DOI: 10.5061/dryad.tb2rbp07j
title: Wood trait preferences of Neotropical xylophagous beetles

description: 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.
description: # Wood trait preferences of Neotropical xylophagous beetles
 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:
 1. 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. 2.
 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." 3. 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.