Butterfly of the Month - September 2023
Indigo Flash (Rapala varuna) belongs to the large family of Lycaenidae. This family covers those small butterflies commonly grouped as Blues, Coppers and Hairstreaks. As the common name suggests, a very intense dark blue on the upper wing side of the male is the dominant feature while the upper wing of the female is much paler and often suffused with a light mauve. The underside of Rapala varuna’s wings shows a light brown, sometimes with a hint of purple. A darker brown is exhibited in the band running across front and hindwing. A roundish black section protrudes from the posterior corner of the hindwing as does a little black tail which features a white tip. A small black spot surrounded by orange can be seen to the side of the lobe at the outer wing margin. Sex scales on the upper side of the male’s hindwing are usually difficult to see as they tend to be covered by the forewing. Please note that hair like scales match up with this location on the underside of the forewing.
The wingspan of this butterfly doesn’t exceed 29mm for the male and 28mm for the female.
The life cycle of the Indigo Flash starts with eggs which are less than half a millimetre in diameter. They show an intricate surface pattern with ridges and depressions. Eggs are laid singly with preferred locations being flower buds.They together with flowers make up the favourite food and may be supplemented by young shoots. The larvae can reach a length of 17mm. They are yellow green. However, the yellow may turn to an almost light rusty colour as the pre-pupal stage in our image shows. The larvae feature four pointed protrusions per segment, all with short setae (hair) at their tips. The pupa is brown turning darker with development and is covered in setae. Ants rarely attend the immature stages of this butterfly.
Among the larval host plants are Soap Tree (Alphitonia excelsa), Hairy Birds-eye (Alectryon tomentosus), Tuckeroo (Cupianopsis anacardioides), Foambark (Jagera pseudorhus).
Images: CM – Cliff Meyer; DM – Deborah Metters; PS – Peter Samson; SA – Sylvia Alexander; TB – Todd Burrows