INSECTS. 369 



autumn and winter months. The female has no wings, 

 but crawls up the tree, and lays her eggs on the branches 

 in Ma J, in clusters of 60 to 100 in each, glued to each 

 other and to the bark by a greyish varnish impervious to 

 water ; the little worms fall upon the leaves, and, when 

 numerous, devour them all, leaving only the mid-ribs. 

 They leave the trees when about four weeks old, and 

 descend into the ground. Their effects are most visible in 

 June, when the trees, divested of their foliage, appear as 

 if scorched by fire. 



As the female cannot fly, the great point is to prevent 

 her from crawling up ; for this purpose various means 

 have been tried and are recommended. One of the most 

 effectual is to tie strij)s of canvas around the tree and cover 

 it with tar, renewing the tar during their whole season of 

 rising, or from October till May. Another is, to make a 

 close fitting collar of boards around the base of the tree, 

 and kee'p them covered with tar. Mr. Jonathan Dennis, of 

 Portsmouth, Rhode Island, obtained a patent for a circular 

 leaden trough filled with oil, which proves an effectual 

 preventive. 



Y. Caterpillars. — Of these there are many kinds that are 

 more or less destructive to the foliage of fruit trees ; but 

 the Caterpillar, described by Professor Harris as the 

 American Tent Caterpillar, is the one that commits such 

 general and extensive devastation in our orchards, and 

 especially in certain seasons. The moth dej^osits its eggs 

 in July, in large rings, on the branches of the trees ; 

 these remain in that state until the following season, when 

 they are hatched in the latter end of May or beginning of 

 June. Each ring produces three or four hundred cater- 

 pillars, and these weave a sort of web to live in. The ap- 

 pearance of a tree with three or four of these tents upon 

 it, and the leaves completely devoured, is really frightful. 

 There are two ways of destroying them : one is, to examine 



