THE MONTHLY BULLETIN. 



213 



bands of black, yellow and white. Very often on young trees a whole 

 colony may be collected, by picking the leaves on which they are 

 clustered during the first stages of their existence, and destroyed. 

 This pest is most abundant during June, July, August and a part of 

 September. If the larvte are fairly abundant and are stripping off 

 many of the leaves, spray the foliage with 6 pounds of arsenate of 

 lead to 100 gallons of water. 



The Cankerworms. 



Two species of cankerworms are found in the central and northern 

 parts of the State, working upon the foliage of apples, cherries, apricots, 

 prunes and other fruits. Ihe 

 larva? are dark or brownish 

 worms, very slender and about 

 one inch in length. On account 

 of their looping motion they 

 are sometimes called measuring 

 worms. The work of these 

 cankerworms, like that of tlic 

 red-humped caterpillars, con- 

 sists in destroying the leaves. 



To control, spray with arse- 

 nate of lead, 5 pounds to 100 

 gallons of water, or use "Black 

 Leaf 40," 1-1000, with 1 

 pounds of soap to 100 gallons 

 of water. Several investigators 

 have had greater success with 

 the "Black Leaf 10," owing to 

 the resistivity of the larvae to 

 the arsenic. 



Plant Lice. 



Various species of plant lice 

 are common on both deciduoiis 

 and citrus fruit trees, during 

 the growing season, particu- 

 larly at the time the foliage is 

 young and tender. The plant 

 lice disappear as the season 

 advances and the leaves become 

 more mature, and also on 



account of the large number of beneficial insects which are present 

 at this time. Often the plant lice become so numerous as to com- 

 pletely curl the leaves, 'in this condition spraying is somewhat 

 difficiilt, and the application of the insecticide must be made before 

 this condition arises, if the best results are to be obtained. Tobacco 

 in some form is generally used as the insecticide, and perhaps the 

 nicotine extract known as "Black Leaf 40" is the most convenient 

 to use. The proportions used are one part of the extract to 1000 

 parts of water. In order to make this spray more effective use 4 pounds 

 of soap to each 100 gallons of the spray. 



Fir.. 40. — 'U^'ork of rnnkerworms on apricot. 

 CAftt-r Craw.) 



