# Exposure to pesticide mixtures does not affect locomotory behaviors in carabid beetles

Raphaël Royauté, Alice Bossard, Colette Bertrand

► To cite this version:

Raphaël Royauté, Alice Bossard, Colette Bertrand. Exposure to pesticide mixtures does not affect locomotory behaviors in carabid beetles. European Conference on Behavioural Biology, Jul 2024, Zurich, Switzerland., 10.17605/OSF.IO/TWUZN. hal-04659832

HAL Id: hal-04659832

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Submitted on 23 Jul 2024

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<figure><img src="image_1.png" /></figure>
# Exposure to pesticide mixtures does not affect locomotory behaviors in carabid beetles

Raphaël ROYAUTÉ (1), Alice BOSSARD (2), Colette BERTRAND (1)

Contact e-mail : raphael.royaute@inrae.fr

(1) UMR ECOSYS, INRAE, AgroParisTech, Université Paris-Saclay, 91120 Palaiseau, France

(2) École Normale Supérieure, Département de Biologie, PSL Université Paris

## Carabids do not vary on average with exposure but behavioral variability does

### 1 Context

* Pesticides have deleterious effects on life-history, physiology and behavior in non-targeted organisms<fnref n="1" />⁻<fnref n="2" />

* Behavioral assays use substance-by-substance approaches that ignore cocktail effects in the field<fnref n="3" />

* Need novel procedures that account for multiple exposures

**Objective:** Determine the effect of pesticide multi-residue exposure on activity and exploration at field-realistic concentrations

<figure><img src="image_2.png" /><figcaption>**Fig 1.** *Poecilus cupreus*, a common generalist carabid predator in agorecosystems</figcaption></figure>

### 2 Methods

**Pesticide exposure**

* 10 agricultural soils

* 1 reference soil

* 198 carabids exposed

<figure><img src="image_3.png" /></figure>

<figure><img src="image_4.png" /><figcaption>**Fig 2.** Carabids were exposed to a gradient of soil pesticide contamination during 6 weeks. Soils were chosen to have similar physico-chemical properties.</figcaption></figure>

**Biological responses**

* Body-mass

* Righting ability

* Reproduction

* Predation efficiency

* **Locomotion**

<figure><img src="image_5.png" /><figcaption>**Fig 3.** We monitored carabid locomotion in 10-minute assays using 9cm Petri dishes as arenas.</figcaption></figure>

**Video Tracking Analysis**

<figure><img src="image_6.png" /><figcaption>**Fig 4.** We used an automated video-tracking software to digitize animal tracks and extract activity (total distance travelled) and exploration (% of arena explored).</figcaption></figure>

### 3 Résultats

<figure><img src="image_7.png" /><figcaption>**Fig 5.** Effect of the number of pesticide residues in soils on carabid exploratory behavior. Top left, the number of residues had little influence on average exploration ($\beta_1$, $\mu$ = 0.01 [-0.01; 0.02], Probability of Direction, $P_d$ = 0.82). Top right, the precision parameter increases with residue number meaning that exploration variance tends to shrink at higher exposures ($\beta_1$, $\phi$ = 0.02 [0.00; 0.04], $P_d$ = 0.95). Bottom, posterior prediction indicating the shifts in exploration mean and precision as pesticide exposure increases. Results based on a Bayesian Linear Hierachical Model fitted with brms.</figcaption></figure>

* No effects on activity

* Exploration variability decreases with exposure

<figure><img src="image_8.png" /><figcaption>**Fig 6.** Correlation between activity and exploration compared across 4 levels of pesticide soil contamination. No effects of contamination class on behavioral correlations were detected (Probability of Direction, $P_d$ < 0.74). Results based on Bayesian Multivariate Hierachical Models fitted with brms.</figcaption></figure>

* Strong Activity x Exploration syndrome

* No influence of soil contamination on behavioral correlations

### 4 Perspectives

* **No overall effect of pesticides on locomotory behaviors**

* **Quantify pesticide concentrations for more precise inference**

* **Explore ingestion route as potentially more potent**

* **Use pose-tracking to detect fine-scale behavioral alterations**

## References

## Acknowledgments

We thank ADEME for financial support through the MixTox Project. We thank A. Bamière, V. Etiévant and P. Legrand for their assistance.

<figure><img src="image_9.png" /></figure>

<footnote n="1">¹ Desneux, N., Decourtye, A., & Delpuech, J. M. (2007). The sublethal effects of pesticides on beneficial arthropods. *Annual Review of Entomology*, 52, 81-106</footnote>

<footnote n="2">² Royauté, R., Buddle, C. M., & Vincent, C. (2015). Under the influence: sublethal exposure to an insecticide affects personality expression in a jumping spider. *Functional Ecology*, 29(7), 962-970</footnote>

<footnote n="3">³ Panico, S. C., van Gestel, C. A., Verweij, R. A., Rault, M., Bertrand, C., Barriga, C. A. M., ... & Pelosi, C. (2022). Field mixtures of currently used pesticides in agricultural soil pose a risk to soil invertebrates. *Environmental Pollution*, 305, 119290</footnote>