LANGIA. 197 



appressed to near tip. where they diverge shortly ; head three 

 times as long as broad ; segment 2 of less diameter than base 

 of head, the segments then increasing in diameter to 1, rest 

 of body cylindrical. Surface of head smooth and moderately 

 shining. Body dull, with a transverse row of small pointed 

 tubercles on each segmental ring ; a dorso-lateral line of larger 

 pointed tubercles from the front of segment 2 to base of horn. 

 Horn very short, thick at base, with a blunt point ; covered 

 with large rounded tubercles ; anal flap and claspers heavy, 

 also covered with large rounded tubercles. 



Coloration. — Head and body apple-green ; apical processes 

 pale yellow ; a white stripe from each process running down 

 cheek to base of antenna, and also down the back of head to 

 nape, meeting the dorso-lateral line of tubercles on segment 2 ; 

 transverse rows of tubercles white ; dorso-lateral line of tubercles 

 yellow or reddish, on a yellow stripe. Horn green with whitish 

 tubercles ; tubercles on anal flap and claspers pale green ; 

 terminal segments of the true legs red. Spiracles oval, 

 very large, pale blue edged with black, and with a black 

 crescent-shaped mark above and below. Length 125 mm. 



Pupa. — Very short and stout, bluntly rounded at both 

 ends ; tongue longer than fore leg, slightly longer than mid- 

 leg, and reaching to the point where the wing-cases meet ; 

 antenna very stout, longer than fore leg in both sexes ; no 

 coxal piece ; abdominal segments raised into high ridges, 

 especially on the dorsum, the divisions between the segments 

 deeply constricted. Surface dull and shagreened, especially 

 on the ridges of the abdominal segments, which are also 

 covered with conical tubercles. Spiracles oval, the lips of 

 the central slit raised into narrow ridges. Cremaster absent 

 or a very small pointed spike. Colour iron-grey, almost 

 black on dorsum, which has a reddish tinge when the pupa is 

 freshfy formed. Length 50 mm. ; breadth 20 mm. 



Habits. — The large eggs are laid singly on the underside 

 of a leaf ; the food-plants are apple, pear, cherry, and medlar, 

 all of the family Rosacea?. The larva lives on the underside 

 of leaves and twigs, and is sluggish. When resting it holds 

 on to a twig with the claspers and two or more pairs of prolegs, 

 and bends the front of the body backwards, the long point 

 of the head continuing in the line of the adjacent segments, 

 the true legs bunched together, and the pairs of unoccupied 

 prolegs held with the feet pressed together. When molested 

 it strikes from side to side with its head, at each stroke making 

 a loud hissing noise. This appears to be produced by the 

 sudden forcing of air through the spiracles, as, if these be 

 wetted, bubbles of air are seen to be forced through the 

 film of water. The full-fed larva is ver}^ large and heavy, 

 and eats a great number of leaves. Before pupating it rests 

 for some days without feeding, then becomes suffused with 



