35 



When the solitary tree has been once completely cleared of eggs, it 

 can be kept clean by putting around the trunk, just below the branch- 

 ing, a broad band of cotton batting. This band should be tied near 

 the bottom by a soft string that will yield to some extent to growth, 

 and then should be turned down so as to form a sort of inverted 

 funnel, making a barrier that cannot be surmounted by any cater- 

 pillar. A belt of tree lime, tree tanglefoot, or other sticky ma- 

 terial will answer the same purpose. 



If a tree is found to be badly infested, and it is desired to pre- 

 vent defoliation, that may be done by spraying with any one of the 

 arsenites. As to the strength and character of the material, reference 

 should be had to the section dealing with insecticides. 



THE BAG WORM, DROP WORM OR BASKET W^ORM. 



Thyridopteryx ephemerwformis, Harr. 



This curious insect is sometimes very troublesome and, unlike 

 most other leaf-feeding caterpillars, attacks conifers as readily as it 



Fig. ao. 



The bag worm : a, the caterpillar removed from its case ; b, male pupa ; c, female adult ; d, male 



adult ; e, a bag cut open to show the egg-mass as it appears in winter ; /, caterpillar with 



bag of ftiU size ; g, very young larvse with little conical bags carried upright. 



does all kinds of deciduous foliage. Arhor vitw hedges are especial 

 sufferers and are often killed when the insects have not- been dis- 

 covered in time. 



