. Annual report. Entomological Society of Ontario; Insect pests; Insects -- Ontario Periodicals. 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). Th
. Annual report. Entomological Society of Ontario; Insect pests; Insects -- Ontario Periodicals. 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
Size: 1984px × 1260px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectinsectp, bookyear1872
