178 NEW YORK STATE MUSEUM 



EXPLANATION OF PLATES 



PLATE 11 



Brown tail moth 

 Euproctis chrysorrhoea Linn. 



1 Egg mass on the underside of a pear leaf and also on twig 



2 Young caterpillars or larvae as they appear in early spring 



3 Half grown and full grown caterpillars 



4 Pupae in portion of a web mass, also a few cast larval skins 



5 Male moth at rest 



6 Female moth with wings partly extended 



7 Hibernating tents in which the winter is passed 



PLATE 2 



Tree 114 was sprayed with undiluted petroleum Ap. 11, 1900, 

 and with a 20^ mechanical petroleum emulsion in the spring of 

 1901 and of 1902. The first application undoubtedly injured the 

 tree considerably, but under the later treatments it has been re- 

 covering, as is evidenced by the new twigs shown in the view 

 taken Mar. 10 and the abundant bloom of May G. 



Tree 66 was treated with a combination of whale oil soap and 

 crude petroleum in April 1900 and with 25^ and 20^ mechanical 

 crude petroleum emulsion in the springs of 1901 and 1902 re- 

 spectively. It was severely cut back in 1901, and the recent 

 growth gives no indication of weakness. 



PLATE 3 



Tree 101 was sprayed with undiluted crude petroleum in April 

 1900 and severely injured. The following spring it was treated 

 with a combination of whale oil soap and petroleum and in the 

 spring of 1902 with a 20;^ mechanical emulsion. It has developed 

 a large amount of vigorous new wood. 



Tree 69 was treated with a combination of whale oil soap and 

 crude petroleum in April 1900, and with 25^ and 20^ mechanical 

 crude petroleum emulsion respectively in the spring of 1901 and 

 1902. The vigorous growth under this treatment is very apparent. 



lExecuted from nature under the author's direction by L. H. Joutel. 



