710 EXPERIMENT STATION RECORD. 



death the nymph rapidly assumes a deep purplish-black hue, the body 

 appears swollen, and in the course of 24 hours or more becomes a sack 

 of grael-like fluids. It can not then be easily lifted without breaking. 

 In adults at death, the body has a moist appearance, especially in the 

 cephalic region of tlie ventral surface of the abdomen. Later this 

 appears evident throughout, but the chitinous crust does not collapse 

 and unless broken the offensive fluids within are not noticed. The odor 

 is characteristic, being more pronounced and putrefactive than that of 

 the normal squash bug. 



A microscopical examination showed short bacilli, single or in pairs, 

 measuring 1.2-1.8/^ by O.G-O.S//, some of which stained homogeneously 

 and others more deeply at the poles. 



As to the general distribution of the bacilli within the body, in bugs 

 at the time of death the microorganisms are to be found in great abun- 

 dance in all parts of the perivisceral cavity and are well differentiated 

 from the blood coagulum. Besides the muscles and the stout walls of 

 the alimentary organs, very few structures of the organism are unat- 

 tacked. Investigation t^howed that the bacteria probably gained 

 entrance through the spiracles. 



Cultures of the microorganisms obtained from dead insects and from 

 the body fluid of a sick nymph showed it to be both aerobic and facul- 

 tative anaerobic, and that it liquefles gelatin. Its characteristics and 

 growth are described in some detail. It grows well at living-room tem- 

 perature, but is easily killed by high temperatures, an exposure to 125° 

 F. for 1 hour on 2 successive days or for 2 hours on 1 day proving fatal. 

 The optinuim temperature proved to be between 83 and 90° F. Experi- 

 ments indicate that the organism is not attenuated by continuous 

 growth in the laboratory. 



Infusions from cultures on agar evidently contain a toxic principle 

 which was found fatal to many insects, including water beetles, 

 immersed in it. 



In the inoculation experiments infusions of the dead bugs together 

 with both fresh and old isolation cultures were emi)loyed. In all (;ases 

 control experiments were carried on in both field and laboratory with 

 Anasa tristis and Blissus leiicoptervs. It was found that Bacillus ento- 

 motoxicon is very readily communicated, especially to the young bugs, 

 and judgnig from the author's tables infusions of the dead bugs are the 

 best material for inoculation. In experiments with grubs and larva' of 

 other insects, external application of infection material did not give 

 successful results. 



A copious bibliography is given. 



Notes from the entomological laboratory, C, W. Woodworth 

 {California ^Sta. lipt. 189.J, pp. 249-253, pi. 1). — Suggestions are given 

 for various pieces of entomological apparatus — a folding net, setting- 

 board, labels, glass and metal insect boxes, dissecting dish, labels for 

 slides, slides for cover mounts, books for cover glass n)ounts, racks for 

 bottles and pocket compound microscope, being the subjects. 



