Seasonal polyphenism of larvae of Hypochrysops ignitus (Leach, 1814) (Lepidoptera: Lycaenidae) in the Australian monsoon tropics

Larvae of Hypochrysops ignitus (Leach) are typically brown and feed nocturnally, retreating to an antbyre at the base of the larval food plant during the day. However, in the ‘Top End’ of the Australianmonsoon tropics, larvae of Hypochrysops ignitus erythrina (Waterhouse & Lyell) have two distinctcolour phenotypes: brown and green morphs. Data on their temporal occurrence suggests the larvalmorphs vary seasonally, with brown morphs predominating during the dry season and green morphsduring the wet season. Moreover, green larval morphs do not retreat to the base of the larval food plantduring the day but remain on the foliage. Rainfall, or some correlate of rainfall, is hypothesised to bethe most likely environmental periodicity factor responsible for the seasonal polyphenism.