The Great Eggfly Hypolimnas bolina bolina (Linnaeus 1758) A female f-nerina Great Eggfly (Hypolimnas bolina bolina) feeding on a flower

Scientific Data and Other Important Notes Family : Nymphalidae SubFamily : Nymphalinae Genus : Hypolimnas (Hubner 1819) Common Name : The Great Eggfly Wingspan: 65-70 mm   Host Plant:  Asystasia gangetica,  Ipomaea battatas and other species of Acanthaceae Similar species: Jacintha Eggfly Forms: There are four principal known female forms - f-nerina, f-alcmene, f-perimele and  f-proserphina Status in Singapore: Seasonally common.   Habitat : Usually found in urban parks and open areas in forest edges.

Description :  The Great Eggfly occurs in Malaysia and Singapore in two subspecies, the other subspecies being the Jacintha Eggfly (H. bolina jacintha).  Of particular interest is the polymorphism in the females of both subspecies.  The males of the Great Eggfly differ from the Jacintha Eggfly in that the postdiscal white dots are absent, whilst in the female, the submarginal white fasciae are much reduced, taking a "V"-shaped form and separated.  The female occurs in four principal forms and two subsidiary forms which are connected by a variable spectrum of intermediates, such that it is difficult to find two exactly matching examples.  

Habitat & habits : This species is seasonally common in Singapore, and is the resident species near the coastal areas of Sg Buloh Wetland Reserve and Pulau Ubin.  Like the Jacintha Eggfly, the males are jealously territorial, and often return to a favourite perch repeatedly even after being disturbed.  Whenever another butterfly flies by, the male will take off from its perch and "attack" the intruder.  The species is strong on the wing, and is known to take part in migratory flights.     

Other Observations :   Males and females are equally common, particularly on Pulau Ubin, depending on seasonal fluctuations. 

Early Stages :  The caterpillar is dark brown, with bright orange spikes and an orange head with two black "horns".  The caterpillars feed voraciously, and can defoliate the host plant in a few days.  Where the Sweet Potato (Ipomaea battatas) plant is cultivated, occasional infestations of the caterpillar cause it to be considered a pest to the farming of this crop. 
  FURTHER READING AND WEB RESOURCES

• Wahlberg, Niklas : "Classification of Nymphalidae by DNA" - voucher specimen of H. bolina from Australia
• Chew, Peter : "Brisbane Spiders & Insects Homepage" - interesting information about H. bolina called the Common Eggfly in Australia
• Mohn, David L : Specimens of H. bolina from Hong Kong.