﻿OF THE STATE ENTOMOLOGIST. 37 



not at all surprising that they should be carried aboard of the waiting vessels, and 

 transported to other part^ of this country, if not to Europe. — [3. S, Eathvon, in Law- 

 caster Fanner, Aug. 187G. 



EATE AT WiriCII IT TRAVELED. 



Walsh estimated, from the rate at which it traveled ia the earlier 

 history of its march, that it would reach the Atlantic in 1881. From 

 subsequent calculations I placed the date at 1878, but it in reality 

 touched the Atlantic seaboard at many different places in 1874. It thus 

 spread at an average annual rate of about 88 miles. But the annual 

 rate was by no means uniform. Earlier in the history of its march 

 the rate was much lower, and until it got east of the Mississippi, did 

 not average fifty miles. A glance at the accompanying map (Fig. 12) 

 will suffice to show that the line of most rapid spread was along the 

 line of greatest human travel and traffic. In fact, after it had reached 

 New York it began to extend and swarm both north and south along 

 the coast, before many of the inland counties on similar parallels 

 were reached by the main line of the immense army. 



now IT TRAVELED. 



As the larva is sluggish and never leaves the plant from which it 

 is hatched, except in quest of more food, until it is ready to pupate, 

 all the journeys of this insect are necessarily made in the perfect 

 ■or beetle state by means of the ample rose-colored wings, which, 

 when the insect is at rest, are compactly folded up beneath the 

 striped wing-covers. Its spread, however, over the more populous 

 portions of the country, is not to be attributed to its powers of flight 

 alone. It undoubtedly availed itself, to no inconsiderable extent, of 

 every means of transportation afforded to other travelers, and often 

 got a lift on eastern bound trains, and most probably crossed the 

 more barren jDlains bordering its native confines through man's direct 

 agency, i. e. by being carried. There is a possibility that in some 

 instances it may have been carried in the egg state on living plants, 

 or in the pupa state in lumps of earth ; but these modes of transit, if 

 they have occurred at all, have necessarily been exceptional. Even 

 the winds and waters aided its progress. Its invasion of Canada, for 

 instance, took place at precisely the two points where we should 

 expect to first meet with it in the Dominion, namely, near Point Ed- 

 ward, at the extreme south of Lake Huron, and opposite Detroit, 

 near Windsor, at the southwestern corner of Lake St. Clair ; for all 

 such beetles as fly into either of the lakes from the Michigan side, 

 would naturally be drifted to these points. 



Many insects that are subject to very great multiplication, though 

 not naturally migratory, often acquire the habit of migrating in 



