76 ENTOMOLOGICAL SOCIETY OF ONTARIO. 



NOTES ON THE SEASON OF 1896. 

 By J. Alston Moffat, London, Ontario. 



The season commenced early and gave promise of being a good one for the collector, 

 but soon showed symptoms of failing to lulfil its promise. The conditions here were 

 unusually favorable for the production of luxuriant vegetation, and might have been 

 considered equally so for the maturing of insect life, and yet the season was marked by a 

 noticeable absence of that profusion usually seen in the early part of the summer particu- 

 larly. And this seemed to be the experience of all the regular collectors I met with. 

 When asked as to their success, the unvarying reply was, "There is nothing to be got." 

 And yet, on the other hand, Mr. Bryce, an electric light trimmer, made during the season 

 a large and varied collection of moths ; not damaged ones taken out of lamps, but fresh 

 specimens in good order, taken mostly at rest in the vicinity of the lights. When looking 

 at that collection one felt like saying that there could have been no scarcity of good 

 material, but it only proved the value of electric light as a means of concentrating them 

 at particular places for observation, and also, that insects have to be somewhat abundant 

 to become conspicuous. The only moths that attracted my attention about the lights 

 were species of Crambidce. 



The climatic conditions in the southern portion of Ontario were remarkably diverse 

 within short distances, the western section having a superabundance of moisture, whilst 

 the eastern section was proportionately dry, vegetation of all kinds there suffering severely 

 from want of rain ; yet there were two injurious insects that seemed to prosper equally 

 well under either condition, namely, the Colorado potato beetle and the imported cabbage 

 butterfly, both being unusually plentiful. 



The newspapers reported grasshoppers as causing considerable damage in specified 

 localities, but within the range of personal observation, they were noticeable mostly for 

 their absence. Even in the dryest localities visited by me they could not be called 

 abundant. 



As was to be expected, after such a superabundant overflow of Hadena arctica last 

 season, the next would be one of corresponding scarcity of the same species, and so it 

 proved to be. Three specimens of it came under my observation, and three only. Many 

 writers have a fondness for giving columns of -figures that are perfectly appalling, illus- 

 trative of the natural cumulative increase of insects in a given number of generations, 

 and the unsuspecting reader taking that as the unvarying rule in nature, reasonably con- 

 cludes that if any species is particularly plentiful one season, it must necessarily be much 

 more so in the following one, and consequently anticipates its advent with more or less 

 alarm ; but nature, whioh is full of surprises, has an easy method oi confusing arithmetical 

 calculations, or even of running counter to them. Long continued observation has led 

 to the conclusion that the rule in nature is rather that an unusual outbreak of an insect 

 in one year will be followed by a more than usual scarcity of the same species the next. 



Two things are necessary for an abundance of any insect form. First, plenty of 

 eggs ; second, favorable conditions for the maturing of the same, in which must be placed 

 an absence of living foes. A noticeable outbreak of a destructive insect is not necessarily 

 preceded by an unusual number of producers. If all the e^gs of any species of insect in 

 any year were to come to maturity, there would undoubtedly be a noticeable increase of 

 that species. But as a rule, it is a very small percentage of the ova of any insect that 

 reaches maturity, many natural causes combining to reduce their numbers all along the 

 line of their advance towards that consummation, and thus the balance is maintained 

 between contending interests. This is what is known in scientific phraseology as " the 

 struggle for existence," a delightfully brief but vague expression that covers much ground 

 but explains nothing. 



It would be a great satisfaction to be able to give a direct answer to the question so 

 frequently put as to the cause of the abundance or scarcity of some insects at particular 



