146 



THE AMERICAN ENTOMOLOGIST. 



the Ash? The actions of the higher animals 

 seem to be governed by a motive power very 

 similar to reason, and differing from it perhaps 

 only in degree, whilst the instinct of insects 

 often lies wholly beyond its domain ; and, there- 

 fore, its nature will probably forever elude the 

 grasp of the human understanding. 



Insects, with respect to their social habits, 

 are divisible into two classes: the gregarious, 

 ■which live together in communities, and the 

 solitary, which seek their subsistence independ- 

 ently, eaeh one for itself. This distinction is of 

 vast importance in its relation to the destructi- 

 bility of the noxious species. This practical 

 point may be illustrated by the habits of the 

 present species at different periods of the day. 

 At one time a brood of well grown caterpillars 

 will be seen scattered over every part of a tree, 

 and the attempt to capture and destroy them 

 would be a hopeless task. But wait an hour 

 or two, and all these insects will return and 

 congregate in a tent eight or ten inches in 

 diameter, when they can be removed by a single 

 grasp of the hand. The solitary or separate 

 feeding insects are generally beyond our con- 

 trol, but there is no excuse for permitting our 

 trees to be damaged by the gregarious species, 

 of which the Tent Caterpillar is an example. 

 A few of these insects may be fouud and de- 

 stroyed in the moth and chrysalis state. A 

 much larger number can be detected and de- 

 stroyed in the egg state, especially on small or 

 nursery trees ; but they for the most part escape 

 our sight on lai-ge trees, owing to their small- 

 ness and to the fact that the varnish which 

 covers them is almost precisely the color of the 

 bark of the tree. But the tents of the cater- 

 pillars, when a week or more old, are very 

 conspicuous objects, and are easily discovered 

 and destroyed, either by crushing them under 

 the foot or throwing them into the fire. When 

 too high on the tree to be reached by hand, they 

 can be captured by thrusting a stick into their 

 nests, and turning it round and round, so as to 

 entangle the web and the caterpillars together. 

 This caterpillar, like others, is subject to the 

 depredations of parasitic insects, but their num- 

 ber and names have not yet been determined. 

 Tlic insectivorous birds generally reject the 

 hairy caterpillars, and therefore we get but 

 little help from them in the extermination of 

 the present species. The Baltimore Oriole, or 

 Golden Robin, is sometimes seen pecking at their 

 nests, but they do not make of them a common 

 article of diet. The only birds that I know 

 which devour them greedily are the American 

 Cuckoos {Coccyzua Americanus and erythroph- 



thalmus). Mr.Nutall, the ornithologist, speak- 

 ing of the former species, says he has known 

 them to make their chief diet, both for them- 

 selves and their young, of the Tent Caterpillar. 

 Bu* these birds are not numerous enough to 

 effect much in checking the spread of this pre- 

 valent insect. Fortunately, however, owing to 

 the gregarious habits of these caterpillars, we 

 have it in our power to protect ourselves from 

 their ravages, by the payment of a small install- 

 ment of that eternal vigilance which is the price 

 of the husbandman's success. 



APPLE TREE BORERS. 



IIV .lOHX F WIELAXDY, JEFFERSON CITY, Mo. 



In Central Missouri the Flat-headed Apple- 

 tree Borer, {Chrysohothris femorata, Fabr.) 

 seems in many localities to be more common, 

 and consequently more destructive, than its 

 congener, the Round-headed Borer, and in most 

 of the orchards I have had occasion to examine, 

 scarcely ten trees out of every hundred can be 

 said to have escaped its ravages altogether. I 

 have, last summer, devoted a considerable share 

 of my leisure time to an investigation of the 

 habits of these mischievous insects, and my 

 researches have resulted in satisfying me that a 

 little care and attention are all that is necessary 

 to guard trees effectually from the ravages of 

 these borers. 



In my own orchard, containing several hun- 

 dred remarkably thrifty young three and four- 

 year-old trees, at least one-half were attacked 

 last summer— not less than twenty eggs, per- 

 haps, being deposited on one tree, i^ some 

 instances — but, by a liberal use of soap, aided 

 by an occasional application of the knife, used 

 before the larvae were old enough to commit 

 any material damage, I have succeeded in 

 eradicating Ihem so completely that not one 

 single Chrysobolhris is left in my orchard to tell 



' ' the tall- of the doom and destruction of his race, ' ' 



while the rows of smooth aud vigorous young 

 trees scarcely show the trace of a scar or an 

 abrasion. 



The first young larvas, last year, made their 

 appearance sometime during the month of June, 

 being noticed, as usual, on the south and south- 

 west sides of the trunks, ranging all the way 

 from the foot to the crotch of the trees, with 

 here and there one on the larger limbs. I am 

 inclined to think that the eggs hatch very soon 

 after they are deposited upon the surface of the 

 bark by the female insect, as, notwithstanding 

 my almost daily examinations, I have seldom 



