Biology
In studies in Europe, eggs are laid from January to June
at the base of the plants or in the soil adjacent to the plants.
Larvae feed on flowers and leaf buds. Larvae mature by mid-May
and pupate in the soil. Adults emerge in early June and feed
on the thistle leaves. Females produce an average of 296 eggs
and most live a single season. A few individuals lived 20
months and produced eggs in two seasons (Dunn and Rizza 1976).
History
After investigations in Europe this species was selected
as a candidate for further study for the biological control
of thistles. Consequently, the biology of this beetle was
studied in Italy (Dunn and Rizza 1976).
Status
One release of this leaf beetle was made in Kerr County about
1995. Establishment of this species has not been confirmed.
Management
Until the species can be established there are few guidelines
for management. Adult flea beetles and larvae can be collected
on the plants and transported for redistribution studies.
Weeds Affected
The musk thistle leaf beetle feeds on several Carduus
species.
Literature
Dunn, P. H. and A. Rizza. 1976. Bionomics of Psylliodes
chalcomera, a candidate for biological control of musk
thistle. Annals of the Entomological Society of America 69(3):
395-398.
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