SUMMARY: Today’s “Museum Monday” features a visit to the Natural History Museum’s new Sensational Butterflies exhibition, where we watch a time-lapse video of their blue morpho butterflies emerging from chrysalises
The Natural History Museum’s filmmakers recently captured a time-lapse video of the first of their blue morpho butterflies emerging from their chrysalises. These butterflies are now on view in their “Sensational Butterflies” exhibition.
Several species of butterflies are commonly known as “blue morphos” so the specific (species) name often precedes the common name: the Sensational Butterflies exhibition’s blue morphos are peleides blue morphos, Morpho peleides.
Blue morpho butterflies are native to Mexico, Central American and the northern regions of South America. In the wild, as they fly through the thick foliage, their wings provide brief flashes of brilliant blue that are visible from a long distance. This helps them find mates and defend their territories.
The blue morpho lives for only 115 days — and most of their lifetime is spent on “the Three Fs”: feeding, flying and … reproduction. As fuzzy caterpillars, blue morphos are nocturnal and herbivorous; munching their way through the leaves from many tropical plant species by night — or they can be cannibals; munching their way through their siblings!
Adult blue morphos lack chewing mouthparts, but instead, they have a long thin hollow tongue, known as a proboscis, that they use as a drinking straw to suck up juices of fermenting fruits, tree sap, and fluids of decomposing animals, fungi, and wet mud. Blue morphos find their food by tasting the air with their club-tipped antennae, and they also can taste with their legs and feet.
The most spectacular feature of butterflies are their wings — all butterflies have four wings — two forewings and two hindwings. Most butterflies’ wings are covered with microscopic scales that provide the colours and patterns — one colour per scale.
Blue morphos are amongst the largest butterflies in the world, with a wingspan that ranges from 7.5–20 cm (3.0–7.9 inches). The underside of their wings are pigmented with black, brown, tan, orange and white, and with a number of eyespots (ocelli). This colouring provides cryptic camouflage to protect them from sharp-eyed predators, especially at night when the adults roost in the foliage to sleep.
The uppersides of the blue morpho’s wings are vivid metallic blue, edged with black. The blue colouring is not supplied by pigments, but by iridescence, where the scales are arranged in a tetrahedral (diamond) pattern across the wing surface, and where individual scales are comprised of several layers, or lamellae, that reflect incident light repeatedly from each successive layer. This reflected light creates interference that produces wavelengths in the green-blue-violet range (450-550 nm), depending upon the angle at which the wings are viewed (doi:10.1098/rspb.1999.0794).
Blue morphos are threatened by deforestation and by habitat fragmentation. Thanks to their spectacular wings, humans also directly threaten blue morphos by hunting them down for display. But morphos and the other butterflies used in butterfly exhibits throughout the world are raised commercially by indigenous peoples, which gives them an economic incentive to protect their rainforests.
It takes a butterfly or moth only a couple minutes to emerge from its chrysalis, a few more minutes to unfurl its wings by filling them with body fluids, and then several hours for its wings to dry and harden so it can then fly. In today’s “Museum Monday” time-lapse video, we watch two hours of blue morpho emergence distilled down to a mere 47 seconds.
Vukusic P., C. R. Lawrence & R. J. Wootton (1999). Quantified interference and diffraction in single Morpho butterfly scales, Proceedings of the Royal Society B: Biological Sciences, 266 (1427) 1403-1411. doi:10.1098/rspb.1999.0794 [₤]
Read more about a similar phenomenon to blue morpho wing colouring; the physics of blue colouring and iridescence in bird feathers.
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This piece has been edited and reformatted from the original.
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