My favorite descrption of aphids http://www.pbrc.hawaii.edu/~kunkel/wanted/bodies/92571-rap.html Aphids This site claims 4000 species of aphids http://eap.mcgill.ca/PCA_2.htm Aphids and high nitrogen there are 200 more sites that say the same http://agri.gov.ns.ca/pt/hort/garden96/gg96-29.htm http://www.urbanext.uiuc.edu/bugreview/aphids.html