Ecological and Genetic Spatial Patterns of Urophora cardui (Diptera: Tephritidae) as Evidence for Population Structure and Biogeographical Processes

Abstract

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Performance of the thistle gall fly, Urophora cardui, in relation to host plant nitrogen and mycorrhizal colonization

“…C. arvense is highly mycorrhizal in the U.K. and there is no reason, given the wide occurrence of mycorrhiza] species (Brundrett, 1991) why it should not be so in Canada. The reduced performance of the fiy over severa] generations, through feeding on mycorrhiza] p]ants, coupled with its relatively poor dispersal ability (Eber & Brandl, 1994). might therefore have contributed to the poor establishtnent record of this insect (Peschken et al, 1982).…”

Ecological comparisons across geographical distributions: The thistle gall fly Urophora cardui (Diptera: Tephritidae) on two different Cirsium hosts

“…At small sites a com plete census was done, whereas large sites were sampled using the time-sampling method. In western Europe, the degree of shading at thistle sites has proved to be important in determining the occurrence of U. cardui galls (Eber & Brandl, 1994). There fore the degree of shading at each C. setosum site except one (n = 19) was estimated on a scale from zero (not shaded) to three (completely shaded).…”

“…Young larvae are mainly attacked by the parasitoids Eurytoma robusta Mayr and Eurytoma serratulae F. (Hymenoptera: Eurytomidae). In local populations these species may kill all of the larvae (Eber & Brandl, 1994;Zwölfer, 1982).…”

“…This was always done by the same individu als. To calibrate the time-sampling data, the total number of galls in 28 C. arvense patches was determined (for details see Eber & Brandl, 1994). The calibration allowed the mean number of galls per thistle stem at a site to be estimated.…”

Rules of Thumb for Conservation of Metapopulations Based on a Stochastic Winking‐Patch Model

“…The models used to estimate (e, c) and (e, c 8 ) are the (uncorrelated) discrete-time model and its analogue for a limited number of eight patches contributing to colonization. The letters denote the source of the turnover data (with the number of patches in parentheses): a, Briers and Warren 2000 (68); b, Eber and Brandl 1994, 1996 (513); c, Hanski et al 1994 (50); d, Lei and Hanski 1998 (50, 22); e, Harrison et al 1988 (59); f, Hecnar and M'Closkey 1997 (160); g, Hill et al 1996 (69); h, Kindvall and Ahlén 1992 (110); i, Morrison 1998 (129); j, Nürnberger 1996 (51); k, Smith and Gilpin 1997 (78); l, Sutcliffe et al 1997 (14); m, Thomas and Harrison 1992 (16, 20); n, Van der Meijden and Van der Veen-Van Wijk 1997 (102, 79); o, Villard et al 1995 (51). Although the data sets are of different quality, we have not included a measure of the error in the parameter estimates because they are intended for illustrative purposes only.…”