Zygaena purpuralis


Zygaena purpuralis, the transparent burnet, is a moth of the family Zygaenidae.

Description

Zygaena purpuralis is a medium-sized moth with a wingspan reaching. Usually the forewings show three bright red longitudinal streaks quite variable in shape, with almost transparent greyish-bluish edges. Hindwings are more extensively or almost completely bright red. Head and thorax are black, while the abdomen is dark blue. Larvae are yellow, with some lines of small black spots.

Technical description and variation (Seitz)

Z. purpuralis Brunnich. In this species the hindmargin of the forewing is all black, while the red wedge-spots situated before it may be shaped entirely as in erythrus Hbn. An aberration with light yellow instead of red markings, already recorded by Ochsenheimer, has more lately been named by Ruhl ab. grossmanni. It is said to have been observed as a constant or at least prevalent form in certain very limited localities. In ab. obscura Tutt the entire wings, inclusive of the red colour, is darkened. — sareptensis Stgr.-Reb. is a large, somewhat paler, lighter red form from South Russia. — diaphana Stgr., from Tauria, has thinly scaled, strongly transparent wings, the central wedge-spot being distally strongly widened. — nubigena Led. is also a very thinly scaled form from the high mountains of Europe and Asia, having moreover a very shaggy body, like Zygaena exulans, with which it occurs occasionally together. — In the rather large form smirnovi Christ., from Turkestan, the distal wedge-spot is constricted before its dilated apex. — pluto O. has a black apex to the hindwing and the central streak of forewing is entirely of even width, not in the least being dilated distally; in South Europe, as far north as Austria. — In polygalae Esp. the black interspaces between the red streaks have entirely disappeared the red being so extended that the forewing is only edged with black, differing from Zygaena rubicundus in the hindmargin of forewing being black ; in the South, especially Northern Italy. — In heringi Zell., from North Germany, the antenna is thinner and the central wedge-spot of the somewhat broader forewing extends to near the distal edge. — In ab. interrupta Stgr. the central streak is broadly interrupted and the posterior one often constricted in middle; more in the North of the area, among the name-typical form. — If all three streaks are interrupted, the red is separated into 6 spots, recalling the pattern of other Zygaenas; this form is ab. sexmaculata Burgeff. — Finally, there occur also specimens which have a red abdominal belt: ab. cingulata Burgeff — Larva bluish white or light yellow; a subdorsal row of heavy black dots; head, pectoral legs and stigmata black.
[Image:Buckler W The larvæ of the British butterflies and moths PlateXVIII.jpg|thumb|140px|Figs. Figs. 4a Anthrocera minos var. nubigena = Zygaena purpuralis (Brünnich, 1763) larvae before last moult 4 larvae after last moult]

Biology

Adult moths are on wing from late May until August, depending on location. They fly during the day, especially with warm and sunny weather, feeding on nectar of various flowers. The larvae feed on wild thyme. They occur from August to May and overwinter once or twice.

Distribution

This species can be is found in most of western, central and southern Europe, from Ireland to France through to Asia Minor, the Caucasus, Russia and across the Palearctic to the Altai Mountains.

Habitat

Zygaena purpuralis prefers sunny and grassy slopes, under cliffs and dry grassland.

Subspecies

There are several distinct sub-species:
  • Zygaena purpuralis purpuralis
  • Zygaena purpuralis austronubigena Verity 1946
  • Zygaena purpuralis caledonensis Reiss, 1931
  • Zygaena purpuralis dojranica Burgeff, 1926
  • Zygaena purpuralis fiorii Costantini, 1916
  • Zygaena purpuralis isarca Verity, 1922
  • Zygaena purpuralis lathyri Boisduval, 1828
  • Zygaena purpuralis magnalpina Verity, 1922
  • Zygaena purpuralis mirabilis Verity, 1922
  • Zygaena purpuralis nubigena Lederer, 1853
  • Zygaena purpuralis sabulosa Tremewan, 1976
  • Zygaena purpuralis segontii Tremewan, 1958