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Recommendations
Literature Cited
Orgyilllelicosligll/(/ (J. E. Smith), 361
understanding of the role of the virus in whitemarked tussock moth epidemiology might
have been gained.
The pattern of development of whitemarked tussock moth outbreaks presents an
opportunity for an elegant approach to biological control; but there are major difficulties.
The most promising strategy is to artificially accelerate the normal virus epizootic that
has occurred consistently in every past outbreak of this insect. The obvious advantage
of such a strategy is that the virus is used as an inoculum rather than as a blanket
insecticide. The resulting epizootic will be one that inevitably would have occurred
later, a consideration that might ease the registration approval of this NPV by Canadian
authorities.
Historically each whitemarked tussock moth outbreak in Nova Scotia appears to have
begun in one or two small locations (epicentres). Virus material from the 1974-79 outbreak
has been stored and the techniques of introducing the virus into a developing
outbreak have been shown to be workable. However, two major problems must be
addressed: first, early detection of epicentres requires constant monitoring of likely
sites for a period of up to 10 years; and second, whitemarked tussock moth hatching
occurs over a period of at least 2 weeks, so although larvae feed on the froth covering of
egg masses for 2 or 3 days, many larvae are likely to disperse before the virus is applied
during peak egg hatching.
A second strategy might be to employ sex pheromones that could be used to disrupt
mating in epicentres. Success would depend on the almost immediate detection of these
epicentres before they become large enough to develop a reservoir of dispersing larvae.
Cunningham, J.e. (1972) Preliminary studies of nuclear polyhedrosis viruses infecting the whitemarked tussock moth, Orgyia lel/costigma.
Canadian Forestry Service In.tect Pathology Research Institl/te, Sal/It Ste. Marie, Ontario, Information
Report.
Elgee, D.E. (1975) Persistence of a virus of the whitemarked tussock moth on balsam fir foliage. Canadian Forestr}' Service Bi-monthly
Research Notes 31(5),33-34.
Kurstak, E. (in press) Microbial and viral pesticides. New York; Marcel Dekker.