# Comparing brown mite, Bryobia rubrioculus Scheuten (Acari: Tetranychidae) sampling methods in almond orchards in California

## TL;DR

This study compares methods for sampling brown mites in California almond orchards to help manage pest populations effectively.

## Contribution

The study identifies shoot tufts as the most effective sampling method for brown mites in almond orchards.

## Key findings

- Shoot tufts collected the highest number of brown mites compared to other methods.
- Tree-band traps collected more mites than leaves but fewer than shoot tufts.
- Results can guide monitoring strategies for B. rubrioculus in almond orchards.

## Abstract

Several arthropod pests infest almond orchards in California’s Central Valley, United States, which produces ~ 80% of the almonds globally. Some are key pests, while others are minor but can cause economic damage due to fluctuations in environmental factors from year to year. Thus, keeping pest levels below the economic injury level is key for sustainable and profitable almond production. As a part of the integrated pest management (IPM) concept, record-keeping for the occurrence of various pests using an adequate sampling plan aids in developing a future pest management program. Thus, we tested sampling methods for the brown mite, Bryobia rubrioculus Scheuten, which is becoming an increasing problem in almond orchards in California. We sampled three almond orchards in the northern San Joaquin Valley from February to July at bi-weekly intervals. We used a tree-band trap on the tree trunk to collect mites from the lower part of the canopy and trunk, and leaf and shoot tuft samplings to collect mites from the top canopy of the plants. Consistent with all orchards, we collected the highest number of mites from shoot tufts than from tree bands, and the lowest number from leaves. Our results provide a foundation for monitoring B. rubrioculus populations in commercial almond orchards in California.