NATURAL ENEMIES. 379 



alighted upon its back, at the same time stinging it upon 

 or near the head, usually from behind. The result of this 

 was to completely paralyze the caterpillar, for a time at 

 least, when the wasp sucked the fluids from the body by 

 cutting holes through the body wall, beginning near the 

 head and working toward the posterior end. In some cases 

 the wasp nearly cut the head and first or second segment 

 from the body, and not unfrequently they were seen to cut 

 off a part of the caterpillar and fly away with it. 



The work of the wasps was not confined to a few isolated 

 cases, but they were busy every day between the hours of 

 9 A.M. and 3 P.M., killing and carrying away the caterpillars. 



One of the most remarkable observations of the season of 

 1895 was made by Mr. C. E. Bailey, a most careful and reli- 

 able field observer. While watching the birds at Wayte's 

 Mount, Maiden, for the purpose of discovering to what ex- 

 tent the different species of birds destroy the gypsy moth, 

 he saw a large insect seizing gypsy moth caterpillars and 

 flying away with them. Being provided with a net, he suc- 

 ceeded in capturing this insect while it was flying away with 

 a third-molt gypsy moth caterpillar. The insect proved 

 to be the American saw-fly ( Cimbex americana) . I am not 

 aware that this species has ever before been discovered to 

 be predaceous in its habits, but its mandibles and other 

 mouth parts are so developed that one can well believe it 

 capable of predaceous propensities. 



Mr. W. L. Tower reported that on July 17, 1894, he saw 

 a specimen of Tremex, or of a closely allied genus, take a 

 full-grown gypsy moth caterpillar and fly away with it. As 

 the insect was not captured, and under the circumstances 

 could not be closely identified, we should not have con- 

 sidered it worth while to mention it here but for the reason 

 that it may also have been the American saw-fly, and, if so, 

 a verification of the predaceous habits of that insect. An 

 examination of the mouth parts of Tremex columba will con- 

 vince one that this insect is not predaceous, and therefore 

 the probabilities are increased that the insect seen by Mr. 

 Tower was the American saw-fly. 



