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OBSERVATIONS ON THE BEAN LEAF-BEETLE. 

 (Cerotoma trifureata Forst.) 



Our knowledge of the life history of this species while not entirely 

 complete, is so nearly so that no special effort has lately been made to 

 learn more concerning it. Nevertheless a few facts have been observed 

 and reported which are deserving of record. Among the cases of 

 reported injury in 1899 that will be cited are some of unusual severity, 

 a circumstance of some interest, since it bears out the prediction made 

 by the writer two years ago (Bui. 9. n. s.. p. 64) that the species was 

 obviously increasing in abundance and injuriousness and liable to 

 become a pest to the bean crop of the central Atlantic portion of the 

 United States. 



Injurious occurrence >n Virginia and northward. — The species was 

 as abundant in 1899 in the localities visited by the writer in and near 

 the District of Columbia as in the two previous years. 



May 30, 1899, specimens of the beetle were brought to this Division 

 by Mr. George G. Hill, who stated that the inject was doing consider- 

 able damage to young beans at Falls Church. Va. 



About the same time Dr. S. D. Judd reported the species in great 

 abundance, and injurious to beans about a foot high, in the vicinity of 

 Marshall Hall, Md. 



June 5 we received word through Mr. E. B. Calvert, of this Depart- 

 ment, that thi- species, a specimen of which was received. wa< doing 

 much damage to string and Butler bean vines at Petersburg. Va. 



June 6. Mr. E. M. Wright. Eureka. 111., observed this species, 

 which he identified from the description and illustration given in Bul- 

 letin No. 9, on wax beans in his vicinity. 



Injurious occurrence >r> Alabama. — June 15 we received specimens 

 of the larva from Mr. E. S. Earle. Auburn. Ala., together with 

 affected bean stalks which were believed to be injured by it. The 

 insect was described as an old offender. Writing- under date of July 

 -I. our correspondent stated that this species had been excessively abun- 

 dant that year and had practically destroyed all the early plantings of 

 beans: those planted after the middle of May, however, escaped injury. 

 The beetles were described as being on hand, waiting for the plants 

 to come up. and when the ground was cracked open by the seedlings 

 the beetles went down and injured the minute plants badly before they 

 could get above ground. In this respect injury resembles that so well 

 known as being caused by the striped cucumber beetle, Diahrotica 

 vittata, to cucumber and other cucurbits. The crop was sprayed 

 three or four times with Paris green, but this did not save it. 



Accompanying Mr. Earle's first letter were specimens of the roots 

 and subterranean stems showing work both of the larva and of what 



