INTRODUCTION, PERMANENT ESTABLISHMENT, AND DISPERSAL IN EASTERN CANADA OF OLESICAMPE GENICULATAE QUEDNAU AND LIM (HYMENOPTERA: ICHNEUMONIDAE), AN IMPORTANT BIOLOGICAL CONTROL AGENT OF THE MOUNTAIN ASH SAWFLY, PRISTIPHORA GENICULATA (HARTIG) (HYMENOPTERA: TENTHREDINIDAE)

Abstract

From 1976 to 1978, 1300 mated females of Olesicampe geniculatae Quednau and Lim were released near Quebec City during a severe infestation of the mountain ash sawfly, Pristiphora geniculata (Hartig). Both cage and open releases were made. The interactions among the mountain ash sawfly, the imported primary parasite O. geniculatae, and the indigenous hyperparasite Mesochorus globulator (Thunb.), and the effect of O. geniculatae on the host population during and after the establishment phase, are reported. In 1984, O. geniculatae was recovered from all over southern Quebec. Parasitism ranged from 6 to 94%. Concurrently, infestation levels by the mountain ash sawfly declined significantly, and since 1985, the insect has almost disappeared in Quebec. With an annual spread of about 50 km per year after successful establishment, O. geniculatae now covers an area 1000 km in diameter. No major infestation by the mountain ash sawfly has been recorded in Quebec during the past 7 years. The introduction of O. geniculatae is rated as a complete success in classical biological control.

Species richness and abundance of native leaf miners are affected by the presence of the invasive horse-chestnut leaf miner

“…No earlyseason species were found at the surrounding sites either, but this may be due to the effect of this large horse-chestnut forest being observed over greater distances. Parasitoids are known to spread quickly and far if necessary (Quednau 1990), and the billions of parasitoids (or predators) emerging in spring from dead horse-chestnut leaves may fly long distances to find suitable hosts. Further studies on C. ohridella and native leaf miners should include an assessment of the spatial scale of the effects of apparent competition on natural leaf miner communities (Morris et al 2005).…”

Insect parasitoids : a Canadian perspective on their use for biological control of forest insect pests

“…Beirne (1967) suggested that thèse catégories were appropriate and should be considered in this exact séquence in ail integrated pest management programs. Those attributes that contribute to a good natural enemy hâve been outlined by several authors (Huffakerand Kennett 1969;Luck 1990;Mackauer 1976;Quednau 1990). …”

“…The success rate of thèse introductions has been the source of considérable controversy, however, it is generally agreed that of thèse attempts, 34-40% hâve become established (Hall and Ehler 1979;Waage and Greathead 1988) and approximately 16% are considered to be successful in terms of control (Myers et al 1989 Reeks and Cameron 1971) and for individual cases on the winter moth (Caltagirone 1981;Murdoch et al 1985;Roland 1988), larch sawfly (Graham 1931), and European pine shoot moth (Juillet 1960;Miller 1967;Pointing and Green 1962). The cost:benefit relationship for the program against the European pine shoot moth was estimated at $300 000:>$6 million (1:75) and that for the winter moth at $160 000:>$12 million (1:20 (Quednau 1990), parasitism levels of the sawfly were 6-94% with no major infestations recorded in Québec during the last seven years. Reeks and Cameron 1971).…”

“…It is generally acknowledged that for improved chances of success, introductions should be made with at least 500 females per release (Greathead 1986;Quednau 1990;Reeks and Cameron 1971). Thèse natural enemies should be collected from as broad a geographical area as possible to improve their genetic heterozygocity (Mackauer 1976) and be introduced without hyperparasitoids (Hulme and Kelleher 1984).…”

“…When more than one species is to be introduced, it has been suggested that the competitively inferior species be brought in first to reduce compétition and improve the chance of establishment (Cock 1986;Pschorn-Walcher 1977). Success or failure should be évident within 3 yr of the initial introduction (Clausen 1951;Quednau 1990). …”