Ecological Entomology (2005) 30, 406-418

J.T. Margaritopoulos, C. Tsourapas, M. Tzortzi, O.M. Kanavaki and J.A. Tsitsipis (2005)
Host selection by winged colonisers within the Myzus persicae group: a contribution towards understanding host specialisation
Ecological Entomology 30 (4), 406-418
Abstract: 1. Myzus persicae sensu lato demonstrates considerable genetic variation in respect to adaptation to host plants. The subspecies M. persicae nicotianae shows a preference for tobacco, while M. persicae sensu stricto (s. str.) for other herbaceous plants. Given that winged colonisers of several aphid species play an important role in selecting host plants, here their role in the host specialisation observed in M. persicae was examined in choice and no-choice tests conducted outdoors, in performance studies, and in DC Electrical Penetration Graph (DC-EPG) studies.
2. In outdoor choice tests, 77% of spring migrants of M. persicae nicotianae chose tobacco, whereas equal proportions of M. persicae s. str. selected tobacco and pepper. In no-choice tests, spring migrants settled more quickly after alighting on host rather than on non host plants, and significantly more alate M. persicae s. str. (27%) than M. persicae nicotianae (2%) left tobacco after walking briefly on the leaf surface, whilst no significant differences were found on pepper. Cross-host transfers significantly reduced the fecundity of both summer and spring migrants of the two subspecies. Finally, the results of no-choice tests and DC-EPG studies showed that winged aphids distinguished their host through cues located on the plant surface or in subcutaneous tissues perceived prior to the initiation of feeding.
3. This study demonstrates the important role of winged colonisers in the evolution of host specialisation in M. persicae. The multifarious divergent selection that the two host forms experience, i.e. the selection against cross-migrants and their subsequent generations, is a crucial factor involved in the development and maintenance of host specialisation and promotes the parallel evolution of improved host-recognition ability.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): John T. Margaritopoulos, John A. Tsitsipis

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Myzus persicae	Green pepper/chilli (Capsicum)
	Myzus persicae	Tobacco (Nicotiana tabacum)