ENTOMOLOGICAL SOCIETY OF ONTARIO- 



23^ 



Some Injurious Insects. 



It has been usual for the President, in his annual address, to present an economic 

 entomological survey of the province. My field of observation has been limited to the six 

 or seven townships around London. 



Last year our Curator, Mr. Moffatt, reported the prevalence of the cut-worm moth* 

 Hadena Arctica (Fig. 5 ) Householders in town and country remember the nightly 

 dance of these moths around the lamps and their soiling of curtains and clothes during the 

 day. This spring I noticed many a patch of spring grain that had been sown on plowed 

 sod so badly eaten that the ground was plowed again and sown with peas or otherwise 

 used. The farmers said the wire-worms are at work, but in any plot I examined it was 

 no trouble to discover the greenish-yellow cut worm, the larvae of the Hadena. Would 

 rolling the affected part of the field at night with a heavy roller across the drills destroy 

 enough of these larvse to save the crop 1 I should like to hear the point discussed whether 

 we may expect another invasion of our homes by this moth next year, such as Mr. 

 Moffat described in the last report. I did not find any specimens that seemed to be 

 parasitized. 



The grasshopper or locust (Melanoplus femur -rubrum, De Geer, Fig. 6) was not 

 nearly so injurious as in 1895. Its partial disappearance is probably mainly due to the 

 increase of its parasite, the red mite, Astoma (Fig. 7).* The spring was favorable for 

 the development of the grasshopper, and in some localities it was present in prodigious 



Fig. 7. 



numbers. I never saw them more numerous or vigorous than on the 18th of June along 

 a side road between Con. vii. and viii. of McGillivray. Two or three miles on either side 

 of this locality but few were to be seen. Where they were numerous I did not find one 

 parasitized specimen; where they were scarce but few had not the red mites adhering to 

 them under the wings. 



In a few limited areas of the country the army-worm, Leucania unipuncta, appeared, 

 in countless numbers and destroyed or greatly damaged oats, barley and corn, In early 

 September the imagines were abundant everywhere in the range I travel. With the 

 moths so numerous and generally distributed one would naturally expect the insect to be 

 destructive next year. If such expectation is fortunately not realized, the interesting 

 question arises — what influences have checked it 1 Is the multiplication of the Tachina 

 fly so rapid as to prevent its appearance in destructive numbers the second year in the 

 same district ? 



* Dr. James Fletcher, of Ottawa, writes that the prevailing opinion of arachnologisfcs is that the 

 Astoma (or Atoma) is the larval form of Tromhidium, and that in Henshaw's Bibliography of Economic 

 Entomology Astoma gryllarium is given as synonymous with Trornbidium locustarum. Further references 

 are Andrew Murray's " Aptera," pp. 128-1*29 ; Riley's " Rocky Mountain Locust," pp. 128-130 ; Linfcner's 

 Eighth Report, 1891, page 180 ; First Annual Report United States Entomological Commission, pp. 306-311. 

 As a rule the six-legged mites are the larval forms. 



