SPH1NGID.E 01? PERU. 99 



303. Pachylia syces syces. (Plates X. h~k ; XV. h.) 

 R. & J. p. 374. 



General Listrlhution. — Continental America, from Mexico to Southern Brazil and 

 Bolivia. 



A common species in the Interior, Avhere its appearance as a caterpillar on the same 

 tree tends to confuse it with its congener _P. j/?CTi5. The range of distribution, however, 

 in the last named extends to the coast, whereas P. s. syces is only found east of the 

 Andes, At many times of year and on one particular tree of Ficus japonensis at the 

 Perene camp the larvae of both species may be taken. Their presence is clearly 

 indicated by the numerous pellets of blackberry-like frass which litter the ground ; 

 and though it is easy thus to trace the nightly wanderings of an individual, it is by 

 no means always easy to locate his exact -whereabouts if situated high up in the tree 

 and amongst thick foliage. It is when wandering on the bare ground in search of a 

 suitable puparium — in position and formation identical with the preceding species — 

 that the larva is most often detected. 



As with P. ficus, there is a great display of muscular force and agility in all stages, 

 but the pupa, which sometimes yields the imago in three weeks, is delicate and often 

 dies. The moth when disturbed in bright sunshine takes instantly to flight. It 

 is sometimes drawn to house-lamps, but the attraction seems less than in the case of 

 most Sphingidaj. 



Ova. — Singly, and in similar positions to P. ficus. 



Lakva. — Early stages not observed. 



Final instar. Contrasted with P. ficus, and allowing for a margin of variation 

 between individuals of either species, three essential points of difference may be noted, 

 viz. : (a) the caudal horn, though very short, is longer, flatter, sharper, and less erect ; 

 (5) the fleshy lobes supporting the three pairs of legs are yellow instead of green ; and, 

 most marked of all, (c) just within a few hours of leaving the tree for pupation an 

 extraordinary change takes place, diametrically opposite to that noted in P. ficus, but 

 equally strange and unexpected. The head instead of turning black retains the two 

 facial stripes in strong orange coloration. The continuation of these stripes, which 

 are nearly white, enclosing the dorsal area can now be faintly discerned only where the 

 ground-colour remains green. The flrst two-thirds of each segment, together with 

 the plate behind the head, the central part of the horn, the anal claspers and flap, 

 become dead black, giving the larva an entirely different appearance. This is 

 heightened by the fact that while still hanging motionless among the leaves it 

 becomes much contracted in length and swollen in the middle. The black coloration 

 produces broad belts transversely across the back, obscuring portions of the two 

 dorsal bands, the upper ends of the eight oblique lateral stripes, and extending to 

 the region below the spiracles on either side, though not completely enclosing them. 

 The ventral area and claspers are still green, but somewhat discoloured with a brownish 



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