▁which ▁Po a ▁ann ua , ▁Fest uca ▁ov ina , ▁A ira ▁pra ec ox , ▁and ▁A . ▁ca esp it osa ▁have ▁been ▁specified ▁as ▁e aten ▁by ▁c ater p ill ars ▁in ▁conf in ement . ▁A ▁distinct ▁preference , ▁however , ▁has ▁been ▁shown ▁for ▁mat ▁grass ▁( N ard us ▁strict us ), ▁and ▁it ▁has ▁been ▁suggested ▁that ▁this ▁may ▁be ▁the ▁natural ▁food . ▁The ▁full - g rown ▁c ater p ill ar ▁appears ▁to ▁be ▁und es cribed . ▁The ▁ch rys alis ▁is ▁described ▁by ▁Buck ler ▁as ▁being ▁" l ittle ▁more ▁than ▁three ▁e ighth s ▁of ▁an ▁in ch ▁in ▁length , ▁rather ▁thick ▁in ▁proportion , ▁being ▁less ▁d um py ▁in ▁form ▁than ▁hyper anth tis , ▁but ▁more ▁so ▁than ▁bland ina ▁[ E reb ia ▁c eth i ops ]. ▁The ▁colour ▁of ▁the ▁back ▁of ▁the ▁thor ax ▁and ▁wing ▁cases ▁is ▁a ▁light ▁green , ▁rather ▁gla uc ous ; ▁the ▁ab d omen ▁a ▁pale ▁d rab ▁or ▁dirty ▁wh it ish ; ▁a ▁dark ▁brown ▁d ors al ▁stre ak ▁is ▁consp ic uous ▁on ▁the ▁thor ax , ▁and ▁there ▁is ▁the ▁f ain test ▁possible ▁indic ation ▁of ▁its ▁being ▁continued ▁as ▁a ▁stri pe ▁along ▁the ▁ab d omen . ▁The ▁eye -, ▁tr unk -, ▁anten na -, ▁and ▁leg - cases ▁are ▁marg ined ▁with ▁dark ▁brown , ▁and ▁the ▁wing ▁nerv ures ▁are ▁indicated