Monday, 16 November 2009
Butterflies of Bristol 4: The Morphos
The most spectacular and instantly recognizable butterflies we have at Bristol are the Common Morpho butterflies, Morpho peleides. Like the owl butterflies, to which they are fairly closely related, they belong to the Satyrinae, the same nymphalid subfamily that includes the familiar brown butterflies of Europe. Currently the Morpho tribe is divided into three genera:
Antirrhea – 11 species
Caerois – 2 species (leaf mimics)
Morpho – 29 species in several subgenera
Only species of Morpho itself have the distinctive iridescent blue on the upper side of the wings, and not even all of them have it. For example, some are white such as (M.polyphemus) or orange (M. telemachus). Although most Morphos are large butterflies, some are quite small (M, lympharis). Usually the males are much bluer than the females. In our common Morphos at the butterfly house, the females can be distinguished by the dark bases of the wings, giving the effect of a blue stripe as opposed to the all-blue upper side of the males.
The underside of the Morphos is also beautiful, often a rich brown with multiple eye spots, although in Caerois species the underside mimics a leaf. The effect when the butterflies are flying is that when the butterfly settles it almost instantly disappears. However, an intruder will quickly make a male take flight to defend its territory, and will even investigate blue card or aluminium foil.
Unlike the other Satyrinae the larval food plant has switched from monocotyledonous plants to a variety of dicots, especially the pea family Leguminosae. M.peleides has a wide range of foodplants, including Arachis, Mucuna, Pterocarpus, and Macherium, and has even been recorded feeding on Medicago sativa (Alfalfa), although I am not sure if larvae reached maturity on that food plant. The larvae are cannibalistic and covered with irritating hairs. Last year we managed to get some larvae to hatch, but did not manage to rear any.
Incidentally, if you wish to discover recognized foodplants of various butterflies or moths the Natural History Museum website has a public searchable database – look at http://www.nhm.ac.uk/jdsml/research-curation/research/projects/hostplants/index.dsml)
Adult butterflies seldom visit flowers. Like many large butterflies, they drink juices from fruit for the most part, but will also visit animal carcasses or dung. Here at Bristol they have fruit laid out for them. However, we have to be careful the fruit does not ferment in the heat – even butterflies can get drunk!