. Annual report - Entomological Society of Ontario. Entomological Society of Ontario; Insect pests; Insects. ENTOMOLOGICAL SOCIETY 49 was clean cut in 1921 and the present growth is all sprout growth since that time. With the appearance of the new stand, the beetles reappeared and all of the trees have been injured and some killed. The highest attack ran 45 to a tree and the average for the stand in all-crown classes was The average number of attacks per crown class was very nearly the same but we found that a high larval mortality occurred on the codominant trees. Over 2,000 of the 3,00
. Annual report - Entomological Society of Ontario. Entomological Society of Ontario; Insect pests; Insects. ENTOMOLOGICAL SOCIETY 49 was clean cut in 1921 and the present growth is all sprout growth since that time. With the appearance of the new stand, the beetles reappeared and all of the trees have been injured and some killed. The highest attack ran 45 to a tree and the average for the stand in all-crown classes was The average number of attacks per crown class was very nearly the same but we found that a high larval mortality occurred on the codominant trees. Over 2,000 of the 3,000 trees on the plot were cut. Accurate data was taken on 767 of the felled trees, which were grouped as follows—130 codominant; 233 intermediate; and 404 suppressed. The diameter, crown class, height and number of attacks were recorded for each tree. When the notes were summarized it was found that a very enlightening graph could be made which I will show you with the lantern. In the small diameter classes the attacks on all three crown classes ran about the same but above the iy2 inch diam. class there was a noticeable difference. In the suppressed class, trees with a diameter oi 2l/2 inches or greater, had an ever increasing rate of attack, while the attacks on the intermediate trees began to decrease in number after the 3-inch diam. class was reached. In the codominant classes the attacks decreased noticeably on trees over 3" in diam. This is strikingly brought out in the Ugend: Crown Class Co-dominant intermediate. Suppressed This graph is wei^ht&J &nd harmonised. I 2 * Diameter (inches) Fig. 1.—Graph showing distribution of locust borer attacks by crown 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. Department of Agriculture.
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectinsects, bookyear1872
