – Diabrotica undecimpunctata – also known as the Southern Corn Rootworm.
Field Marigold – Calendula arvensis.
Adult Cucumber Beetles are yellow to green with eleven black / dark spots on the elytra (for a better look at the coloration and spots, try this photo). This particular specimen was bright yellow but appeared orange underneath the petal of this Field Marigold.
Spotted Cucumber Beetles, or Southern Corn Rootworm Beetles, are considered big-time pests of crops and other plants. Click here for information on a related species, the Northern Corn Rootworm. Both beetles are known as skeletonizing leaf beetles (along with flea beetles and a host of others), because they eat the fleshy parts of the leaf but leave the “veins” and other thicker parts of the leaf untouched, leaving the leaves looking like skeletons.
For most of the year I only noticed a few Spotted Cucumber Beetles and only in my yellow Day Lillies. I now have dozens of them all over my Mums (especially the yellow ones), as well as the Field Marigolds, sunflowers, and yellow Day Lillies. Maybe they flew in from the nearby corn fields now that it is getting harvest time… In any event, they seem to prefer the yellow flowers.
Photo taken with the Canon Digital Rebel XT / 350D and the Sigma 70-300mm Lens on October 5, 2008 in Davenport, Iowa.