GB: Smoky Spurge Hawkmoth, IT: sfinge dell'euforbia sarda.Sphinx dahlii Geyer, , in Hübner, Samml. eur. Schmett., Sphingidae: pl. 36, figs 161--164.
Type locality: Cagliari, Sardenia [Sardinia].
(Taxonomic notes. (i) Subsp. balearica (Rebel, 1926) is probably not tenable. Rebel described it from one specimen from Mallorca, thinking it represented an isolated form; however, most specimens from there cannot be distinguished from those from Corsica and Sardinia. This is in agreement with the findings of Meerman (1993). However, judging by the photo below (from s'Albufera des Grau) the population of H. dahlii on Menorca may contain a trace of H. euphorbiae.
(ii) The findings of Meerman (1993) also indicate that H. dahlii and H. tithymali may share a common ancestry and that H. dahlii evolved in isolation on Corsica and Sardinia. A near identical course of evolution appears to have been followed by the butterfly Papilio hospiton Gene, 1839, which appears to have evolved from an isolated population of the North African P. saharae Oberthür, 1879 (Pittaway et al., 1994).)
Holarctic; western Palaearctic region. Pleistocene refuge: Monocentric -- the Tyrrhenian subsection of the Mediterranean refuge, from whence it appears to have colonized the Balearic Islands.
Wingspan: 65--85mm. Superficially similar to a dark, heavily blotched H. t. tithymali; not very variable. A characteristic feature of this species is the presence of three black dots down each side of the abdomen; all related Hyles species in the area have two.
A species of rocky mountainsides and sand-dunes scattered with shrubs and pine trees.
May/June and August/September, in two broods, with a partial third in warm years.
OVUM: As H. euphorbiae.
LARVA: On hatching, the 3--4mm-long larva is off-white.
Fully grown it is dark grey with a profusion of small, whitish spots; head usually pink and horn orange. Instead of a solid dorso-lateral line, there are two oval, white eye-spots set in a velvet-black patch on each segment. Narrow orange dorsal line; laterally, a red and yellow chequered line runs below the white spiracles. Ventral surface yellowish.
Occurs from June to October.
Hostplants. Herbaceous Euphorbia spp., especially E. paralias, E. myrsinites (Roueast, 1883), E. characias, E. dendroides, E. pityusa, E. pinea and E. terracina.
PUPA: Very similar in appearance to that of H. euphorbiae. Overwinters as a pupa.
Tachinidae: Exorista larvarum (Linnaeus), Masicera sphingivora (Robineau-Desvoidy).
Corsica, Sardinia and the Balearic Island of Mallorca (Rebel, 1934). Considered to be restricted to these islands, although there are occasional reports of its occurrence in Sicily. In October 1975, several larvae of this distinctive species were also found on the Catalan coast, north-east Spain (Masó et al., 1979). Recorded in 1998 from the island of Pianosa off the Tuscan coast, Italy (Dapporto et al., 1999).
Recently reported from Tunisia, where individuals were deliberately released in the mid 1980's (Hundsdörfer, 2004).
Extra-limital range. None.