NOTES ON [NSECTS IN CENTRAL ALBERTA. 125 



NOTES ON INSECTS IN CENTRAL ALBERTA. 

 By P. B. Gbegson, Blackfalds, Alberta, Canada. 



With so large and ever increasing immigration from the United 



States, a few note- from the grain section of central Alberta may 

 not be without interest. The early season of 1906 in this district 

 was notable for the phenomenal outbreak of "cutworms," chiefly 

 Noctua clandesiina Ilarr.. Ghorizagrotis auxiliaris Grt., and Para- 

 grotis ochrogaster Guen. — extraordinary because climatic conditions 

 had not seemed to warrant such an outbreak. 



The preceding year (1905) was normal: the fall dry. the November 

 mean minimum temperature being -20.15 c F.. -now 5.85 inches; and 

 December mean minimum 8.30 c F.. snow 0.7.") inch. The mean mini- 

 mum temperature for January. 1000. was — 0.70" F.. and snow 4.40 

 inches. Hot suns on February 1. 2. and 3 dispelled nearly all of what 

 little snow there was, and from the middle of February to the end of 

 March was characterized by cold snowless weather, touching — 19° F. 

 on March 12. with all fields bare of >now. and being in fact the dryest 

 season for ten years The total moisture from November, 1905, to 

 May 1G. 1906 (from snow and rain combined), did not exceed two- 

 tftirds of an inch. Xinety per cent of the local winter wheat was killed 

 off. The total precipitation for the month of April and till May 16 

 was only 0.115 or 0.1 of an inch of moisture, a very warm and dry 

 period, the mean maximum shade temperature for April being *>0.G8° 

 F. and for May (up to the 18th) 66.10° F— a temperature above the 

 average for ten year-. 



Studying these weather conditions — the reverse of a cold, wet 

 spring — it would seem that parasite- would at least have an equal 

 chance with cutworm- for surviving. But what was the result \ 

 The outbreak of cutworms was without precedent, ami of parasites 

 few could be discovered. 



Every kind of vegetation seemed to be attacked by the cutworm-. 

 Among the instances of which the writer made special observation 

 a few may be mentioned as showing the catholic nature of their food. 

 A nursery gardener had planted in the fall of L905 (in a brome-grass 

 field which had been plowed up in the previous spring) an orchard 

 of several hundred gooseberry, currant (red. while, ami black), 

 raspberry, and blackberry bushes and some hundreds of strawberry 

 and rhubarb plant-. In the spring of 1906 the young -hoot- of the 

 raspberry and blackberry bushes were persistently cut through ju-i 

 below the -oil and every bush died. The runners of the gooseberry 

 and currant bushes shared the same fate, even the leaves being cleared 

 oil'. \ot one strawberry survived the attack, and the rhubarb also 

 suffered severely. Circular pit- had been dug round each bush in the 



