Photo: Arne Ader
Swallowtail on dandelion
Our largest and most striking and therefore easily recognisable butterfly fluctuates in numbers over the years. The basic wing colour is yellow on both sides, with a network of black veins and bands. The hind wings have a band of blue scales and a coloured eye spot, paler on the underside of the wing. The hind wings also have narrow protruding tails that have given the swallowtail its name. As a rule the male butterflies are smaller; the wing span of the female butterflies can reach up to nearly ten centimetres for larger individuals. In north-western Estonia I saw a pair of male butterflies in action that both patrolled their own territories in order to meet female butterflies. They checked their paths, about four hundred meters long, continuously during the day – so, too, sex can be determined in addition to the smaller size.
Partners find each other by chemical signals; for our sense of smell these are unperceivable. The female butterfly lays eggs on umbellate plants, even in the garden on for instance carrots and dill. When their mission has been filled the imagos or "butterflies“ die.
At the end of June and beginning of July we already see the next generation of swallowtails.