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Vol. LHI. GUELPH, JUNE, 1921. No. 6 



POPULAR AND PRACTICAL ENTOMOLOGY. 

 STRIGODERMA ARBORICOLA FAB.— ITS LIFE-CYCLE (SCARAB. 



COLEOP). 



BY VVM. I'. IIAVHS. 

 Assistant Entomologist* Kansas Agricultural Experiment Station. 



*Contribution No. 59 from the Entomological Laboratory, Kansas State Agric- 

 ultural College. This paper embodies some of the results of the investigations under- 

 taken by the author in the prosecution of project No. 100 of the Kansas Agricultural 

 Experiment Station. 



Introduction. 



Continuation of the work on the hfe-cycle of insects injurious to the roots 

 of staple crops, begun at this station in 1916, has revealed the following life- 

 cycle of Strigodcnna arboricola Fab. This species of the family Scarabseidae, 

 sub-family Rutelini. occurs somewhat generally throughout the state of Kansas. 

 Popenoe (1877) records the beetles from western Kansas, and states that they 

 are quite rare at Topeka. Casey (19LS) gives the range of Strigodenna arbor- 

 icola as occurring from New Jersey and Canada to Kansas. Only at rare in- 

 tervals are they stifficiently abundant in Kansas to be of economic importance. 



An opportunity to secure enough specimens to begin life history studies 

 was afforded the writer by the collection of a number of the beetles by Prof. 

 Geo. A. Dean at Abilene, Kansas, June 20, 1919. At this place they were 

 found abundantly feeding on rose blossoms in a nursery where they were doing 

 considerable damage. These beetles were brought to Manhattan where their 

 subsequent life history was worked out. To date, the writer has been unable 

 to find any reference to the life-cycle of this species in American literature. 



The beetles were kept in large, covered tin pails containing damp soil. 

 \ arious blossoms were fed to the adults and the soil examined daily after ovi- 

 position began. Tlie freshly laid eggs were transferred to small depressions 

 in closely packed soil in one ounce tin salve boxes where they were examined 

 daily for hatching. Upon hatching, the young grubs were placed in individual 

 salve boxes containing loose, damp soil, which was changed once or twice a 

 week during the warm weather. They were kept constantly in a rearing cave 

 (McColloch, 1917), where a somewhat constant temperature was maintained. 

 The young grubs were fed bran until the second molt, when wheat grains were 

 substituted/ When the prepupal condition occurred, fresh soil was packed 

 tightly in the salve box to ai)proximate the natural condition of the pupal cell 

 in which the transformations to the pupal and adult conditions took place. 



Food Plants. 



Hart and Gleason ( 1907, p. 244) record Strigodcnna arboricola adults on 



flowers of clover, rose, Opuntia hidiiifiisa and Monarda punctata. Blatchley 



( 1910, p. 986) records the beetles as occurring most con>monly on flowers of 



wild rose, blackberry and the water willow, Dianthcra americana Linn. The 



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