1912 ENTOMOLOGICAL SOCIETY. 11 



On the 9th of ISTovember of this year puparia and full-grown larvae were found 

 beneath cabbage plants. 



The White Cabbage Butterfly (Pontia rapes, L.). This well-known pes^ 

 of the market gardener was more than usually abundant the past season. In the 

 latter half of August it was specially complained of and was doing much injury all 

 through the district. 



Another insect which was destructive to cabbages is the Diamond-back Moth 

 {Plutella maculipennis, Curt-) (Eig. 2). This insect has not occurred at Ottawa 

 in destructive numbers for some years. The nature of the season affects consider- 

 ably the abundance of this insect. In hot dry seasons, such as that of this year, 

 the outbreak is always more serious. Continued damp weather is, of course, de- 

 trimental to this insect. At the end of August its ravages in many market gardens 

 was very noticeable. On September 1st, I examined some cabbages and found the 

 caterpillars in various stages of development from 3 mm. to 8 mm. in length. 

 IVIany cocoons were also attached to the leaves, and one cocoon was seen from 

 which the moth had evidently just emerged. As a remedy, kerosene emulsion 

 has given good results, but the mixture must be applied as an under- 



I 



Fig. 2. Diamond-back Moth — a, caterpil- 

 lar; d, pupa; e, cocoon; / and h, moth 

 (all much enlarged). 



epray. In fields where the insect has been troublesome all leaves and left-overs 

 of cruciferous crops should be gathered up and destroyed so as to reduce as much 

 as possible the over-wintering brood of the insects. 



• Attacking Feuit Trees. 



Fruit insects were not particularly complained of during the season, but there 

 are a few which require mention. 



The American Tent Caterpillar {Malacosoma americana, Harr.) was the 

 most conspicuous insect of the orchard in the Ottawa district during the past 

 season. In orchards where no control measures were adopted many trees were 

 entirely stripped of foliage. Further mention will be made of this insect and the 

 Forest Tent Caterpillar under insects affecting forest and shade trees. 



Cankerworms were also reported as having been destructive in apple orchards, 

 particularly in the neighbourhood of Hull. 



The Lesser Apple Worm {Enarmonia prunivora, Wal^.). I regret to have 

 to report the finding of this insect in an orchard near Ottawa on August 10th. 

 Fortunately the infestation was very slight, only three apples of the variety Lub's 



