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XI. On the Pupal suspension of Thais. 

 By T. A. Chapman, M.D., F.Z.S. 



[Read February 1st, 1905.] 



Plate XII. 



It is now some ten years since I ventured to question the 

 view quoted in Scudder's great work on the American 

 Butterflies as to the suspension of the pupa of Thais 

 (Ent. Record, Vol. VI, pp. 125, 126), and somewhat Inter I 

 obtained (Ent. Record, Vol. VII, pp. 81, 82) tolerably 

 strong evidence that my opinion on the subject was correct. 

 Up till the present time, however, no one has chosen to 

 report actual observation of how the larva and pupa of 

 Thais actually manage to make the girth (incidentally 

 proving that it is the girth) leave its usual situation and 

 become attached to the nose-hooks. This Spring (1904) I 

 made an effort to supply the deficiency, and obtained a 

 number of larvae of Thais polyxena, Schiff., var. cassandra, 

 Mann, from Hyeres. I was successful in observing the 

 whole operation by one specimen or another; whether I 

 can successfully describe what I saw is I fear doubtful, 

 but I will make the attempt. I was so interested in the 

 matter, even someway outside the chief point in question, 

 that I also made a successful attempt to see Papilio 

 machaon and Pieris rapte (as examples of Papilionidm 

 and Pieridx, respectively) make their silken holdfasts 

 for their pupae. Though there is no novelty about my 

 observations of these, there are one or two points that 

 may bear description again. 



The first spinning done by the larva of Thais is to form 

 what we must call a cocoon, though it consists merely of 

 three or four, or at most a dozen, rather strong silken 

 cables, sometimes simple, sometimes branching, tying 

 together the objects surrounding the position chosen for 

 suspension. This structure must be correlative with a 

 habit of retiring for pupation into a situation surrounded 

 by not very fixed materials, such probably as dead herbace- 

 ous material round shorter stems near the ground-level or 

 below it. Having prepared a carpet of silk of rather more 



TRANS. ENT. SOC. LOND. 1905. — PART II. (JULY) 14 



