150 



A Destructive Cut-ivorm. 



For several years past we have received specimens of a cut-worm 

 which has proved very injurious to the grass fields iu many locali- 

 ties. This caterpillar is about one and three-fourths inches in 

 length when full grown, and quite stout, tapering slightly from the 

 middle towards each end. The head and top of the second 

 segment are very dark brown, and the body of a glossy bronze- 

 green color, with lighter longitudinal stripes. They feed by night 

 on corn, grasses and knotweed, i^emaining concealed during the 

 day under pieces of boards or in any other convenient hiding place. 

 They pass the winter as partly grown caterpillars, and specimens 

 bred at the insectary reached their full growth and pupated August 

 4, and the moths emerged September 2, of the second year. 



The moth belongs to the great family Noctuidm, which includes 

 the army worm and a host of other noxious insects, and is known 

 by the name of Neplielodes minians Guen. A fuller account of it 

 will be published at some future time in one of the bulletins. 



A series of experiments was conducted, during the early part of 

 the summer, on the gypsy moth, to ascertain whether this insect 

 can be wholly exterminated with Paris green. The proportion 

 used in each case was one pound of Paris green to one hundred 

 and fifty gallons of water. This was sprayed upon branches of an 

 apple tree, and the caterpillars of the gypsy moth in their different 

 stages of growth were placed on the leaves. From these experi- 

 ments we learn that the newly hatched caterpillars can live on 

 poisoned leaves from four to six days ; just before the first molt, 

 from one to seven days ; between the first and second molts, from 

 one to two days ; between the second and third molts, from one to 

 seven days ; between the third and fourth molts, from one to 

 twelve days ; between the fourth and fifth molts, from three days 

 to two weeks or more ; or, in other words, the experiments verify 

 the field observations on this insect in Maiden, namely, that Paris 

 green seems effective in reducing their numbers, but it does not 

 appear that all the caterpillars on a tree can possibly be destroyed ; 

 for in these experiments, where the leaves were sprayed more 

 evenly and effectually than it could be done on tall trees in the 

 field, some of the caterpillars lived long enough for all the Paris 

 green to be washed from the leaves. All the puptfi that came 

 from the poison-fed caterpillars were kept, and from the majority 

 of them the moth successfully emerged, showing that, in their 

 cases at least, they had not taken poison enough to prevent them 

 from completing their transformations. These experiments prove 



