In May and June of 1948, a huge fire swept the Mississagi region of Northern Ontario and left in its wake the dead and dying remains of a once great pine forest. Studies on the part played by wood-boring insects in the deterioration of the standing, burned timber were initiated the following year. Most of the damage to the firekilled trees was found to be caused by two cerambycids, Monochamus notatus (Drury) and M. scutellatus (Say). The biology of these beetles is discussed by Craighead (1923, 1950). The two species are commonly separated on the basis of colour (Knull, 1946). M. notatus is dark brown with lighter brown elytra and is covered by a greyish-white pubescence, while M. scutellatus is usually a shining black (Plate 9). The scutellum of each bears a dense, white pubescence which, in M. notatus, is divided by a bare, median line. Such a line also occurs in M. scutellatus but it is usually incomplete. The elytra of the females are generally marked by elongate spots. Length is also used to separate the two species. For example, Chagnon (1938?) gives the range of length for M. notatus as 27-32 mm. and that for M. scutellatus as 19-24 mm. Actually, no such clear-cut difference in size ranges occurs; instead, a very considerable overlap is found in the field. It was also apparent in the field that the two species acted almost as one population. Both caused the same type of damage, and bred freely in the same locality at the same time and in the same host trees. [...]
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.124000 |
| Date | January 1952 |
| Creators | Gardiner, Lorne Marvin. |
| Contributors | DuPorte, E. (Supervisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science. (Department of Entomology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000597921, Theses scanned by McGill Library. |
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