REPORT OP^ THE SOCIETY 35 



The Cabbage Butterfly, Pieris rapae L. 



The green caterpillar of the White Cabbage Butterfly, generally called 

 the cabbage worm, destroys large numbers of cabbages every year. (See 

 fig. 1, page d>2i). The butterflies are very common in gardens where they 

 may be seen depositing their eggs on the leaves of cauliflowers and turnips 

 in addition to cabbages, as well as, frequently, on the foliage of nasturtium 

 and mignonette. 



Remedies. — Dusting the infested plants with fresh pyrethrum insect 

 powder and cheap flour, one part of the former in four of the latter, is a use- 

 ful remedy. The powder and flour after throughly mixing together should 

 be kept in a tight vessel for 24 hours before using. The mixture may be 

 applied from a duster, sold by seedsmen, or from a cheese cloth bag tied on 

 the end of a short stick, the operator holding the bag over the plants and 

 tapping the stick with a cane held in the other hand as he walks along the 

 rows. 



Paris green ^ of a pound to 40 gallons of water, or dry arsenate of lead 

 2 pounds to 40 gallons, may be safely used as a spray for cabbages until the 

 heads are half formed. If either is used add the "sticker" mentioned on 

 page 39. 



The Diamond-Back Moth, Pliitella macidipenms Curt. 



The small green caterpillars of this moth are in some years decidedly 

 destructive to the leaves of cabbages, turnips, etc. The caterpillars are ver^' 

 active and when disturbed wriggle backwards. When full grown, at which 

 timetheyare about three-eighths of an inch in length, they spin open netAvork 

 cocoons on the lower sides of the leaves, and then change to the pupal state, 

 (See fig. 2, page 34). 



Remedies. — In gardens, spraying the infested plants with kerosene emul- 

 sion (page 40) will destroy the caterpillars if applied, as an under spray, to 

 come into contact with them. The remedies mentioned for the Cabbage 

 Butterfly are also useful if the mixtures are forced up among the leaves. 



The Zebra Caterpillar, Ceramica picta Harr. 



This insect occurs, intermittently, in eastern Canada in numbers suffi- 

 cient to cause considerable anxiety to growers of cabbages and turnips. 

 Fortunately, however, such outbreaks have generally occurred late in the 

 season, consequently the injury has not been so important as would other- 



