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Rhyaciollia blloliallll (Schiff.). 3M!)
pine shoot moth has remained an unimportant pest of ornamental pines in the cities of St.
John's and Comer Brook in Newfoundland (A.G. Raske 1981 personal communication).
The progressive distribution of the shoot moth in North America since 1968 suggests
that the shipping of infested nursery stock has contributed strongly to its dispersal,
resulting in a rapidly spreading but spotty distribution. This was particularly evident in
the Maritime Provinces. The Forest Insect and Disease Survey has recorded the spread
in that area as well as in British Columbia. Declining populations were noted in Quebec.
In Ontario, the nothern limit of continuous distribution has held, as predicted (Green
1962), at about the -29"C mean minimum temperature isotherm. The populations on
Manitoulin and Cockburn islands in the North Channel of Lake Huron have collapsed
because the host trees have outgrown susceptibility, and populations declined generally
throughout the province during the 1970s. Changes in the economics and marketing of
red pine, at least in Ontario, have further reduced the importance of the European pine
shoot moth; deformed stems may be acceptable under some circumstances.
In the rest of Canada, the situation remains static. In New Brunswick it is not known
why the insect has not penetrated to the northern part of the province, although a lack of
susceptible hosts could be an important factor.
Background Although considerable work was done on various biological aspects of the European
pine shoot moth before 1968 (Syme 1971), the research emphasis and the parasitoid
monitoring capability changed after 1969. For example, studies on R. buolialla in
Ontario were virtually confined to the effects of wild carrot, Daucus carola L.. and
other flowering plants on the effectiveness of Orgi/us obscuralor (Nees), the most
effective introduced parasitoid of the pest. Meanwhile, the earlier literature on the
biology. behaviour, history, distribution, ecology. damage, and control were well reviewed
(Pointing & Green 1962, Pointing & Miller 1967, Miller 1967, Syme 1971). Since 1973
virtually no new research has been done in Canada on either the European pine shoot
moth or its parasitoids.
Releases and Recoveries The following brief descriptions of species of parasitoid include recoveries or significant
range extensions of species released before 1968, and significant developments and
findings on their possible effectiveness determined since 1968. The origin and numbers of
released parasitoids are summarized in Tables 97 and 98. With the exceptions of O.
obscurator (Nees), Lypha dubia (Fall.), and Parasierola lIigri/emllr (Ashm.). little can
be reported.
Table 97 Open releases and recoveries in Ontario of parasitoids against Rllyacionill bllolimuJ (Schiff.)
Species Year of release Origin No. Released Year of recovery
Agathis binominata
Mues. 1969 Ontario 52
1970 Ontario 33 1973
Lyplla dubio (FaiL) 1969 Germany 496 1970
Orgilus obscurator (Nees) 1969 Germany 218
1970 Germany 45
1971 Germany 225
1972 Germany 82 1978
Parasierola nigrifemur
(Ashm.) 1974 Argentina (l}5