NOTES ON INSECTS TN CENTRAL ALBERTA. 125 



NOTES ON INSECTS IN CENTRAL ALBERTA. 



By I'. I>. (Jkkgson. BlachfaliJx. Alhrrta. fUniada. 



With so large and t'vor increasing- innnigration from tlie United 

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

 not be without interest. The earl}^ season of 1906 in this district 

 Avas notable for the phenomenal outbreak of '' cutworms," chiefly 

 Noctua chunh'stuKt Ilarr.. ('h()rh(i</rotis anxiliaris (irt., and Pdra- 

 grotis ochrogaster (luen. — extraordinary because climatic conditions 

 had not seemed to warrant such an outl^reak. 



The preceding year (1905) was normal; the fall dry, the November 

 mean niininnun temperature being 20.15° F.. snow 5.S,') jnciies; and 

 December mean mininuun 8.30° F., snow 0.75 inch. The mean mini- 

 mum temperature for January. 190(5, was — 0.70° F., and snow 1.40 

 inches. Hot suns on Fel)ruary 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 snow, and being in fact the dr3'est 

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

 May It). 190() (from snow and rain combined), did not exceed two- 

 thirds of an inch. Ninety per cent of the local winter wheat was killed 

 off. The total precipitation for the month of April and till May 10 

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

 period, the mean nuiximum shade temperature for April being ()0.(»8° 

 F. and for May (up to the 18th) ()().10° F — a temperature above the 

 average for ten years. 



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

 spring — it would seem that parasites would at least have an equal 

 chance with cutworms for surviving. But what was the result? 

 The outlu'cak of cutworms was without precedent, and of parasites 

 few could be discovered. 



Every kind of vegetation seemed to be attacked In' the cutworms. 

 Among the instances of which the writer made special observation 

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

 A nursery gardener had planted in the fall of 1905 (in a brome-grass 

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

 of several hundred gooseberry, currant (red. white, and black), 

 raspberry, and blackberry bushes and some hundreds of strawberrv 

 and rhubarb plants. In the spring of 190C> the 3'oung shoots of the 

 raspberry and blackberry bushes were persistently cut through just 

 below the soil and every bush died. The runners of the gooseberry 

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

 oft'. Not one strawberry survived the attack, and the rhubarb also 

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



