116 ENTOMOLOGICAL SOCIETY 



CochliopocUs, are shed, and a decided change in color is the 

 general rule, but no true molting occurs. 



In general, after this molt the larvae of different species of 

 Saw-flies become strikingly alike in coloration, assuming a 

 dull greenish or slate color on the dorsum and sides and 

 yellowish below the stigmata and bordering the anterior mar 

 gin of the first segment. The shining black head of some Saw- 

 flies, as, for instance, Monophadnus bardus Say, after this molt, 

 becomes in general whitish, with a smoky shade above ; the 

 black thoracic feet also become light. 



This molt is not accompanied, as in the earlier ones, with 

 an increase in the size of the head, and after it the larva does 

 not feed, but wanders about in search of a suitable place to 

 form its cocoon. 



The loss of spines and tubercles has been noted particularly 

 in the case of the Raspberry Saw-fly, Monophadnus rubi Harris 

 and allied spiny larvae feeding on the ash and oak, the loss of 

 efflorescence in Harpiphorus varianus Nort, and the alteration 

 in color in the species mentioned and a considerable number of 

 additional species. 



The first reference to this feature in the history of Saw-fly 

 larvae in American writings on Tenthredinidae occurs, I be 

 lieve, in an account of the Ash Saw-fly {Monophadnus bardus 

 Say) by Prof. Popenoe and the writer, in the annual report of 

 the Kansas Experiment Station for 1888. 



Mr. J. G. Jack also notes this feature in his recent account 

 of the Dogwood Saw-fly {Harpiphorus variamis Norton) in 

 Garden and Forest (Vol. II, p. 520). 



A somewhat extensive examination of European works on 

 Tenthredinidae leads to the belief that this final molting has 

 been generally overlooked. As an illustration of this, Andre, 

 in his very valuable and complete Monograph of the Tenth 

 redinidae of Europe and Algiers, certainly does not refer to it. 



Cameron, however, in his Monograph of the British Phyto 

 phagous Hymenoptera, states that such change is undergone 

 by most Tenthredinid larvae, and that with certain species the 

 larvae become brighter colored rather than duller and less con 

 spicuously marked. I have not observed this latter to be the 

 case in any of our American species, and the assumption of a 

 more showy coloration is certainly the exception. His expla 

 nation of this molt, with accompanying change in appearance, 

 is on the ground of protection, which he argues is especially 

 needed during the period in which the larvae, after abandoning 

 their food-plant or galls, are wandering about before entering 

 the ground or otherwise concealing themselves. The dull 

 coloring protects the edible forms from enemies by rendering 



