481 



Usually it takes about a year after the appearance of tlie fly for the 

 red or brown fungi to become established naturally, but this may be 

 much accelerated artificially. A good time for such measures as 

 pinning up infected leaves is when the fly has become abundant, as 

 the insects will then help to spread the spores mechanically. Spraying 

 with a solution containing the spores is more effective about two 

 weeks later, when many eggs have hatched and while the insect is in 

 the susceptible larval stage. This should not be done with an apparatus 

 that has been used for fungicides, and any apparatus must be well 

 washed out before use. Brown fungus should be rubbed off the leaves 

 into the water with the aid of sand to break up the mycelium. 



The sooty film or blight on leaves and fruit is not necessarily due 

 to the fly. Heavily sooted trees have been observed quite free from 

 fly, but infested by a scale which also gives rise to cases of sooty 

 bhght on mango. On this account fly infestation cannot be certainly 

 inferred from sooty fruit seen at the packing houses, though most 

 of the fruit thus aft'ected is due to it. 



Blackmoee (E. H.). Entomology. — Rep. Brit. Colunibia Prov. Mus. 

 Nat. His., 1919 ; Victoria, 1920, pp. P16-P23, 2 plates. 



The caterpillars of Malacosoma jiluvialis, Dyar (forest tent cater- 

 piller) were particularly numerous in the early spring, but before 

 becoming fully fed were killed in large numbers by a disease of fimgous 

 or bacterial origin. Several species of locusts caused great damage 

 in the south-eastern part of the Province. Hemerocampa vetusta 

 gidosa has apparentlv only one brood and not two as was previouslv 

 thought [R.A.E., A, \m, 479]. 



This report also includes a hst of the less common insects taken in 

 British Columbia during the year. 



KoMP (W. H. W.). The Use of Carbon Bisulphide against the White 

 Grub. — Soil Science, New Brunswick, N.J., x, no. 1, July 1920, 

 pp. 15-28. 



The damage done to lawns, strawberry beSs, etc., by subterranean 

 insects, and the difficulties of controlhng the grubs concerned are 

 discussed. Experiments described indicate that carbon bisulphide 

 may be an efl'ective soil fumigant in situations where the grubs cannot 

 be reached by cultural methods. The maximum dose that can be 

 used without injury to grass is sHghtly less than 5 oz. per square foot, 

 while the minimum dose for white grubs [Lachnosterna] is about 

 1 oz. Temperature greatly influences the effectiveness of fumigation, 

 less than 1 oz. at 85° F. or above being as effective as 1 oz. at 65° F. , 

 while the maximum dosage for plants is probably affected also. Injec- 

 tions should be made about 6 inches apart. The soil moisture should 

 be medium (10 per cent.) to wet (20 per cent.) to get good results. 

 Wetting the surface of soil that is too dry seems to increase the effective- 

 ness of the treatment. The charge should be placed several inches 

 below the point where the grubs are working. These small dosages 

 seem to have a stimulating effect upon la'wn grasses, but the high cost 

 of carbon bisulphide will considerably restrict its use. 



(717) ^ B 



