Morphological and olfactory tree traits influence the susceptibility and suitability of the apple species Malus domestica and M. sylvestris to the florivorous weevil Anthonomus pomorum (Coleoptera: Curculionidae)

Benjamin Henneberg; Torsten Meiners; Karsten Mody; Elisabeth Obermaier

doi:10.7717/peerj.13566

Morphological and olfactory tree traits influence the susceptibility and suitability of the apple species Malus domestica and M. sylvestris to the florivorous weevil Anthonomus pomorum (Coleoptera: Curculionidae)

PeerJ. 2022 Jul 15:10:e13566. doi: 10.7717/peerj.13566. eCollection 2022.

Authors

Benjamin Henneberg¹, Torsten Meiners², Karsten Mody³, Elisabeth Obermaier¹

Affiliations

¹ Ecological-Botanical Garden of the University of Bayreuth, University of Bayreuth, Bayreuth, Germany.
² Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Ecological Chemistry, Plant Analysis and Stored Product Protection, Berlin, Germany.
³ Department of Applied Ecology, Hochschule Geisenheim University, Geisenheim, Germany.

Abstract

The florivorous apple blossom weevil, Anthonomus pomorum (Coleoptera: Curculionidae), is the most economically relevant insect pest of European apple orchards in early spring. Neither efficient monitoring nor ecologically sustainable management of this insect pest has yet been implemented. To identify heritable traits of apple trees that might influence the host selection of A. pomorum, we compared the susceptibility of apple tree species using infestation rates of the domesticated apple, Malus domestica (Rosaceae: Pyreae), and the European crab apple, M. sylvestris. We evaluated the suitability of the two apple species for A. pomorum by quantifying the mass of weevil offspring. Because volatile organic compounds (VOCs) emitted from flower buds of the domesticated apple have previously been suggested to mediate female weevil preference via olfactory cues, we conducted bioassay experiments with blossom buds of both apple species to explore the olfactory preference of adult weevils and, furthermore, identified the headspace VOCs of blossom buds of both apple species through GC-MS analysis. The infestation analysis showed that A. pomorum infested the native European crab apple more prevalently than the domesticated apple, which originated from Central Asia. The European crab apple also appeared to be better suited for weevil larval development than the domesticated apple, as weevils emerging from M. sylvestris had a higher body mass than those emerging from M. domestica. These field observations were supported by olfactory bioassays, which showed that A. pomorum significantly preferred the odor of M. sylvestris buds compared to the odor of M. domestica buds. The analysis of headspace VOCs indicated differences in the blossom bud volatiles separating several M. domestica individuals from M. sylvestris individuals. This knowledge might be employed in further studies to repel A. pomorum from M. domestica blossom buds.

Keywords: Anthonomus pomorum; Curculionidae; Insect pest; Malus domestica; Malus sylvestris; Olfactory attraction; Volatile organic compounds (VOCs).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Coleoptera*
Humans
Malus*
Smell
Trees
Volatile Organic Compounds* / analysis
Weevils*

Substances

Volatile Organic Compounds

Associated data

Dryad/10.5061/dryad.v15dv41xr

Grants and funding

This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) (491183248) and by the Open Access Publishing Fund of the University of Bayreuth. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.