# Genetic Effects for Individual Honeybee Grooming Behavior in Response to Varroa Mites and Its Relationship with the Mite Infestation Levels of Honeybee Colonies

## TL;DR

This study finds that honeybee grooming behavior against mites has a genetic basis and is linked to mite infestation levels in colonies.

## Contribution

The study identifies genetic effects influencing honeybee grooming behavior and its impact on Varroa mite infestation levels.

## Key findings

- Genetic groups differ in grooming behavior expression (p < 0.01).
- Grooming behavior follows a genetic additive and dominance model (r2 = 0.95).
- Higher grooming behavior correlates with higher Varroa infestation levels (r = 0.57).

## Abstract

Background/Objectives: The objectives of this study were to identify the genetic effects involved in the expression of individual honeybee grooming behavior in response to Varroa destructor and to determine if there is an association between the expression of this behavior and the infestation levels of Varroa in the honeybee colonies. Methods: The study was conducted in a population of 112 colonies composed of six segregating genetic groups that were derived from two honeybee lines that were selected for high and low individual honeybee grooming behavior. The individual honeybee grooming behavior of 3974 workers from the 112 colonies was measured by the time it takes a bee to respond in performing grooming behavior after a mite was placed on her body. The population growth of Varroa in the colonies was measured over a period of six months. Results: Differences between the genetic groups were found in the expression of individual honeybee grooming behavior (p < 0.01). The distribution of means of the genetic groups fits a genetic additive and dominance effects model for the expression of individual honeybee grooming behavior (r2 = 0.95; p < 0.01). Differences between the genetic groups were found in the colony population growth of Varroa over a period of six months (p < 0.01). A positive correlation was found between the mean individual honeybee grooming behavior of the colonies and the Varroa level of infestation in the colonies (r = 0.57; p < 0.01). Conclusions: The results indicate that additive and dominance genetic effects are associated with honeybee individual grooming behavior and that this trait has an effect on the levels of Varroa infestation in the colonies.