Andrade, Samara M.M.Dutkiewicz, DavidBorges, Marcelo E.Smith, Sandy M.Allison, Jeremy D.2026-03-112026-03-112026-02Andrade, S.M.M., Dutkiewicz, D., Borges, M.E., Smith, S.M. & Allison, J.D. The effects of host and habitat preferences in mate location of Monochamus maculosus, Monochamus notatus, and Monochamus scutellatus (Coleoptera: Cerambycidae', Canadian Entomologist, vol. 158, art. e5, pp. 1-24, doi : 10.4039/tce.2025.10042.0008-347X (print)1918-3240 (online)10.4039/tce.2025.10042http://hdl.handle.net/2263/108904SUPPLEMENTARY MATERIAL 1 : Figure S1. Dorsal, lateral, and ventral view of a larva tentatively identified as Monochamus scutellatus. Zoomed-in sections on the left focus on two morphological characters used to identify north American Monochamus larvae to species level, according to Craighead (1923). Arrows in the zoomed-in sections point to the following distinctive features: A, fine group of hairs on the anterior lateral angle of the pronotum that extend in a less dense discontinuous band across the area, and B, thin asperites on the tubercules of the ventral ampulla. Scale bars, 1000 μm. (Photos by David Dutkiewicz 2024). SUPPLEMENTARY MATERIAL 2 : Table S1. Measurements and estimates of individual softwood pieces of down coarse woody debris sampled in the four plots established in field site #1 and the five plots established in field site #2 with the line-intersect sampling method for forest inventory and analysis from the United States Department of Agriculture Forest Service (2019). Log volume (m3), cubic volume per hectare (m3/ha), density (log/ha), and % cover were calculated following the methodology described by Waddell (2002). Diam. small-end (cm), diameter at the small end of log (cm); Diam. large-end (cm), diameter at the large end of log (cm); % cover = percentage of dead wood cover on ground (transect-level value). SUPPLEMENTARY MATERIAL 3 : Table S2. Total number of larvae collected from 90 bole sections from field site #1 (n = 5 bole sections per tree species, wood position, and bole section level) and 60 bole sections field site #2 (n = 10 bole sections per wood position and bole section level) and their corresponding identification (Larvae ID) and origin in terms of tree species, wood position (lying or standing dead tree), and bole section level (60-cm-long sections removed from 30% – “lower”, 50% – “middle”, and 70% “upper” parts of each experimental tree height, as measured from the tree base).Several Monochamus species (Coleoptera: Cerambycidae) use monochamol as an aggregation-sex pheromone, raising questions about how they maintain reproductive isolation. Herbivorous insects use host plant semiochemicals as cues for mate location and, with or without habitat cues, these could confer reproductive isolation among sympatric Monochamus spp. To test this hypothesis, host and habitat preferences in mate location were examined for sympatric populations of Monochamus maculosus, Monochamus notatus, and Monochamus scutellatus in the Algoma District, Ontario, Canada. Field experiments were performed to investigate whether differences in host preference, vertical distribution across the forest canopy, spatial distribution within down and standing dead trees, or any combination of these factors could minimise cross-attraction to monochamol. Results showed that more M. maculosus were attracted to monochamol combined with jack pine foliage than with balsam fir or white spruce, whereas no differences in host attractivity were observed for the other species. Vertical abundance of M. maculosus and M. scutellatus was similar across forests. Spatial distribution provided limited evidence for species segregation within hosts. No evidence was found that host or habitat preferences contribute to reproductive isolation in M. maculosus, M. notatus, or M. scutellatus, suggesting that vertical distribution could be driven by resource availability.en© The Author(s), 2026. Published by Cambridge University Press on behalf of Entomological Society of Canada. This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives licence (https://creativecommons.org/licenses/by-nc-nd/4.0/).Monochamus maculosusMate locationReproductive isolationMonochamus scutellatusMonochamus notatusArticle