HYLOICUS PINASTRI. 281 



then buff before becoming brown ; tint yellowish-green towards its 

 nadir. The contents also give rise to longitudinal yellow bands, again 

 evidently the embryo. The micropylar area itself is slightly de- 

 pressed. There is considerable variation in size, some of the eggs 

 having apparently not more than J the cubical contents of others. 

 The eggs are evidently attached, those described having been separated 

 from the surface on which they were laid (Tutt. Described 

 July ioth, 1901, from ova received from Mr. Head, and laid July 

 6th). The eggs are as large as those of Smerinthus populi, but 

 not so round, the shape being roundish ovate; the surface smooth 

 and glossy, and their colour, when received, of a. light greenish- 

 ochreous-yellow, or pale olive-yellow ; some were clouded within 

 with brown, in some instances with quite dark brown at the end ; 

 the shell had a pearly lustre. Before hatching, the dark lobes 

 of the- embryonic head were distinctly visible at one end (Buckler). 

 Yellowish, shining, oval, of the size of millet seed (Roesel). The 

 eggs are figured by Ratzeburg {Forst-Insecten, ii., pi. ii., fig. y). 



Habits of larva. — The newly-hatched larva is quite unlike 

 that of any young Sphingid larva that I have previously seen both in 

 general appearance and behaviour. It is short, stout, active and 

 restless in crawling, curves its body and has a writhing or wriggling 

 manner that is quite foreign to the usual method of crawling adopted 

 by young Sphingid larvae; it appears also to be less stiff and more 

 flaccid than other Sphingid larvae (Bacot). The young larvae, when 

 first hatched, eat along the side of the needle-like leaves of Pinus, 

 but, after the second moult, they attack it from the end and bite 

 it quite through, thus continuing to eat as they gradually step 

 backwards and as the needle becomes shortened, until the leaf is 

 consumed close up to the sheath at the twig or stem. Just before 

 entering the earth, the larvae cover their skins all over with some 

 fluid discharged from their mouths (Poulton makes a similar ob- 

 servation about the larva of Sesia stellatarum) [Buckler] ; Thellusson 

 observes [Ent. Pec, vii., p. 132) : The first and last moults appear to 

 be the most dangerous periods for the larvae, otherwise they seem to 

 be fairly easy to rear ; feeding them on too green and succulent food, 

 also, produces diarrhoea and the larvae turn almost to water. ■ They 

 feed exclusively on the pine, beginning on the top of the firs and eating 

 downwards to the stalk, and, in confinement, they appear to eat by 

 night and day. The young larvae are stated by Ratzeburg to spin silk 

 for a holding surface, and he adds that the habit is continued even 

 after the second moult ; he also observes that, when quite young, they 

 merely nibble the needles, but later eat them right off. Nickerl says that, 

 in 1827, the larvae appeared at Brandreis, in such numbers that, in 

 certain firwoods, the trees were completely stripped, and that the pupae 

 were so abundant in the autumn that they were used for feeding 

 swine. Alderson notes {in litt.) that the larvae imitate excellently 

 the needles and twigs of fir ; he observes that, as the larvae commence 

 eating from the top of a needle and continue downwards, the green 

 colour of the young larvae matches well the tint of the needles, whilst, 

 as they become larger they match the twig, i.e., the -bark whence 

 the needles spring, so that, by the time they clear off the needles 

 from a branch, they are difficult to see because they match the 

 bark so closely. Bartel notes {Pal. Gross-Schmelt., ii., p. 49) 



