254 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



beetle. The studj^ of this species was taken up as a result of its grow- 

 ing importance as a pest of staple crops, and is being carried on as a 

 part of the project on ''Insects Injurious to the Roots of Staple Crop 

 Plants" of the Kansas State Agricultural Experiment Station.^ 



Ligyrus gihhnsus belongs to the coleopterous family Scarabseidse, sub- 

 family Dynastini. Fortunately, the references to this species have not 

 been interspersed with synonymical confusion. Two described species, 

 L. morio Lee. and L. juvencus Oliv., have been united with gibhosus by 

 Horn (1875, p. 143). 



The common names "carrot beetle," "muck beetle," "sunflower 

 beetle, " and " Ligyrus stalk beetle" have been proposed, none of which, 

 because of their limitations, seem appropriate.^ 



History and Economic Importance 



First mention of damage due to this insect is made by Comstock 

 (1880, p. 274), who records adults as preying upon dahlias and the roots 

 of sunflowers, both wild and cultivated. Webster (1889, pp. 382-383) 

 records the beetle injuring carrots in Indiana, and Bruner (1891, p. 

 17) found them destructive to sugar beets in Nebraska. Weed (1895, 

 pp. 156-157) reported the adults burrowing into and destroying stalks 

 of corn in Mississippi, the damage being confined to limited areas, 

 principally on corn land that had recently been in pasture. Howard 

 (1898, p. 93) writes of injury to corn in Louisiana and carrots and 

 dahlias in Wisconsin. The beetles are reported by Forbes and Hart 

 (1900, p. 513) as abundant in Illinois and a brief account of the species 

 is given. Chittenden (1902, pp. 32-37) describes the egg and adult and 

 gives some notes from the United States Entomological Bureau on this 

 species which he calls the "carrot beetle." The length of the egg 

 stage was found to be ten days. Carrots are mentioned as the favorite 

 food, while cotton and sweet and Irish potatoes are added to the list 

 of host plants. Control methods are also suggested. This paper, 

 although meager, is, by far, the best discussion of the species. Wash- 

 burn (1902, pp. 47-49) reports damage to sweet corn and cites a futile 

 attempt to use trap-lanterns in infested fields as a means of control. 

 Essig (1915, pp. 245-246) states that adults have been reported feeding 

 on the foliage of oak and elm and thinks that the grubs may be re- 

 sponsible for much damage to crops in California. A recent paper by 

 Davis (1916, p. 264) states that "Ligyrus gibhosus and L. relictus have a 

 one-year life cycle, the beetles pupating and appearing above ground 

 in fall and reentering the ground to pass the winter, not laying eggs 



1 The writer wishes to acknowledge his indebtedness to Prof. Geo. A. Dean, Dr. 

 P. S. Welch, and Mr. J. W. McColloch for kindly advice and assistance in preparing 

 this paper. 



