Herbivore deme formation on individual trees: a test case.
Oecologia
; 94(4): 496-502, 1993 Jul.
Article
em En
| MEDLINE
| ID: mdl-28313989
ABSTRACT
We examined the deme-formation hypothesis, which states that sessile herbivores on long-lived hosts become locally adapted to the defensive phenotypes of individual trees. We showed a five-fold increase in resistance by individual pinyon pines (Pinus edulis) to the pinyon pine needle scale (Matsucoccus acalyptus). Although such variation could represent a significant selection pressure favoring deme formation, two lines of evidence led to rejection of the hypothesis. First, there were no significant differences in mortality among scale populations in a reciprocal transfer experiment. Second, a seven-year experiment showed that mortality of newly founded, incipient scale populations was similar to established scale populations. While our experiments fail to support the deme-formation hypothesis, they do demonstrate significant variation in the resistance traits of a natural tree population. Although we feel that demeformation is still probable in this system, it is likely to occur on a larger geographic scale than individual trees as proposed by Edmunds and Alstad.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Oecologia
Ano de publicação:
1993
Tipo de documento:
Article
País de afiliação:
Estados Unidos