204 



seeming' like an auimated dagger directed at the mouth of her 

 prey. This moment of attack is the most dangerous of the 

 ordinary life of the insect and is always preceded by a care- 

 ful examination of the surroundings and the establishing of 

 special means of retreat by gnawing away retreats into the 

 rotten wood if this is necessary. Even with these precautions 

 taken, if the prey is active and particularly^ if it is a species 

 with ])owerful mandibular development the conflict may result 

 in the death of the Sclerodernuis. ]\rany such deaths were 

 observed under experimental conditions when Scleroderinus 

 immigrans was placed with the larger CVrambycid larvae, such 

 as those of Lagocheirus obsoletus Thomson, Copt ops aedificator 

 (Fabricius), and even Prosop]ii.'< lianl-ii ( Fabricius), and 

 it was also the case in many instances Avitb the endemic s]iecies 

 in conflict with Lepidopterous larvae. 



.Vfter the initial attack upon the licad. th ' S'rlrrodci'niu-'^ 

 proceeds more at leisure to paralyze the remainder of the larva 

 and this is frequently a long drawn out and protracti'd ]iro- 

 cess. While some 2:)articular effort seemed to be directed to- 

 ward the presumed position of thoracic and anal ganglia, the 

 observation of hundreds of such struggles has convinced , me 

 that the stinging reflex is in no way precise Imt that sooner 

 or later the grul> will be stung in every region which gives 

 a muscular response to the feeding of the female or to her 

 exploratory movements over the body of the grid). To me it 

 seems the venom is injected into the body fluid and produces 

 its paralyzing effect when finally it comes in contact witli the 

 nerve centers. Frequently tlie earlier stinging di(l not result in 

 complete and permanent paralysis and in cases where the 

 female was removed from the prey soon afttr oviposition, 

 lhe grubs revived and were able to dislodge the feeding larvae 

 of ScJerodermiis. The venom did not appear to arrest the 

 transformations of beetle larvae if they had been attacked dur- 

 ing the prepupal stage after completing feeding and instances 

 occurred where such larvae completed their transformations 

 after the larvae of Sclerodcrinns had beo-un to feed. 



