EPOW - Ecology Picture of the Week

Plight of the Great Eggfly

Great Eggfly (Hypolimnas bolina), Family Nymphalidae
Howard Springs, Northern Territory, Australia

Explanation:  Here perches a widespread butterfly found from Madagascar, to south Asia, to southeast Asia, to Australia and islands of Oceania:  the Great Eggfly, also called the Common Eggfly.  I found this specimen in Howard Springs in the "Top End" of Northern Territory, Australia.  With such a widespread distribution, what would be the concern?

Apparently, in the South Pacific, there is the invasive bacterium Wolbachia, that has oddly specialized in the decimation of male Great Eggfly butterflies and males of two other butterfly species.  It it not unusual situation, though, as bacteria that kill male hosts during embryogenesis occurs across a wide range of other insect species.  

Luckily, Great Eggflies might be becoming more resistant to the attack due to the emergence of a suppressor gene.  

Highly territorial, Great Eggflies seem to often engage in lachryphagy, or the feeding on sweat of people.  This is an interesting behavior in butterflies that we explored with a different species in a previous EPOW episode.  

Information:
     Charlat, S., E.A. Hornett, E.A. Dyson, P.P.Y. Ho, N. T. Loc, M. Schilthuizen, N. Davies, G.K. Roderick, and G.D.D. Hurst.  2005.  Prevalence and penetrance variation of male-killing Wolbachia across Indo-Pacific populations of the butterfly Hypolimnas bolina.  Molecular Ecology 14(11):3525-3530.
     Dyson, E.A., M.K. Kamath, and G.D.D. Hurst.  2002.  Wolbachia infection associated with all-female broods in Hypolimnas bolina (Lepidoptera: Nymphalidae): evidence for horizontal transmission of a butterfly male killer.  Heredity 88:166-171.