scholarly journals Host specificity of Aceria centaureae (Nalepa), a candidate for biological control of Centaurea dίffusa De Lamarck

2017 ◽  
Vol 7 ◽  
pp. 27 ◽  
Author(s):  
R. Sobhian ◽  
Β. Ι. Katsouannos ◽  
J. Kashefi
Keyword(s):  
Biological Control ◽  
Host Plant ◽  
Carthamus Tinctorius ◽  
The Other ◽  
Centaurea Solstitialis ◽  
Gall Formation ◽  
Centaurea Diffusa ◽  
Gall Mite ◽  
Diffuse Knapweed ◽  
Test Plants

Filed collected rosettes or twigs of Centaurea diffusa De Lamarck, infested by the gall mite Aceria centaureae, were fixed onto appropriately grown and planted test plants of ten different species in the area of Thessaloniki, Greece, in 1985 and 1986. The test plants were inspected for presence of galls and mites a few to several days after their contact with the infested twigs. Gall formation occurred on all of the Centaurea diffusa test plants, either of Greek or U.S. origin, and on some of the Centaurea solstitialis, L. test plants. No galls or other mite damage could be found on the other test plants, which were Carthamus tinctorius L. (safflower), Cirsiton creticion (De Lamarck) D’Urville, of local origin and six Cirsium species of U.S. origin, i.e. cymosum (Greene) J. T. Howell, occidentals (Nutt) Jeps., pastoris Howell, andersonii (Gray) Petrak, brevistylum Crong; and undulation (Nutt.) Spreng. These results suggest that A. centaureae most probably has a very restricted host plant range, feeding only on weedy Centaurea spp. Thus the mite should be considered as a possible candidate for biological control of diffuse knapweed in the U.S.A. and Canada.

Biological Control of Diffuse Knapweed (Centaurea diffusa) and Spotted Knapweed (C. maculosa)

Weed Science ◽  
1982 ◽  
Vol 30 (1) ◽  
pp. 76-82 ◽  
Author(s):  
Donald M. Maddox
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Reproductive Potential ◽  
Control Agent ◽  
Flower Head ◽  
Spotted Knapweed ◽  
Centaurea Diffusa ◽  
Weedy Species ◽  
Diffuse Knapweed ◽  
Number Of Seeds

Diffuse knapweed (Centaurea diffusa Lam.) and spotted knapweed (C. maculosa Lam.) presently infest approximately 1.5 million ha of pasture and rangeland in Washington, Montana, Idaho, Oregon, and California. The serious losses caused on lands where returns from herbicidal control are marginal or less prompted the testing and introduction of two strains of a seed-head fly (Urophora affinis Frlfld.) as a biological-control agent in these states. Over 27 000 flies were released in about equal numbers on both weeds during the years 1974 to 1977 and in 1979 and 1980. The fly became established in all states where it was released. The adult was found to disperse over 76 m from release point from 1974 to 1976, and to reduce the number of seeds per flower head in sampled heads by 80% in northern Washington and over 64% at the Heppner, Oregon site. A newly released moth (Metzneria paucipunctella Zell.) and a root-boring beetle (Spbenoptera jugoslavica Obenb.) are expected to cause additional pressure on these plants. The reproductive potential of the knapweeds is such that more natural enemies will be needed to provide enough stress to reduce these weedy species to an acceptable level.

FIRST REPORT OF THE DISPERSAL INTO MONTANA OF UROPHORA QUADRIFASCIATA (DIPTERA: TEPHRITIDAE), A FLY RELEASED IN CANADA FOR BIOLOGICAL CONTROL OF SPOTTED AND DIFFUSE KNAPWEED

1985 ◽  
Vol 117 (8) ◽  
pp. 1061-1062 ◽  
Author(s):  
Jim M. Story
Keyword(s):  
Biological Control ◽  
British Columbia ◽  
The United States ◽  
Flower Head ◽  
The Other ◽  
Centaurea Maculosa ◽  
Spotted Knapweed ◽  
European Origin ◽  
Mature Flower ◽  
Diffuse Knapweed

Two tephritid flies of European origin have been introduced into North America for biological control of spotted knapweed, Centaurea maculosa Lam., and diffuse knapweed, C. diffusa Lam. One, Urophora affinis Frauenfeld, was released in British Columbia in 1970 and in 5 states, including Montana, in 1973 (Hanis 1980a; Maddox 1979; Story and Anderson 1978). The other, Urophora quadrifasciata (Meigen), was introduced at Ned's Creek, British Columbia but was not released in the United States. The larvae of both flies induce galls (1 larva/gall) in immature knapweed flower heads and thus reduce seed production. Galls of Urophora affinis occur in the flower-head receptacle whereas galls of U. quadrifasciata are in the ovary wall. In contrast with U. affinis, which has only a partial second generation, U. quadrifasciata normally has 2 complete generations per year, induces thinner galls, and attacks more-mature flower heads than does U. affinis (Harris 1980a).

HOST SPECIFICITY OF TINGIS AMPLIATA (TINGIDAE: HETEROPTERA): A CANDIDATE FOR THE BIOLOGICAL CONTROL OF CANADA THISTLE (CIRSIUM ARVENSE)

1977 ◽  
Vol 109 (5) ◽  
pp. 669-674 ◽  
Author(s):  
D. P. Peschken
Keyword(s):  
Biological Control ◽  
Host Plant ◽  
Host Specificity ◽  
Biocontrol Agent ◽  
Carthamus Tinctorius ◽  
Cirsium Arvense ◽  
Globe Artichoke ◽  
Canada Thistle ◽  
Cynara Scolymus

AbstractThe only confirmed host plant of Tingis ampliata H.-S. (Tingidae: Heteroptera) is Canada thistle (Cirsium arvense (L.) Scop.). For this and other reasons, T. ampliata appeared to be a promising biocontrol agent for use in Canada. However, in the laboratory, T. ampliata developed fertile eggs while feeding on the two economic plants globe artichoke (Cynara scolymus L.) and safflower (Carthamus tinctorius L.), and nymphs developed to adults on globe artichoke. Therefore, T. ampliata should not be released in Canada.

Successful biological control of diffuse knapweed, Centaurea diffusa, in British Columbia, Canada

2009 ◽  
Vol 50 (1) ◽  
pp. 66-72 ◽  
Author(s):  
Judith H. Myers ◽  
Caroline Jackson ◽  
Hillary Quinn ◽  
Shannon R. White ◽  
Jenny S. Cory
Keyword(s):  
Biological Control ◽  
British Columbia ◽  
Centaurea Diffusa ◽  
Diffuse Knapweed

BIOLOGY OF CYPHOCLEONVS ACHATES (COLEOPTERA: CURCULIONIDAE), PROPAGATED FOR THE BIOLOGICAL CONTROL OF KNAPWEEDS (ASTERACEAE)

1999 ◽  
Vol 131 (2) ◽  
pp. 243-250 ◽  
Author(s):  
Brian M. Wikeem ◽  
George W. Powell ◽  
Allen Sturko
Keyword(s):  
Biological Control ◽  
Adult Emergence ◽  
Larval Survival ◽  
Specific Information ◽  
Spotted Knapweed ◽  
Degree Days ◽  
Centaurea Diffusa ◽  
Larval Production ◽  
Competition For Food ◽  
Diffuse Knapweed

AbstractCyphocleonus achates (Fahraeus) is a weevil used for the biological control of diffuse knapweed, Centaurea diffusa Monnet Del La Marck, and spotted knapweed, Centaurea maculosa Monnet Del La Marck, in North America. This research provided specific information on the biology of this insect in British Columbia. Adult weevils were released at six densities (1, 2, 4, 8, 16, and 32 male–female pairs) in each of 2 years into plots containing spotted knapweed. Larvae per plant, larval mass, larval survival, adult emergence, and air temperature were measured. Larval production increased with the release density of weevils in both the 1992 cohort and the 1993 cohort. Larval mass did not differ between years. Larval mass also did not vary with the release density of adults or the number of larvae per root. Larval survival of the 1993 cohort ranged from 17 to 48%, whereas that of the 1994 cohort ranged from 0 to 91%. Adult emergence began after the accumulation of 726–1144 degree-days. For both cohorts the date of first emergence occurred earlier, as the average number of larvae per plant increased for both cohorts. Increasing competition for food or space in the roots can induce early emergence. Sex ratios did not vary with date of emergence or release density of adult weevils. Adult emergence increased with the release density in the 1992 cohort, suggesting the average larval densities did not exceed the carrying capacity of the roots. The peak emergence rate increased with the release density in the 1992 cohort, but not in the 1993 cohort because of lower larval survival.

scholarly journals The influence of two wildfires and biological control agents on the population dynamics of Melaleuca quinquenervia in a seasonally inundated wetland

2021 ◽  
Vol 14 (1) ◽  
pp. 3-8
Author(s):  
Philip W. Tipping ◽  
Melissa R. Martin ◽  
Jeremiah R. Foley ◽  
Ryan M. Pierce ◽  
Lyn A. Gettys
Keyword(s):  
Biological Control ◽  
Population Dynamics ◽  
Seedling Recruitment ◽  
Additional Treatment ◽  
Seed Rain ◽  
The Other ◽  
Melaleuca Quinquenervia ◽  
Biological Control Agents ◽  
Seedling Mortality ◽  
Sapling Growth

AbstractThe potential of Melaleuca quinquenervia (Cav.) S.T. Blake to reinvade cleared areas was evaluated over a 13-yr period that included two wildfires and the introduction of biological control agents. The first wildfire occurred in 1998 and was followed by a mean of 591.5 recruited seedlings m−2. Recruits from that fire were cleared 7 yr later in July 2005 for a second experiment to evaluate seedling recruitment into cleared areas. Seed rain, seedling recruitment and mortality, and sapling growth rates were measured in four plots located around individual large reproductive trees. A second natural wildfire in 2007 burned through those plots, leading to increases in seed rain followed by a pulse in recruitment of 21.04 seedlings m−2, 96.5% fewer than after the 1998 fire. Recruits in half of the plots around each tree were then treated with regular applications of an insecticide to restrict herbivory by biological control agents, while herbivory was not restricted in the other half. There was no difference in seedling mortality between treatments 1,083 d post-fire (2007) with 96.6% seedling mortality in the unrestricted herbivory treatment and 89.4% mortality in the restricted herbivory treatment. Recruits subjected to the restricted herbivory treatment grew taller than those in the unrestricted herbivory treatment, 101.3 cm versus 37.4 cm. Many of the recruits were attacked by the biological control agents, which slowed their growth. Although solitary M. quinquenervia trees retain some capacity to reinvade areas under specific circumstances, there was a downward trend in their overall invasiveness at this site, with progressively smaller recruitment cohorts due to biological control agents. Land managers should prioritize removing large reproductive trees over treating recently recruited populations, which can be left for many years for the biological control agents to suppress before any additional treatment would be needed.

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