PROC. ENT. SOC. WASH., VOL. 23, NO. 3, MAR., 1921 57 



New Jersey, 4 October, 1920; coll. C. H. Hadley; among mixed 

 material of various Scarabaeid larvae of same size. Species not 

 reared.) 



(Figs. 19, 20, 22, 26 and 27.) 



Length of mature larva, nearly 25 mm. ( = one inch). 



Extreme, width of head, 3.1 mm. 



Larva close to Popi/lia japonica and identical with this species in every 

 character mentioned in the "brief characterization" of that form (p. 5). Both 

 have same size, same general proportions; however, the unidentified form differs 

 in the following structural details from Popillia japonica. 



Frons (fig. 19) with only two setae between the interior marginal seta and the 

 middle of frontal suture. 



Labrum (fig. 19) with posterior transverse elevation rather distinct and 

 sculptured with closely set, rather large, obtuse, oval protuberances. 



Molar part of right mandible (fig. 26) with heel (ca) almost square; dorso- 

 posterior angle (a) slender, twice as wide and projecting over and entirely cover- 

 ing the bristle bearing base; small anterior lobe (cr 1) of crown fusiform, with 

 elongate elliptical outline. 



Last abdominal segment (fig. 27) with two parallel rows of about ten spines; 

 distance between posterior end of rows and anal slit somewhat shorter than 

 length of rows. 



The present larva probably belongs to the genus Strigoderma, 

 being that North American genus which most closely approaches 

 Popillia. According to the size of the mature grub and the fact 

 that the only Strigoderma species which occurs in the locality in 

 question is Strigoderma arboricola Fabricius, the larva must 

 belong to this species, if it is a Strigoderma larva at all. That 

 possibility, namely, can not be disregarded that the grub might 

 be an Anomala larva. All the American species at present 

 included in the genus Anomala may not be congeneric, and con- 

 sequently the brief characterization given by Schiodte of 

 Anomala aenea may agree only with part of the many Anomala- 

 species. The larva of Anomala binotata Gyllenhal, which is 

 reared from egg by Dr. F. C. Craighead (Hopk. L T . S. 1 1872 x) 

 corresponds exactly with Schiodte's characterization of Anomala. 

 If, however, the grubs, mentioned by John J. Davis (I.e.) as 

 Anomala spf>., really belong to that genus, it certainly will be 

 necessary to separate those species from the rest of the genus, as 

 they according to Davis are "distinguished by the angular anal 

 split." It must at the same time be borne in mind that this 

 character never, like the arrangement of the anal spines, has 

 been considered one of specific or generic value, but always as a 

 character of tribal value. 



Serving as a summary the following key may express the 

 systematic differences between those North American and 

 European grubs which are closely related to or recorded as most 

 likely to be mistaken for Popillia japonica. 



