PUPA 



327 



the body being glued together by an exudation so as to form a 

 single continuous outer skin. Tliis form of perfect pupa is called 

 " pupa obtecta." The obtected pupa is exhibited in various stages 

 of perfection in the Lepidoptera ; the maximum of perfection is 

 attained by the pupae of such butterflies as are exposed without 

 protection or concealment ; on the other hand, we find in various 

 small moths conditions of the p)upa that do not differ in any 

 marked manner from the pupae of Insects of other Orders. 

 Moreover, certain Coleoptera and Diptera exhibit obtected pupae 

 of a more or less perfect kind. Hence the pupa obtecta is to be 

 considered as a perfected condition that exists more frequently 

 in the Lepidoptera than in other Orders. 



The pupa has no orifices to the alimentary canal or sexual 



Fig. 167.— Section of 

 female pupa of 

 Anosia plexipptis^ 

 3-4 days old. I, 

 pro-, II, meso-. III, 

 meta-thorax ; 1-9, 

 abdominal seg- 

 ments ; IS, anten- 

 na (?) ; ac, aortal 

 chamber ; ag^ - arj^^ 

 abdominal ganglia ; 

 ai/i, ^accessory 

 glands ; ao, aorta ; 

 &r, brain ; c, colon ; 



cp, bursa copulatrix ; c?-, cremaster ; f^, first femur ; fr, food-reservoir ; A, dorsal vessel ; 



i, part of intestine ; iiiv, Malpigliian tube ; inx, base of maxilla ; oe, oesophagus ; ov, ovary ; 



ph, pharynx ; sd, salivary duct ; sgl, salivary gland ; st, stomach ; t}-, first tarsus ; tg, 



compound thoracic ganglion ; ts'-, fa', second and third tarsus.. (After Scudder. ) 



organs, but the respiratory openings are pervious. It has no 

 means of locomotion, but it can move a certain number of the 

 posterior segments (the number variable according to kind). In 

 some cases it is provided with spines, " adminicula," by means of 

 which, aided by the wriggling movements of the abdominal seg- 

 ments, considerable changes of position can be effected. The 

 pupae of the genus Micropteryx apparently use the legs for 

 locomotion, as do the pupae of Trichoptera. 



The study of the pupa of Lepidoptera is less advanced than 

 that of the imago and larva, between which it is, in many points 

 of structure, intermediate.^ The interior of the pupa contains a 



1 The student will find important information as to the varieties of external 

 form of pupae in Dr. T. A. Chapman's writings ; see especially Tr. ent. Soc. London, 

 1893, 1894, and 1896. 



