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Tlie folio vriug notes were presented by tlie author : 



NOTES ON INJURIOUS INSECTS IN CANADA IN 1892. 



By James Fletcher, Ottawa, Canada. 



There liave been uo outbreaks of injurious insects in Canada during 

 the past season which demand special mention. 



Cutworms, usually so abundant, were very little complained of. The 

 species most abundant at Ottawa was Agrotis ochreog aster. I was 

 able to clear up part of the life-history of this species during the past 

 season. Eggs laid by a female caught in the iield during October only 

 hatched the following spring (April 20). They were fidl-grown and 

 pupated on June 10, and the first moths appeared July 20. These 

 eggs were laid by a female of the form ochreogaster, and all the thirteen 

 larv?e carried to maturity produced that form also. The larv?e from 

 the time they first hatched had the apx)earance and habits of cut- 

 worms. This is one of our most injurious species in Canada, the 

 larv?e as a rule lasting from the end of May to the first week in July. 

 Notwithstanding the late apj)earance of the moth which laid the eggs 

 above referred to, and the fact that they did not hatch until the 

 following spring, I am of the impression that there is only one brood 

 in a year, and that some of the larvae hatch from early eggs in the 

 autumD, but others not till the spring. Larvae which are apparently 

 too large to have grown to such a size the same season are frequently 

 found early in the spring; but this matter requires further investiga- 

 tion. The moths of this usually abundant species have been remark- 

 ably rare during the present summer. 



The root maggots of cabbages, onions, radishes, and turnips, have 

 been perhaps the most destructive pests of the year. For garden appli- 

 cation hellebore tea and kerosene emulsion applied at the roots have 

 been successful, but for field practice I must confess that so far I have 

 been unable to discover a practical remedy, and I lay the matter before 

 the Association, and shall be obliged for any suggestions, as this is now 

 a most serious matter, x)articularly in turnii) fields. 



Grass insects have received much attention. The injury known as 

 ^^ Silvertoi) " has been remarkably prevalent, and is due to several insects, 

 primarily to small leaf-hoppers, in the stems of some of the larger grasses 

 to Jleromyza americcma, and perhaps to a Thrix)S. Considerable injury 

 has undoubtedly been done on lawns and in meadows by a Thrips which 

 attacks the blades of grass, and leaves undoubted evidence of its pres- 

 ence by the very characteristic injury. The question as to whether 

 Thrix)id8e attack vegetation is quite settled, so far as I am concerned. 

 I can recognize the injury of these insects at once by the whitened tis- 

 sues of the leaves dotted with dark excrementitious matter. 



During the past summer Thripidae have been most troublesome in our 

 greenhouses at Ottawa, attacking almost every jdant, but particularly 



