10101 ECONOMIC ZOOLOGY ENTOMOLOGY. 851 



genus Anuraphis. AplitH hrevis of Handerson represents the same species and 

 therefore becomes a synonym. 



Trench fever, R. T. Strong et al. {London: Henri/ Froicde. and Hodder & 

 Stoughton, 1918, pp. VIII +U6, pis. 12, figs. lJf6).—A. detailed report of the 

 Commission Medical Research Committee, American Red Cross, of which a pre- 

 liminary report has been previously noted (E. S. R., 39, p. G58). 



Included in this report are the details of two groups of transmission experi- 

 ments with rcdiculus huinanus (pp. 143-274). The authors' conclusions are 

 that P. humanus corporis is capable of transmitting trench fever, not only when 

 it passes directly from an infected man to a new host but also even to a third 

 man, to whom it may be transferred two days later. The relative frequency of 

 positive results in these experiments, which closely simulated natural condi- 

 tions, indicates that tliis louse is an important agent in the spread of trench 

 fever in France. It does not appear to transmit the infective quality to its 

 offspring through the egg. " Lice were certainly rendered infective in 9.5 days 

 and probal)ly in 6 to 7 days by feeding them on a trench-fever patient from the 

 latter part of the first to the seventh days of illness, inclusive, and then on a 

 healthy man for about three days. . . . There is evidence that, if the virus 

 undergoes development in the louse, it requires 6 to 10 days to do so ; there is 

 a little evidence that suggests the minimum incubation period to be about four 

 days. Lice may remain infected for at least 10 days and possibly 13. 



" Lice may transmit trench fever under conditions in which the injection of 

 the saliva appears to be a more prominent feature than the presence of a few 

 minute granules of louse feces in the vicinity of the bitten ai-eas during the 

 feeding process. The incubation period of the disease produced under the con- 

 ditions cited in [one case] was more protracted tlian in some of the other 

 transmission experiments; after exi^osure twice a day for 21 days one man 

 developed the disease in 27 days and the otlier in 38 days from the time of 

 first being bitten. 



" The exact role of the mouthparts in transmitting the virus is still unde- 

 termined. In four experiments, in wliich infective louse feces were rubbed 

 into scarifications, the average period of incubation of the disease was 9 days, 

 ranging between 7 and 10 days. From two experiments it would appear that 

 the blood of recovered cases is not infective 100 days after onset of the disease." 



Mosquitoes in relation to yellow fever, H. Noguchi {Jour. Expt. Med., 30 

 {1919), Ng. Jf, pp. 4OJ-J1IO). — The experiments here reported show that symp- 

 toms and lesions closely resembling those of yellow fever in man can be in- 

 duced in guinea pigs by the bite of female stegomyias ( [Stegomyia] Aedes 

 calopus) that have previously sucked the blood of a yellow fever patient or of 

 an animal experimentally infected with Leptospira icteroides. 



" With mosquitoes infected directly from a yellow fever patient the infec- 

 tivity seems to become manifest after a longer period of incubation than with 

 those infected with the animal blood. In the former, at least 12 days are said 

 to be necessary before they become infectious, and this hypothesis seems to 

 he borne out by the present experiment. On the other hand, the mosquitoes 

 Avhich were engorged with the infected blood of the guinea pig were found to 

 be capable of transmitting the disease within 8 days after the feeding. This 

 discrepancy may be explained by the fact that the number of leptospira exist- 

 ing in experimentally infected guinea pigs is far greater than that in human 

 blood. The frequency with which positive transmission by the stegomyia was 

 obtained in both instances was very small, indeed, in view of the number of 

 mosquitoes employed. . . . 



" Whether or not L. icteroides can survive and multiply only in the body of 

 6". calopus and not in other varieties or genera is yet to be determined. 



