DOI: 10.5061/dryad.j6q573nsc
title: Data from: Black garden ants reduce aphid predation by native and invasive ladybirds

description: We established microcosms with a bean plant (Vicia faba) infested with
 black bean aphids (Aphis fabae). The microcosms were divided into the
 following treatments: no ants, aphids tended by common red ants (Myrmica
 rubra), and aphids tended by black garden ants (Lasius niger). We added
 either a native ladybird (Coccinella septempunctata) or an invasive
 ladybird (Harmonia axyridis) to the microcosms. We compared deterrence of
 ladybirds from plant-based aphids by ants and the number of aphids
 remaining at the end of the experiment. We present the data of remaining
 aphids [Aphids] and observations of ladybirds on plants [Plant] in two
 versions: 1) data_all: with the respective variables in one single column
 and observation [Observ] as an additional variable and 2) data_per_observ:
 presenting the measured variables in individual columns for the respective
 time of observation (h after the start of the experiment). Explanatory
 variables include the identity of the microcosm [No], experimental block
 [Block], observation time within each block [Observ], treatment
 combination [Treat], ant treatment [Ant], and ladybird treatment
 [Beetle].  Treatment combinations consist of the presence of
 Myrmica rubra [MR], Lasius niger [LN], Coccinella septempunctata [CS],
 Harmonia axyridis [HA], and no ant or ladybird [None].
description: # Data from: Black garden ants reduce aphid predation by native and
 invasive ladybirds Dataset DOI:
 [10.5061/dryad.j6q573nsc](10.5061/dryad.j6q573nsc) ## Description of the
 data and file structure Background Intraguild interference between
 predators can hamper top-down regulation. For example, aphid-tending ants
 often defend their mutualistic partners against antagonists. Greater ant
 aggression against native ladybirds compared to non-native ladybirds might
 benefit the non-native predator, due to predator-predator naïveté. As a
 consequence, non-native ladybirds are expected to consume more aphids and
 might thus outcompete native ladybirds. Methods We established microcosms
 with a bean plant (*Vicia faba*) infested with black bean aphids (*Aphis
 fabae*). The microcosms were divided into the following treatments: no
 ants, aphids tended by common red ants (*Myrmica rubra*) and aphids tended
 by black garden ants (*Lasius niger*). We added either a native ladybird
 (*Coccinella septempunctata*) or an invasive ladybird (*Harmonia
 axyridis*) to the microcosms. We compared deterrence of ladybirds from
 plant-based aphids by ants and the number of aphids remaining at the end
 of the experiment. ### Files and variables
 Data_BucherMasson_EcolEntomol_25-0055-EEN.xlsx The data of this
 publication is in two sheets presenting the identical data in two
 different formats: '**data_all**' and
 '**data_per_observ**' (and a short version of the information
 provided below in the sheet named '**meta_data**'):
 '**data_all**' shows all data for all observations of
 [**Aphids**] and [**Plant**] with a seperate column for the identity of
 observation [**Observ**] '**data_per_observ**' shows the same
 measured variables [**Aphids_1**], **Aphids_2**],... and [**Plant_1**],
 **Plant_2**],... per observation time in seperate columns (i.e. repeated
 measurements of the same microcosm) and the number in the header indicates
 the identity of the observation (e.g. 1 hour, 2 hours... after the start
 of the experiment) In both sheets, variables are defined as: \[**No**] is
 the identity of the microcosm (a continuous number) \[**Block**] indicates
 the experimental block (i.e. microcosm experiments that were conducted at
 the same time) \[**Observ**] is the observation (i.e. repeated
 measurement) of the respective microcosm measured as number of hours after
 the start of the experiment; This column occurs only in the
 sheet '**data_all**' \[**Treat**] is the combination of ant and
 ladybird treatment, which is the combination of the columns
 [**Ant**]_[**Beetle**], see below \[**Ant**] is the ant treatment: either
 **MR** for *Myrmica rubra*, **LN** for *Lasius niger*, or **None** for
 microcosms without ants \[**Beetle**] is the ladybird treatment: either
 **CS** fro *Coccinella septempunctata*, **HA** for *Harmonia axyridis*, or
 **None** for microcosms without ladybirds \[**Aphids**] is the observed
 number of living aphids in the microcosm (i.e. counts of remaining
 aphids); This column occurs only in the sheet '**data_all**'
 \[**Plant**] is the observed position of the ladybird: **1** indicates
 ladybird is on the plant, **0** indicates ladybird is elsewhere (e.g. on
 the ground, on the wall/ceiling of the microcosm; This column only occurs
 in the sheet '**data_all**' \[**Aphids_1**], [**Aphids_2**],…
 counts of aphids (see above) at the respective time of observation (1, 2,…
 hours after the start of the experiment); These columns only occur in the
 sheet '**data_per_observ**' \[**Plant_1**], [**Plant_2**],… is
 the observation of the position of the ladybird (see above) at the
 respective time of observation (1, 2,… hours after the start of the
 experiment); These columns only occur in the
 sheet '**data_per_observ**' \[**Plant_cum**] is the cumulative
 obervations (sum) of ladybirds observed on the plant (see above) across
 all observations; This column only occurs in the
 sheet '**data_per_observ**' Information on NA's: **NA** in
 [**Plant**] are for treatments without ladybirds ([**Beetle**] ==
 **None**) as there is no position of the ladybird if there is no ladybird
 in the treatment (i.e. not applicable), NA is included here for the use in
 R* \* Exception: for microcosm 37 we lack the 5th observation of *C.
 septempunctata* (i.e. not available; Ladybird might have been hidden in
 the soil), [Plant_cum] = 0 as the ladybird was never ovserved on the plant
 in this microcosm See also information in the sheet
 '**meta_data**' in the file. For more detailed information
 consult the method section of the article or contact Dr. Bucher via:
 [Roman.Bucher@b-tu.de](mailto:Roman.Bucher@b-tu.de) ## Code/software
 Excel/R