You may want to check out these links:

http://www.entomology.museums.ualberta.ca/searching_species_details.php?s=908

https://www.ndsu.edu/pubweb/~gefauske/ndmoths/names/8887.htm

http://pnwmoths.biol.wwu.edu/browse/family-noctuidae/subfamily-plusiinae/tribe-argyrogrammatini/trichoplusia/trichoplusia-ni/

Hope this helps,

From wiley there is also "Aphids on the World's Crops" from the same authors as above with a dichotomous key separated by host plant. It has sufficient figures and photographs and is not too complicated. The only drawbacks are that only adults are covered by the key (at least in the first edition) and only aphid genera occurring on crops (but no problem with Brevicoryne).

Can send a pdf if necessary from the first edition.

 thank you Hondelmann, and please send me the pdf. thanks again

Here is a nice link with description: http://www.aphidsonworldsplants.info/d_APHIDS_B.htm#Brevicoryne

Pdf comes later