190 



with bodies identified as R. pediculi. The Commission regards these 

 as identical with R. quintana and R. wolhynica, all three being forms 

 that have been described by different observers as the causal agent of 

 trench fever. 



MiJLLER (A.) & Rasch (W.). Schadliche Insekten und Nager. [In- 

 jurious Insects and Rodents.] — Frankfurt a. Main, Deutsche Ges. 

 f. Schadhngsbekampfung, 1922, 23 pp., 2 col. plates. 



The pests dealt with include the principal insects attacking man 

 or his household goods and foodstuffs. In the case of each insect 

 general notes are followed by short descriptions of the various stages 

 and of their biology. The aim of this pamphlet is to popularise exact 

 information regarding these pests, and this is achieved in a simple 

 and effective manner. 



Rudolfs (W.). Chemotropism of Mosquitoes. — New Jersey Agric, 

 Expt. Sta., New Brunswick, BuU. 367, March 1922, 23 pp., 1 fig. 

 [Received 1st August 1922.] 



The object of these experiments was to investigate the general 

 causes that excite mosquitos to attack man. Previous work on the 

 effect of colour, light, humidity, odour and temperature, is reviewed, 

 and the technique employed in the present observations is described. 

 As no " standards " for the behaviour of mosquitos upon reception 

 of chemical stimuli were known to the author, this has been recorded 

 in terms of activity, particulars of which are given. The work was 

 carried out on Aedes sollicitans and A. cantator in open salt marsh 

 meadows near the coast of New Jersey, 8-14 freshly caught indi- 

 viduals being used for each experiment. Attractive and " activating " 

 substances were tested again in the open with larger quantities. The 

 observations on the influence of temperature and the human breath 

 are similar to those of other authors [R.A.E., B, x, 135]. 



The substances are divided into several classes : attractive, acti- 

 vating merely, indifferent and repellent, and the results are summarised 

 by the author as follows : — 



Perspiration, blood, urine and sebaceous secretion (human and cow) 

 proved unattractive. Some of their constituents and intermediate 

 decomposition products were decidedly attractive (phenylalanine, 

 haemoglobin). Several amino-acids influenced the activity of mos- 

 quitos or induced them to suck. Carbon dioxide and ammonia, 

 ultimate decomposition products of the human body, proved to be 

 strongly activating, inducing the insects to stab and to exhibit " satis- 

 faction " or " pleasure." A combination of carbon dioxide and 

 ammonia with a particular temperature and degree of moisture (such 

 as to reproduce the conditions of the breath) was highly activating. 

 It seems that these stimuli, produced in quantity by the human body, 

 play an important role in the attraction of mosquitos. This explains 

 why a motionless sleeper and animals of great variety, amphibians, 

 reptiles, birds and mammals, are all subject to attack. 



Baerg (W. J.). Regarding the Habits of Tarantulas and the Effects 

 of their Poison. — Scientif. Mthly., Garrison, N.Y., xiv, no. 5, 

 ■May 1922, pp. 481-488, 5 figs. 



Experiments made in Arkansas to determine the degree of noxious- 

 ness of the poison injected by the tarantula, Eurypelma steindachneri,. 



