254 EXPERIMENT STATION EECORD. 



attacks of Nematus erichsonl. The larv:p of this pest may be jarred from in- 

 fested trees or the trees may be sprayed with helleboi-e. Paris green, or lead 

 arsenate. 



Bombyx pini, G. Roeig {Min. Bl. K. Prenss. VerioaU. Landio., Domiinen u. 

 Forsten, 3 (1907), No. 3, Anz. Beilaffe, pp. 51-60, figs. -J). — A brief account is 

 given of the life history and habits of this pest of the pine with notes on its 

 natural enemies. In combating it the use of sticl^y bands about the trunks of the 

 trees is recommended. They should be applied not later than the end of March. 

 The operation under German conditions costs not more than .$4 or .$5 per hectare. 



The development of the larvae of Hypodernaa bovis, H. Jost (Ztschr. Wiss. 

 Zooh, 86 (1907). Xo. ',. pp. 6U-'^'15, pi. 1, figs. 3).— The present account of the 

 life history and developmental stages of the ox warble fly is one of the most 

 complete and satisfactory studies of this insect which have thus far been pub- 

 lished. The author finds that the egg of Hypodenna hovis does not develop on 

 the skin of the host but begins its development in the gastric portion of the 

 esophagus. In this position the first stages of the larva are regularly found In 

 large numbers soon after the season when the warble flies are most numerous. 



A majority of the larviB migrate through the submucous tissue of the esopha- 

 gus during the season from .July to November or occasionally until February and 

 then return to the lower^end of the esophagus, from which point they bore their 

 way through the subserous tissues of the thoracic and abdominal cavities and 

 finally reach the spinal canal. In the greater percentage of cases the larvse, in 

 making this migration, follow the mediastinum, pillars of the diaphragm, renal 

 capsule, and intermuscular connective tissue of the lumbar muscles. 



In the si>inal canal the larva' live largely in the ei>idural tissue where they 

 are foimd, as a n}le, from December to March. After remaining about 3 months 

 in this ])osition the larv;v wander (mtward through tlie intervertel)ral foramina 

 and finally reach the subcutis, where they remain from .January until .June. 



As a rule, the lifeVycle of this insect requires about a year and 9 months. 

 Some of the larvte seem to be greatly delayed in their development and a few 

 may fail to complete their growth. The larvae of the first stage are supplied 

 with rows of spines. 



The role of the wood tick in Rocky Mountain spotted fever, and the sus- 

 ceptibility of local animals to this disease, II. T. Kicketts (Jour. Aiiier. Med. 

 J.sxoc, .'I'.i (1907), Xo. 1, PI). 2'i-27). — A study of the life history of the wood 

 tick disclosed the fact that it may be found at almost any time during the winter 

 attached to horses and cattle. The tick is almost everywhere present in the 

 region where spotted fever occurs, and numerous experiments with guinea pigs 

 showed conclusively that the disease may be carried by them. Gophers are 

 readily infected with the disease, although they are not quite so susceptible as 

 are guinea pigs. It is likely that gophers are largely responsible for the main- 

 tenance of the disease. 



Ticks on fowls, A. Hempel (B(A. Agr. [Hdo Paulo], 7. set:, 1906, No. 10. pp. 

 Ji73-.'i75). — The life history and habits of Argas persiciis, A. miniatus, and A. 

 reficrus are briefly described. 



The comparative effect of certain poisons on insects, J. Bars acq (Rev. 8ci. 

 [Paris], 5. ser.. 7 (1907), No. 23, pp. 721, 722). — A comparison was made to 

 note the effects of barium chlorid, Paris green, and arsenate of lead upon insects 

 in various stages of development, particularly species of Hyponomeuta. In 

 these experiments it was found that the effect of poisons upon Insects varies 

 not only according to the amounts used but according to the structure and stage 

 of growth of the insect. The action of poisons is greatly modified by the meta- 

 morphosis of insects and appears to be entirely suspeuded during the processes 



