BURLAPPING. 167 



there will be nothing for them to climb upon, and they may 

 be all destroyed by burning the ground over with a cyclone 

 burner. (See Plate XX.) If it is desired to prevent a new 

 growth of brush, the ground should be burned over in August 

 while the sap is in the plants, and again in the following 

 spring. After such treatment the plants will not so readily 

 sprout and a frequent repetition of the burning will result 

 in killing their roots. 



Burlapping. 



Early in the summer of 1891 burlap or bagging was first 

 used by the employees of the State Board of Agriculture as 

 a means of assembling the gypsy-moth caterpillars so that 

 they might be readily found and destroyed. It was noticed 

 that before the caterpillars had attained half their growth, 

 they daily left the leaves on which they had fed during the 

 night and clustered in sheltered places, such as cavities in 

 the trunks of trees or the under sides of branches or other 

 natural objects. They began thus swarming in the second 

 week in June. As they grew larger the tendency to seek 

 shelter during the day became more and more noticeable. 

 They often wandered in search of shelter, leaving trees 

 which did not offer secure hiding-places and retiring to 

 rubbish heaps, stone walls and other places of refuge to 

 pass the day. It was seen that whenever old garments, 

 cloth or paper were thrown in the forks or wound around 

 the trunks or branches of infested trees, the shelter of such 

 materials was sought by the larvae during the heat of the 

 day. The bulky nests of the English sparrow also served 

 them as hiding-places. 



The conclusion having been reached at this time that 

 spraying with Paris green was only partially successful in 

 destroying the caterpillars, other means of destruction were 

 sought. Experiments were made to find an inexpensive yet 

 durable shelter which would prove attractive to the cater- 

 pillars, and which could be readily examined by the men, 

 thus serving in a measure the purpose of a trap. A cheap 

 eight-ounce burlap was found to be the best material for 

 this purpose. A large quantity of baled burlap was pur- 

 chased and cut into strips about twelve inches wide. These 



