579 



with fertilisers to enrich the soil and stimulate plant growiih. Maize, 

 sorghum and allied crops sown in fields liable to infestation should be 

 planted as early in the season as possible, to enable the plants to get 

 a good start before the insect becomes active. 



Melaxder (A. L.). The Strawberry Root Weevil. — Separate, dated 5th. 

 January 1917, from Rept. Proc. Washington Stale Hortic. Assoc, 

 Pullman, 1917, 4 pp. [Received 23rd October 1917.] 



The strawberry root weevil, Odorrhi/nchus ovatus, an important 

 pest of strawberries in British Columbia [see this Review, Ser. A, v, 

 ]3. 469] occurs in the northern States all across the continent, having 

 been introduced from Europe about fifty years ago. The insect 

 hibernates in the larval stage, from 2-4 inches in the soil, pupating in 

 the spring, the adults emerging when the strawberry crop is ripe and 

 ovipositing bv the time it is picked. Mowing and harrowing the 

 ]:)lants in midsummer simply serve to scatter the weevils broadcast, 

 and they cannot be starved out of a field by ploughing out the plants, 

 as they can subsist on many host-plants. Experiments undertaken in 

 May, when the insects were all beneath the soil, reduced the problem 

 of their control to one of subterranean treatments. Crushing the 

 insects in the ground by means of sledge-hammers till the ground was 

 ])ulverised was found to be ineffective, as only half the weevils were 

 thus killed. Attempts to drown the weevils were a failure, as they 

 revived unharmed from a submergence of two days. Burning out the 

 insects was equally impossible, the insects just beneath the baked 

 surface being quite unharmed. Soaking the soil with contact 

 insecticides, such as strong soapsuds, oil emulsions and copperas 

 solutions, killed the plants, but failed to affect the weevils or their 

 larvae. Killing b}' poisonous fumes and gasses was attempted with 

 various substances including carbolineum, crude pretroleum, gasoline, 

 kerosene, turpentine, chloroform, carbon bisulphide, chlorine, sulphur 

 dioxide, acetylene and hydrocyanic acid gas. Of these, only the 

 last-named and carbon bisulphide gave any results, as the effects did 

 not extend for more than a few inches from the point where the 

 materials were used. Owing to the danger attending its use and the 

 fact that it killed the plants, the cyanide was discarded, but good 

 I'esults were obtained Avith carbon bisulphide in the following way. 

 The infested rows were covered with a 30-foot strip of canvas or 

 cloth sheeting made gas-tight by painting with linseed oil, under which, 

 at intervals of 5 ft., saucers each containing f oz. of carbon bisulphide 

 were placed. When necessary, the canvas was raised above the 

 saucers by wooden props to allow of free evaporation and made air- 

 tight at the edges by earth shovelled on to it. This treatment killed 

 the adults, larvae and pupae, as well as wireworms, Tipulids and 

 other insects, and is best ajsplied during the few days after the crop is 

 gathered, before migration and egg-laying begin. 



Maskew (F.). Quarantine Division. Report for the Month of June 



1917. — Mtkly. Bull. Cal. State Gommiss. Horiic., Sacramento, vi, 

 no. 9, September 1917, pp. 376-377. 



The following pests were intercepted : — ^From China : Lepidopterous 

 larvae in dried herbs, and weevil larvae in sweet potatoes. From 



