Monday, October 7, 2013

The missing comma ........... a butterfly with two different life histories

This comma butterfly has been flitting around our garden all day but only once landed on the ripe plums on the bird table - the butterfly magnet that's now attracting several red admirals. Then it disappeared, or so it seemed ...........

.... until I eventually found it under the bird table, drinking the fermenting plum juice that was oozing through the mesh trays - you can see its tongue drinking from the dark patch of sweet juice here .

If you take a look at the top image and this one (another comma sunbathing on the beech hedge a couple of days ago), it's clear that there are distinct differences compared with .....

....... this specimen which was photographed in summer. It's the form of comma known as hutchinsonii, which is much paler and has wings that are not so deeply scalloped around the edges as the dark-winged form.

These are the  two forms of comma which have different life histories. Darker, deeply scalloped and paler, less scalloped forms are produced in the first generation to hatch, in early summer, but only the pale form (form hutchinsonii) then lays eggs in summer - the dark form just feeds then eventually hibernates. Dark-winged progeny from eggs laid by the pale form emerge as a second brood in late August and these will hibernate alongside the much older, non-breeding, dark-winged first brood individuals.

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