The Ecology of Maine Species of Altica. 161 



The general appearance is that characteristic of chrysome- 

 lid pupae : wings and elytra pushed ventrad ; the legs sharply 

 bent at the femoro-tibial joint, the femora extending away from 

 the meson, the tibiae toward it, and the tarsi caudad along the 

 middle line of the body; the metathoracic legs passing under 

 the wings, the antennae extending caudad and bent under the 

 mesothoracic legs. 



There are nine abdominal segments (unless the anal plate 

 may be reckoned as a vestigial tenth), the last bearing a pair 

 of strong black caudal spines. The arrangement of the setae 

 is that characteristic of the whole genus and does not present 

 any specific character, except that it belongs to the group hav- 

 ing two setae on each femur instead of three. 



Seven pairs of spiracles are present. The first pair is lo- 

 cated on the mesothorax, ventrad of the base of each elytron. 

 The other six pairs are located on the first six abdominal seg- 

 ments. The last pair is smaller than the rest. 



There is a considerable range of variation in the pupal 

 setae. The typical arrangement is shown in figures nC (dorsal 

 aspect), and nD, (dorsal aspect of tip of abdomen). The pupa 

 of the elm flea-beetle which is almost identical is shown in fig- 

 ures 12F and 12G. 



Homologies of pupal and larval setae. There are constant- 

 ly three setae on each side of the head throughout the Alticini, 

 which the writer has not yet succeeded in homologizing with the 

 larval setae. There are eight setae on the prothorax, which are 

 homologous with those on the cephalic shield of the larva. There 

 are two setae on each side of the mesothorax and the meta- 

 thorax, homologous with the setae of tubercles ii and iv of the 

 larva. There are four setae on each side of the first 8 abdomi- 

 nal segments ; these are homologous with the larval setae of 

 tubercles ii, iv, vi, and viii respectively, and the spiracle occurs 

 between setae vi and viii as in the larva; the spiracle is not 

 developed on segments 7 and 8 of the pupa. On segment 9, 

 there are four setae and a caudal spine on each side, these five 

 probably homologous with the five larval setae. 



Any one of these setae may be lacking in any given pupa, 

 and very rarely the caudal spines themselves may be lacking. 

 An extra seta corresponding to the seta of tubercle vi in the 

 larva is sometimes present on the mesothorax or metathorax. 



