29 



[Aspidiotus perniciosus] were entirely cleared of that pest. The 

 author still advocates the use of liquid sprays in apple orchards until 

 improved dust substitutes and machinery are available and until 

 further successful tests have been made. The value of dusting as 

 regards brown rot in sweet cherries and plums is also discussed. 



LocHHEAD (W.). New Notes on the Ecology of Insects. — 48th Ann. 

 Rept. Entom. Soc. Ontario for 1917, Toronto, 1918, pp. 85-91. 

 [Received 16th November 1918.] 



The aspects of insect ecology touched upon in this paper include 

 the inter-relations between insects and plants and the adaptations 

 of each to the other, the carriage or encouragement of plant diseases 

 by insects, the influence of birds on insect increase, and the behaviour 

 of insects to such stimuli as light, heat, moisture, chemical contact, 

 wind, etc. 



Brittain (W. H.). Notes on Two unusual Garden Pests in Nova 

 Scotia. — 48th Ann. Kept. Entom. Soc. Ontario for 1917, Toronto, 

 1918, pp. 94-99, 3 plates. 



The particulars of the habits of Gortyna tnicacea, Esp. (potato stem 

 borer) and Ceramica picta, Harr. (zebra caterpillar), given in this paper 

 have already been recorded from another source [see this Review, 

 Ser. A, vi, p. 241]. 



Veth (H. J.) & vAjsr Run (W.). Eenige Mededeelingen over de 

 Lasioderma-'Pla.2ig en hare Bestrijding. [Some Communications 

 on Lasioderma and Methods for combating this Pest.] — 

 Besoekisch Proef station, Djember, Java, 1915, 48 pp. [Received 

 11th October 1918.] 



This is a reprint of a report on investigations conducted in 1910- 

 1911. The authors then identified Lasioderma serricorne as the 

 tobacco pest concerned and established the fact that infestation 

 occurs before the tobacco is shipped from the Dutch East Indies, 

 where the most scrupulous cleanliness is imperative in the packing 

 sheds. The life-cycle of L. serricorne was foimd to require 80 days 

 under average conditions of moisture and a temperature such as 

 30° C. (85° F.). Temperatures up to 50° C. (122° F.) in the hold of a 

 ship do not hinder development, as this beetle can live at temperatures 

 up to 55° - 60° C. (131°-140° F.). At the summer temperatures 

 obtaining in Holland development is slow and a slight decrease gives 

 rise to a latent state and, finally, death. Though tobacco is not 

 damaged by contact with the fumes or liquid of carbon bisulphide, 

 all stages of L. serricorne are killed by direct exposure for 24 hours 

 in an air- tight container to the fumes of 60 c.c. per cubic metre of 

 space. If the insects are within bundles of tobacco the quantity 

 of carbon bisulphide must be increased to 180 c.c. These quantities 

 are efficacious at 45°-55° F. (8°-12° C), and at the temperatures 

 obtaining in the Dutch East Indies they must be increased 50 per 

 cent. Treated tobacco must be well aired afterwards. 



In a supplement to their original report, the authors confirm the 

 efficacy of carbon bisulphide, used under the above conditions, in killing 



