1906.] BIRDS ABOUT OUR FARM HOMES. 185 



of which would soon overrun a continent. Kirkland has com- 

 puted that the unrestricted increase of the gypsy moth would 

 be so g-reat that the progeny of one pair would be numerous 

 enough in eight years to devour all the foliage in the United 

 States. 



Many insects are remarkably destructive because of the enor- 

 mous amount of food which they must consume to grow rapidly 

 to maturity. ]\Iany caterpillars eat daily twice their weight of 

 leaves, which is as if an ox were to devour every twenty-four 

 hours three-quarters of a ton of grass. Their voracity and 

 rapid growth may be shown by the statement of a few facts : 

 A certain flesh-feeding larva will consume, in twenty-four 

 hours, two hundred times its original weight; a parallel to 

 which, in the human race, would be an infant consuming, in 

 the first day of its existence, fifteen hundred pounds of food. 

 There are vegetable feeders, caterpillars, that during their pro- 

 gress to maturity within thirty days, increase in size ten thou- 

 sand times. To equal this remarkable growth, a man at his ma- 

 turity would have to weigh forty tons. Mr. Leopold Trouve- 

 lot, who introduced the gypsy moth into this country, says: 

 " The food taken by a single American silkworm {Telea Poly- 

 phemus) in fifty-six days equals in weight eighty-six thousand 

 times the primitive weight of the worm." In view of such 

 statements, need we wonder that the insect world is so de- 

 structive and so potent a power for harm ! 



When we consider the dangers arising from the immense 

 numbers, fecundity, and voracity of insects, the fact that 

 insects new to cultivated crops are constantly appearing be- 

 comes a source of grave apprehension. Every year economic 

 entomologists, who are constantly increasing our knowledge 

 regarding insect pests, discover new insects attacking important 

 crops or trees. Dr. Lintner made a list of insects injuring 

 apple trees in the United States, which was published in the 

 appendix to his first report as entomologist of New York state. 

 It contained one hundred and seventy-six species, while large 

 though lesser numbers have been found on the plum, pear, 

 peach, and cherry. Dr. Packard described four hundred and 

 forty-two species which prey upon our -oaks, and believed it not 

 impossible that ultimately the number of species found on the 

 oaks of the United States would be from six to eight hundred or 

 even one thousand. The list of insects which feed on grasses, 



