INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



393 



young tires, grapevines, etc., but are seldom practical for forage 

 crops. 



Poisoned bait, composed of a pound of Paris green to 40 or 50 

 pounds of bran and sweetened either with cheap sugar or molasses, 

 with sufficient water added to make a stiff mash, placed in the infested 

 areas, will kill countless numbers of the worms. The citric bran mash 

 should also be given a trial. 



Light traps are also used to capture the adults, but these have never 

 seemed to greatly lessen the attacks, because large numbers of the 

 moths captured have previously laid their eggs. 



Natural Enemies.— By far the most important factors in the control 

 of army worms and cutworms are natural enemies. The parasitic 

 tachinid flies kill countless numbers of them. Hymenopterous para- 

 sites of the family Ichneumonidm also prey upon the young. The pre- 

 daceous ground beetles of the family 

 Carabidce devour the worms and de- 

 stroy great numbers. That these 

 insects are not injurious every year 

 is undoubtedly due to the work of 

 these natural enemies. 



THE GREASY CUTWORM 



Agrotis ypsilon ( Rottembiirg) 

 (Fig. 39 3) 



Description. — The moths are dull 

 reddish or brownish-gray with 

 silvery patches at the bases and tips 

 of the front wings. The hind wings 

 are silvery gray, as is also the abdo- 

 men. The thorax is dark with light 

 markings on the dorsum. The an- 

 tennas are dark and about half as 

 long as the body. The length of the 

 body is 1 inch and the wing expanse 

 If inches. The caterpillars are dull- 

 brown or nearly black with a pale 

 broken yellowish line on the back, 

 two faint lines on each side and a 

 few black shining spots on each seg- 

 ment, The length is about H inches 

 when full grown. 



Life History. — The life history of 

 the greasy cutworm is practically the same as for the variegated cut- 

 worm, Lycophotia margaritosa (Haw.). 



Nature of Work. — The larvae usually feed at aight, devouring suc- 

 culent growth and the foliage of hardy plants. They very often work 

 underground and cut the plants just below the surface of the soil, 

 thus doing- great damage, especially to young plants. 



Distribution. — This is a very common species throughoul the State 

 and country. 



Fig-. 393. — Adults of the greasy 

 cutworm, Ai/ratis uii-sihni (Rott.) 

 Slightly enlarged. (Original) 



