Related Experiment Video
Updated: Jun 17, 2026

Characterizing Herbivore Resistance Mechanisms: Spittlebugs on Brachiaria spp. as an Example
Published on: June 19, 2011
Genetic differentiation between resistance phenotypes in the phytophagous flea beetle, Phyllotreta nemorum
Peter W de Jong1, Casper J Breuker, Helene de Vos
1Laboratory of Entomology, Wageningen University, PO Box 8031, 6700 EH Wageningen, The Netherlands. Peter.dejong@wur.nl
Abstract:
The flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae) is genetically polymorphic for resistance against the defences of one of its host plants, Barbarea vulgaris R.Br. (Brassicales: Brassicaceae). Whereas resistant flea beetles are able to use B. vulgaris as well as other cruciferous plants as food, non-resistant beetles cannot survive on B. vulgaris. This limitation to host plant use of non-resistant beetles could potentially lead to asymmetric gene flow and some degree of genetic isolation between the different resistance-genotypes. Therefore, we studied the extent of genetic differentiation at neutral allozyme loci between samples of flea beetles that were collected at different locations and first tested for resistance phenotype. Since earlier work has shown a weak, but significant, effect of geographical distance between the samples on their genetic differentiation, in the present study variation at the neutral allozyme loci in P. nemorum was partitioned between geographical distance and resistance-phenotype. Both sources independently contributed statistically significantly to population differentiation. Thus, there appears to be a limitation to genetic exchange between the resistant and non-resistant flea beetles when corrections are made for their geographic differentiation. This is consistent with the presence of some degree of host race formation in this flea beetle.
More Related Videos
Related Concept Videos
Genetics of Speciation
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
Mutation, Gene Flow, and Genetic Drift
Frequency-dependent Selection
Position-effect Variegation

