1-This guy was found on the lima beans at the Enchanted Garden this morning. Is he good, bad? What is he? 2-Others are on asclepsis covered with milkweed aphids. Are these beneficial? Also, the plant's leaves are turning dark, is this a problem? Thank you.
The beautiful creature on the lima beans is a grasshopper. They typically proliferate in late summer and although they do some foliar feeding, it is too late in the season to be a problem. You have two types of insects on your Asclepias; the small yellow guys are aphids and they produce a sticky residue called honeydew. The aphids can cause some weakening of the plant and, if necessary, can be controlled by simply spraying them off the plant periodically with a hard spray of water. They can also be controlled by spraying them with insecticidal soap or horticultural oil, but be sure to read the label carefully before using those products in hot weather. The honeydew, in turn, provides the basis of a material known as 'sooty mold'. The sooty mold doesn't really harm the plant, but it is unsightly and can cause a diminished ability to photosynthesize. The larger, orange and black insects are 'milkweed bugs' and although they feed extensively on asclepias, they, too, are a late season pest and rarely cause lethal damage. Your asclepias will return next year.