SPHINX LIGUSTRI. Si 5 



of the ventral surface of the segments in the larva of this species 

 is reproduced by Packard (Textbook of Entomology, p. 212) and a 

 brief summary of the musculature is given (loc. cit., p. 213). Re'aumur 

 gave an excellent description and figure of the larva in 1736 

 ( Memoires, ii., pp. 253-256). Newman describes the larva (Ent., hi., 



P- 34). 



Larval moult. — The whole body is wrinkled and contracted 



in length, and there are occasional powerful contractions and twitch- 

 ings of its entire body ; the skin becomes dry and shrivelled, and 

 is gradually separated from the new and very delicate one of the 

 next instar beneath. After several powerful efforts of the larva, the 

 old skin cracks along the middle of the dorsal surface of the 

 mesothoracic segment, and, by repeated efforts, the fissure is extended 

 into the 1st and 3rd thoracic segments whilst the covering of the 

 head divides along the vertex and on each side of the clypeus. 

 The larva then gradually presses itself through the opening, with- 

 drawing first its head and thoracic legs, and subsequently the 

 remainder of its body, slipping off the skin from behind like the 

 finger of a glove. This process, after the skin has once been 

 ruptured, seldom lasts more than a few minutes. When first 

 changed the larva is exceedingly delicate, and its head, which does 

 not increase in size until it again changes its skin, is very large 

 in proportion to the rest of the body (Newport). Hellins observes 

 that the larva always eats its cast skin. 



Relation of the colour of the larva of Sphinx ligustri to those 

 of its foodplants. — Poulton notes {Trans. Ent. Soc. London, 1886, 

 p. 153) that he found two full-grown larvae upon wild guelder-rose, 

 that the ground-colour of the larvae was bright green, like that of larvae 

 on privet, but the coloured borders to the stripes were of a very bluish- 

 lilac and rather duller than those in larvae found upon the latter plant. 

 On August 1st, 1885, a larva found upon privet possessed the bright 

 colours usually associated with this foodplant. Fed upon lilac 

 during the last stadium (August ist-i2th), there was a gradually in- 

 creasing change towards the duller colours which are always caused 

 by lilac, which, however, were not ultimately produced to such an 

 extent as is seen after feeding the larvae upon this foodplant for their 

 whole life. Sich notes (Ent. Record, xii., p. 53) that he saw, August 

 1 6th, 1899, what he thought was a curious thickening of the petiole of 

 an ash-leaf, investigation proving that the swellings were the prolegs 

 of a fine larva of Sphinx ligustri, which was otherwise hidden by 

 the leaflets. It was excellently protected by its tint, which was of a 

 greyer shade of green than the specimens one usually finds on privet. 



Variation. — Besides the variation in ground-colour that ap- 

 pears to be due merely to a response to the tint of the particular 

 foodplant on which the larva is feeding and already described, there 

 is a marked aberration, which Buckler has excellently figured (Larvae, 

 &c, ii., pi. xxii., fig. 2) of a bright reddish colour, the thoracic 

 segments, ventral areas below spiracles, and anal area behind the 

 last oblique stripe of a deeper, duller red tint, with white oblique 

 stripes, preceded anteriorly by strong black fusiform margins, not 

 at all similar to the usual purple margins. The white stripes become 

 pale violet in their continuation over the dorsum, whilst the head, 

 prothoracic plate, area at base of caudal horn posteriorly, and 



