Insect I.D. ?

Question: Hi, I found these tiny 1 millimeter size black insects all over my egyptian walking onions this evening. The onions are infested! I squished one bug and it stained my finger purple. I was working in my garden all day, they were not on my onions today till this evening around 7 p.m. They are very tiny, black, and appear to have 6 legs and 2 antenna. I have never seen anything like them before. Can you identify them? Are they harmless, or should I be concerned?

responder: Sarah Vradenburg  Replied June 19, 2023, 11:35 AM EDT
response: I’m not an entomologist but I am a gardener and from what I can see you have a nasty aphid infestation. Aphids are soft-bodied insects that use their piercing, sucking mouth parts to feed on plant sap. They can have up to 15 generations per season because the females do not need males to reproduce. They give birth to live larvae, which look like the adults but are much smaller. I researched other small insects that might look like aphids. The closest would be a flea beetle, a tiny black insect that looks and acts like fleas. However flea beetles only feed on leaves, and because of their hard exoskeleton are not easy to crush. There are several ways to manage aphids, although unless the infestation is completely engulfing the plant, they are not a serioius threat to your plants. The honeydew — secretions from the aphids of the extra sap they ingest but cannot use — makes the leaves sticky. The sooty mold that grows on honeydew is possibly the most worrisome outcome because the dark mold, if allowed to cover entire leaves, can block photosynthesis. Probably the best thing to do is leave them alone because several predators of aphids would be attracted to the insects and eat them. Among those are lady beetles and lacewings. If the predators don’t show up, the next management tool is to give your plants a good spray of water, not strong enough to damage the plant but enough to wash the pests off the plant. Once they are knocked off, they cannot get back to the plant. Be sure to spray the undersides of leaves as well. There are horticultural oils and soaps that are effective against aphids but not toxic to humans and pets. Be sure whatever you use is labeled for aphids. If you choose to use a pesticide (I cannot recommend any because of my affiliation with a publicly funded university), be sure you get one that is effective against aphids. Read the label carefully and follow directions exactly. Be sure to apply the insecticide early in the morning, before bees become active. All insecticides are lethal to bees and other pollinators, beneficial insects that provide countless ecosystem services.  Good luck. https://extension.umn.edu/yard-and-garden-insects/aphids

responder: The Question Asker Replied June 20, 2023, 1:44 AM EDT
response: Thank you for your reply. These are most certainly not aphids or flea beetles. I am quite familiar with flea beetles, they enjoy ravaging my eggplants, these are definitely not flea beetles, they are much smaller than flea beetles, and don't have the jumping back legs. My kale has an infestation of aphids, so I know they are not aphids either. They have no wings.I have never seen these insects before in my gardens, and I have been gardening for well over 60 years in multiple states. Maybe I have been lucky!I did try washing them off with water, exactly as you mention, since that is very effective with aphids. They were back with a vengeance this morning. So far they are only on the onions, hopefully they don't  spread. I will try looking them up online. Thank you for your help. On Mon, Jun 19, 2023, 11:35 AM Ask Extension <<personal data hidden>> wrote:

responder: Sarah Vradenburg  Replied June 20, 2023, 7:31 AM EDT
response: Thank you for correcting me. All I could go on were your pictures, which make it hard to be certain as to the identity of these insects.  My only suggestion is to contact OSU’s  Entomology department. If possible, get a closer shot of the insects or, better, freeze a section of the plant with heavy infestation for an ID.  The OSU Department of Entomology has offices both at the Columbus and Wooster campuses. The phone and email addresses are the same:<personal data hidden> and <personal data hidden>  Sorry I wasn’t more helpful.