Effect of shifts of the larval biology on the radiation of Microlepidoptera (Pyralidae, Yponomeutidae) feeding on gymnosperm hosts

• Applicant: Dr. Andreas H. Segerer
• Subject Area: Evolution and Systematics of Plants and Fungi
• Term: from 2002 to 2005
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5363137

Diversification and possible coevolution of two unrelated genera of gymnosperm feeding Lepidoptera (Dioryctria; Argyresthia) shall be investigated with respect to host plant shift and ecological niche strategies in order to test general evolutionary hypothesis. Gymnosperm feeding Lepidoptera exhibit a high number of sibling species groups, the relative amount of which is evidently higher than in angiosperm feeders. Hypothesis: This is the result of speciation processes accelerated by insect-host interactions. The 'escalation/ diversification' model of Ehrlich & Raven (1964) predicts that herbivore clades adapted to host plants with distinctive chemical defense systems should exhibit accelerated radiation compared to their sister groups. It has also been suggested that endophagy might limit the ability to colonize alternative hosts and restrict the potential for speciation, i.e. transition to ectophagy should promote evolutionary success. Both ideas are to be tested by reconstruction of a phylogenetic tree of the model genera using both molecular and morphological data and by subsequent analyzing host plant associations, colonization patterns and niche preferences ("telling the trees"). As a 'spin-off', it is expected that the study will provide key features for identification of economically important sibling pest species.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1127: Radiations - Origins of Biological Diversity