ECONOMIC ZOOLOGY — ENTOMOLOGY. 353 



stages of the larvae. It may, however, cause injury to young seedlings and is 

 not a safe remedy for plants recently set in the field. 



" The value of tar pads, or hexagonal tar paper collars, for the purpose of 

 preventing the adult of the cabbage maggot from placing eggs about the stems 

 of the plants has been previously demonstrated, but, in spite of its effec- 

 tiveness, this method of protecting cabbage has not been generally adopted by 

 truck growers. The tests herein described show that tar pads will protect 

 early cabbage from the pest at a cost of about $1.40 per thousand plants. 

 Truck growers who are subject to losses by the cabbage maggot are urged to 

 test the tar pads experimentally as a basis for more extensive operations against 

 this pest." " In the employment of tar pads as a means of protecting early 

 cabbage, truckers should arrange to transplant seedlings of good size with 

 rather long stems. Disks can not be satisfactorily adjusted about small plants, 

 for in setting such seedlings it is necessary to place them low in the soil 

 so that only the leaves protrude." 



Descriptions are given of the tar pads and the tool for making them. 



A study of the bionomics of the common rat fleas and other species asso- 

 ciated with human habitations, with special reference to the influence of 

 temperature and humidity at various periods of the life history of the 

 insect, A. B.\cot {Jour. Hyg. [Cambridge] Plague Sup. 3 (Wl.'f), pp. U7-654, 

 pis. 8, figs. 15). — Ceratophyllus fasciatus, Pulcx irritans, Ctenocephalus canis, 

 Lcptopsylla miiscuJi, and Xenopsylla cheopis were experimented with in the 

 studies here reported. The author describes the apparatus and methods em- 

 ployed in making the observations, reports general observations on the bionomics 

 of fleas, and gives accounts of an experimental study of the influence of external 

 conditions and the influence of low temperature on the various stages. 



On the survival of bacteria in the alimentary canal of fleas during meta- 

 morphosis from larva to adult, A. W. Bacot (Jour. Jlyg. [Cambridge] Plague 

 Sup. 3 (1914), pp. 655-664). — The results of the experiments here reported show 

 (1) that the alimentary canal of the flea larva may become infected with the 

 following bacteria if mixed with its food, namely, Bacillus pyocyaneus, B. en- 

 teritidis, Staphylococcus albus, and S. aureus; (2) that an infection of the 

 larval gut may persist until the resting period of the larva in the cocoon, and 

 (3) that there is no satisfactory evidence that such infection can survive the 

 pupal stage. No infection of the larval gut was demonstrated in the experiment 

 with B. riolaccus. 



The effect of the vapors of various insecticides upon fleas (Ceratophyllus 

 fasciatus and Xenopsylla cheopis) at each stage in their life history and 

 upon the bedbug (Cimex lectularius) in its larval stage, A. W. Bacot (Jour. 

 Hyg. [Cambridge], Plague Sup. 3 {19U), pp. 665-681, fig. 1).—The results of 

 investigations with the vapor of various insecticides are presented in tabular 

 form. 



A coleopterous (clerid) larva predaceous on codling moth larvae, D. E. 

 Merrill (Jour. Econ. Ent., 7 (1914), ^'O. 2, pp. 251, 252).— The larva of an 

 undetermined clerid beetle is quite an important enemy of the codling moth at 

 Mesilla Park, N. Mex., where the observations were made. 



Studies of the Arizona Thurberia weevil on cotton in Texas, B. R. Coad 

 and W. D. Pierce (Proc. Ent. Soc. Wash., 16 (1914), No. 1, pp. 23-27).— The 

 experiments here reported demonstrate the ability of the two varieties of the 

 boll weevil to interbreed and produce fertile offspring. The work has also re- 

 sulted in the determination of the developmental period for certain seasons of 

 the year. 



Reducing insect injury to stored com, W. E. Hinds (Jour. Econ. Ent., 7 

 (1914), No. 2, pp. 203-211). — This paper deals with some preliminary facts 



