14S FIRST ANNUAL REPORT OP 



my attention during' the past summer. Of these, the insect whoso 

 transformations are illustrated above, is by far the most common and 

 injurious. It apparently flourishes better south of latitude 39° 

 north of that line. It occurs on Long Island, and in different localities 

 in Pennsylvania, Ohio, Maryland, District of Columbia, the Oarolinas, 

 Georgia, Alabama, Kentucky, South Illinois and in the southern half of 

 our own State, and doubtless in some of the other States, though I 

 have no records to judge by. In St. Louis county it is very plentiful. 

 Year after year shade trees are planted along the streets and avenues 

 of this city, and year after year a great proportion of them dwindle 

 and die, until at last the opinion very generally prevails among land- 

 owners that it is of little use to try and grow them. Cons 

 they are not as generally planted as they should be, and St. L 

 With all her natural advantages, lacks to a great extent, those beau- 

 tiful vistas and Ions; rows of trees which so characterize and adorn 

 some of our more Eastern cities. 



Why is it that so many of these trees dwindle ? No one seems 

 to know ! Can it be owing to the character of the soil, or of the cli- 

 mate ? Most emphatically, no! — in these respects there is no more 

 favored city on the continent, and for the proof we need only to 

 Mr. Shaw's beautiful gardens, or Lafayette Park, or any of the nur- 

 series around the city. What then, is the cause ? Why, the very I i 

 worm which forms the sub is article. It swarms all over 



city proper, but decreases in numbers, as a general rule, as one ap- 

 proaches or gets beyond the limits, and is comparatively rare in the 

 above mentioned places. The reason for this is obvious when we 

 understand its history, for it ca . radually, and has natur- 



ally multiplied most in those places where it has longest existed — 

 namely, in the older parts of the town. 



The natural history of the insect is interesting, and may be thus 

 briefly given : 



Thoughout the winter the weather-beaten bags may be seen I 

 ing from almost every kind of tree. Upon plucking them mam. 

 be found empty, but the greater proportion of them will, on being 

 cut open, present the appearance given at Figure 84, 'e\ they are in 

 fact full of soft yellow eggs. Those which do not contain eggs are 

 the male bags and his empty chrysalis skin is generally found pro 

 ing from the lower end. About the middle of next May these 

 will hatch into active little worms, which, from the fir 

 their lives, commence to form for themselves little bags. They crawl 

 onto a tender leaf, and, attached to their anterior Jeet with their 

 hoisted in the air, they each spin around themselves a ring of sil 

 which they soon fasten bits oi leaf. They continue adding to i he I 

 edge of the ring, pushing it up as it increases in width, till it re;., 

 the tail and forms a sort of cone, as represented at Figure 84, g. As 

 the worms grow, they continue to increase their bags from the bot- 

 tom, until the latter become so large and heavy that the worms let 



