88 [A88EMBLT, 



seen. Now the ground is thickly scattered with cut-off heads, and 

 at the same rate of progress by the time the grain is ripe a consid- 

 erable reduction in the yield per acre must be the result. Many 

 farmers seem to know nothing of its presence. Its damaging work 

 will escape the notice of any who do not enter their fields for a close 

 inspection. Last year its damage in reported cases was very slight. 

 This year, in some fields, a loss of one bushel in yield per acre to 

 date would be a fair estimate. 



Editorial mention is also made in the " Weekly Press," that the 

 insect is reported in the " Wilmington Every Evening " as ravaging 

 the wheat fields of Delaware. 



The above inquiries and notice refer to the same insect. I think 

 that I am safe in designating it as a new insect attack, for nothing 

 of the kind has before been brought to my observation. I find no 

 reference to it in any of our entomological writings ; nor is it 

 noticed in such European works as I have been able to consult. 



The chief interest of the attack, next to the injury that appears to 

 be resulting from it — a loss of ten per cent in the fields attacked — 

 lies in the fact that the depredator is the larva of a saw-fly, holding 

 a family relationship to our well-known currant saw-fly, Nematus 

 ventricosus. None of our saw-fly larvae hitherto known to us, 

 possess this cutting habit, or attack the wheat ; thus, the honey- 

 suckle saw-fly, the gooseberry saw-fly the currant saw-fly, the 

 strawberry, raspberry and ash saw-flies, all eat the leaves, making 

 incisions into the margins; others eat the surface of the leaves, as 

 the rose-slug ; some produce galls. A species occurring in Europe, 

 known as the corn saw-fly, Oepkus pygmceus, eats into the stalk of 

 the wheat, and then burrows downward in the stem. 



Curtis, in his "Farm Insects," has given an interesting account 

 of the sudden appearance of a saw-fly larva, in large numbers rest- 

 ing upon the heads of the wheat or fastened in the awns. They 

 were nearly dead when seen and had probably come there to die, 

 but where they came from could not be discovered. His description 

 of the larva corresponds so closely with an example of this new wheat 

 depredator above noticed, that it may possibly prove to be the 

 same. The mature insect was not obtained by Curtis, but judging 

 from the larval structure, he thought that it might be a species of 

 Tenthredo. 



The larva now before me is quietly feeding upon a tender stalk 

 of grass given it, stretched out to a length of an inch and a tenth 



