DOI: 10.5061/dryad.hqbzkh1s8
title: Data characterizing symbiosis between the alder bark beetle and Neonectria bordenii

description: This dataset describes a symbiosis between the alder bark beetle,
 Alniphagus aspericollis, and Neonectria bordenii in red alder, Alnus
 rubra. These data were used to assess tree-killing by the alder bark
 beetle (i.e., beetle colonization status in relation to red alder
 condition) and the ability of the alder bark beetle to vector N. bordenii
 among host red alders (evaluated according to Leach’s postulates). Data
 were collected from five sites in southwestern British Columbia, Canada.
description: Data for assessing the ability of the alder bark beetle to kill
 trees were collected from 400 m<sup>2</sup> fixed-area plots.
 Data for evaluating, according to Leach’s postulates, the ability of the
 alder bark beetle to vector (i.e., carry and transmit)
 <em>Neonectria bordenii</em> were obtained from emergent
 beetles and infected phloem tissues in the field and laboratory.
 <em>Neonectria bordenii</em> was detected via culturing from
 the exoskeletons of beetles and applying a qPCR assay to individual beetle
 DNA extractions.
description: # Data characterizing symbiosis between the alder bark beetle and
 Neonectria bordenii
 [https://doi.org/10.5061/dryad.hqbzkh1s8](https://doi.org/10.5061/dryad.hqbzkh1s8) ## Description of the data and file structure This study evaluated the hypothesis that the alder bark beetle­–*Neonectria bordenii* association represents a symbiosis similar to mutualisms between tree-killing bark beetles and ophiostomatoid fungi in conifer systems. Data were collected to assess the ability of the alder bark beetle, *Alniphagus aspericollis*, to kill red alder, *Alnus rubra*, trees, and to vector *N. bordenii* among trees (according to Leach’s postulates). Results indicated that the alder bark beetle can kill apparently healthy red alders and revealed a unique symbiosis between the alder bark beetle and a non-ophiostomatoid fungus in a hardwood system. ### Files and variables #### File: 01_alder_bark_beetle_symbiosis_2024_2021_fixed_area_plots.csv **Description:** Data collected to assess the ability of the alder bark beetle to kill red alders (beetle colonization and condition data for red alders). ##### Variables * Site: The location in southwestern British Columbia, Canada at which data were collected in 2021 (PSP = Pacific Spirit Regional Park; MK = Malcolm Knapp Research Forest; ARP = Aldergrove Regional Park; VW = Greater Victoria Water Supply Area, inclusive of sampling locations within the Sooke Hills Wilderness Regional Park; RR = Royal Roads University campus). * Colonization_score: Alder bark beetle colonization score for each red alder within a 400 m2 (11.28 m radius) fixed-area plot (one plot per site). Colonization scores are defined as follows: 1 = no recent evidence of alder bark beetle bole activity, appearing healthy and with a full crown; 2 = lightly to moderately attacked with no overwintered broods present, crown usually full or just beginning to thin; 3 = heavily attacked with no overwintered broods present, usually a thinning crown; 4 = overwintered broods present and with few emergence holes, usually little to no crown; 5 = overwintered broods present and with many emergence holes, crown usually absent; 6 = many emergence holes and with no recent evidence of beetle infestation, crown deteriorated or absent. * Branch_score: Branch score for each red alder within a 400 m2 (11.28 m radius) fixed-area plot (one plot per site). Branch scores are defined as follows: 1 = full complement of fine branches in crown; 2 = fine branches starting to shed; 3 = missing many fine branches but with secondary branches intact; 4 = missing all fine branches and some secondary branches but with primary branches intact; 5 = only some primary branches remaining; 6 = no primary branches remaining, snag. #### File: 02_alder_bark_beetle_symbiosis_2024_qPCR_vs_culturing.csv **Description:** Data collected to assess the ability of the alder bark beetle to vector *N. bordenii* among red alders (beetle qPCR versus culturing data). ##### Variables * Flight: Alder bark beetle flight from which beetles were collected in 2019; 1 = Flight 1 (spring), 2 = Flight 2 (summer), 3 = Flight 3 (late summer/early autumn). * Detection_method: Method by which *N. bordenii* was detected for each alder bark beetle (qPCR = application of *N. bordenii* qPCR assay to whole beetle DNA extractions, culturing = isolated from the exoskeleton). * Number_Neonectria_bordenii_positive_beetles: Number of alder bark beetles for which *N. bordenii* was positively detected. * Number_Neonectria_bordenii_negative_beetles: Number of alder bark beetles for which *N. bordenii* was not detected. #### File: 03_alder_bark_beetle_symbiosis_2024_F1_branch_culturing.csv **Description:** Data collected to assess the ability of the alder bark beetle to vector *N. bordenii* among red alders (Flight 1 beetle culturing data). ##### Variables * Site: The location in southwestern British Columbia, Canada at which alder bark beetles were collected in 2019 (PSP = Pacific Spirit Regional Park; MK = Malcolm Knapp Research Forest; VW = Greater Victoria Water Supply Area, inclusive of sampling locations within the Sooke Hills Wilderness Regional Park). * Branch: Identifier for red alder branch from which alder bark beetle samples emerged (one branch per tree). * Mean_number_beetles_per_collection_unit_binned: The mean number of emergent beetles in each collection container (i.e., unit), binned (1, or 2 = 2+ beetles per unit), per branch. * Number_Neonectria_bordenii_positive_beetles: Number of alder bark beetles for which *N. bordenii* was positively detected by culturing. * Number_Neonectria_bordenii_negative_beetles: Number of alder bark beetles for which *N. bordenii* was not detected by culturing. #### File: 04_alder_bark_beetle_symbiosis_2024_F2_culturing.csv **Description:** Data collected to assess the ability of the alder bark beetle to vector *N. bordenii* among red alders (Flight 2 beetle culturing data). ##### Variables * Site: The location in southwestern British Columbia, Canada at which alder bark beetles were collected in 2019 (PSP = Pacific Spirit Regional Park; MK = Malcolm Knapp Research Forest; ARP = Aldergrove Regional Park; VW = Greater Victoria Water Supply Area, inclusive of sampling locations within the Sooke Hills Wilderness Regional Park; RR = Royal Roads University campus). * Tree: Identifier for red alder from which alder bark beetle samples emerged. * Mean_number_beetles_per_collection_unit: The mean number of beetles collected from an emergence trap cup at a single timepoint, per tree. * Number_Neonectria_bordenii_positive_beetles: Number of alder bark beetles for which *N. bordenii* was positively detected by culturing. * Number_Neonectria_bordenii_negative_beetles: Number of alder bark beetles for which *N. bordenii* was not detected by culturing. #### File: 05_alder_bark_beetle_symbiosis_2024_F3_culturing.csv **Description:** Data collected to assess the ability of the alder bark beetle to vector *N. bordenii* among red alders (Flight 3 beetle culturing data). ##### Variables * Site: The location in southwestern British Columbia, Canada at which alder bark beetles were collected in 2019 (PSP = Pacific Spirit Regional Park; ARP = Aldergrove Regional Park; RR = Royal Roads University campus). * Tree: Identifier for red alder from which alder bark beetle samples emerged. * Mean_number_beetles_per_collection_unit: The mean number of beetles collected from an emergence trap cup at a single timepoint, per tree. * Number_Neonectria_bordenii_positive_beetles: Number of alder bark beetles for which *N. bordenii* was positively detected by culturing. * Number_Neonectria_bordenii_negative_beetles: Number of alder bark beetles for which *N. bordenii* was not detected by culturing. #### File: 06_alder_bark_beetle_symbiosis_2024_transmission_experiment.csv **Description:** Data collected to assess the ability of the alder bark beetle to vector *N. bordenii* among red alders (transmission experiment phloem qPCR data). ##### Variables * Cage: Experimental cage from which phloem was sampled. * Tree: Red alder from which each experimental bolt originated. Bolts were cut from three apparently healthy (i.e., full crowns, lacking evidence of alder bark beetle activity on the bole) red alders that were felled at a site in Roberts Creek, British Columbia, Canada. * Bolt: Identifier for experimental bolt (= six healthy bolts per cage). * Attack_status: Whether a phloem punch sample was obtained from a region of experimental bolt tissue that had been Attacked (= sample punch) by one or more alder bark beetles or Not_attacked (= control punch). * Phloem_thickness_mm: Phloem thickness (mm) of each sample (mean of pair) and control phloem punch per bolt. * Number_Neonectria_bordenii_positive_phloem_punches: Number of phloem punches for which *N. bordenii* was positively detected by qPCR. * Number_Neonectria_bordenii_negative_phloem_punches: Number of phloem punches for which *N. bordenii* was not detected by qPCR. #### File: 07_alder_bark_beetle_symbiosis_2024_field_phloem.csv **Description:** Data collected to assess the ability of the alder bark beetle to vector *N. bordenii* among red alders (field-collected phloem qPCR data). ##### Variables * Site: The location in southwestern British Columbia, Canada at which phloem punches were obtained in 2021 (PSP = Pacific Spirit Regional Park; MK = Malcolm Knapp Research Forest; ARP = Aldergrove Regional Park; VW = Greater Victoria Water Supply Area, inclusive of sampling locations within the Sooke Hills Wilderness Regional Park; RR = Royal Roads University campus). * Tree: Identifier for red alder [not attacked (denoted by \_CT#) or attacked] from which phloem punches were collected. * Attack_status: Whether a phloem punch sample was obtained from a region of tree tissue that had been Attacked (= sample punch) by one or more alder bark beetles or Not_attacked (= control punch). * Phloem thickness_mm: Phloem thickness (mm) of each sample (mean of pair) and control phloem punch per tree. * Number_Neonectria_bordenii_positive_phloem_punches: Number of phloem punches for which *N. bordenii* was positively detected by qPCR. * Number_Neonectria_bordenii_negative_phloem_punches: Number of phloem punches for which *N. bordenii* was not detected by qPCR. #### File: 08_alder_bark_beetle_symbiosis_2024_raw_qPCR_data.csv **Description:** Data collected to assess the ability of the alder bark beetle to vector *N. bordenii* among red alders (raw qPCR data). ##### Variables * Sample_type: Type of sample (Alder_bark_beetle or red alder Phloem_punch). * Sample_source: Experimental source of each sample (Branch_emerged = Flight 1 alder bark beetle collections, Emergence_trap = Flights 2 and 3 beetle collections, Transmission_experiment = phloem punches from the transmission experiment, and Field_collected = phloem punches from trees in situ). * Site: The location in southwestern British Columbia, Canada at which each sample originated (PSP = Pacific Spirit Regional Park; MK = Malcolm Knapp Research Forest; ARP = Aldergrove Regional Park; VW = Greater Victoria Water Supply Area, inclusive of sampling locations within the Sooke Hills Wilderness Regional Park; RR = Royal Roads University campus; SC = Roberts Creek, Sunshine Coast). * Sample_ID: Identifier for each sample [alder bark beetle source flight indicated by F1 = Flight 1, F2= Flight 2, F3 = Flight 3; phloem samples (i.e., punches from beetle-attacked phloem regions) are indicated by -S#, and control punches (from phloem regions that were not attacked) are denoted by -C#; phloem punches from trees in situ that were not attacked are indicated by -CT#]. * Ct1: qPCR reaction threshold cycle (Ct) for replicate 1 (two replicates per sample). Missing values are indicated with a period (.) * Ct2: qPCR reaction threshold cycle (Ct) for replicate 2 (two replicates per sample). Missing values are indicated with a period (.) * Mean_Ct: Mean qPCR threshold cycle (Ct) for each sample. Missing values are indicated with a period (.) * Neonectria_bordenii_positive1_negative0: Whether *N. bordenii* was positively detected (1) or not detected (0) by qPCR for each sample. ### Change Log * **11 Sept 2025**: Updated definition for variable "Mean_number_beetles_per_collection_unit" in README. No file changes.