# Effects of cyclotide-producing plants on the development and life history parameters of Leipothrix violarius

## TL;DR

This study examines how two violet species affect the mite Leipothrix violarius, finding that mites perform better on V. odorata than V. uliginosa, possibly due to differences in cyclotide content.

## Contribution

The study identifies cyclotides as potential mediators of plant resistance in Viola species against mite herbivory.

## Key findings

- Mites reared on V. odorata showed faster egg development and higher population growth than those on V. uliginosa.
- Population growth occurred on all tested host species, but performance varied significantly.
- Cyclotides in Viola plants may influence mite performance, offering a model for studying plant-mite interactions.

## Abstract

Leipothrix violarius (Acariformes: Eriophyoidea) is a phytophagous mite specialized in feeding on plants from the genus Viola. It has been recorded on five host species, including Viola uliginosa, which is rare or endangered in much of its range. Despite taxonomic revisions, little is known about the biology or host specificity of L. violarius. In this study, we compared the effects of V. uliginosa and V. odorata on the development, survival, and population parameters of L. violarius, and assessed its host range using selected ornamental and naturally occurring violets. Development from egg to adult took approximately seven days on both host plant species, with no sex-related differences. However, mites reared on V. odorata exhibited faster egg development and greater population increase per generation than those reared on V. uliginosa. Population growth occurred on all tested host species, although mite performance varied. Viola plants produce cyclotides—bioactive cyclic peptides with antimicrobial and insecticidal properties. The observed differences in mite performance may reflect interspecific variation in cyclotide content or composition, suggesting a role for these compounds in plant resistance. Due to its narrow host range and epidermal feeding behavior, L. violarius offers a promising model for studying plant–mite interactions at the surface level. This system may help clarify how cyclotides mediate and respond to herbivory in Viola species.