entomologists since 1895, and the results in the main show that this is 

 not an effective measure. In 1912, however, the Prefectural Agri- 

 cultural Experiment Station at Ehime reported that Chilo simplex 

 may be entirely destroyed by immersing infested rice-stalks in water 

 for a minimum of 28 hours. 



In the course of laboratory experiments to determine this point 

 the author first examined the question as to how long the borer can 

 survive without air. For this purpose he placed the insects in the 

 vapour of carbon bisulphide, assuming, as many authors have done, 

 that this gas does no harm to the insects. Though there is some 

 variation according to the stage of the insects and the temperature, 

 after 24 hours in the gas 82 per cent, of the insects exposed were 

 dead at ordinary temperatures. 



In investigations as to the resistance of the borer to heat, no 

 deaths occurred in any of the instars exposed to a temperature of 

 35-6° C (96° F.) for 24 hours; in the case of the second and third 

 instars exposed to 41-8°— 43-1° C. (108°— 110° F.) for 6 hours, of 

 the former 27-7 per cent, were dead, while of the latter none died ; 

 in the fourth and fifth instars at 38°-41° C. (101°— 106° F.) for 

 24 hours, only 4-4 per cent, were dead ; 45° C. (113° F.) killed all of 

 the first instar larvae within an hour, of the second instar 74 • 7 per cent, 

 and of the fourth and fifth 35-7 per cent. ; 45° C. (113° F.) killed all 

 instars within 2 hours, as did 50° C. (122° F.) within 5 minutes. 



In warm water death is caused by the combined effect of heat and 

 suffocation. All of the first instar are killed in water at 45° C. (1 13° F.) 

 after 5 hours ; of the second instar after 1 hour ; the third, fourth and 

 fifth instars in water at 40° C. (104° F.) after 5 hours, and in water at 

 45° C. (113° F.) after 1 hour. In water at 50° C. (122° F.) all instars 

 can be killed in 5 minutes. In this experiment the temperature of the 

 water was constant. Warm water, the temperature of which gradually 

 decreases, is not effective. 



When rice-stalks infested with the borers were submerged, the great 

 majority escaped, and 50 per cent, of the remainder were^ only killed 

 in water at 23°— 33° C. (73°— 91° F.) after 24 hours' submergence. 

 In field experiments the ratio of borers killed is still less. 



As some entomologists are of opinion that petroleum might be 

 effective for killing the escaping borers, tests of this were made, but it 

 was not found effective at a strength tliat does not injure the rice-plant. 



Lambert (F.) & Peronne (P.). Le Tche {Ciuirania triloba, Hance). — 

 Ann. d'Ecole Nat. Agric, Montpellier, xvii, no. 2, July 1918- 

 July 1919, pp. 86-104, 10 figs. [Received 2nd November 1920.J 



In the course of this paper dealing with the cultivation and uses of 

 Cndrania triloba, it is suggested that silkworms {Bombyx mori) fed on 

 these leaves are less susceptible to disease. B. pernyi also thrives on 

 them. 



ZoATTi (— ). La Cocciniglia o Pidocchio del Fico. [The Fig Scale, 

 Ceroplastes nisei.]— Riv. Agrie., Parma, xxvi, no. 44, 29t]i October 

 1920, p. 549. 



The fig scale, Ceroplastes nisei, is common in Italy. From May to 

 June, or even later, the female lays from 800 to 1.500 eggs. After an 

 incubation period of 15 days the very mobile larvae spread over the 

 plant and are carried by the wind to neighbouring ones. They attach 



