SPHINX MAURORUM (Jordan, 1931)

GB: Southern Pine Hawkmoth; Spanish Pine Hawkmoth, F: Sphinx Mauresque; Sphinx des Maures

Hyloicus pinastri maurorum Jordan, 1931, Novit. zool. 36: 243.

Type locality: Hammam R'Irha, Algeria.

(Taxonomic notes. (i) Eitschberger et al. (1989) raised Sphinx pinastri maurorum to specific rank but gave no reasons for doing so. However, there are pronounced and consistent differences between the male genitalia of both species, as well as between the eggs, larvae and pupae. Although Sphinx maurorum and Sphinx pinastri Linnaeus, 1758 interbreed quite freely in central and eastern France, and have formed natural intermediate populations, this hybrid zone is narrow and stable. It is probable that Sphinx maurorum evolved for some time in isolation in North Africa and the Iberian Peninsula and that only since the end of the last ice age has it come into contact again with Sphinx pinastri, which appears to have retreated to south-east Europe during that ice age. Kernbach (1958) reached similar conclusions.

(ii) 'Subsp.' massiliensis is synonymized with Sphinx maurorum for the same reasons as given for the subspecies of Sphinx pinastri described by Jordan, namely, that it is a hybrid race between Sphinx maurorum and Sphinx pinastri, but one which is closer to the former.)


BIOGEOGRAPHICAL AFFILIATION

Holarctic; western Palaearctic region. Pleistocene refuge: Monocentric -- Atlantomediterranean/Mauritanian subsections of the Mediterranean refuge.


ADULT DESCRIPTION AND VARIATION

Pale male of Sphinx maurorum, Les Pias, Algeria.

Wingspan: first generation 70--80mm; second generation smaller. First generation generally indistinguishable superficially from central European examples of Sphinx pinastri. Second generation often very pale.


Male Sphinx maurorum, Catalonia, Spain. Photo: © Tony Pittaway Male Sphinx maurorum, Pyrenees, Spain. Photo: © Frank Deschandol.

In the male genitalia, unlike those of Sphinx pinastri, both branches of the sacculus are short, the upper one flat, pronged, triangularly elongated and pointed (see below left). However, as in Sphinx pinastri, the apical apophysis and aedeagus are long (see below right).


Male genitalia of Sphinx maurorum and Sphinx pinastri.

ADULT BIOLOGY

Apart from its preference for dry pine forests, nothing is known of the adult biology of this subspecies.


Typical habitat of Sphinx maurorum, Catalonia, Spain. Photo: © Ben Trott. Adult Sphinx maurorum feeding from soapwort (Saponaria), Catalonia, Spain. Photo: © Ben Trott.

FLIGHT TIME

Univoltine or Bivoltine. In some years May/June and August as two broods; however, in most years there is only a single brood, with adults mainly on the wing during the second half of July and early August (Cifuentes, 1997; Pittaway, pers. obs.). Odd individuals can sometimes be met with as early as early April or as late as mid September, but this is rare.


EARLY STAGES

OVUM: Large, oval and slightly dorso-ventrally flattened (2.1 x 1.75mm); shiny pale yellow at first, but developing a reddish-brown blush at one end after a few days.


Ovum of Sphinx maurorum, Valencia, Spain. Photo: © Tony Pittaway

Each female lays approximately 100 of these huge, thin-walled and delicate eggs, usually singly in close proximity to each other, on the needles or young twigs of isolated or small groups of trees. Development takes about 10 days. Just before hatching the dark head of the larva becomes visible through the now transparent shell.

LARVA: Full-fed 75--80mm.


Early first instar larva of Sphinx maurorum, Casserouge, France. Photo: © Jean Haxaire. Late first instar larva of Sphinx maurorum, Casserouge, France. Photo: © Jean Haxaire. Second instar larva of Sphinx maurorum, Catalonia, Spain. Photo: © Ben Trott. Third instar larva of Sphinx maurorum, Catalonia, Spain. Photo: © Ben Trott. Fourth instar larva of Sphinx maurorum, Catalonia, Spain. Photo: © Ben Trott.

On hatching, the larva consumes part of its eggshell. At this stage it is approximately 6mm long and dull pale yellow, although the prolegs, true legs and horn are black, with the latter having a forked tip. The disproportionately large head is mahogany-brown with a pair of near-vertical black streaks on the upper part of the face. With feeding, the body colour changes to olive-green and, after the first moult, six longitudinal creamy-yellow lines appear (three per side), with the ventro-lateral being the broadest. During this stage, the larva sits lengthways on a pine needle and nibbles holes in the surface. Young needles on growing shoots are avoided as they ooze too much sticky resin, which may trap the young larva.

Still disproportionately large, the head is now a paler green than the pine-needle green body and bears a black '/\' mark on the face, which may be edged with white on the outside. The horn and true legs are black, and there is a dot of the same colour on each proleg. Apart from the longitudinal lines becoming broader and more yellowish, and the horn and legs acquiring a wine-red tint, little change takes place to its appearance over the next two moults. It now starts to consume whole needles, which are grasped between the true legs and eaten from the tip down.

Towards the end of the fourth instar the green areas of the body may become speckled with white and the black streaks on the face may be replaced with reddish-brown. The dark, transverse divisions of each segment, so characteristic in the final instar, also start to appear.

Immediately after the final moult the larva resembles that of Sphinx pinastri, in being basically green with a brown dorsal band, dark transverse divisions to each segment and broken longitudinal white lines. However, as the cuticle hardens, all trace of green is lost. Fully grown, the larva is rather slim and of equal thickness throughout its length. The thin, slightly curved and granular horn is black. The large head is ochreous yellow with a brownish blush on the face, particularly in the lower area. The black lines of the face, so evident in the early stages, disappear in most individuals, to be replaced by black cheeks. The intersegmental cuticle behind the head is black. This is prominently exposed if the larva is 'attacked', probably in imitation of the band of poisonous black hairs found in the pine-feeding lasiocampid Dendrolimus pini (Linnaeus, 1758). (This behaviour can also be found in the Californian Sphinx perelegans Henry Edwards, 1874, which has violet intersegmental cuticle and a pair of eye-like black spots on top of the head.) The shield on the first abdominal segment sports longitudinal yellow and black bands, and the spiracles are orange.


Full-grown larva of Sphinx maurorum, southern France. Photo: © Jean Haxaire Full-grown larva of Sphinx maurorum, Catalonia, Spain. Photo: © Ben Trott.

So far, this description is similar to that of Sphinx pinastri; however, in Sphinx maurorum the basic body colour is medium grey. Dorsally, this is suffused with brown so that the brown dorsal band is no longer distinct. The body segments are distinctly separated one from another, and each segment in turn is subdivided by sunken, dark, transverse lines so that the entire body appears to consist of numerous narrow rings joined together. As in Sphinx pinastri, the longitudinal white lines are now fragmented into streaks. On the posterior edge of each segment, and between the white 'lines', there appears a rectangular black dot. The body is smooth, but not glossy, unlike the head, underside, legs and shield. However, an oily appearance extends over the entire body as the larva darkens prior to pupation.

Throughout its entire life the larva is very well camouflaged. Although young larvae rest along pine needles, the fully grown larvae prefers to snuggle down at the base of those needles along the twig, with which it blends.

Major Hostplants. Pinus spp., especially Pinus halepensis and Pinus pinaster.

Minor Hostplants. Cedrus.

PUPA: As Sphinx pinastri, but with a slightly shorter projecting tongue case. May diapause two or three years, especially when the spring is cold or late. The overwintering stage.


Early stage pupa of Sphinx maurorum, Casserouge, France. Photo: © Jean Haxaire. Hardened-off pupa of Sphinx maurorum, Casserouge, France. Photo: © Jean Haxaire.

PARASITOIDS

Tachinidae: Drino (Zygobothria) atropivora (Robineau-Desvoidy).


Tachinid fly (Drino (Zygobothria) atropivora) reared from the final instar larva of Acherontia lachesis lachesis, Singapore. Photo: © Leong Tzi Ming.

DISTRIBUTION

The Iberian Peninsula, including both the north and south slopes of the Pyrenees; southern and central France as far north as Corrèze (Haxaire, 2009), and the Atlas and Rif Mountains of North Africa (Rungs, 1981). The population on Corsica (Bretherton & de Worms, 1963) also appears to be Sphinx maurorum (Haxaire, 2009). Its discontinuous distribution is due to a preference for dry pine forests at higher altitudes (to 2000m).

The situation in France appears to have changed over the last 20 years, with this species displacing Sphinx pinastri from many southern areas. True Sphinx pinastri can now only be found north of Chateauroux, in the Alps and Var. Populations around Toulon are clearly intermediate hybrids (J. Haxaire & J.-M. Bompar, pers. comm.).

Extra-limital range. None.


Global distribution of Sphinx maurorum. Map: © Tony Pittaway.

OTHER SUBSPECIES

None.


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