108 MASSACHUSETTS AGRICULTURE. 



thousand acres of pine trees, many of them from two to three 

 feet in diameter and a hundred to a hundred and fifty feet 

 high." And many other like instances of the destructiveness 

 of insects might be mentioned ; but we pass to the consideration 

 of what must follow the destruction of birds. 



The reproductive energy of insects is truly wonderful. It is 

 said that a single pair of grain weevils have produced 6,000 

 young between April and August. The common varieties of 

 aphides, or plant-lice, which are found on almost every kind of 

 plant, are produced first from eggs laid the season before, and 

 then through the summer only females are developed. At 

 the last of the season males and females both appear, and eggs 

 are laid for the brood that hatches early in the spring. Reaumer 

 says that one individual in one season may become the progen- 

 itor of six thousand millions. The silk-worm moth produces 

 about 500 eggs ; the great goat-moth, about 1,000 ; the tiger 

 moth, 1,600 ; the female wasp, at least 30,000. There is a spe- 

 cies of white ants, one of which deposits not less than 60 eggs 

 per minute, giving 3,600 per hour. Such, then, is the enor- 

 mous fertility of insects, and some of them breed several times 

 a year, while most insectivorous birds breed but once a year, 

 and then produce but four or five young. But nature has 

 given to birds an appetite and an instinct which teaches them 

 exactly when and how to go to work to capture and destroy in- 

 sects and their eggs ; and if the number of eggs produced by 

 insects is wonderful, so the number destroyed by a single bird is 

 marvellous. Bradley says that a pair of sparrows will destroy 

 3,360 caterpillars in a single week. A young martin on a 

 church spire, opposite our window, was visited five times in as 

 many minutes by the parent bird, each time with an insect. A 

 brood of partridges will nearly exterminate the denizens of an 

 ant-hill in a single day. Woodpeckers are incessantly employed 

 in ridding the orchards of insects and their eggs, which they 

 skilfully discover under the pieces of dead bark. Robins, 

 throughout the spring and summer, are continually digging for 

 worms and grubs, which they find concealed beneath the surface 

 of the ground. A day or two since we noticed a common chip- 

 ping-sparrow capture a moth, and, upon depriving her of it, we 

 found it to be that of the common apple-tree caterpillar (Clisi- 

 ocampa Americana), so destructive to the orchards of New 



