pdf, 57.71Mb - Entomological Society of Canada

308 K. J. Griffiths and F. W. Qucdnau
Borrelinsyirus
reprlmens Holmes
Bad11us tburingiemis
Berliner (B.t.)
Evaluation of Control Attempts
recent work. Dowden (1962) found attacks of 40-45% in Massachusetts and Connecticut.
Weseloh (1972) gives a total summer attack of 29-42% in Connecticut. Thus its
introduction into Canada was justified and preliminary investigations of the ability of the
overwintering mated female adult to withstand low temperatures were undertaken
(Griffiths & Sullivan 1978). It was found that adults were unable to survive continuous
exposure to O°C for 30 days, and it was concluded that this species would be incapable of
surviving in the current range of the gypsy moth in Canada. To test this hypothesis,
approximately 25 000 adults supplied by the New Jersey Department of Agriculture
were released on Wolfe Island, Ontario, on 24 September 1976 (Table 81). Gypsy moth
egg masses have been collected in the release area in late August or early September
each year since the release. There were no recoveries of O. kuvanae until 1978, when 28
adults were recovered from two egg masses. A single adult was obtained from the
release area in 1980. In addition, 45 adults of O. kuvanae were recovered from two egg
masses collected near Glen Norman, Glengarry County, Ontario, in September 1980.
Because this recovery site is approximately 180 km from the Wolfe Island release site, it
is unlikely that there is any relation between the two; the parasitoids must have dispersed
there naturally.
Two experimental techniques for the application of NPV were tested by Cardinal &
Smirnoff (1973) in Missisquoi and St-Jean Counties, Quebec, in 1972. They handapplied
an aqueous solution of NPV at 40 x 10' polyhedral inclusion bodies (PI B) per
millilitre to egg masses in early May and recorded nearly 100% mortality in the larvae
emerging from them. They also sprayed foliage by mist blower with an aqueous solution
at 4 x 10' PIBlml when larvae were in the second or third instar, resulting in higher
mortality than was seen in larvae on unsprayed foliage.
Jobin & Caron (1982) made aerial applications of B.I., using the commercial product
Thuricide® 32B (Sandoz Inc.) in Chambly and Rouville Counties, Quebec, in 1979.
There were two applications in each area at dosages of 19.6 and 39.52 x W"I.U.fha. All
applications included a sticker and chitinase and the B.I. was applied at a rate of 9.36
Vha. Spraying was carried out in late May when 60-70% of larvae were in the second
instar. Mortality of larvae in the treated areas 20 days after treatment was 100%,
compared to a decrease of 70-76% in control areas over the same time period.
The establishment of exotic insect parasites on the gypsy moth in Canada is proceeding
well, largely through natural dispersal. We now know that 8 of the 13 established exotic
species are attacking gypsy moth in the infested zone in Canada and we are confident
that a 9th species, Anaslalus disparis Ruschka, will become established. Two of the
remaining four species are already present in Canada on other hosts. They are Apanleles
klcteicolor Viereck, essentially a parasitoid of the browntail moth, which was established
against that species in the maritimes and Quebec in 1915 (Tothill 1916); and M. versicolor,
introduced against browntail moth and satin moth in Canada (TothillI916) and recovered
in Ontario from Rlleumaplera lIaslala L. by Forest Insect and Disease Survey staff. M.
versicolor is infrequently recovered from the gypsy moth in the United States. The
other two exotic species are Eupleromalus hemiplerus (Walker) and Monodonlomerus
aereus Walker. The former species is a common parasitoid of the satin moth in the
United States but is rarely obtained from the gypsy moth there (Burgess & Crossman