LARVAL FORMS OF C0LE0PT?:RA 



PREFACE 



Tlie cliaraetor of this publication is d()nl)le, both s'niphie and de- 

 scriptive. It disi)hiys a series of liabitns-figiires and detail-draw- 

 ings of typical larvae pertaining- to the different families and sub- 

 families of the beetle order and it presents keys for their determina- 

 tion and classification. 



The figures are all original Avith the exception of one copied 

 from Schiodte's paper on the buprestid larvae^-^ and two figures 

 pertaining to Hydrochus from Avery Richmond's paper on the 

 IIydi'o])hilids,^'' which are properly accounted for in the explana- 

 tion to i)lates 22 and 80. All the figures on plates 84 to 86 and 

 most of the figures on plate 69 were drawn by Mr. J. A. Hj^slop. 

 the remainder by Mr. R. A. St. George and by one or the other of 

 the authors, from specimens in alcohol or from slides with micro- 

 scopic details present in the collection of beetle larvae in the United 

 States National Museum. There will be found only a few figures of 

 larvae belonging to the suborder Adephaga and to some of the 

 series of the Polyphaga. such as the Cerambycoidea and the Scara- 

 baeoidea. because the larvae of these groups have been particularly 

 well and completely illustrated by former authors in generally 

 known and in most cases easily available publications. 



The descriptions in the keys are based on original studies of 

 larval material at hand. 



These keys are intended to serve not only as a practical means 

 for the determination of beetle larvae, but also as a contribution to 

 the taxonomic discussion of the natural systematic grouping of the 

 (V)l(M)j)tera. 



In the selection of the sj^stematic characters for the single series, 

 families, and subfamilies preference has been given to those which 

 are most easily observed and least variable throughout the individ- 

 ual groups and which at the same time express the taxonomic rela- 

 tionshii) between associated groups, thus making it possible in most 

 cases to list these groups in a natural systematic sequence. Only in 

 the series key (pp. 10-15) has it not been possible or, rather, not 

 practical to do this. 



As a rule the classification of the larvae agrees with the com- 

 monl.v recognized classification of the imagines, and particularly 



^•^ J. C. Schiodte: "De metamorphosi Eleutheratorum observa- 

 tiones," Xaturhist. Tidssk. ser. TIT, vol. 6, 1869. 



'"^ E. Avery Richmond: "Studies on the biology of the aquatic 

 Ilydrophilidae," Bull. Amer. Museum of Natural Historj^ vol. 42. 

 1920. 



