Type locality: Gilroy, Santa Clara County, California, USA.
Wingspan: 98--110mm. A species which can be confused with Sphinx drupiferarum J. E. Smith, 1797, Sphinx asella (Rothschild & Jordan, 1903) or Sphinx vashti Strecker, . Very similar to a black, grey and white version of the european Sphinx ligustri L., 1758. The forewing is dark grey to black with a paler costa and pale area from the base to the wing's centre. The abdominal ribs are black/dark grey and white, as are the hind-wings. There is no sexual dimorphism, although most females are generally larger than males.
A species of montane woodland and mixed chaparral-type vegetation. It is particularly common in areas of oak (Quercus) woodland.
This species starts to fly at dusk and continues until well past midnight; however, females only call between nightfall and midnight. The adults rarely feed and may go their entire life without sustenance, although some have been observed visiting flowers of Oenothera and Rhododendron. A nervous species, which reacts to disturbance by flicking its wings up at a 45 degree angle to the horizontal, placing its antennae forwards parallel to each other, hopping around and, in the male, curving the abdomen around with terminal claspers splayed. By day likes to rest concealed up against a solid surface.
Univoltine in the north, with adults mainly in June and July. In California univoltine or partially bivoltine, with adults in May/June (sometimes late April), and again in August/September as a partial second brood. Even in southern California, upward of 50% of pupa of the first brood may not hatch until the next year; some may even diapause for two or more winters.
OVUM: Glossy apple-green, ovoid to almost spherical, 2.00 x 1.80mm, becoming paler with development: large for a species of Sphinx. Up to 200 eggs are laid by each female on the underside of the leaves of the hostplant, usually singly, although two or three together are not uncommon.
LARVA: Full-fed 70--75mm. Dichromatic: glaucous or apple-green.
On hatching, the pale yellow larva measures approximately 5mm and bears a long dark horn. This is red at the base and strongly bifurcated at the tip. The head is disproportionately large. With feeding, the primary colour changes to pale green.
After the first moult, whitish lateral streaks appear and both body and head become covered with fine pale tubercles. The head is round, with only a hint of yellow cheek stripes. The elongate horn becomes banded below the bifurcated tip, being red at its base, then black or reddish-black, and pale below the tip. It is a very good mimic of the stigma and style on developing berries of Gaultheria shallon.
In the third instar a purple blush appears at the base of each proleg, along the true legs and around the mandibles and ocelli. As the larva grows the horn may lose all trace of black, this being replaced by red.
In the second and third instar two colour forms become apparent -- bluish grey-green and pale apple-green, both tending to whitish dorsally. The whole larva is noticeably cylindrical, being of even thickness from head to horn.
With the fourth instar the purple blush on the head and legs becomes more pronounced, with the head becoming more oval and of a paler green than the body. The yellow cheek stripes are now very pronounced. The horn is long and straight, with a pale base, reddish lower third, creamy upper two-thirds and a dark, less bifurcated tip. The pale oblique side stripes are pale cream and not very pronounced.
In the final instar the basic body colour can be either glaucous or apple-green, slightly paler dorsally, and without the earlier body tubercles, which fade away. The oblique side stripes are now pure white, tending to yellow caudad in the apple-green form. These are edged frontad with purple, a spot of the same colour being also located at the base of each proleg. The hindmost oblique stripe extends up to but not onto the horn, which is sky blue (purple at first). The true legs are ochreous yellow (often tinged purple), as is the head. The latter is tinged with brown on the face, and the cheeks bear a purple-brown band caudad of the now indistinct yellow cheek stripes. The spiracles are pale orange and the anal flap is edged with yellow.
A unique feature of this larva is a shield on the first thoracic segment, which is of the same colour as the body and which forms a tight-fitting hood over the vertex of the head. This hides a pair of glossy black spots on top of the head, which are revealed if the animal is disturbed. The eye-like appearance of these is enhanced by pale purple intersegmental cuticle behind the head. The full-grown larvae also bite.
Young larvae rest stretched out beneath the midrib of a leaf, but as they grow they assume a typical upside-down sphinx-like attitude, clinging to a petiole or stem by their anal and last two prolegs, with the thoracic segments hunched. Larger larvae often rest on or under a stem some way back from their feeding area in amongst a cluster of leaves, and climb up to a growing shoot at night. On Gaultheria shallon the larvae are extraordinarily well camouflaged, often resting deep down amongst the tangle of twigs and leaves.
Hostplants. In California mainly on Arctostaphylos manzanita and Arbutus menziesii; however, larvae are occasionally found on Cercocarpus betuloides and Prunus ilicifolia. In captivity will feed freely on Gaultheria shallon, indicating that this plant is probably a natural host in the Pacific North-west (USA) and British Columbia (Canada). Attempts to rear Sphinx perelegans on Malus pumila, Prunus cerasifera, Ligustrum ovalifolium and Syringa vulgaris failed. Some larvae started feeding on these, but only got as far as the second or third instar. Reports of this species feeding on various species in these genera need to be verified due to possible confusion of the larva with that of Sphinx drupiferarum. Other reports of this species feeding on Symphoricarpos are erroneous and are due to confusion with Sphinx vashti.
Sphinx perelegans thrives in captivity on the european Arbutus unedo and, under some instances, some larvae can also be persuaded to take Salix or some species of Prunus. Attempts to use Rhododendron ponticum were a total failure, with larvae being poisoned after the first few bites. This species will probably take Vaccinium in captivity.
PUPA: 45--47mm. Pale mahogany brown. Tongue-case short (6.5mm), free, lying parallel to the ventral surface. Cremaster short, dorso-ventrally flattened, broadly triangular, with two terminal spines. Very active prior to emergence. Pupation normally takes place in soft, loamy soil up to 10cm deep, in a hollowed-out chamber lined with a few strands of silk. The overwintering stage.
A species of western North America, ranging mainly from northern Baja California (Mexico) north through California (USA), Oregon (USA), Washington State (USA) to southern British Columbia (Canada). It has been found farther east in small numbers, with records from Idaho, Nevada, Utah, Colorado, Arizona, New Mexico, and west Texas.
Extra-limital range. None.
Brown, J. W. & Donahue, J. P. (1989). The Sphingidae (Lepidoptera) of Baja California, Mexico. Journal of the Lepidopterists' Society 43(3): 184--209.
Essig, E. O. (1926). Insects of western North America. New York, USA: Macmillan Co.
Hodges, R. W. (1971). Sphingoidea, Hawkmoths. In: Dominick, R. B. et al. [Eds]. The moths of America north of Mexico (including Greenland) 21. London, UK: E. W. Classey.
Holland, W. J. (1968). The Moth Book (2nd edn). New York, USA: Dover Publications Inc.