Zygaena erythrus, common name sluggish burnet, is a species of moth in the family Zygaenidae.
This endangered species can be found only in France and Italy.[1] It prefers dry and rocky areas with sparse vegetation and limestone substrate, but it is also present in heathlands, in nutrient-poor grasslands and in broad verges in oak forests with the host plant Eryngium species, from sea level to over .[2]
Zygaena erythrus has a wingspan of 25–33 mm.[3] These quite large moths show enlarged and confluent red spots on the forewings, surrounded by black in the distal part. Females are little bigger than males, with a yellow golden dusting and less defined markings. The mature larva is rather dark greyish, with two series of dorsal black spots.[4]
This species is very similar to Zygaena purpuralis, but it has red scales in the axillary area of the forewings, up to a third of the length.[2]
Z. erythrus Hbn. (= saportae Boisd.; minos Boisd.) (4a). Larger; antenna longer, with thicker club. The red colour of forewing restncted to 3 streaks, the distal one being wedge-shaped ; moreover, only the basal third of the hindmargin of forewing is red. South France, Italy and Sicily. In ab. irpina Zickert, from the Riviera, the cuneiform spots are confluent. — As magna [Seitz, [1907] ] (4 a) a very large form from the Abruzzi is sold by Staudinger; the posterior cuneiform spot is strongly widened and distally straight-truncate.— Larva dull greenish yellow, witli heavy black dots subdorsally and yellow side-spots (Sapokta); in some districts not distinguishable from the larva of purpuralis. On Eryngium and Thyme (Rouast). Hibernating; pupation at end of May. Imago in June and July; frequently sitting on Thyme and Eryngium.[5]
The life cycle involves only one generation per year.[4] Adults are on wing from the end of June to the beginning or mid August.[6] The hatching occurs between June and July.[4] The larvae feed on Eryngium species,[7] including Eryngium campestre[8] and Eryngium maritimum.[9] Full-grown larvae can be found from June. Pupation occurs within a cocoon usually adherent to the lower surface of the leaves,[4] but also on the ground between lichens, moss and parts of plants.