ISSN:
1432-1939
Keywords:
Dioecy
;
Ephedra trifurca
;
Plant-insect interactions
;
Gall midges
;
Sex-biased herbivory
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We examined patterns of herbivory in the dioecious desert shrub, Ephedra trifurca (Ephedraceae), along a small watershed in the northern Chihuahuan Desert. We documented significant (p=0.002) sexual dimorphism in densities of Lasioptera ephedrae and L. ephedricola (Diptera: Cecidomyiidae), with male E. trifurca supporting higher densities than did females. Densities of gall midges varied significantly (p〈0.001) among four sample populations of E. trifurca arrayed along the watershed and exhibited an inverse gradient with elevation. There was also a significant (p=0.006) sex-by-site interaction such that the degree of intersexual variation in gall densities decreased down the watershed. Variation in gall densities and intersexual variation in gall densities exhibited inverse trends with variation in soil water and inorganic nitrogen concentrations along the watershed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00318030
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