▁pun ct uration ▁bas ally , ▁prominent ▁anterior ▁corners , ▁a ▁well ▁defined ▁bas al ▁gro ove ▁and ▁two ▁later al ▁not ches . ▁E ly tra ▁and ▁pron ot um ▁are ▁sh iny ▁light ▁brown - or ange . ▁ ▁This ▁species ▁is ▁very ▁similar ▁to ▁S pha er oder ma ▁rub id um ▁( G ra ë ll s , ▁ 1 8 5 3 ). ▁It ▁can ▁be ▁distinguished ▁from ▁the ▁previous ▁one ▁on ▁the ▁basis ▁of ▁a ▁smaller ▁size ▁and ▁quadr ate ▁el y tra , ▁but ▁especially ▁with ▁a ▁close ▁study ▁of ▁the ▁gen ital ia . ▁ ▁Bi ology ▁Ad ult s ▁can ▁be ▁found ▁from ▁May / J une ▁to ▁September . ▁P up ation ▁occurs ▁in ▁the ▁spring ▁and ▁new ▁adult s ▁may ▁be ▁seen ▁from ▁May . ▁Over w inter ing ▁occurs ▁as ▁ 3 rd ▁( final ) ▁inst ar ▁lar va e , ▁sometimes ▁as ▁im ago . ▁ ▁Both ▁lar va e ▁and ▁adult s ▁feed ▁on ▁leaves , ▁especially ▁on ▁various ▁species ▁of ▁Th ist le ▁( Card u us , ▁Carl ina , ▁Cir si um , ▁On op ord um ▁and ▁C yn ara ▁species ), ▁on ▁Common ▁Kn ap we ed ▁( C enta ure a ▁n ig ra ), ▁on ▁Ser rat ula ▁species ▁and ▁on ▁Cir si um ▁ar ven se ▁( in ▁Canada ). ▁ ▁Bibli ography ▁ ▁Anderson , ▁R ., ▁Nash , ▁R . ▁& ▁O ' Con nor , ▁J .