THE TENTHREDITES. 1 75 



The females lay their eggs by inserting them with their saw- 

 ovipositor between the skin or cuticle of the turnip leaf and its 

 cellular or parenchymatous structure. The c^^ is therefore only 

 separated from the atmosphere by a most delicate membrane, 

 so that the heat and moisture soon affect it and hatch the little 

 AtJialia caiHfolics very rapidly. It appears necessary that this 

 egg should be exposed to much heat in order to hasten the birth 

 in time for the turnip to be enjoyed by the larva. Newport 

 states that the cocoon of this insect is lined with silk. 



The larvae of the genus Selandria are of a somewhat peculiar 

 shape. Their legs are extremely short, and their bodies are lubri- 

 cated with a viscid secretion which makes them look like small 

 slugs. Reaumur, in fact, called them slug larvae. The larvae of 

 Selandria ^tJiiops often become very injurious to cherry, pear, 



Lophyms pini. 



and other fruit trees. They remain perfectly quiet during the 

 heat of the day, and seem to draw their heads within the first 

 segment of their bodies, and they are then covered over with 

 the slimy moisture so as not to look like insects at all. By 

 night and during the early morning they are lively enough, 

 and they then devour the foliage. 



The Lyditcs form a small group of saw-flies Avhich are charac- 

 terised by having a great number of joints to their antennae. They 

 are the saw-flies of the north, and they attack fir trees and pines. 



The Lophyri, which belong to this group, have a thick body, 

 and the males have doubly pectinated and feathery antennae. The 

 species are very difficult to separate, and entomologists have had 

 to take into consideration the disposition of the nervures of the 

 mngs, in order to decide upon particular forms with certainty. 



The commonest species is Lophyrus pini. The male is quite 



