266 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



of coarse hairs or spines inclined more or less inwardly. These rows 

 may be straight and parallel or more or less curved; short or long; and 

 the spines in the rows may be sparsely or closely placed according to 

 species. The anal slit is in the form of an obtuse angle. 



Grubs of other genera which resemble the Lachnosterna grubs by 

 having the two rows of spines on the underside of the last abdominal 

 segment are Anomala, PhytaUs, Listochelus, Polyphylla, Euphoria, 

 and Cotinis {^ Allorhina) . 



The living larva? of Euphoria and Cotinis are at once separable be- 

 cause of their dorsal locomotion. The relatively small head which is 

 j&nely reticulated, short legs, the transverse anal slit, two rows of 

 unusually stout spines on the ventral surface of the anal segment and 

 the straight hairs and spines on the same segment at once separate 

 grubs of these genera from grubs of Lachnoster^ia. Euphoria grubs 

 differ from those of Cotinis by their smaller size; the spines of the two 

 median longitudinal rows on the anal segment are directed inwardly 

 and are not so thick or stout, and the ventral surface of the anal seg- 

 ment is not uniformly clothed with hairs, there being bare spaces not 

 to be found in Cotinis. 



Polyphylla grubs are noticeably larger than those of Lachnosterna, 

 when mature, the head is darker, and has a slight roughened reticula- 

 tion. The two rows of stout spines, about ten spines in each row, on 

 the under surface of the anal segment are short, being about a third 

 the length of the segment and the upper surface of the anal segment is 

 thickly covered with fine recumbent hairs. The anal slit is obtuse. 



The grubs of Ano7nala, Listochelus and PhytaUs are ver}^ close to 

 those of Lachnosterna and we are at present unable to satisfactorily 

 distinguish between grubs of these four genera except by direct com- 

 parison but no doubt substantial characters will be found when we 

 obtain a sufficient number of grubs of the first three mentioned genera. 



Grubs of such common species as Trichius piger, Cotalpa lanigera, 

 Ligyrus relictus, L. gibhosus, Osmoderma eremicola, Cyclocephala spp. 

 Dyscinetus trachypygus and Stratcegus antceus are sometimes mistaken 

 for grubs of the genus Lachnosterna but may at once be separated by 

 the absence of the two rows of spines on the ventral surface of the anal 

 segment and all of these species have a transverse anal slit. 



Cyclocephala and Cotalpa are the most fikely to be confused because 

 they are found in fields with Lachnosterna grubs and attack the same 

 crops. Cyclocephala grubs have a rather smooth light brown colored 

 head which is inconspicuously reticulated. The spines on the under- 

 side of the anal segment are sparsely and uniformly placed, moderately 

 long, and hooked, Cotalpa grubs have a brownish or tan colored head 

 which is very slightly and noticeably reticulated and the under surface 



