130 



clover and timothy fields in low-lying pasture lands, but which dis- 

 appeared Suddenly owing to a fungous disease caused by the unusually 

 wet weather. Cutworms were very numerous in old sod lands, par- 

 ticularly the glassy cutworm [Sidemia devastatrix]. Potato flea-beetles 

 {Epitrix cucumeris) were extremely abundant, but can be controlled 

 by lead arsenate sprays. Potato beetles {Leptinotarsa decemlineata) 

 were more abundant than usual, but did not attack potatoes that were 

 planted late. The leaf-hopper, Empoasca mali, has recently begun 

 to attack potatoes. Some success has been obtained by using one 

 tablespoonful of Blackleaf 40 to one gallon of water, with 2 oz. of soap. 



DowNES (W.). The Strawberry Root Weevil in British Columbia. — 



oOth Ann. Rept. Ent. Soc. Ontario, 1919, Toronto, 1920, pp. 

 84-88. [Received 8th January 1921.] 



Otiorrhynchns ovatiis, L. (strawberry root weevil) has been the object 

 of study for some ten years in British Columbia, where it is one of the 

 most destructive pests of small fruits [R.A.E., A, i, 92; iii, 7 ; v, 

 469 ; etc.]. The most recent observations have proved that this is 

 undoubtedly an indigenous and not an introduced weevil. To the 

 previously known wild food-plants of the larvae must be added the 

 snowberr}' {Symphoricarpiis racemosns) and the oak ; and to the 

 cultivated plants, red clover. For this reason, strawberries should 

 never be planted following clover. Oviposition extends from mid- 

 May to mid-September. The eggs are laid promiscuously around the 

 plants, sometimes against the crown and sometimes a little below 

 the surface. It is evident from investigations in 1919 that not only 

 the summer generation, but also the over-wintered adults, deposit 

 eggs in large numbers, beginning in mid-May and continuing luitil 

 30th August, some individuals laying nearly 200 eggs. The adults of 

 the summer generation begin to oviposit in July, and continue to do so 

 until mid-September. It is thought that a proportion of the summer 

 generation does not die, but hibernates after ovipositing, and emerges 

 in the spring to oviposit again. Parthenogenesis has been proved 

 for 0. ovatiis by rearing adults from pupae, which oviposited though 

 isolated in glass vials, the eggs hatching into normal larvae. The 

 fertility of eggs varied from 68 per cent, in the case of those laid by 

 over-wintered adults to 80 per cent, in the case of those laid by the 

 summer generation. The weevils leave their hibernation quarters 

 (which may be in houses, among piles of stones, or, in warm climates, 

 in the crown of the strawberry plants) with the first fine weather, 

 generally about March, and are fairly active until May, when they 

 settle down on the strawberry plants ; migration is again observed 

 with the summer generation, which reaches a climax at midsummer, 

 gradually lessening until the time of hibernation. 



Following the principles of remedial measures that have previously 

 been laid down [loc. cit.'\, it is intended to demonstrate the possibility 

 of control in a badly infested district, the procedure being to pull up 

 and burn the strawberry plants at the end of August or beginning of 

 September. Leaving them until this time induces the adults to remain 

 in the field and oviposit there. The field will then be ploughed and 

 left fallow for about a month, all strawberry roots being removed from 

 the soil. Young larvae present in the soil should thus be starved, 

 and the land might be sown with autumn wheat, with vetches or 

 clover. The land may remain in clover two years, and should then be 



