Dec, 8,1923 
Hornworm Septicemia 
485 
A treatment of hornworm septicemia would be of interest especially to 
those who rear the worms for study. Preventive measures are sug¬ 
gested as the most promising. The facts recorded in the present paper 
may aid in devising such means. 
SUMMARY AND CONCLUSIONS 
(1) A disease is occasionally encountered among larvae of Protoparce 
sexta and P. quinquemaculata of the family Sphingidae in which death is 
preceded by a marked septicemia and followed by a dark and almost 
black discoloration of the remains. 
(2) The name hornworm septicemia is here suggested and used for 
this disorder. 
(3) The disease in the worms inoculated by puncture runs a course of 
from 18 hours to 2 or 3 days in which the most prominent symptoms 
are loss of appetite, stupor, diarrhea, and a thin vomitus. The more 
important post-mortem changes are a softening and blackening of the 
remains, which on drying become shriveled. 
(4) The organism of the bacteriemia is a short, actively motile, non- 
sporulating bacillus to which the name Bacillus sphingidis is given. 
(5) The bacillus is readily destroyed by heat, drying, direct sunlight, 
and chemical disinfectants, but lives a long period in a moist environment 
at room temperature. 
(6) A comparatively small percentage of healthy worms die following 
inoculation with the virus of the disease by the feeding method, but 
practically 100 per cent of them succumb following puncture inocula¬ 
tions. 
(7) Cutworms, catalpa-moth larvae, and grasshoppers are very suscep¬ 
tible to puncture inoculations with Bacillus sphingidis and die speedily 
from septicemia. Indeed no insect species thus inoculated has been 
found immune. 
(8) No appreciable loss of virulence has been noted in cultures of this 
bacillus kept four years on artificial media. 
(9) Bacillus sphingidis is similar in many respects to B . (Coccobacillus) 
acridiorum d’Herelle, the cause of a grasshopper disease discussed by 
d’Herelle. They show, however, a distinct serological difference. 
(10) The transmission of the disease in nature probably takes place as 
a rule by way of the alimentary tract, the portal of entry of the germ 
not being definitely known. 
(11) The diagnosis of hornworm septicemia is suggested by the symp¬ 
toms and post-mortem appearances and can be made positive by the iso¬ 
lation of Bacillus sphingidis from the sick larvae or from the remains of 
those recently dead. 
(12) Apparently comparatively few hornworms die of the disease in 
nature during the more active growing season of the crops on which these 
worms feed. 
(13) Preventive methods are recommended to students of hornworms 
who may desire a treatment for this disease. Facts given in the present 
papers will serve as a guide in devising such means. 
(14) There is need for a much more comprehensive study of the group 
of insect diseases of which hornworm septicemia is a member, and the 
group of bacteria to which Bacillus sphingidis belongs. It is hoped that 
the facts given in the present paper will be useful in answering many 
