46 



AMERICAN FORESTRY 



CHICKADEES CLEAN THE BRANCHES OF INSECT EGGS 

 These little fellows are a valuable addition to every woodlot. 



of orchards and shade trees, and in forests we must, of 

 course, depend entirely upon the birds and the other 

 natural enemies of insects, for spraying is impossible. 

 Let us consider for a moment why birds are much more 

 effective in controlling certain pests than any other 

 means. Take the codling moth as an example, the worst 

 pest of the orchard and one that destroys over a million 

 dollars worth of apples every year. The little brownish 

 moth lays its eggs on the newly formed apples shortly 

 after the petals fall. The egg hatches and the larvae 

 immediately begins to dig down into the fruit. If the 

 spray has been put on at just the right time and has been 

 put on evenly and has not been washed off, so that the 

 larvae gets it in biting through the skin at its first meal, 

 the larvae is killed and the apple is saved. If, on the 



other hand, the poison does not happen to be on the 

 right spot at the right time, the larvae continues its way 

 to the center of the apple and is safe from all enemies. 

 The apple falls to the ground, the larvae matures and 

 leaves the apple and crawls up the trunk of the tree. It 

 then hides under a loose flake of bark where it spins a 

 cocoon about itself and prepares to spend the winter. 

 The next spring it transforms into the little moth that 

 goes about laying its numerous eggs on the newly form- 

 ing fruit. During its entire life cycle, therefore, there 

 are but a few hours when the poison spray is effective 

 against it and, inasmuch as all of the eggs do not hatch 

 at exactly the same time, it is obvious that the chances 

 of killing all of the larvae are very slight. With birds 

 as the destroying agents, however, there are two periods 

 when the codling moth can be controlled and each one 



A WINTER CREEPER 



The Brown creeper searches tlic^ bark cf trees (or insect eggs ami 

 hibernating insects. 



WOODPECKERS DESTROY BARK BEETLES 

 A useful downy woodpecker at work. 



is of considerable duration. First, when the moths trans- 

 form in the spring and the warblers and vireos and 

 other migrating birds are passing through the orchards, 

 and second, during the entire winter when the nuthatches, 

 and woodpeckers, and creepers are scrutinizing the trunks 

 of the trees for any possible insects that may be in 

 hiding. It is little wonder, therefore, that the birds form 

 a better method of control. 



Another familiar pest is the tent caterpillar which 

 is very destructive to all fruit trees. The reddish brown 

 moth lays its eggs in the form of incomplete belts on the 

 smaller branches, each belt or packet consisting of hun- 

 dreds of tiny eggs glued together and covered with a 

 varnish-like substance. These eggs hatch early in the 

 spring when the leaves are just beginning to unfurl and 

 the young caterpillars make their way to the nearest fork 

 where they spin a little tent of silk to protect them. They 

 work out from this tent, feeding on the leaves and adding 

 to the tent as they need more room. If there are many 

 colonics working on a tree they soon strip it of all its 





