LAOTHOE AUSTAUTI (Staudinger, 1877)

GB: Maghreb Poplar Hawkmoth, D: Riesenpappelschwärmer

Smerinthus austanti Staudinger, 1877, Petites Nouv. ent. 2: 190.

Type locality: Nemours [Ghazaouet], Algeria.

(Taxonomic notes. (i) Laothoe austauti is almost certainly a good biospecies closely related to Laothoe populi; this is in agreement with the findings of Eitschberger et al. (1989). F1 hybrids between Laothoe austauti and Laothoe populi populi (either way) are intermediate between both species. These hybrids, when back-crossed with either parent species, produce F2 hybrids in which the genitalia are slightly to severely atrophied -- a phenomenon which was noted earlier by Denso (1913b) -- and of which the pupae rarely overwinter and tend to produce a preponderance of males. Furthermore the adult male genitalia and early stages are distinct from those of Laothoe populi.

(ii) Originally described by Staudinger in 1877 as Smerinthus austanti, where he states that the moth was named after 'J.-L. Austant'. Unfortunately, the latters name was actually 'J.-L. Austaut'. This error was subsequently 'corrected' by Staudinger, with this species being known in publications as Laothoe austauti since about 1880. Due to long-term, consistent usage, under Article 33.3.1 of the ICZN Laothoe austauti can be regarded as the correct spelling.)


BIOGEOGRAPHICAL AFFILIATION

Holarctic; western Palaearctic region. Pleistocene refuge: Monocentric -- Mauritanian subsection of the Mediterranean refuge. Part of the present-day relict Mauritanian faunal element centred on the Middle and High Atlas Mountains (see de Lattin, 1967).


ADULT DESCRIPTION AND VARIATION

Female Laothoe austauti, Meridje, Algeria. Photo: © Tony Pittaway, BMNH.

Wingspan: 95--120mm. Considerably larger and generally paler than Laothoe populi populi, although manifesting all the colour forms of that species, with a dark brown form (f. brunnea Huard) being quite common. In the male, the antenna more triangular in cross-section and compressed than in Laothoe populi populi; apical lobes of the sacculus more triangular (pointed); uncus obviously broader.


Female Laothoe austauti (upperside), Dadés Gorge, Morocco. Photo: © Frank Deschandol. Female Laothoe austauti (underside), Dadés Gorge, Morocco. Photo: © Frank Deschandol.

ADULT BIOLOGY

Frequents poplar- and willow-lined streams and rivers, even in desert areas; also fields, plantations and oases.


Typical desert habitat of Laothoe austauti, Dadés Gorge, Morocco. Photo: © Tony Pittaway.

FLIGHT-TIME

Usually bivoltine; April/May and July/August. In some years there is a third brood.


EARLY STAGES

OVUM: Identical to that of Laothoe populi populi, but slightly larger.


Egg of Laothoe austauti, Dadés Gorge, Morocco. Photo: © Frank Deschandol.

LARVA: Full-fed 90mm. Dimorphic: green and bluish white.


First instar larva of Laothoe austauti, Dadés Gorge, Morocco. Photo: Frank Deschandol. Second instar larva of Laothoe austauti, Dadés Gorge, Morocco. Photo: Frank Deschandol.

The newly emerged larva is about 6mm long and pale green. The rough body is covered with fine yellow tubercles and yellow spots, upon which there are seven yellow, oblique lateral stripes and a noticeable dorso-lateral line of the same colour. The head is rounded and the long horn pale orange.


Third instar larva of Laothoe austauti, Dadés Gorge, Morocco. Photo: Frank Deschandol. Fourth instar larva of Laothoe austauti, Dadés Gorge, Morocco. Photo: Frank Deschandol. Fourth instar larva of Laothoe austauti, Dadés Gorge, Morocco. Photo: Frank Deschandol. Final instar larva of Laothoe austauti, Morocco. Photo: Frank Deschandol. Final instar larva of Laothoe austauti, Dadés Gorge, Morocco. Photo: Frank Deschandol.

In most individuals, this colour scheme and pattern persists into the fourth instar, with the horn becoming stouter and the head more pointed. The first and last oblique side-stripes become much more prominent than the rest. The yellow cheek-stripes become more pronounced and the dorso-lateral line disappears in the second instar. In the bluish white form these markings are paler, almost white.

When full-grown, much larger than Laothoe populi populi, and very stout. The area within the now orange, inverted V-mark on the forehead is glossy and blue in colour. Compared with Laothoe populi populi, the horn is mainly orange but dorsally blue-green, more glossy, longer and cylindrical in cross-section.

Found from April until October, usually high in a tree, rarely near ground level.

Hostplants. Species of Populus and Salix, including most of the introduced cultivars.

PUPA: 45--55mm. More reddish than Laothoe populi populi but in shape similar to Smerinthus ocellatus; in colour and texture very similar to M. tiliae. Pupation takes place up to 10cm deep in the soil. The overwintering stage.


Pupa of Laothoe austauti, Dadés Gorge, Morocco. Photo: Frank Deschandol.

PARASITOIDS

Encyrtidae: Ooencyrtus telenomicida (Vassiliev).


DISTRIBUTION

The Atlas Mountains and coastal plains of Morocco (Bleton, 1938), northern Algeria and Tunisia, and the neighbouring desert areas (Rungs, 1981; Pittaway, 1983b).

Extra-limital range. None.




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