REPORT OF THE EXTOMOLOaiST AXl) KOTAXIST. 



SESSIONAL PAPER No. 15 



229 



pillar, close to the head, and only relaxed their hold when full-grown, to spin their 

 light silky cocoons among the leaves close to the dead body of the caterpillar, which 

 they had destroyed. ' 



THE CABBAGE PLUS I A 

 (Plusia hrassicae, Riley). 



Fig. 15. — The Cabbage Flusia : a, caterpillar ; 

 b, cocoon ; c, moth. 

 (Cut kindly len'. by Dr. S. H. Forbes.) 



This insect is frequently a serious enemy to the market gardener in the United 

 States; but I have never received, a complaint concerning its work in Canada until the 

 present year. This has been a matter of some surprise to me, because it has been the 

 cause of much loss in States of the Union close to our boundaries, both in the East and 

 in Minnesota. In July last, specimens of the caterpillars were sent in from the i^orth- 

 west, and moths were taken at Ottawa and St. John, N.B., for the first time. 



' Regina, Assa., July 18. — The caterpillars I send have been doing some damage ia 

 gardens here. I observed them first on potatoes about three weeks ago ; they ate small 

 round holes in the leaves. They have since turned their attention to lettuce. In my 

 own garden they ate a row of green lettuce right to the ground before I found out 

 what was the matter. They have since got into the bronze variety ; but do not appear 

 to devour it so voraciously as the other. I have found them in a neighbour's garden 

 eating the leaves of celery mi.ch in the way they attack potatoes. The colour of the 

 caterpillar is a bright, rather blue, shade of pea-green, somewhat whitish along the 

 back. It is very lively, especially when small, and when disturbed rolls itself into a 

 ball. Some of the caterpillars are now spinning their cocoons in the lettuce leaves. 

 Please let me know what species it is, and what remedy to apply.' — J. R. C. Honeyman. 



The Cabbage Plusia, also known as the Cabbage Moth, and, in the caterpillar form, 

 as the Cabbage Looper, is said to be, where it occurs, the worst pest known on lettuces 

 grown in forcing houses. It would appear as though this insect were becoming year 

 by year a worse pest, and that the area where it occurs as an injurious insect is 

 enlarging. It may be that before long we may, in Canada, have to reckon with this 

 insect as a regularly recurring enemy. 



The most practical means of preventing- the work of the caterpillars on lettuces 

 in forcing houses is stated to be the keeping of the ventilators closed with mosquito 

 netting. It is thought that the eggs are sometimes laid on plants before they are taken 

 into the houses, but probably the moths gain access to forcing houses more generally 

 through the ventilators. There are many other plants in greenhouses which are 

 attacked by this caterpillar. In the autumn they have been found troublesome among 

 chrysanthemums, cutting off the flower buds. Smilax and other plants have also been 

 injured. In the open ground the caterpillars are most destructive to cabbages and 

 related plants, such as have smooth leaf surface. They feed on the surface of the 



