I have been searching for hours to try to find out what this bug is that has taken over one of my butterfly weed plants. Should I worry about it infesting the rest of my garden? I was reading some of the other posts and this is such a great resource for curious folks like me! Hope you can help me identify this bug.
Thanks, Timlie Reis
Gulf Coast Mississippi
You have Aphids. These pests can easily infest many types of plants. You have some winged sexual adults which mate in the typical manner. They then produce generations of female aphids which do not need a mate, but can give live birth without the help of a male. The aphids then become very plentiful. They damage plants by sucking the juices from new growth. They are uaually very host plant specific but other aphids are more general feeders. You can easily eliminate them or at least contro them with diligent daily hosing. Use a strong spray to wash them away. You can also spray them with soapy water. It clogs their breathing aparatus and causes them to drown.
This is an additional comment relating to the milkweed in Temile’s photo. It was a milkweed plant which is the host plant for a number of butterflies, including monarchs. Your advice about using soapy water to rid it of aphids was correct but would also kill off butterfly eggs, caterpillars & chrysalises. A strong stream of water will also wash off eggs, caterpillars and possibly chrysalises. There is hope, however! The natural predator for the aphids is the lady beetle. My experience is that lady beetles usually come along about 2 weeks after the start of an aphid infestation. If the infestation is not overwhelming I usually leave the aphids for the lady beetles. The lady beetles may also lay eggs and the larva will devour the aphids. But if my plants are overwhelmed by aphids or there are caterpillars feeding which need the leaves right away I control by carefully hand-squishing aphids (while they’re still on the stems & leaves) until the lady beetles show up. Yech! But having monarchs around the yard all year is worth it. You do a fabulous job!