HORTICULTURAL DIVISION 



70S 



tion occupies a more important role; single complete defoliations can kill 

 outright trees of this nature. 



Control. Leaf eating caterpillars, sawfly larvae or beetles can be com- 

 bated by spraying with a lead arsenate and water mixture, using one pound 

 of powdered lead arsenate to fifty gallons of water. 



Certain species of defoliating insects are more often met with and 

 are far more abundant and more injurious than others. The habits of 

 these species vary as to host plant, time of appearance and manner of 

 work, and, since these are important items in prevention of attack and 

 control, a few of the principal defoliators will be treated here briefly. 



THE BAGWORM. The 

 bagworm is a caterpillar that 

 lives in a sack or bag of silk. 

 ornamented with portions of 

 the plant fed upon. The body 

 is soft except for the head 

 and thoracic plates, and is 

 dull brownish to blackish in 

 color. The bagworm feeds on 

 a wide variety of plants, both 

 deciduous and evergreen, 

 but apparently prefers arbor- 

 vitse and juniper. 



Control may be effective 

 by spraying, as soon as the 

 bagworms are observed, with 

 lead arsenate, using one to 

 two pounds of lead arsenate 

 to fifty gallons of water. Pick- 

 ing and destroying bags dur- 

 ing the fall, winter and early 

 spring, when they contain the 

 eggs for the next year's gen- 

 eration, is also an excellent 

 means of preventing attack. 



THE ELM LEAF BEETLE. 

 Elms are very subject to de- 

 foliation by the elm leaf 



1.1 i , . PLATE No. 267. THE ELM LEAF BEETLE 



beetle, and when the trees 



i j i r.. a > Elm leaves showing adults, larvae, and feeding work of the 



are denuded year after year beetle; b, adult beetle; c, eggs; d, young larvae; e, full-grown larva; 



death follows The elm leaf mou o h parts f _ full " 8r ? wn larva; g > pupa ' Drawin g s by United 

 uw& * iedl States Bureau of Entomology. 



