.266 MAINE AGRICULTURAL EXPERIMENT STATION. 1917. 



in the position normal to the pupa. The wings and elytra lie 

 pushed ventrad beneath the old larval skin in about the same 

 relations that they show in the pupa. The pupa is always formed 

 with the ventral aspect uppermost, and it remains in this posi- 

 tion throughout this period. 



Description. The general appearance of the pupa is that 

 typical of the chrysomelids : wings and elytra pushed ventrad ; 

 the femora extending away from the middle line, the tibiae 

 toward it, and the tarsi caudad along the mesal line; the meta- 

 thoracic legs passing under the wings ; the antennae extending 

 caudad, bent under the mesothoracic legs. 



There are 9 abdominal segments (unless the anal plate may 

 be counted as a vestigial loth), the last bearing a pair of strong 

 black caudal spines. The arrangement of the setae is that char- 

 acteristic of the genus Altica, and does not present any specific 

 characters. The only specific variation which the writer has 

 noted in the pupal setae of the genus Altica is the number of 

 setae present on the femora. Sometimes there are 3, and some- 

 times but 2. In A. bimarginata there are 3: a pair of pre-apical 

 setae and one apical, on each femur. 



Great variation prevails in the setae which may be present 

 in any individual specimen. Any given seta may be wanting 

 (though the writer has never found a pupa in which any of the 

 head setae were absent), and certain extra setae are sometimes 

 present on the thoracic segments. The greatest variation is to 

 be found in the pygidial setae. Very rarely the caudal spines 

 themselves may be wanting entirely. Where the setae are seri- 

 ally homologous, and the arrangement the same on both sides 

 of the body, as on the abdomen, a seta missing on one segment 

 is usually present on the others, and may be absent only on one 

 side. 



The setae occur only on the dorsal aspect of the body and 

 serve to ket the insect from contact with the sides of the pupal 

 cell, as it lies with the ventral aspect uppermost. 



The average length of the pupa is 5 mm. ; the average width 

 is 2.5 mm. 



When formed, the pupa is bright orange yellow, with the 

 appendages a more translucent yellow ; the setae are brown, and 

 the caudal spines and the spiracles (which occur on the first 6 

 abdominal segments) black. Packard (1890) described the 

 pupae as white, but this is without doubt a mistake. Lintner 



