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140
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Vol.8: no.5
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NOTES ON THE OCCURRENCE OF ALSOPHILA POMETARIA (GEOMETRID^) AT BAIE D'URF£ AND MACDONALD COLLEGE, QUEBEC, IN 1953
The first male Alsophila pometaria Harris was seen on Oct. 16, when 2 were captured. Females were sought on Ash, Elm, and Manitoba Maple on Oct. 9, 11, and 14, and were not found; 9 were taken on Oct. 16. Trees were examined by day as well as at and after 6 p.m., up to Dec. 2, except on nine dates. Observations and captures were made mainly on 12 trees in the home garden; some on 25 trees in the next neighbour's garden, and some on 48 trees in a grove at Macdonald College, distant about one-half mile. The majority of the specimens were taken on the trees in the home garden: relatively few were found at each search on the other groups of trees. A few of the specimens were found on Sugar Maple, Soft Maple, and Poplar. The weather was mainly fine and warm, with a light frost on Nov. 4/5; that was followed by a sleet storm on Nov. 7, during which several of the female moths were found frozen in the ice on the trees. Mild weather followed, and there was a heavy rain on Nov. 25. The temperature fell on Nov. 26, and snow and a ground-heaving frost occurred on Dec. 1.
The captures and observations have been divided into two periods, as shown below, before the first frost and after it.
Males Females F/M
Oct. 16 —Nov. 4 242 1062 4.3
Nov. 5 — Dec. 4 3 707 236.0
The approximate ratios of females to males on selected dates were as shown below:
Oct. 16 — 24 7.0 Oct. 27 5.0
Oct. 25 4.5 Oct. 30 2.0
Oct. 26 3.0 Nov. 2 8.0
The greatest number of mating pairs was observed on Oct. 29, when the number of males was 38 and of females 125 on 12 trees. The last male was seen on Nov. 14, after which about 400 females were taken or observed.
It was noted that most of the specimens of both sexes were found below the 6 ft. height on the boles; the proportion of females found at the 10—14 feet height to those found up to 6 feet on the same (four) trees was ascertained on one occasion to be as 1 : 10 (14 to 143).
Emergences appeared to be most numerous before 6 p.m. When all of the visible specimens were taken between 6 and 8 p.m. there were none or very few visible up to 6 feet on the 12 trees the next morning. Observations have not been made of insectivorous birds being responsible for any depletion.
The observations show that in the fall of 1953 in this locality almost all of the males had emerged from the pupas a day or so before the first frost; about one-third of the females emerged after the first frost.
P. H. H. GRAY, Box 236, Macdonald College, Que., CANADA
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The Fifth Annual Meeting of the Society will be held Tuesday, Wednesday, and Thursday, 28 - 30 December 1954. We will meet at the Carnegie Museum in Pittsburgh, Pennsylvania. A special feature will be the opportunity to see the great collection of Lepidoptera assembled by W. J. Holland, William Henry Edwards, B. Preston Clark, Andrey AviNOFF, W. R. SWEADNER, and many others. The curator of the Lepidoptera collection is HARRY K. CLENCH. Dr. G. E. WALLACE (Chairman), Mr. & Mrs. C. G. MERKER, and Mr. CLENCH comprise the Committee on Local Arrangements; Mr. CLENCH is Chairman of the Program Committee. A large attendance seems assured, with very wide geographic representation.
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