132 ENTOMOLOGICAL SOCIETY 



on Pinus inops and P. tceda ; and fine blown and alcoholic 

 specimens are in the Museum, collected by Mr. Koebele. 

 Prof. Riley then presented the following : 



ON THE TIME OF TRANSFORMATION IN THE GENUS 

 LACHNOSTERNA. 



BY C. V. RILEY. 



At the late meeting of the Association of Economic Ento 

 mologists, at Champaign, one of the most interesting papers 

 read was that by Prof. S. A. Forbes on the larvae of Lachnos- 

 terna the paper being a summary of several years' study of 

 the larvae of different species. Prof. Forbes had found certain 

 satisfactory larval characteristics that permit the distinguish 

 ing of the different species in the arrangement and character 

 of the stiff hairs on the underside of the anal segment. This 

 fact will prove of great value to us, for it has always been 

 extremely difficult to refer any particular L,achnosterna larva 

 to its species. I have heretofore endeavored to do so by the 

 characters of the head and trophi, but have never felt great 

 confidence when it came to closely-allied species. How gen 

 erally applicable the distinguishing features recorded by Prof. 

 Forbes will prove to be experience alone will determine ; 

 but his studies cover several well-known species that occur 

 in Illinois. The feature, however, of Prof. Forbes' s paper 

 which I wish more particularly to call attention to relates 

 to the time of year when transformation takes place in this 

 genus. From recent experiments, Prof. Forbes is inclined 

 to believe that the history of the White Grub, as given by 

 authors, is a comedy of errors, and that the transformation 

 invariably takes place in late summer or early autumn. 

 The fact that transformation in some species, notably fusca, 

 takes place normally in the fall has been quite generally 

 known, at least to the members of this Society, and was 

 brought out in a discussion of Mr. Smith's paper, presented 

 before the Society at its October (1888) meeting, in which he 

 showed the value of the genitalia in determining the different 

 species. In my earlier writings onfusca, notably in the first 

 Report on the insects of Missouri, (1868), I mentioned the 

 spring transformation as the normal and the fall transforma 

 tion as the exceptional, having up to that time had more 

 occasion to obtain the insect in spring, with the turning up of 

 the ground, than in the fall. In later articles (notably in the 

 New York Semi -Weekly Tribune of November 12, 1875) I 



