The evolution of host associations in the parasitic wasp genus Ichneumon (Hymenoptera: Ichneumonidae): convergent adaptations to host pupation sites

Tschopp, Andreas; Riedel, Matthias; Kropf, Christian; Nentwig, Wolfgang; Klopfstein, Seraina (2013). The evolution of host associations in the parasitic wasp genus Ichneumon (Hymenoptera: Ichneumonidae): convergent adaptations to host pupation sites. BMC evolutionary biology, 13(1), p. 74. BioMed Central 10.1186/1471-2148-13-74

[img]
Preview
Text
kropf_nentwig.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (600kB) | Preview

Background: The diversification of organisms with a parasitic lifestyle is often tightly linked to the evolution of their host associations. If a tight host association exists, closely related species tend to attack closely related hosts; host associations are less stable if associations are determined by more plastic traits like parasitoid searching and oviposition behaviour. The pupal-parasitoids of the genus Ichneumon attack a variety of macrolepidopteran hosts.They are either monophagous or polyphagous, and therefore offer a promissing system to investigate the evolution of host associations. Ichneumon was previously divided into two groups based on general body shape; however, a stout shape has been suggested as an adaptation to buried host pupation sites, and might thus not represent a reliable phylogenetic character. Results: We here reconstruct the first molecular phylogeny of the genus Ichneumon using two mitochondrial (CO1 and NADH1) and one nuclear marker (28S). The resulting phylogeny only supports monophyly of Ichneumon when Ichneumon lugens Gravenhorst, 1829 (formerly in Chasmias, stat. rev.) and Ichneumon deliratorius Linnaeus, 1758 (formerly Coelichneumon) are included. Neither parasitoid species that attack hosts belonging to one family nor those attacking butterflies (Rhopalocera) form monophyletic clades. Ancestral state reconstructions suggest multiple transitions between searching for hosts above versus below ground and between a stout versus elongated body shape. A model assuming correlated evolution between the two characters was preferred over independent evolution of host-searching niche and body shape. Conclusions: Host relations, both in terms of phylogeny and ecology, evolved at a high pace in the genus Ichneumon. Numerous switches between hosts of different lepidopteran families have occurred, a pattern that seems to be the rule among idiobiont parasitoids. A stout body and antennal shape in the parasitoid female is confirmed as an ecological adaptation to host pupation sites below ground and has evolved convergently several times. Morphological characters that might be involved in adaptation to hosts should be avoided as diagnostic characters for phylogeny and classification, as they can be expected to show high levels of homoplasy.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Ecology and Evolution (IEE)
08 Faculty of Science > Department of Biology > Institute of Ecology and Evolution (IEE) > Community Ecology

UniBE Contributor:

Kropf, Christian; Nentwig, Wolfgang and Klopfstein, Seraina

Subjects:

500 Science > 570 Life sciences; biology
500 Science > 590 Animals (Zoology)
500 Science > 580 Plants (Botany)

ISSN:

1471-2148

Publisher:

BioMed Central

Language:

English

Submitter:

Alexander Strauss

Date Deposited:

18 Jun 2014 10:34

Last Modified:

26 Jun 2016 01:49

Publisher DOI:

10.1186/1471-2148-13-74

BORIS DOI:

10.7892/boris.46280

URI:

https://boris.unibe.ch/id/eprint/46280

Actions (login required)

Edit item Edit item
Provide Feedback