DOI: 10.5061/dryad.d2547d8c7
title: Data from: Effect of tillage intensity on the inter-row plant community and microlepidoptera predation rates in arid vineyards in Argentina

description: Microlepidoptera pose a significant threat as vineyard pests. Yet,
 information about inter-row management effects on natural enemies remains
 limited. We evaluated the impact of an inter-row tillage gradient
 on plant cover and the predation rate of microlepidopteran larvae and
 pupae as a model to estimate potential predation rates of Lobesia botrana
 in vineyards. The percentage of bare soil measured at the surface
 level in the inter-rows was the only variable that correlated with the
 tillage intensity gradient. Predation rates of larvae and pupae
 showed significant differences between tillage intensities, but did not
 follow the expected pattern based on the tillage gradient. Bare
 soil measured at the surface level had a strong influence on predation
 rates when the tillage gradient was simplified into high and low intensity
 categories. Ants were the only observed predators, with 11
 species identified. They were able to respond quickly in locating and
 preying on the larvae and pupae offered.
description: <strong>Vegetation cover</strong>
 To evaluate the effect of the tillage gradient on the plant
 community of inter-rows and on predation rates, four vineyards with
 different tillage regimes were selected: continuous tillage throughout the
 season, annual tillage at the end of winter, tillage every three years,
 and no tillage. The survey of the plant community present in the vineyard
 inter-rows was conducted using the Point Quadrat method during the summer
 of 2019 and fall 2020. Ten sampling sites, spaced by at least 50 m from
 each other, were established for each of the four tillage levels analyzed.
 At each sampling site, a 15-meter transect was set up, along which all
 plant species intercepting the line every 30 cm were recorded.
 Additionally, we quantified the condition of bare soil at the surface
 level, the total vegetation cover, and the cover of individual species.
 Based on traits sensitive to tillage practices we grouped species and
 calculated cover categories such as grasses, dicots, native, and exotic
 species. Here bare soil was recorded as the surface area free of
 vegetation and litter, whether or not there was overhead plant cover,
 while vegetation cover, on the other hand, refers to the presence of
 vegetation either at or above the surface level. The ratios of native to
 exotic species and dicots to grasses were calculated, with native species
 and dicots as the numerator. Due to the presence of many zeros in the
 dataset, a constant was added to each value before calculating the natural
 logarithm and then determining the respective proportions.
 <strong>Sentinel traps</strong>
 Trials using living prey were conducted using the sentinel prey
 technique, for this purpose, we used larvae and pupae of <em>Plodia
 interpunctella</em> (Hübner). In December 2022, 10 pairs of sentinel
 traps were installed in each vineyard to assess pupal predation. They were
 placed on the ground, at the base of the grapevine trunks. The traps
 consisted of a plastic Petri dish filled with sieved soil and 10 partially
 buried pupae. Each pair of traps was located in two consecutive grapevine
 rows; one of them was covered with wire mesh to exclude large predators,
 while the other remained exposed. This approach allowed us to
 differentiate between predation by arthropods and by birds or small
 mammals. The traps were checked every 24 hours, and the number of pupae
 predated was recorded as the difference between the total number of pupae
 offered and those remaining in the trap after 24 hours. Then pupae were
 replaced for another observation period of 24 hours. In
 April 2023, we assessed larval predation using ten sentinel traps, each
 consisting of a cork affixed to a grapevine branch with five last instar
 larvae pinned to the final segment.  The predation rate was recorded as
 the difference between the larvae offered and the larvae that remained at
 the trap after 24 hours. After 24 hours of exposure, the remaining larvae
 were confirmed to be alive and active, and were recorded as non-predated.
 Subsequently, the trap was replaced with a new one containing five fresh
 larvae. In this trial, the exclusion treatment for birds and mammals was
 not applied.
description: # Data from: Effect of tillage intensity on the inter-row plant community
 and microlepidoptera predation rates in arid vineyards in Argentina
 [https://doi.org/10.5061/dryad.d2547d8c7](https://doi.org/10.5061/dryad.d2547d8c7) ## Description of the Data and File Structure This dataset contains information from a larval and pupal predation trial using sentinel prey in vineyards, as well as data on vegetation in the inter-rows. The data were collected in December 2019 and April 2020 in four vineyards with different tillage intensities. The primary objective of the study was to evaluate larval and pupal predation rates under different tillage regimes (high = continuous tillage throughout the season, medium = annual tillage at the end of winter, low = tillage every three years, and null = no tillage) and to assess the influence of vegetation on predation. ## Files and Variables ### File: `Larvae.csv` **Description:** This file contains data on larval predation rates in vineyards under different tillage intensities. Sentinel traps were used to offer larvae, and predation was recorded every 24 hours over three days. **Variables:** * **day**: The trial was conducted over three days, with larvae removed and replaced every 24 hours. * **Intensity**: Tillage intensity: * High = continuous tillage throughout the season, * Medium = annual tillage at the end of winter, * Low = tillage every three years, * Null = no tillage. * **sample**: Ten samples were used in each vineyard. * **larvae.offered**: Number of larvae offered in each sentinel trap (fixed at 5 larvae per trap). * **larvae.predated**: Number of larvae predated after 24 hours. * **bare.soil**: Tillage intensity levels pooled into two categories: * High = high and medium tillage intensities, * Low = low and null tillage intensities. ### File: `Pupae.csv` **Description:** This file contains data on pupal predation rates in vineyards under different tillage intensities. Sentinel traps were used to offer pupae, and predation was recorded every 24 hours over three days. Two types of traps were used: open (accessible to all predators) and closed (covered with wire mesh to exclude larger predators). **Variables:** * **day**: The trial was conducted over three days, with pupae removed and replaced every 24 hours. * **Intensity**: Tillage intensity: * High = continuous tillage throughout the season, * Medium = annual tillage at the end of winter, * Low = tillage every three years, * Null = no tillage. * **sample**: Ten samples were used in each vineyard. * **cover**: Type of sentinel trap: * Open = accessible to all predators, * Closed = covered with wire mesh to exclude larger predators. * **pupae.predated**: Number of pupae predated after 24 hours (out of 10 pupae offered per trap). * **bare.soil**: Tillage intensity levels pooled into two categories: * High = high and medium tillage intensities, * Low = low and null tillage intensities. ### File: `Vegetation.csv` **Description:** This file contains data on vegetation cover in vineyard inter-rows, collected during two seasons (summer and fall). Vegetation was sampled along transects, and plant cover was recorded at regular intervals. **Variables:** * **season**: Periods in which vegetation was sampled: * Summer = December 2019, * Fall = April 2020. * **Intensity**: Tillage intensity: * High = continuous tillage throughout the season, * Medium = annual tillage at the end of winter, * Low = tillage every three years, * Null = no tillage. * **transect**: Ten transects were assessed in each vineyard, each 15 meters long, with readings taken every 30 cm (50 points per transect). * **Cob_tot**: Total plant cover per transect. * **SD**: Bare soil recorded as the surface area free of vegetation and litter, regardless of overhead plant cover. * **CobG**: Coverage of grasses. * **CobD**: Coverage of dicots. * **CobN**: Coverage of native plant species. * **CobE**: Coverage of exotic plant species. * **logD.G**: Logarithm of the ratio of dicots to grasses. * **logN.E**: Logarithm of the ratio of native to exotic plant species. ### File: `Script vegetation & larvae and pupae predation.R` **Description:** This file contains the script in R software to run vegetation, and larval and pupal predation analyses. It also contains the script to generate the graphics presented in the manuscript.