THE CHALCID SEED WASP, MEGASTIGMUS NIGROVARIEGATUS HYMENOPTERA: TORYMIDAE, ON ROSA RUGOSA THUNB. IN NOVA SCOTIA

AbstractTwo naturalized populations and two planted populations of Rosa rugosa Thunb. were studied with respect to chalcid seed wasp infestation. Megastigmus nigrovariegatus Ashmead was found in hips from planted R. rugosa in Halifax and Dartmouth, Nova Scotia, but not from bushes at naturalized sites. The percentage of infested hips at the Halifax and Dartmouth locations was 26 and 31%, respectively. The percentage of infested achenes within a single hip varied widely from 3 to 79% at the Halifax site and 7 to 60% at the Dartmouth site.Adult emergence was over 75% successful when achenes were over 2 mm in diameter but less than 15% for smaller achenes. The exit hole on the achene faced the outer wall of the hip. Adults emerged later in Nova Scotia than in the United States and between 59 and 72% were female. More than one adult wasp was observed ovipositing on a single hip.

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DISTRIBUTION OF CHRYSOLINA SPP. (COLEOPTERA: CHRYSOMELIDAE) IN EASTERN ONTARIO, 18 YEARS AFTER THEIR INITIAL RELEASE

The Canadian Entomologist ◽

10.4039/ent120937-10 ◽

1988 ◽

Vol 120 (10) ◽

pp. 937-938 ◽

Cited By ~ 1

Author(s):

Paul G. Fields ◽

John T. Arnason ◽

Bernard J.R. Philogène

Keyword(s):

United States ◽

British Columbia ◽

Weight Gain ◽

Nova Scotia ◽

Hypericum Perforatum ◽

The United States ◽

Biocontrol Agents ◽

St John's Wort ◽

Initial Release ◽

Eastern Ontario

Hypericum perforatum L., St. John's - wort (Hypericaceae), is a cosmopolitan weed that, when eaten by livestock, causes photodermatitis, reduced weight gain, and, in extreme cases, death (Giese 1980). Chrysolina hyperici (Forester) and Chrysolina quadrigemina (Suffr.) (Coleoptera: Chrysomelidae) dramatically reduced populations of H. perforatum when introduced into Australia (Clark 1953) and the United States (Holloway and Huffaker 1951; Holloway 1957). These species also have served as effective biocontrol agents when introduced into central British Columbia (Smith 1958), Ontario, and Nova Scotia (Harris and Maw 1984). This paper surveys the distribution of Chrysolina spp. in eastern Ontario, 18 years after initial release of both species.

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Phryxe vulgaris (Fall.) (Diptera: Tachinidae), a New Parasite of Pieris rapae (L.) (Lepidoptera: Pieridae) in Canada

The Canadian Entomologist ◽

10.4039/ent89546-12 ◽

1957 ◽

Vol 89 (12) ◽

pp. 546-546 ◽

Cited By ~ 1

Author(s):

Marcel Hudon

Keyword(s):

United States ◽

Nova Scotia ◽

New Brunswick ◽

Pieris Rapae ◽

The United States ◽

European Countries ◽

Pseudaletia Unipuncta ◽

Northern European ◽

Parasitic Larva ◽

Experimental Plots

In July, 1956, a pupa of the imported cabbageworm, Pieris rapae (L.), was found attached to the undersurface of a corn leaf in experimental plots at St. Jean. After the pupa had been incubated at 75°F. for six months, a dipterous parasitic larva emerged and pupated immediately; a tachinid fly emerged two weeks later. The parasite was identified by Mr. J. G. T. Chillcott, Entomology Division, Ottawa, as Phryxe vulgaris (Fall.). P. vulgaris has been reported as a parasite of Pieris rapae, P. brassicae (L.), P. napi (L.), and Vanessa urticae (L.) from many central and northern European countries (Thompson, 1946, pp. 467-469; 1947, p. 598). Aldrich and Webber (1924), Chittenden (1926), and Schaffner and Griswold (1934) reported this parasite from P. rapae in the United States. P. vulgaris has been reported from Canada only on larvae of the armyworm, Pseudaletia unipuncta (Haw.), in Nova Scotia and New Brunswick (Gibson, 1915, p. 14).

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