ORDER HYMENOPTERA 215 



eyes and ocelli form months before the pupal stage is at- 

 tained and the adult characters of the head may be plainly 

 seen through the skin of the larvae shortly before the last 

 larval moult. 



To enter the ground (or, in some cases, rotten wood) in 

 preparation for pupation is a very common habit among 

 sawflies, but the leaf-miners of the Phyllotominae have 

 departed from the habits of their relatives and developed, 

 for sawflies, very eccentric methods. Three or more species 

 of Phyllotoma in Europe are reported to spin in the sixth 

 instar circular disclike cocoons in the leaf. One of them, 

 Phyllotoma aceris, goes so far as to spin this cocoon in the 

 leaf and to free it by cutting out the circular piece of the 

 leaf's upper cuticle to which it is attached. Case and larvae 

 blow to the ground where pupation takes place late the next 

 season. 



The pupae. The pupae are pale, whitish, greenish or 

 yellowish in color. The antenna, leg and wing cases are 

 free, and the wings are pad-like. In twelve to fifteen days 

 after the pupae are revealed the adults emerge from the 

 pupal skin. When the wings are fully expanded and the 

 chitinous parts hardened they roughly cut away one end of 

 the cocoon and work up through the soil. 



The adults. Adult sawflies of the particular species 

 adapted to leaf-mining, though some are giants among 

 miners, are never-the-less small compared with the adults 

 of free-living sawfly larvae. After emergence they may be 

 found about their host plants mating and ovipositing, or on 

 cold, dark days hidden away in a cluster of leaves or a 

 crevice of bark. Some have but one generation; the major- 

 ity have two. 



PHYLLOTOMINAE 



Most of the known Phyllotominae are European in dis- 

 tribution. According to Professor A. D. MacGillivray, most 



