LIGHT AND BAIT TRAPS. 319 



the ligbt, Ij shall illumine these regioDS, causing the itisects which have 

 entered to seek exit at these places where no outlet is to be found. 

 Curved metal strips, nj, serve best to hold the net expanded in ui)ward 

 and lateral directions. From the insects caught the injurious ones 

 should be selected and crushed in the folds of the net or otherwise 

 killed, while the beneficial insects are set free through a large opening, 

 z, in the base of the net. An easy way to keep this opening closed is 

 to i)ucker it together and lay a brick or chunk, z, n^on it, or tie it to- 

 gether. 



This device, constructed and tested some years since, was intended 

 to overcome such objections as have already been made to light traps, 

 or in former pages, and also for the use of naturalists in collecting in- 

 sects for their cabinets. 



The indiscriminate killing of insects is certainly very unscientific and 

 not to be recommended, yet where parties wish to adopt this abandoned 

 I)ractice to avoid the trouble of selecting the good from the bad, in 

 which they often work against their own interests, a trough of destruc- 

 tive substance may be placed beneath the bottomless inlet, the end of 

 the trough resting on the cleat, c. In case it is for drowning the in- 

 sects, the trough should bear a projecting ledge a short space above the 

 liquid, as in the bait traps to be noticed farther on. Such a trough 

 supplied with attractive bait may be used as a bait trap apart from or 

 in combination with the glass, which it still a valuable auxiliary to it. 



But when bait is used it is preferable that the insects be not mixed 

 in the bait and drowned thereby. It is better to use a shallow trough 

 with flaring sides, or merely substitute for it a board on which the bait 

 may be spread. Then the insects feed without drowning. In seeking 

 the footl they crawl down through the slot-shaped opening of the bot- 

 tom of the trough-shaped hopper, toward the bait below it. Therefrom, 

 instead of trying to escape through the hopper-slot, they fly off into 

 the larger space surrounded by the net, and are thereafter to be selected 

 and freed or killed. 



I find the cotton moth is extravagantly fond of juicy canned peaches, 

 and believe these are the best and most convenient bait for all seasons 

 of the year, though any other sweet, succulent fruits may be employed 

 in their season. Where divers species of insects are sought several 

 kinds of bait may be inserted at once. 



Stith^s Cotton-Moth Exterminator (Plate LXI, Fig. 3).— "This exter- 

 minator is of the class which lures to self-destruction the mother moth 

 on her first flight to deposit the worm -producing e:gg^ and its essential 

 peculiarities are (1) a day and night attractor-lanteru, and (2) such em- 

 baying of the lantern side that the approaching moth falls a more cer- 

 tain prey into the usual trap-basin below. 



•' In the cut A and A are sides of the attractor-lantern ; these sides are of opal glass, 

 which by day is brilliant white and in twilight or by night, lighted by a lamp within, 

 ifl most attractively luminous; each pane of the lantern is flanked by an out-reaching 



