▁produce ▁w ax ▁from ▁special ▁g lands ▁on ▁the ▁ab dom inal ▁ter ga ▁and ▁other ▁parts ▁of ▁the ▁body . ▁These ▁are ▁hydro ph ob ic ▁and ▁help ▁conce al ▁the ▁insect s . ▁Ad ult ▁females ▁of ▁many ▁families ▁also ▁produce ▁w ax ▁which ▁may ▁be ▁used ▁to ▁protect ▁eggs . ▁ ▁Ful gor oid ▁n ym ph s ▁also ▁possess ▁a ▁bi ological ▁g ear ▁mechanism ▁at ▁the ▁base ▁of ▁the ▁h ind ▁legs , ▁which ▁keeps ▁the ▁legs ▁in ▁synchron y ▁when ▁the ▁insect s ▁jump . ▁ ▁The ▁g ears , ▁not ▁present ▁in ▁the ▁adult s , ▁were ▁known ▁for ▁dec ades ▁before ▁the ▁recent ▁description ▁of ▁their ▁function . ▁ ▁Plan th opp ers ▁are ▁often ▁vectors ▁for ▁plant ▁dise ases , ▁especially ▁ph y top las mas ▁which ▁live ▁in ▁the ▁ph lo em ▁of ▁plants ▁and ▁can ▁be ▁transm itted ▁by ▁plan th opp ers ▁when ▁feed ing . ▁ ▁A ▁number ▁of ▁ext inct ▁members ▁of ▁Ful g oro idea ▁are ▁known ▁from ▁the ▁foss il ▁record , ▁such ▁as ▁the ▁L ut et ian - age ▁Emil iana ▁from ▁the ▁Green ▁River ▁Form ation ▁( E oc ene ) ▁in ▁Colorado . ▁ ▁Classification ▁As ▁mentioned ▁under ▁Auch en or rh yn cha , ▁some ▁authors ▁use ▁the ▁name ▁Arch ae or rh yn cha ▁as ▁a ▁replacement ▁for ▁the ▁Ful gor om or pha . ▁ ▁The ▁ext ant ▁families ▁of ▁Ful g oro idea ▁are : ▁ ▁A can al