318 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
The Net Trap. — A net trap of my own invention, and which I con- 
sider the best of this class, deserves the following consideration : Ob- 
Observing how moths attracted by light approach panes of illuminated 
glass, descending or ascending thereon, that most of the moths allured 
by light do not plunge into the blaze, but pass near it by a more or less 
circuitous course, often describing ellipsoid figures and returning to re- 
peat the same, so that such moths are not caught by the common lamp- 
traps which have more or less cylindrical or cubic form, with the several 
horizontal diameters not extremely unequal, I planned a screen, made 
preferably of glass or glass and sheet metal in combination with a light, 
or bait, and other arrangements for taking moths and other insects, as 
represented in Plate LXI, Fig. 1. The two ends of the apparatus are 
alike. Observing one end with reference to the lettering, s is a stake 
having a slit sawed down into its top, on its side a cleat, c, and above 
this two opposite notches, x. In the slot is supported one end, i, of a 
large plate of glass, £, the larger the better. It had better be 3 feet 
square or more. A sheet of metal, v r, is bent to have two slight slopes 
like a roof, and is placed with its angle fitting upon the top edge of 
the glass. This angle may be bent up into a narrow fold, v, which will 
pinch firmly upon the glass. The roof may be very narrow, and good 
results are obtained when it is entirely omitted. Its outer margin 
should bend suddenly downward. The stake should straddle the glass 
to near the top thereof. The lateral halves of the stake thus form wings 
or flanges projecting at right angles from the glass. These may be 
made wider or with an edge projecting toward the light from the outer 
margins of each. Such a recurved flange is easily formed by tacking 
a strip of sheet metal upon the side of the stake. The projecting parts 
of the sides and the roof have a specific function, since the lantern is 
placed opposite a lower corner of the glass and the insects, attracted by 
it or by bait placed below, approach by a more or less circuitous course 
to strike against the glass. If the insect strike with but little force it 
flutters on the glass while sliding downward to fall into the other catch- 
ing-devices below. But when the insect strikes the plate swiftly or at 
an angle it will be deflected off. The insect is observed habitually to 
move upward or horizontally as a rule on Hearing the light and the 
plate, hence if it fly or glance suddenly off horizontally, the lateral 
wings catch it, or if it dart upward it strikes the roof, so that in either 
case it is precipitated downward into the devices beneath. The lower 
edge of the glass forms a septum through the long, wide, slot-shaped 
opening of the bottom of a trough-shaped hopper, jj, which has flaring 
sides so that moths descending from either side of the pane shall fall 
through it. The end of this hopper is supported upon the stake in 
notches, ./ , or otherwise. A large net, n ra, of foundation lace or GFfeher 
line netting has its mouth attached to the upper margins of the trough, 
Which forms a narrowing entrance passage, projecting into the net. 
The top of the net is preferably held wide and upward, at nn, so that 
