l82 



INSECTS INJURIOUS TO VEGETABLES 



tions, may be passed in five weeks, but the outdoor spring and 

 fall generations require a longer period. There are at least 

 two, and frequently three, generations produced in the open; 

 and in a warm equable indoor temperature there is a possibility 

 of four and perhaps five. 



Remedies. — In greenhouses this leaf-tyer is controlled by 

 trimming away and destroying infested leaves as often as they 

 are detected. The moths are killed in great numbers by placing 

 lights over vessels of water on which a thin scum of kerosene 

 floats. These remedies are less valuable in the field, but Paris 

 green and other arsenical sprays, if applied at ths outset of 



Fig. 1 1 7.— Celery looper. Male moth at left, larva at right. Somewhat enlarged 

 (Author's illustration, U. S. Dept. Agr.) 



attack, will destroy the larvae, though less effective after they 

 have become concealed in their tied-up leaves and in the growth 

 of leaves about them. Spraying should be thorough, and an 

 underspray is desirable. 



The Celery Looper (Plusia simplex Guen.). — This species is 

 the commonest of its kind in Illinois, and is rather gierterally 

 distributed in the United States east of the Rocky Mountains, 

 from Canada to New Mexico. It is described by Messrs. 

 Forbes & Hart as a very destructive celery insect, and occurs 

 also on sugar beet and lettuce. 



The moth (fig. 117) has a greater wing expanse than the 

 cabbage looper, measuring nearly two inches, has different 

 coloration, and differently shaped upper-wings. The border of 

 the fore-wings is not scalloped, the color is somewhat purplish 



