Wednesday, July 23, 2014

Coral Hairstreak (Satyrium titus)

Encountered any time from mid-May until late August, the Coral Hairstreak (Satyrium titus) is easily identified by the row of coral colored spots on the underside of its hind wings and lack of a tail.

Coral Hairstreak caterpillars feed on Wild Cherry and Chokecherry, and although these trees were present in the area the males were found perching on Common Milkweeds in a high and fry neglected field at a significant distance from the larval host plants. They were very agressive in defending their turf, attacking not only others of their own species but leaving their perches to pursue skippers that were just passing by.

This has been a good year to find Acadian Hairstreaks (Satyrium acadicum). The larvae feed on various willows, so not surprisingly the butterflies were found perching at about waist height on the low vegetation bordering a local marsh that supports Peachleaf, Sageleaf and Pussy Willows. The adults fly from June through to August.

When resting many Satyrium spp have a habit of constantly moving their hind wings up and down. It's thought that the prominent – often orange with contrasting blue or black capped – spots, and tails, are are form of deception meant to resemble eyes and antennae and dupe a predator into aiming at this non-vital area of the insect's body. The butterflies draw even more attention to the false head by the motion of their wings and as the next image illustrates, this is a plausible theory and probably correct.

Surprise, surprise ... an encounter with Canada's only carnivorous butterfly, the Harvester (Feniseca tarquinius). This subtly beautiful little lep is not very common and it's been two years since the last local sighting. It's the caterpillars that are the carnivores, feeding on Woolly Aphids or scale insects that in turn feed on Alder, Hawthorn or Ash, all of which were plentiful where the butterfly was photographed. The adults don't visit flowers but will "puddle" at moist soil or imbibe aphid "honeydew". Expect to see this butterfly in damp woodlands near marshy areas from mid-June to mid-August.

EDIT ... as of August 06, although getting a bit rough around the edges, the Coral Hairstreaks are still flying. This one was encountered west of Tweed at a marsh bordering the trans-Canada Trail.