. Annual report. Entomological Society of Ontario; Insect pests; Insects. 44 REPORT OF THE ENTOMOLOGICAL As a check on the light trap located at Chatham, a second trap was operated frequently at the Experimental Station, Harrow, Ontario, 56 miles southwest of Chatham, where the corn borer infestation has been severe every year. RESULTS AND DISCUSSION The total numbers of moths taken during 5-day periods for each 5-year interval are shown in Fig. 1. The trend in the development of the multivoltine strain is very evident. A summary of the main details of the flight (TABLE I) shows that even in 1
. Annual report. Entomological Society of Ontario; Insect pests; Insects. 44 REPORT OF THE ENTOMOLOGICAL As a check on the light trap located at Chatham, a second trap was operated frequently at the Experimental Station, Harrow, Ontario, 56 miles southwest of Chatham, where the corn borer infestation has been severe every year. RESULTS AND DISCUSSION The total numbers of moths taken during 5-day periods for each 5-year interval are shown in Fig. 1. The trend in the development of the multivoltine strain is very evident. A summary of the main details of the flight (TABLE I) shows that even in 1934 moths were flying as late as October. This established that the multivoltine strain was present in Ontario at least since that year. NUMBER OF MOTHS 11 -1932-1936 -1937-1941 \.^1942, 1944 AND 1945 ,V-4 947-1951. 28 8 28 AUGUST SEPTEMBER OCTOBER Fig. 1 Fig. 1. Average numbers of Pyrausta nubilalis (Hbn.) caught in a light trap, Chatham, Ont. during 5-year periods, 1932-1951 (trap not operated in 1943 and 1946). From 1932 to 1936, at least 97 per cent of the population belonged to the single-generation strain. The moth flight increased progressively during the season and reached its peak not later than July 14. The flight dropped abruptly after the peak, but the appearance of second-generation moths in early August sustained it until September in 1934-1936. Two very late moths appeared in October in 1934 and Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Entomological Society of Ontario; Ontario. Dept. of Agriculture. Toronto, The Society
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectinsects, bookyear1872
