Domestic cat damage to plant leaves containing iridoids enhances chemical repellency to pests

Reiko Uenoyama; Tamako Miyazaki; Masaatsu Adachi; Toshio Nishikawa; Jane L Hurst; Masao Miyazaki

doi:10.1016/j.isci.2022.104455

Domestic cat damage to plant leaves containing iridoids enhances chemical repellency to pests

iScience. 2022 Jun 14;25(7):104455. doi: 10.1016/j.isci.2022.104455. eCollection 2022 Jul 15.

Authors

Reiko Uenoyama^{1

2}, Tamako Miyazaki³, Masaatsu Adachi^{4

5}, Toshio Nishikawa⁴, Jane L Hurst⁶, Masao Miyazaki^{1

2

3}

Affiliations

¹ Division of Agriculture, Graduate School of Arts and Sciences, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan.
² United Graduate School of Agricultural Sciences, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan.
³ Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan.
⁴ Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
⁵ Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
⁶ Mammalian Behaviour & Evolution Group, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, CH64 7TE Neston, UK.

Abstract

Catnip (Nepeta cataria) and silver vine (Actinidia polygama) produce iridoids with arthropod-repellent effects. Cats rub and roll against these plants, transferring iridoids to their fur that repels mosquitoes. Cats also lick and chew plant leaves during this response, although the benefit of this additional behavior has remained unknown. Here, we show that feline leaf damage substantially increases iridoid emission from both plants while also diversifying iridoids in silver vine. Cats show an equivalent duration of response to the complex cocktail of iridoids in damaged silver vine and to the much higher level of a single iridoid produced by damaged catnip. The more complex iridoid cocktail produced when silver vine is licked and chewed by cats increases mosquito repellency at low concentration. In conclusion, feline leaf damage contributes by releasing more mosquito-repellent iridoids. Feline olfactory and behavioral sensitivity is fine-tuned to plant-specific iridoid production for maximizing the mosquito repellency gained.

Keywords: biological science; ethology; zoology.