Canadian Forest Service Publications

The pine root-collar weevil, Hylobius radicis Buch., in southern Ontario. 1962. Finnegan, R.J. The Canadian Entomologist 94(1):12-17.

Year: 1962

Issued by: Laurentian Forestry Centre

Catalog ID: 36698

Language: English

Availability: PDF (request by e-mail)

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Interest in this insect was first aroused by the reports of Felt (1926a, 1926b) and York (1933), who attributed injury to several species of pines in the State of New York to Hylobius pales (Hbst.). Later it became apparent that the injury reported was not caused by H. pales, but by a new species that Buchanan (1934) described as H. radicis. This insect was first reported in Canada at Angus, Ont. (Wallace, 1954), and has since become abundant in pine plantations totalling about 500 acres in Simcoe County. This County supports the principal infestations in Ontario, but other widely separated infestations have been reported near Sault Ste. Marie and from five plantations totalling 50 acres in Renfrew County. H. radicis is now known to be widely distributed. In addition to New York State and Ontario, the insect has been reported from Virginia, Massachusetts, Connecticut, Pennsylvania, Michigan, Minnesota, Wisconsin, and Manitoba.

The weevil attacks many species of pines, including Scots pine, Pinus sylvestris L., Austrian pine, P. nigra Arn., Mugho pine, P. mugho Turra., jack pine, P, banksiana Lamb., pitch pine, P. rigida Mill., red pine, P. resinosa Ait., eastern white pine, P. strobus L. (Schaffner and McIntyre, 1944), and lodgepole pine, P. contorta Dougl. (Prentice, 1955). Schaffner and McIntyre (1944) noted that the weevil was particularly injurious to Scots, Austrian, and Corsican pines. Prentice (1955) reported up to 25 per cent mortality from weevil attack in Scots and lodgepole pine plantations in Manitoba, whereas mortality of 90 per cent or more has been found in Scots, and red pine plantations in southern Ontario.

Because of the role of this insect as a serious plantation pest in southern Ontario, investigations were conducted in this region from 1955 to 1959. Field observations were made in several widely separated, mixed plantations of white, red, jack, and Scots pines. Laboratory observations were conducted at a field station in Angus, Ont.