Chemoecology (2006) 16, 241-251

N. E. Fatouros, M. Hilker, J. Gross (2006)
Reproductive isolation between populations from Northern and Central Europe of the leaf beetle Chrysomela lapponica L.
Chemoecology 16 (4), 241-251
Abstract: Allopatric populations of the leaf beetle Chrysomela lapponica are known to feed upon either willow (Salicaceae) or birch (Betulaceae). This study aimed to elucidate the differentiation process of these allopatric populations. We investigated whether these allopatric populations specialized on different host plants are still able to produce fertile offspring when interbreeding. Individuals from a population in Finland (willow specialists) and one in the Czech Republic (birch specialists) were crossed in laboratory. Hybrid formation succeeded only between females from the Czech, birch specialized population and males from the Finnish, willow specialized population, while no eggs were produced by females of the willow specialists having mated males of the birch specialists. Behavioral, morphological, physiological, and chemical features of the F₁ hybrids were studied. The chemical composition of larval defensive secretion and feeding preferences of the resulting F₁ hybrids mainly showed similarities with the paternal phenotype, while the area of black coloring on the offspring’s elytra was intermediate between those of the parental elytra. F₁ hybrids did not accept the host plant (birch) of their mothers for feeding and only survived on willow. Thus, since mothers only lay eggs on birch, we found evidence for a postzygotic isolation mechanism between the individuals of the two investigated populations: when having been mated with willow specialized Finnish males, the birch specialized Czech mothers place the hybrid eggs on a plant species (birch), on which the hatching larvae cannot survive.
(The abstract has been supplied by the author or ISPI and is excluded from the Creative Commons licence.)
Link to article at publishers website
Database assignments for author(s): Jürgen Gross, Monika Hilker

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Chrysomela lapponica	Willow (Salix)	Finland
	Chrysomela lapponica	Birch (Betula)	Czech Republic
	Chrysomela lapponica	Birch (Betula)	Finland