REPORT OF THE STATE ENTOMOLOGIST I914 27 



practically unharmed. Apple orchards are occasionally injured by 

 the caterpillars, the larvae apparently thriving upon this tree. 



In addition to these, this species has been recorded as feeding upon 

 linden, locust, peach, plum, cherry, rose, sweet gum, dogwood, black 

 gum, sour gum, black walnut and hickory. 



Natural enemies. Some thirty- two species of native birds are 

 known to feed upon forest tent caterpillars, the robins, orioles, vireos 

 and nuthatchers being particularly serviceable. The encouragement 

 and protection of native birds would seem to be one of the most 

 economical methods of preventing periodical outbreaks by this and 

 other destructive leaf feeders, particularly those confining their 

 attacks largely to forest trees. 



A number of predaceous and parasitic insects prey upon the 

 caterpillars. It is probable that prior to the studies of Mr A. F. 

 Burgess on certain Carabidae, the value of predaceous beetles as 

 natural enemies had been greatly underestimated. His work has 

 shown that the introduced European Calosoma sycophanta 

 is a remarkably efficient enemy of the gipsy moth and there is no 

 reason why it and its allies should not be of material service in con- 

 trolling outbreaks by native species. Several Hymenopterous para- 

 sites have been reared in numbers from the cocoons of the forest 

 tent caterpillar, though certain Dipterous parasites appear to be 

 even more efficient natural checks. 



Rearings last summer from lots of cocoons received from various 

 localities showed a relative scarcity of natural enemies, considering 

 the fact that this outbreak was of several years standing. For ex- 

 ample, from one lot received from Westbury, 8 moths and only 6 

 parasites were obtained, another from Port Henry produced 39 moths 

 and but 7 parasites, while a third lot from New Russia yielded 3 

 moths and no parasites. These figures would indicate that material 

 reduction in the pests another season can hardly be attributed to 

 the beneficial activity of parasites. 



Remedial measures. Forest tent caterpillars are easily con- 

 trolled by early and thorough applications of a poison, such as 

 arsenate of lead, using 2 pounds to 50 gallons of water. The best 

 results are secured if the application is made before any material 

 injury is caused. The need of this treatment, as pointed out above, 

 can be accurately forecasted by examining the trees any time during 

 the winter for the purpose of determining the abundance of the egg 

 belts. Recent advances in the development of spraying outfits have 

 resulted in an equipment which makes it possible to spray fairly open 

 forest lands for the very moderate sum of $5 or $6 an acre. These 



