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RAGWEEDS, Ambrosia spp. -- Asteraceae

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Three species targeted for biological control in the Soviet Union are Ambrosia artemisiifolia L., A. psilostachya deCandolle and A. trifida L. (Goeden & Andrés 1999). These allergenic and competitive plants were accidentally introduced to the Soviet Union from their native North America sometime after 1920, and they quickly became troublesome and by 1980 had spread into the southern part of European Soviet Union, Transcaucasia, Kazakhstan and the Maritime Territory (Kovalev 1974, 1980; Goeden & Andrés 1999). The most important of the three, Ambrosia artemisiifolia, infests most crops and is costly and difficult to control with chemicals or by cultural and mechanical means.

An informal cooperative project began in 1965 with Canadian, United States and Soviet scientists, which revealed the identity of 450 species of insects, mites and fungi that are natural enemies of 17 species of Ambrosia in North and South America (Harris & Piper 1970, Kovalev 1971, 1980; Goeden & Ricker 1976). Over 30 species of natural enemies were introduced to the Soviet Union during 1967-79 (Kovalev 1971, 1980; Goeden et al. 1974b). Host plant specificities of the candidate natural enemies were tested in quarantine in the Soviet Union, which involved eight varieties of sunflower, Helianthus anuus L. (Asteraceae), as the critical test plants, 18 species of Helianthus and 80 species of cultivars representing 46 genera and 18 families of plants (Kovalev 1970), using a procedure named the "centrifugal testing method" (Wapshere 1974).

Four species of insects that were obtained from the same species of plants in their native North America had been released by 1980 to establish a complex of natural enemies in the Soviet Union. Ragweed insects included Tarachidia candefacta Hübner (Lepidoptera: Noctuidae), a defoliator from Canada and California and released on A. artemisiifolia in 1969 and on A. psilostachya in 1972, respectively (Kovalev & Runeva 1970, Kovalev & Samus 1972, Gilstrap & Goeden 1974, Goeden et al. 1974). Brachytarsus tomentosus (Say) (Coleoptera: Anthribidae), a pollen-feeding beetle was first released in the northern Caucasus in 1978. Euaresta bella Loew (Diptera: Tephritidae), a monophagous seed feeding fly obtained from Canada was released in the northern Caucasus in the 1970's with unknown results. Zygogramma saturalis (F.) (Coleoptera: Chrysomelidae), another defoliator obtained from Canada and the United States, was released in 1978 (Kovalev 1980, Julien 1982, Goeden & Andrés 1999).

The first natural enemy released for ragweed control in the Soviet Union was Tarachidia candefacta, and the first natural enemy intentionally introduced into Europe from North America for biological control of a noxious plant. Specially designed oviposition units were used in mass rearing this species, where eggs were deposited on hanging threads. Larvae were fed a prepared diet (Kovalev & Runeva 1970, Kovalev & Nayanov 1971). Although established on both A. artemisiifolia and A. psilostachya, it seems to have been unsuccessful as a biological control agent primarily because of predation of the exposed larvae (Goeden & Andrés 1999).

Spectacular results were, however, obtained with Zygogramma saturalis. This beetle was mass reared at several laboratories beginning in 1979 and following its initial winter's survival, it was released in the southern Soviet Union and Transcaucasia to the Far East (Kovalev & Medvedev 1983, Kovalev & Vechernin 1986). Larvae and adults feed on leaves and flowers throughout the growing season and range of A. artemisiifolia from April to mid September. Two complete and a partial third generation are produced annually (Kovalev 1980). Seventh generation Z. suturalis formed feeding fronts consisting of a stable nondeclining wave of beetles which moved at a constant rage and which were considered an isolated population wave (Kovalev & Vechernin 1986). In one locality at Stravropol the insects were concentrated in a narrow band at 5,000 individuals per m³, which completely destroyed all the ragweeds as it moved across an infested field at a rate of 3 me per day (Goeden & Andrés 1999). About 10 million beetles were concentrated in a circular feeding front with a length of 1.5 km and a breadth of ca. 10 m. The controlling action of these feeding fronts on ragweed, greatly increased yields of sainfoin, maize and alfalfa 2-3 times (Goeden & Andrés 1999).

REFERENCES: [Additional references may be found at: MELVYL Library ]

Gilstrap, F. E. & R. D. Goeden. 1974. Biology of Tarachidia candefacta, a Nearctic noctuid introduced into the U.S.S.R. for ragweed control. Ann. Ent. Soc. Amer. 67: 265-70.

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.

Goeden, R. D. & D. W. Ricker. 1976. The phytophagous insect fauna of the ragweed, Ambrosia psilostachya, in southern California. Environ. Ent. 5: 1169-77.

Goeden, R. D., L. A. Andrés, T. E. Freeman, P. Harris, R. L. Pienkowski & C. R. Walker. 1974a. Present status of projects on the biological control of weeds with insects and plant pathogens in the United States and Canada. Weed Sci. 22: 490-95.

Goeden, R. D., O. V. Kovalev & D. W. Ricker. 1974b. Arthropods exported from California to the USSR for ragweed control. Weed Sci. 22: 156-58.

Harris, P. & G. L. Piper. 1970. Ragweed (Ambrosia spp.: Compositae): its North American insects and possibilities for its biological control. Commonw. Inst. Biol. Contr. Tech. Bull. No. 13: 117-40.

Julien, M. H. (ed.). 1982. Biological control of weeds: a world catalogue of agents and their target weeds, 1st ed. Commonw. Agric. Bur., Slough, U.K. 108 p.

Julien, M. H. (ed.). 1987. Biological control of weeds: a world catalogue of agents and their target weeds, 2nd ed. Commonw. Agric. Bur. Int., Wallingford, U.K. 150p.

Julien, M. H., J. D. Kerr & R. R. Chan. 1984. Biological control of weeds: an evaluation. Prot. Ecol. 7: 3-25.

Kovalev, O. V. 1970. Biological control of Ambrosia weeds, p. 354-55. In: Proceedings of the 7th International Congress of Plant Protection, 1969, Paris, France.

Kovalev, O. V. 1971. [Phytophages of ragweeds (Ambrosia L.) in North America and their application in biological control in the U.S.S.R.]. Zoologichesky Zhurn. 50: 199-209. [in Russian].

Kovalev, O. V. 1973. Modern outlooks of biological control of weed plants in the U.S.S.R. and the international phytophagous exchange, p. 166-71. In: P. H. Dunn (ed.), "Proceedings of the III International Symposium on Biological Control Of Weeds, 1971, Rome, Italy.

Kovalev, O. V. 1974. Development of a biological method of controlling weeds in the USSR and the countries of Europe, p. 302-309. In: E. Fm. Shumakov, G. V. Gusev & N. S. Fedorinchik (eds.), Biological Agents For Plant Protection. Publ. House "Kolos," Moscow. 408 p. [in Russian].

Kovalev, O. V. 1980. Biological control of weeds: accomplishments, problems and prospects. Zashchita Rasteniy. 5: 18-21. [in Russian].

Kovalev, O. V. & L. N. Medvedev. 1983. Theoretical basis of introduction of ragweed leaf beetles of the genus Zygogramma Chevr. (Coleoptera: Chrysomelidae) in the USSR for biological control of ragweed. Ent. Obozr. 62: 17-32. [in Russian].

Kovalev, O. V. & N. I. Nayanov. 1971. A moth against ragweed. Zemledelie 6: 36.

Kovalev, O. V. & T. D. Runeva. 1970. Tarachidia candefacta Hubn. (Lepidoptera: Noctuidae), an efficient phytophagous insect for biological control of weeds of the genus Ambrosia L. Acad. Sci. U.S.S.R. Ent. Rev. 49: 23-36. [in Russian].

Kovalev, O. V. & V. I. Samus. 1972. Biology of Tarachidia candefacta Hubn. and prospects of its use to control common ragweed. U.S.S.R. Agric. Biol. 7: 281-84. [in Russian].

Kovalev, O. V. & V. V. Vechernin. 1986. Description of a new wave process in populations with reference to introduction and spread of the leaf beetle Zygogramma suturalis F. (Coleoptera: Chrysomelidae). Ent. Obozr. 65: 21-38. [in Russian].

Wapshere, A. J. 1974. A strategy for evaluating the safety of organisms for biological weed control. Ann. Appl. Biol. 77: 201-11.