HYMENOPTERA. 119 



females possess an ovipositor in the form of a saw or 

 auger, hence the term, from terehra, " a borer;" in the 

 latter the females are provided with a venomous sting. 

 The Terebrantia are again divided into two sub-sections, 

 the Phytophaga, because the larvce feed on plants, and 

 the Entomophaga, wliose larvce (with the exception of 

 those of the gall-flies) feed on other insects. In th^ 

 Plant-eating Borers and Saw-flies the abdomen 

 sessile, that is, attached to the thorax by its whole 

 width ; in the Insect-eaters the abdomen is attached to 

 the thorax by stalk of short or extended length. The 

 instrument by means of which the Saw-fly {Tenthredo) 

 forms a depression in a branch or leaf, or notch for the 

 attachment of her eggs, consists of a double serrated 

 auger, the teeth of the saw being themselves toothed. 

 " The perfection of this minute weapon," Professor 

 Duncan observes, "suggests that manufacturers might 

 take a lesson from it, and invent a cutting saw with 

 double serrations, which might be of infinite use in the 

 arts." The Saw-flies larvae are eminently destructive in 

 gardens and turnip fields, causing ver}^ serious losses at 

 times. 



The Gooseberry-leaf eater must be familiar — at least, 

 its damages must — to all who have strolled in the 

 kitchen garden. The eggs, little white specks, are 

 placed down the mid-rib of the leaf, and the hatched 

 larvse begin their devastations at once, in a short time 

 eating the whole of the leaf, with perhaps the exception 

 of the thick parts of the mid-rib. I have just brought 

 in two larvse of the Gooseberry Saw-fly {Nematus 

 grossularke) from the garden ; the bush is stript ab- 

 solutely bare of leaves. The larva might at first be 



