UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 828 
Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
Washington, D. C. PROFESSIONAL PAPER May 10, 1920 
BACTERIAL WILT OF CUCURBITS. 
By Frederick V. Rand, Assistant Pathologist, and Ella M. A. Enlows, formerly 
Assistant Pathologist. Laboratory of Plant Pathology. 
CONT 
Page. 
Foreword 1 
ENTS. 
Virulence tests 
Page. 
25 
Snmmpr t.ra.risTni.^inn of wilt , ?, 
Some host relations 
31 
Winter transmission of wilt 16 
Distribution of bacterial wilt 
34 
Relation of the wilt bacteria to cucumber 
beetles 21 
Control 
Summary 
36 
41 
FOREWORD. 
The studies of the writers on bacterial wilt of cucurbits (caused by 
Bacillus tracheipMlus Erwin F. Smith), published in 1915 and in the 
spring of 1916, have been continued during the past three seasons. 
The previously published work 1 demonstrated that the striped cu- 
cumber beetle (DiahroticavittataF&b.) and also the 12-spotted cucumber 
beetle (D.duodecimpunctataOliY.) are the most active and probably the 
only summer carriers of this bacterial wilt in the localities investi- 
gated. Some evidence was given that the striped cucumber beetle 
may be also a winter carrier. 2 It was shown that the soil had no 
relation to the disease either as a source of early spring or of summer 
infection. Seed from wilted plants in all cases failed to transmit the 
disease, and all attempts at infection through the stomata gave 
negative results. A fair degree of control was obtained by early 
treatments with Bordeaux mixture and lead arsenate combined, and 
it was shown that this control was related not only to the repellent 
and insecticidal qualities of the mixture, but also to a direct bacte- 
ricidal action upon the wilt organism. 
The present paper deals with further studies of the relation of soil 
and insects to the distribution and control of the disease, and includes 
also a portion of our work with the causal organism itself. 
1 Rand, F. V. Dissemination of bacterial wilt of cucurbits. (Preliminary note.) In Jour. Agr. Re- 
search, v. 5, no. 6, p. 257-260, pi. 24. 1915. 
Rand, F. V., and Enlows, Ella M. A. Transmission and control of bacterial wilt of cucurbits. In Jour. 
Agr. Research, v. 6, no. 11, pp. 417-434, 3 figs., pi. 53-54. 1916. 
2 Other species of Diabrotica have not been tested. 
142179°— 20— Bull. 828 1 
