178 NEW YORK STATE MUSEUM 
EXPLANATION OF PLATES 
PLATE 1! 
Brown tail moth 
Euproctis chrysorrhoea Linn. 
Egg mass on the underside of a pear leaf and also ov. twig 
Young caterpillars or larvae as they appear in early spring 
Half grown and full grown caterpillars 
Pupae in portion of a web mass, also a few cast larval skins 
Male moth at rest . 
Female moth with wings partly extended 
Hibernating tents in which the winter is passed 
NAA »arwwnv ke 
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 6. 
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 204 mechanical 
crude petroleum emulsion respectively in the spring of 1901 and 
1902. The vigorous growth under this treatment is very apparent. 

1Executed from nature under the author’s direction by L. H. Joutel. 
