164 Control of Parasites 



large caterpillars or bringing them down by a stream of 

 water, or cutting off the infested branches while the cater- 

 pillars are still young and closely gregarious. 



Army-worms or Cut-worms comprise a number of species, 

 some of which spin cocoons, others do not. They are typ- 

 ical, medium-sized, night-moths; the usually hairless cater- 

 pillars are also frequently night-prowlers. While mostly 

 non-gregarious, some of them develop in such large masses, 

 wandering over the ground, that the first name is applied 

 to them, while the habit of cutting off buds and leaf parts 

 leads to the second name. Some of the caterpillars are 

 borers; others live underground, feeding on roots; the 

 majority, however, \\\q on the foliage of the host plant. 

 The true Army-worm, a brownish, white-striped caterpillar, 

 from one and a half to two inches in length, with a brownish 

 moth, making two or three generations in the year, more 

 frequently damages grass crops than trees. The veh'ety 

 black, yellow-lined, hairy caterpillar of the Erratic Army- 

 worm, the mottled gray worms of another cut-worm, as well 

 as many others, climb the oak, elm, cherry, etc., by night, 

 revealing their presence by the cut-ofif buds and leaf par- 

 ticles which fall to the ground. Both deciduous and co- 

 niferous trees find enemies in this group. Most of the moths 

 of this group fiy in summer and fall, usually wintering under- 

 ground as caterpillars or pupae. 



The climbing cut-worms, which winter as such under- 

 ground, can be prevented from climbing the trees by various 

 bands. They can also be baited with poisoned bran (one 

 ounce of Paris Green to three ounces of bran) , placed at the 

 base of the tree. If whole areas are infested, in addition 

 to banding the trees, ditching and collecting in the ditches 

 is recommended. 



Inch-worms or Canker-worms (Geometrids) , also called 



