Embargo: Monday 02 September 2019 16:00 (BST) Journal: Nature Plants
Ecology: Weevils thwarted by leaves’ complicated geometry *VIDEO*
The leaf shapes of certain species of the Isodon group of flowering plants act as deterrents against a leaf-rolling weevil, according to a paper published in Nature Plants.
The physical properties of leaves — such as their toughness or the presence of a waxy or hair-like surface — are a plant’s first line of defence against attacks by herbivores.
Yumiko Higuchi and Atsushi Kawakita observed the behaviour of the leaf-rolling weevil (Apoderus praecellens), which lay their eggs on plants of the Isodon genus. After landing on a leaf and inspecting its surface, female weevils cut it, bite it and roll it up to provide shelter for one or two eggs that are laid inside. The roll also provides food for the larvae once they hatch. The authors noticed that the female weevils preferred the relatively simple-shaped leaves of Isodon trichocarpus over those of Isodon umbrosus var. hakusanensis, which have a complicated multilobed shape. The authors then cut the leaves to create lobed I. trichocarpus, which dampened the preferences of the weevils.
The authors observed that complicated leaf shapes interfere with the weevils’ ability to investigate the leaves before rolling them up. Further research is needed to determine whether the shape of I. umbrosus leaves has specifically evolved as a defence against the weevil.
Leaf shape deters plant processing by an herbivorous weevil
Kyoto University, Center for Ecological Research, Otsu, Shiga, Japan
Email: [email protected]
Please link to the article in online versions of your report (the URL will go live after the embargo ends): https://nature.com/articles/s41477-019-0505-x