Canopy position and tree size structure the distribution of honeydew‐producing scale insects ( H emiptera: C occoidea) in a temperate hardwood forest

Forest canopies are vertically stratified habitats in which microclimate and host tissue quality vary with height. Scale insects (Hemiptera: Coccoidea) are ecologically important components of temperate forest canopies, producing honeydew exploited by bees, wasps and lepidopterans. The spatial distribution of tree scale insects thus has direct consequences for the availability of these resources but has not been described in North American hardwood forests. We quantified the abundance of three scale insect species and unidentified crawlers across upper‐, middle‐ and lower‐canopy strata of 33 sugar maple ( Acer saccharum Marsh.) trees in south‐central Ontario. We tested whether canopy position, tree size and year‐over‐year growth predicted scale abundance using per‐species negative binomial generalized linear mixed‐effects models (GLMMs). Scale insect communities were strongly vertically stratified, with all taxa reaching highest densities in the upper canopy. Species differed in their association with internode age: Lepidosaphes ulmi (L.) and crawlers peaked on the current year's leader, while Parthenolecanium corni (Bouché) peaked on the prior year's internode, particularly in large‐diameter trees. Tree size had no significant main effect for any taxon, though species‐specific patterns emerged within canopy strata. Shoot elongation was positively associated with subsequent scale abundance across multiple canopy positions and growth stages, while radial growth was negatively associated with abundance in the upper and mid canopy. After controlling for shared habitat use, Phenacoccus acericola King, Parthenolecanium and crawlers showed positive co‐variation at the branch scale; the crawler pool was most closely associated with Parthenolecanium . Within‐tree habitat heterogeneity, rather than tree‐level traits, drives the spatial structure of scale insect communities, with implications for the distribution of honeydew resources supporting canopy‐dependent arthropods.