270 



AN ECONOMIC ENTOMOLOGY. 



are prevented from crawling' up the trunk Ironi the surrounding 

 points. A band of " dendrolene" six inclies in width and half an 

 inch thick on a sheet of heavy \vrapi)ing-paper will serve as a 

 complete protection if the tree has been cleared of eggs during the 

 preceding winter. It is easy to see how this is done ; the female 

 is absolutely incapable of flight, and no eggs can be laid upon a 

 tree until a caterpillar has first made its way upon it and has 

 changed to a female moth. Instead of " dendrolene " a broad 

 band of fluffy cotton will answer for a time, as the caterpillars 

 become entangled in and are unable to cross it. This sort of 

 protection must be carefully watched, however, because other- 

 wise the wet and dirt will harden anc^ cause its failure to act as a 

 bar. A trough of oil or an inverted tin cone tightly fixed to the 

 tree may also serve, as will anything else that prevents the cater- 

 pillars from crawling upon the tree. 



Belonging about here in the series comes the European 

 "gypsy moth," Ocneria dispar, which, imported into Massa- 

 chusetts in 1868, has caused enormous damage in that State, and 

 has cost annually many thousands of dollars to keep it in check. 

 The caterpillar when full grown is about one and one-half inches 

 in length, of a creamy white, so thickly sprinkled with black that 

 it seems dark brown, the ground color appearing in the broken 

 dorsal and lateral lines. It is furnished with distinct dorsal and 

 lateral tubercles, blue anteriorly and crimson behind the fifth 

 segment, from each of which arise tufts of long black and yel- 

 lowish hair. It changes to a chocolate-brown pupa, held in place 

 by a few threads forming the merest apology for a cocoon, from 

 July to September, and a few days thereafter the moths emerge. 

 The males expand from one and one-half to two inches, are 

 brownish yellow in color, the secondaries paler with a darker 

 outer margin, the primaries smoky with darker, irregular, trans- 

 verse lines. The females are much larger and more heavily 

 built, the wings often expanding two and one-half inches. They 

 are creamy white in color, the irregular, transverse lines gray or 

 blackish. They lay their eggs in masses of from four hundred to 

 five hundred in all conceivable localities, alid cover them with 

 yellow hair and scales from the end of the abdomen. They are 

 deposited from July to late in September, and the larvae hatch 

 early the following year, ranging from April to June, according 



