Butterflies (Lepidoptera)

Butterflies are arguably the best known and most colourful of our local insects. They are really only well known in their adult, winged form but to achieve this state they have to pass through a series of immature stages. Butterflies lay inconspicuous eggs on or nearby their larval foodplant. The eggs hatch and release the larval stage which is commonly referred to as a caterpillar. Caterpillars have only one function in life and that is to build up their body weight and to this end they spend their entire time eating leaves. Eventually they go into a resting or dormant phase known as pupation. At this time they turn into a chrysalis or cocoon which is often hidden away to protect it from predators and adverse weather. Eventually very complex changes occur within the chrysalis and an adult appears from within it having broken through the case of the chrysalis. On emerging the wings of the adult are folded and shrunken and it takes an hour or so as fluid is pumped through the veins of the wing before the adult is able to fly away.

In reality, butterflies are an artificial group that also includes moths. As a general rule, butterflies are active by day, have clubbed ends to their antennae (feelers) and fold their wings vertically above their backs at rest. These distinctions are not absolute and there are exceptions. For instance, some skipper butterflies cannot fold their wings vertically and most butterflies hold their wings out horizontally to bask in the sun. Similarly some moths fly by day and have clubbed antennae a good example being the burnet moths.

Twenty-six species of butterflies are considered to be permanent residents in the Plymouth area. None of them are national rarities although one or two such as the Green Hairstreak, Callophrys rubi, and the Dingy Skipper, Errynis tages, must be considered as locally endangered as their habitats fall under threat. A number of other species are occasionally recorded from the City such as the Grayling, Hipparche semele, and the migratory Monarch butterfly, Danaus plexihippus. Recent evidence would suggest that the White-letter Hairstreak, Strymonidia w-album, Brown Argus, Aricia agestis, and the Small Blue, Cupido minimus, may also occur in the City but no adults have been observed as yet.

The individual species accounts are straightforward. A double click on the thumbnails will blow them up into 15x12 cm images. Be aware that the bar chart associated with the 'When to look for it' heading on the individual species page applies to adult specimens only. The distribution maps show the outline of the City's boundaries superimposed with a five kilometre grid. Note that the grid in the map below is a ten kilometre grid. Records, in the species accounts, are represented by a red circle superimposed on the one kilometre grid from which the species has been recorded.