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172 P. Harris and M. Maw
Releases and Recoveries
Agrllus hyperici
(Crotch) (Coleoptera:
Buprestidae)
Analtis plag/aIB (L.)
(Lepidoptera:
Geometridae)
Aphis chloris (Koch)
(Homoptera:
Aphididae)
Renewed attempts to establish the root boring beetle A. hyperici in the Cranbrook, British
Columbia, area (Table 45) were not successful. This beetle is established at Mt. Shasta.
California, and the climate of southern British Columbia is within the range of the species in
Europe. The problem seems to be related to shipping stress in the newly emerged beetles,
two shipments arrived dead at Cranbrook airport and no eggs or larvae were found from the
release of live beetles. If further attempts are made to establish this insect, it is suggested
that it should be done by transferring newly hatched larvae to plants growing at the release
site.
Two releases of A. plagiala were made in the Cranbrook British Columbia area and one
in New Brunswick. No establishment has been reported from New Brunswick. In
British Columbia, two moths were caught in September 1980, about 3 km from the
release site and on 23 June 1981, when the first flowers had opened, an egg, a first instar
larva, and several moths were seen. The moth was also found in 1981 near Grandforks,
an area where it had been released in 1967 and not previously recovered. The moths
were flying actively between the widely scattered clumps of the weed and had survived
in spite of strong populations of C. quadrigemina. Many larvae were found at Grandforks in
late July and a few near Cranbrook in late July and early October (K. Williams 1981
personal communication). The colony at Agassiz, British Columbia, in 1981 caused
browning and defoliation of H. perforalum in patches (L. Sigurgeirson 1981 personal
communication).
The A. plagiala larvae released in 1977 at North Tay Creek, New Brunswick, may have
been killed by insecticide drift from aerial spray of the adjacent forest for spruce
budworm (D. Finnamore 1981 personal communication).
(a)Ecology
The sexual generation of the aphid A. chloris appears in the fall (October in Cranbrook)
in response to lower temperatures and shortened day length. During this period and in
early November. an average of four (maximum of eight spread over a month) yellow
eggs, which tum shiny black, are laid per female at the base of the flowering stems or on
the procumbent foliage. Hatching occurs in April or May giving rise to a generation of
apterous females. These mature in about a month and several generations of apterous
viviparous females are produced. During midsummer, when colonies become crowded.
alate viviparous females develop and disperse to found new colonies.
A. chloris has a wide geographic range. It is found in Sweden near the northern limit of
St. John's-wort (Johansson 1962). in Poland (Czechowskii 1975), in Israel (Neser. 1973,
personal communication), in Britian in cool and damp conditions, and in the arid south
of France, from sea level to 1500 m in the mountains (Wilson 1943).
In the south of France and at Cranbrook, the aphids in summer are found near the tip
of the shoots or beneath the flowers. In contrast, in England, northern France. and in the
Alps, they are normally found at the base of the stems. Wilson (1943) suggested that the
feeding site depends on conditions of heat and moisture. If so, the ability of the aphid to