I have seen this on my own ginseng. If you do a yahoo search under \"Plant Lice on Ginseng with Andy Hankins\" there will be a 63 page pdf. On page 34 the picture looks like the same thing to me. Also, in Scotts book page 130, look for jumping plant lice. Hope this helps. Sang.ocd
I agree that it does look a little like aphids. But, normally with aphids it is obvious they are insects on close inspection. Assuming they have been closely examined and did not appear to be clearly aphids...well. Of course, I am not familiar with the plant 'lice' you are talking about, so I could be all together wrong on this one.
They mostly hatch out on Hackberry leaves before they head to find a host plant to feed on.
If you've ever seen little nodes like these below on the bottom side of certain tree leaves then they are what caused it.
They cover their self in their own fuzzy secretion and camouflage themself on the seed stem. You never know they are there until you touch close to them and you'll then see a bit of the fuzz move and sometimes jump off and fly away.
They will flat out hijack a seed crop. I virtually didn't have but a handful that produced last year. On my plants, along the stem they would create lesions to suck the juice being pumped to the seed pods. In some cases they girdled it completely and it fell off.
Pretty much any insecticide will work on these devils. Sevin, Diazinon, Imidicloprid or, if going the organic route insecticidal soaps and other such products listed for aphids will work. Late May and into June is the time to watch out for them in my area or when the flower sacks begin to swell. When you see the first sign of one on a plant you had better get busy. You'll come back in a couple days and 90% of your plants will be hit.
Thanks for all of your input here. I agree with Hill that this is a situation that can build up real fast in a planting. Hill and I talked through the season this past year about how to deal with this problem, if it is an insect, so I'll pass on my thoughts to all of you if you decide to use an insecticide to help with the matter. If you don't spray at the proper time you could damage your pollinating insects. We've seen Sweat Bees and the little shiny green wasp on the flower buds pollinating them so be careful with your timing so as not to kill the beneficial insects. For me it is a little different because I have the early blooming and ripening strain mixed in with later ripening plants and I don't want to harm my little helpers if I can keep from it. Let's follow this as the season goes along.
I have seen this in eastern Ohio on a lot of wild plants, so I guess this has made it this far north already. Does anyone know if pyrethrum is safe for seng? Would it kill these little boogers? It should be considered organic since it is made from the flowers of Chrysanthemum.