Canadian Forest Service Publications
Morphology of antennal sensilla of the brown spruce longhorn beetle, Tetropium fuscum (Fabr.) (Coleoptera: Cerambycidae). 2015. MacKay, C.A.; Sweeney, J.D.; Hillier, N.K. Arthropod Sturcture & Development 49(5): 469-475.
Issued by: Atlantic Forestry Centre
Catalog ID: 36312
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The antennal sensilla of the brown spruce longhorn beetle, Tetropium fuscum (Fabr.) (Coleoptera:Cerambycidae) were examined with particular focus on the sensilla present on the apical flagellomere. T. fuscum antennae are composed of 11 segments, namely the scape, pedicel, and nine flagellomeres. Nine types of sensilla were observed: three types of sensilla chaetica, sensilla trichodea, two types of sensilla basiconica, grooved peg sensilla, thick-walled sensilla, and Böhm bristles. Seven of these types were present on the apical flagellomere, the exceptions were sensilla chaetica type 3 and Böhm bristles. There were no significant differences in the distribution or density of sensilla present on the ninth flagellomere of males and females, except that males had significantly more sensilla chaetica type 1, which are put forward as the putative contact chemoreceptors for T. fuscum.
Plain Language Summary
Longhorn beetles respond to the smells of compounds emitted from their host trees, as well as smells emitted by members of their own species (i.e., pheromones) when they are looking for food, mates, and places to lay their eggs. They detect these compounds using specialized nerve cells located inside tiny hair-like projections called sensilla on their antennae. This study examined the shape and structure of different kinds of sensilla on the antennae of the brown spruce longhorn beetle (BSLB), an invasive pest from Europe that was accidentally introduced to Canada and which is killing mature spruce trees that are under stress. Better knowledge of the kinds of sensilla that the BSLB uses when searching for trees and mates may lead us to new and improved ways of managing this pest. We found nine different types of sensilla on the BSLN antennae, including types that typically detect airborne chemical odors and others that typically “taste” chemicals on contact.