18 FIELD WORK AGAINST GIPSY AND BROWN-TAIL MOTHS. 



man's shoulder and fastened in the center with twine, the upper part 

 being folded down, forming an excellent shelter for the caterpillars. 

 By examining the burlaps frequently and crushing the larvae under- 

 neath great progress was made in destroying the pest. The free edges 

 of the burlap should be kept loose from the trees so that the larvae 

 can easily crawl under the folds. This method can not be used 

 advantageously until the caterpillars are about half grown, as they 

 do not often seek shelter until that time. The expense entailed is 

 considerable, but it is one of the most effective measures where exter- 

 mination of the insect is desired. 



STICKY BANDS. 



Numerous attempts were made to use a sticky material, such as 

 printer's ink, tar, or other substances, applying them to bands of 

 tarred paper on the trunks of trees to prevent the caterpillars from 

 ascending. Several tons of a German product, known as "raupen- 

 leim," were tried but none of these preparations proved satisfactory 

 for wholesale use. Success in using such bands was not attained 

 until the material known as tanglefoot came into use, about five 

 years ago. 



CUTTING AND BURNING. 



In order to prepare infested territory so that it could be treated 

 effectively and economically, it was necessary to cut out and burn 

 the brush and sprout growth, as well as trees that were hollow and 

 partially decayed. This method reduced to a minimum the number 

 of trees to be burlapped or otherwise treated, and by removing the 

 low growth the larvae were forced to feed on the trees where they 

 could be more easily destroyed. 



A method employed against the young caterpillars hatched from 

 egg clusters located in stone walls or rocky areas was to clean out all 

 brush and undergrowth during the winter. As soon as the larvae 

 appeared in the spring the ground and walls were burned over by 

 using a device known as a cyclone burner. This consisted of a 15- 

 gallon oil tank, on which was mounted a small force pump. The oil 

 was conducted through a hose to an iron extension rod, at the end 

 of which a nozzle of the Vermorel type was fitted. The fine mist 

 of oil forced from the nozzle was ignited and the ground and walls 

 burned over. To secure best results a large ball of flame should be 

 maintained which can be forced .into the cracks or cavities in walls or 

 ledges in order to destroy the larvae. Paraffin gas oil or a light grade 

 of crude petroleum can be used. Two men are required to operate 

 this outfit satisfactorily. The action of the oil soon destroys the hose, 

 so that it seldom lasts more than one season. 



