FOREST INSECTS AND FUNGI lOQ 



or buff color, and with a wing spread of about two inches, is 

 too heavy to fly. 



Life History. — In this country as well as in Europe this 

 insect has but one generation a year. The minute eggs are laid 

 in clusters of from four hundred to five hundred eggs each. 

 Yellowish hairs give to these clusters a sponge-like appearance, 

 and although they are usually on the trunk of the tree, or the 

 side of a log, they are often concealed in crevices and under 

 rocks. Eggs are laid in the latter part of the summer and 

 usually do not hatch into caterpillars until the following spring, 

 from the end of April until the middle of June. The cater- 

 pillars reach full growth in about ten days, spin filmy cocoons 

 usually on the trunks of trees, and finally emerge as moths in 

 late July or August. Most of the damage is done in the cater- 

 pillar stage, and the dissemination of the insect is also due 

 largely to the activity of the caterpillar. Eggs and caterpillars 

 are distributed by artificial means, as on cars, automobiles, etc. 



Treatment. — The conspicuous color of the egg mass and the 

 long duration of the insect in this stage make this the most 

 vulnerable stage to combat. The masses may be collected and 

 burned, or, as is most generally done now, they may be treated 

 with a coating of creosote. In the woods, extreme vigilance is 

 necessary to find these clusters. All brush, especially near 

 stone walls, should first be removed. 



Several methods of destroying the caterpillars are employed. 

 During the month just after hatching — from the middle of May 

 to the middle of June — the trees may be sprayed effectively 

 with arsenate of lead. This spray will not injure the tenderest 

 foliage when diluted with water in the ratio ten pounds to one 

 hundred gallons of water. One method of preventing the cater- 

 pillars from climbing trees is either to bind the trunks with tar 

 paper, or to smear the bark with fish oil or a sticky German 

 product known as " raupenleim " (caterpillar glue). This glue 

 remains viscid for months. Another kind of band, used as a 

 trap, consists of a strip of common burlap a foot wide which 

 is tied around the trunk with a single string at its middle and 



