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RUSH SKELETONWEED, Chondrilla juncea L. -- Asteraceae Rush skeletonweed is a perennial herbaceous species belonging to
the tribe Cichorieae of the Asteraceae family. It was introduced to Australia around 1910, and spread rapidly
throughout the wheat belt of southeastern Australia. Chemical and cultural methods alone or in
combination did not give satisfactory control. A program aimed at biological control was initiated by the CSIRO
in 1966. An experimental station was
established at Montpelier, in southern France, so that the ecology of the
weed might be studied in its native range and potential natural enemies
identified. AT the same time, studies
in Australia revealed the presence of three morphologically and genetically
distinct forms of C. juncea. A strain of the rust, Puccinia
chondrillina Bubak &
Sydow, was introduced from southern Italy to Australia in 1971 and spread
rapidly to all infested areas. But
this particular strain of rust caused significant reductions in densities of
Form A in all areas. Other organisms
introduced, but having a lesser impact on skeletonweed, included a gall
midge, Cystophora schmidti Rubsaamen (Diptera:
Cecidomyiidae), a gall mite, Aceria
chondrillae Can. (Acari:
Eriophyidae), and a root moth, Bradyrrhoa
gilveolella Tr. (Lep.:
Phycitidae). There were indications
that Form B and C of the skeletonweed would continue to spread and eventually
fill the vacant niche left by Form A.
Another strain of the skeletonweed rust has been recently introduced
and it attacks only Form B. Other
organisms are through to be necessary to control Form C (Wells 1970, Wapshere
et al. 1974, Groves & Cullen 1977, Burdon et al. 1981, Cullen & Moore
1983). In summary, the biological control of rush skeletonweed, Chondrilla juncea L. in Australia was the first project to involve
the intentional international transfer of a phytopathogen for the biological
control of a plant, i.e., the rust fungus Puccinia
chondrillina Bubak &
Sydenham (Uredinales) between Italy and Australia in 1971 for the successful
biological control of a noxious plant (Goeden & Andrés 1999). This project also was one of the first to
target a plant pest of cropland (dryland wheat). It established procedures for testing phytopathogens for host
specificity under quarantine conditions and involved the first intentional
importation in 1971 of a phytophagous mite, Eriophyes chondrillae
for biological control (Cullen 1974, 1978). REFERENCES: [Additional references may be found at: MELVYL
Library ] Burdon, J.
J., R. H. Groves & J. M. Cullen.
1981. The impact of biological
control on the distribution and abundance of Chondrilla juncea
in south-eastern Australia. J. Appl.
Ecol. 18: 957-66. Cullen,
J. M. 1974. Seasonal and regional variation in the success of organisms
imported to combat skeleton weed Chondrilla
juncea L. in Australia, p.
111-17. In: A. J. Wapshere
(ed.), Proceedings of the III International Symposium on Biological Control
of Weeds, 1973, Montpellier, France. Cullen,
J. M. 1978. Evaluating the success of the programme for the biological
control of Chondrilla juncea in Australia, p.
233-39. In: T. E. Freeman
(ed.), Proceedings of the IV International Symposium on Biological Control of
Weeds, 1976, Gainesville, Florida. Cullen,
J. M. & A. D. Moore. 1983. The influence of three populations of Aceria chondrillae on three forms of Chondrilla juncea. J. Appl. Ecol. 20: 235-43. Goeden,
R. D. & L. A. Andrés. 1999. Biological control of weeds in terrestrial
and aquatic environments. In: Bellows, T. S. & T. W. Fisher (eds.), Handbook of Biological Control:
Principles and Applications.
Academic Press, San Diego, New York.
1046 p. Groves,
R. H. & J. M. Cullen. 1977. Chondrilla
juncea: the ecological control of a weed, p.
7-17. In: Kithing &
Jones (eds.), The Ecology of Pests.
CSIRO, Australia. 253 p. Wapshere,
A. J., S. Hasan, C. K. Wahba & L. Caresche. 1974. The ecology of Chondrilla juncea in the western Mediterranean. J. Appl. Ecol. 11: 783-800. Wells, C.
J. 1970. The ecology and control of skeleton weed (Chondrilla juncea)
in Australia. J. Aust. Inst. Agric.
Sci. 37: 122-37. |