This readme.txt file was generated on 2024-11-01 by Rose Picklo. Recommended citation for the data: Picklo, Rose; Eidson, Erika; Steed, Brytten; Aukema, Brian. (2024). Eastern larch beetle reproductive success in western and subalpine larch. Retrieved from the Data Repository for the University of Minnesota (DRUM), https://doi.org/10.13020/9p01-rr31. ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset: Eastern larch beetle reproductive success in western and subalpine larch 2. Author Information Author Contact: Brian Aukema (bhaukema@umn.edu) Name: Rose Picklo Institution: Montana Department of Natural Resources & Conservation Email: rose.picklo@mt.gov ORCID: 0009-0007-0671-7300 Name: Erika Eidson Institution: Idaho Department of Lands Email: eeidson@idl.idaho.gov ORCID: 0000-0002-0462-6284 Name: Brytten Steed Institution: United States Forest Service Email: brytten.steed@usda.gov ORCID: 0000-0001-5608-3755 Name: Brian Aukema Institution: University of Minnesota Email: bhaukema@umn.edu ORCID: 0000-0003-4370-0499 3. Date published or finalized for release: 2024-10-31 4. Date of data collection: 2023-06-29 to 2024-01-10 5. Geographic location of data collection (where was data collected?): NA 6. Information about funding sources that supported the collection of the data: AVR Foundation Minnesota Agricultural Experimental Station Project MIN-17-117 Minnesota Environment and Natural Resources Trust Fund: Legislative-Citizen Commission on Minnesota Resources (LCCMR), project 2020-047a 7. Overview of the data (abstract): Eastern larch beetle Dendroctonus simplex LeConte has been outbreaking for the past two decades in the Great Lakes region of North America, impacting approximately 400,000 hectares of eastern larch Larix laricina (tamarack) forest in Minnesota, United States, alone. Range expansions of some Dendroctonus species driven by climate change have occurred across North America as rising temperatures increase climatically suitable habitats across latitudes and elevations. The range of eastern larch beetle is currently sympatric to that of its host, eastern larch, but the insect could, in theory, eventually access ranges of other species of Larix native to North America. We compared host suitability of two potential novel hosts, western larch (Larix occidentalis Nutt.) and subalpine larch (Larix lyalli Parl.) against the beetle’s native host, eastern larch, using a reproductive success experiment conducted in cut bolts of all three species. We measured fertility, maternal gallery length, and offspring size and lipid content as metrics of reproductive success. We share data here upon publication of this work in the journal Frontiers in Forests and Global Change. -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: Attribution-NonCommercial-ShareAlike 4.0 International (http://creativecommons.org/licenses/by-nc-sa/4.0/) 2. Links to publications that cite or use the data: Picklo RP, Eidson EL, Steed BE, and Aukema BH. (2024) Eastern larch beetle (Dendroctonus simplex LeConte) as a potential threat to western (Larix occidentalis Nutt.) and subalpine larches (Larix lyalli Parl.). Front. For. Glob. Change 7:1490888. doi: 10.3389/ffgc.2024.1490888 3. Was data derived from another source? No If yes, list source(s): 4. Terms of Use: Data Repository for the U of Minnesota (DRUM) By using these files, users agree to the Terms of Use. https://conservancy.umn.edu/pages/policies/#drum-terms-of-use --------------------- DATA & FILE OVERVIEW --------------------- Filename: Reproductive Success Metadata.csv Short description: Metadata for reproductive success metrics (number of offspring, reproductive gallery data) and physical characteristics of infested bolts (phloem thickness, phloem moisture, weight, size and surface area). Filename: Reproductive Success Data.csv Short description: Reproductive success metrics (number of offspring, reproductive gallery data) and physical characteristics of infested bolts (phloem moisture, weight, size and surface area). Filename: Lipid Metadata.csv Short description: Metadata for lipid extractions Filename: Lipid Data.csv Short description: Lipid data includes extraction results (lipid weight and percent body mass) and information on the beetles upon which extractions were performed. Filename: IMG_2913.JPG Short description: Subalpine larch harvested for study -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: Four trees of each North American Larix species were harvested for this experiment. Western larch Larix occidentalis was harvested from Couer d’Alene National Forest, ID, USA on 6/30/23 with the assistance of the Idaho Department of Lands. Subalpine larch Larix lyalli was sourced from within the Beaverhead-Deerlodge National Forest, MT, USA on 7/4/23 with assistance from the United States Forest Service. Eastern larch Larix laricina was harvested with assistance from the Minnesota Department of Natural Resources on 7/10/23 from Hill River State Forest, MN, USA. Each tree was cut into 30.5cm long bolts. Phloem thickness measurements were taken on each cut surface of the bolt; cut surfaces were then sealed with paraffin wax to mitigate desiccation. Waxed bolts were stored in black body bags at ambient temperature during transport from field to lab. Eastern larch beetles Dendroctonus simplex LeConte were collected from sites within the Sax-Zim Bog and Beltrami Island State Forest (both MN, USA) using Lindgren funnel traps baited with seudenol lures (release rate = 7.5mg/day at 30°C; Synergy Semiochemical, British Columbia, Canada). Beetles were triple-sexed by listening for stridulation and stored at room temperature for up to five days before use. Prior to infestation, physical characteristics of each bolt (percentage moisture, weight, and surface area) were recorded. We introduced five mating pairs per bolt (n = 49 bolts total, 16 of western and subalpine larch bolts and 17 eastern larch bolts) with females added 24 hours prior to males. We used pre-drilled entrance holes and sealed beetles in by capping with 1.5mL microcentrifuge tubes. We observed presence/absence of frass to determine successful female introduction prior to adding males. Any entrance holes that did not have presumed successful reproduction after three introduction attempts were struck from the study. Once all five entrance holes were either presumed successful or eliminated, the bolt was placed in a cardboard emergence tube with a glass jar attached to it. Emergence tubes were stored at 24.7°C. After 30 days post-male introduction we pulled one bolt from each species and debarked to assess beetle development. Jars were checked daily for beetle emergence, and emerged beetles were collected and counted. After emergence concluded (53 days after the experiment began), all bolts were debarked and any remaining lifeforms, mature and immature were counted and saved. Adult beetles were frozen and stored at -20°C while larvae and pupae were stored in ethanol. Prior to debarking, bolts had a second weight and moisture reading performed as well. Gallery length for each entrance hole was recorded using a digital plan measure (Calculated Industries, Scalemaster Classic). Lipid extractions were performed on a subset of emerged and manually-extracted beetles (N = 252), with the number of beetles/bolt proportional to the total number of emerged and extracted beetles that came from each bolt. Prior to lipid extraction, beetles were sexed by examining the 7th tergite for medial tines (present on males) and pronotal widths (size) were measured using a digital micrometer. Beetles were then dried at 55°C for 24 hours and weighed to the nearest 0.01mg (Metler Toledo AX105 DeltaRange) to obtain a pre-extraction dry weight. Lipids were extracted using petroleum ether and a Soxhlet apparatus for 8 hours before being dried an additional 12 hours at 55°C to evaporate any remaining petroleum ether, after which they were then weighed again. Total lipid content (mg) was calculated by taking the difference in pre- and post-extraction weight; percent lipid content was calculated by dividing the total lipid content by the beetle’s pre-extraction weight. 2. Methods for processing the data: Reproductive success data: -Phloem moisture reads were taken in six locations (three on the top surface, three on the bottom surface) of each bolt and averaged. -Only galleries with successful reproduction (as evidenced by larval galleries) were included in this study. An average gallery length for each bolt was reported. -Average diameter of each bolt was calculated by measuring the diameter around the top, center, and bottom of each cut bolt; surface area was calculated using the average diameter. Lipid data: -Any beetle where sex could not be determined was removed as a datapoint. -Any beetle that had lost appendages/elytra during the extraction process was removed as a datapoint. -Any beetle that had a higher post-extraction weight than pre-extraction weight was removed as a datapoint. 3. Instrument- or software-specific information needed to interpret the data: Data was analyzed using R software v. 4.3.3. 4. Standards and calibration information, if appropriate: NA 5. Environmental/experimental conditions: Bolts were stored at ambient temperature in body bags during transit from field to lab, and then stored at room temperature (24.7°C) before and after infestation. Adult beetles were frozen and stored at -20°C while immature lifeforms were stored in ethanol at room temperature. 6. Describe any quality-assurance procedures performed on the data: We performed ANOVAs to determine if physical characteristics (phloem thickness, phloem moisture or bolt weight) varied between species prior to measuring the effect of species on our reproductive success metrics. 7. People involved with sample collection, processing, analysis and/or submission: Authors: Rose Picklo, Erika Eidson, Brytten Steed, Brian Aukema Idaho Department of Lands personnel: Tom Eckberg, Isabella Valdez, Mikayla Cotton United States Forest Service: James Steed MN Department of Natural Resources: Eric Otto Volunteers: Drew Krank (partner of author), Joshua Smith and Jennifer McNew Lab personnel/graduate students: Abigail Brett, Ian Grossenbacher-McGlamery, Hunter Ness, Emily Althoff, Grace Graham, Sayesha Khanna, and Jessica Rootes ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Reproductive Success Data.csv ----------------------------------------- *copied from metadata tab* 1. Number of variables: 24 2. Number of cases/rows: 50 3. Missing data codes: “.” = missing data 4. Variable List Species: EL = eastern larch, WL= western larch, SAL = subalpine larch Tree: 4 trees harvested for species, which tree bolt came from Bolt: position of bolt from bole, 1 being closest to ground (12'' sections) Bolt ID: "Species" "Tree"-"Bolt" ex. WL2-4 is western larch, tree 2, bolt 4 Average Phloem Thickness: Average phloem thickness (mm) based on six measurements (3 each side, ~120 degrees apart) and averaged Infest Date: Date females introduced to bolt Pre-infest moisture percentage: Percent moisture at time of infestation, used moisture meter calibrated to larch, 40% considered saturated Post infest moisture percentage: Percent moisture at time bolts were debarked, 40% considered saturated Percent moisture lost: Difference in moisture pre- and post-infestation Pre infest weight: in kg Post infest weight: in kg Weight lost: Weight difference before and after infestation Peel Date: Date bolts debarked Extracted Beetles: Number of beetles present when bolts debarked Larvae: Number of larvae present when bolts debarked Pupae: Number of pupae present when bolts debarked Emerged Beetles: Number of beetles that were collected from jars during collection period Total number adults: Total number adults = emerged + extracted beetles Total Lifeforms: Total number life forms = total number of adults + larvae + pupae Number reproductive galleries: Number of galleries with larval tunnels Average Gallery Length (cm): Average gallery length calculated by first calculating the average measure for each individual gallery and then dividing the sum of all individual gallery averages by the total number of galleries present. Height (cm): Height of bolt (cm) Average diameter (cm): Diameter (cm) measured at both ends of bolt and averaged Surface area (dm2): Surface area calculated by multiplying height by diameter by pi (excludes cut ends of bolt). Converted from cm2 to dm2 by dividing by 100. Used to standardize emergence/fecundity by size. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: Lipid Data.csv ----------------------------------------- *copied from lipid metadata* 1. Number of variables: 14 2. Number of cases/rows: 268 3. Missing data codes: “.” = missing 4. Variable List Extraction date: date extraction performed Species: EL = eastern larch, WL= western larch, SAL = subalpine larch Tree: 4 trees harvested for species, which tree bolt came from Bolt: position of bolt from bole, 1 being closest to ground (12'' sections) Bolt ID: "Species" "Tree"-"Bolt" ex. WL2-4 is western larch, tree 2, bolt 4 Plate: R1, R2, R3, R4 or R5, refers to which extraction run Beetle type: Emerged (beetles flew into jars in emergence tubes) or Peeled (beetles were manually extracted from bolts) Beetle ID: location in 96 well plate- A1, B2, etc Pronotal Width: Width of pronotum measured in mm using Leica video software at processing Sex: M or F, determined by opening wings and looking for medial tines between 7th-8th tergite on dorsal side of abdomen. "." indicates unable to determine or unknown Pre-extract Weight: Weight in mg of beetles frozen and then dried at 55C for 24hrs Post-extract Weight: Weight in mg of beetles dried minimum of 12 hrs post extract at 55C to evaporate any remaining petroleum ether Lipid content: Pre-extract minus post-extract to get mg lipid Lipid Percent: Lipid content/Pre extract weight