Orange Tip

Anthocharis cardamines — the orange tip — is one of the most familiar spring butterflies in temperate Europe and a flagship species of cuckoo-flower meadow ecology. The species is widespread across Europe, North Africa, and into central and eastern Asia. Adults are 4-5 cm wingspan with sex-limited coloration: MALES have brilliant orange wing tips against pure white wings (the orange marks are confined to the apical third of each forewing, with the rest of the wing being pure white); FEMALES are entirely white with small dark wing-tip marks but no orange. The sex-limited orange coloration is aposematic warning coloration — males sequester glucosinolate (mustard oil) compounds from larval host plants and become bird-aversive. Females are not similarly defended chemically and rely on cryptic white coloration to evade predators while egg-laying. The underside of both sexes is dramatically different from the upperside — bright green-and-white mottled pattern that perfectly camouflages the resting butterfly against cuckoo flower seed heads. Caterpillars are bright green with white side stripes and feed primarily on cuckoo flower (Cardamine pratensis) and garlic mustard (Alliaria petiolata) — both Brassicaceae plants. The species' caterpillars exhibit notable CANNIBALISM: older instar caterpillars actively consume younger eggs and small first-instar caterpillars they encounter on the same plant, ostensibly to eliminate competition for limited host plant resources. Females respond to the cannibalism risk by detecting (via chemoreceptors on the legs) whether a host plant already has eggs or young caterpillars and avoiding it for oviposition — one of the most-cited examples of insect chemical detection of conspecifics in evolutionary biology curricula. The species is a flagship of British and European spring butterfly conservation.