Wood trait preferences of Neotropical xylophagous beetles
Data files
Nov 22, 2023 version files 164.79 KB
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README.md
4.03 KB
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Torresetal_Pan10_data.xlsx
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Abstract
Tree life history strategies are correlated with functional plant traits, such as wood density, moisture content, bark thickness, and nitrogen content; these traits affect the nutrients available to xylophagous insects. Cerambycid beetles feed on substrates that vary in these traits, but little is known about how they affect community composition. The goal of this project is to explore the community composition of two cerambycid subfamilies (Cerambycinae and Lamiinae) according to the wood traits in the wood they eat. In a salvage project conducted adjacent to the Panama Canal, trees were felled and exposed to Cerambycidae for oviposition. Disks from branches of differing thickness from the same plant individuals were used to calculate wood density, moisture content, and bark thickness in the field; nitrogen data were acquired offsite. Thick and thin branches tended to differ in wood trait values; therefore, data were analyzed separately in subsequent analyses. In thin branches, cerambycid abundance and species richness were higher in samples with less dense, moister wood, and thicker bark. Thick branches showed similar trends, but the wood traits accounted for little variability in beetle abundance or species richness. There were no significant regressions between beetle data and nitrogen. Cerambycines emerged more slowly, and from denser, drier wood, than lamiines. Cerambycines might be more drought-tolerant than lamiines, and therefore more resistant to the longer, more severe dry seasons that are predicted to occur due to climate change.
README: Wood trait preferences of Neotropical xylophagous beetles
https://doi.org/10.5061/dryad.tb2rbp07j
This rearing project examines the community composition of wood-boring beetles (family: Cerambycidae) in Panama. We reared cerambycids from freshly cut trees on a 1 ha headland on the W bank of the Panama Canal (9º07’N, 79º45’W, Prov. de Colon, approximately 20 km from Barro Colorado Island). The site, supporting tall secondary forest, was approximately 80 years old. Sixty branch segments, approximately 8 cm x 85 cm, were suspended in three large trees. The felled plants and canopy baits were exposed to beetles for two months; this two-month window included the late dry season and transition into the rainy season. Near the beginning of the rainy season (17-21 May 2010) we enclosed branch sections (when possible: the canopy bait, three equivalent segments from a ground stratum branch, and six segments of thinner ground branches, approximately 2 cm x 85 cm) separately in bags constructed from finely woven polyester mosquito netting, and transported them to an outdoors Smithsonian rearing facility in Gamboa. The cages were monitored at least once a week for emerged adult beetles (22 May 2010 through 22 May 2011). Because baits were exposed for two months and we do not know exactly when females oviposited, mean emergence week was calculated as the number of weeks post-cut.
We collected thin and thick wood disks from each plant specimen (approximately 2 cm x 1 cm and 8 cm x 1cm, respectively). Disks were collected when the plants were initially felled (fresh), and when we retrieved sections for rearing (aged). Bark thickness (BT) was calculated as the mean of four measurements taken in mm around the circumference. Basic density (WD) was calculated, for each disk, as oven dry weight divided by wet volume. A moisture content index (MC) was calculated as (fresh weight – dry weight) divided by dry weight x 100; weight was used as a proxy for mass. A moisture retention index was calculated (MRI = moisture content aged / moisture content fresh) for canopy thick, ground thick, and ground thin branches. Nitrogen content (mg/g and delta 15N) was measured for productive samples.
Description of the data and file structure
These data contain wood trait and beetle data from this rearing project. We have organized this into three sheets:
Wood traits: This is sorted by plant family, species, and voucher codes. Each plant voucher has the stratum (canopy or ground) and branch diameter (thick or thin). Wood traits included are bark thickness, wood density, moisture content fresh and aged, moisture retention index, and nitrogen (mg/g and delta 15N). This dataset also includes the number of cerambycid individuals that emerged from each plant specimen.
Cerambycid Ind: This is sorted by cerambycid beetle subfamily, tribe, species, and species code. This dataset includes wood trait data for the plant specimen each beetle individual emerged out of. Plant data includes plant family, plant species, plant voucher, stratum, branch diameter, bark thickness, wood density, moisture content fresh, and nitrogen (mg/g and delta 15N). Week of beetle emergence is also included with a date range, and summarized with emergence week of the study under "emergence week."
Cerambycid species: This is sorted by cerambycid beetle subfamily, tribe, species, species code, and the number of beetle individuals collected from each beetle species. This includes the weighted mean wood traits of the plant specimens that beetle individuals emerged from by species. Mean wood traits included are bark thickness (BT), wood density (MD), moisture content fresh (MC), moisture retention index (MRI), and nitrogen (N mg/g and delta 15N). The mean emergence week of each beetle species is also included.
Units for each metric are detailed in the column headings. Formulas for any calculations are includes at the bottom of each sheet. Any missing data is indicated with "missing" in the dataset.