LE3 .A278 2013

2013

Hillier, Kirk
Sweeney, Jon

Acadia University

Master of Science

Masters

Biology

Biology

Tetropium fuscum (Fabr.) (Coleoptera: Cerambycidae), is an invasive forest pest from Europe, established in Nova Scotia, Canada, since at least 1990. Semiochemical-baited traps are used to monitor its spread and research trials using pheromone-mediated mating disruption show good potential for its control. The two main objectives of this project were to compile a morphological survey of the sensilla present on the antennae of T. fuscum, and to create a response profile for 13 antennally-active compounds using single sensillum recording (SSR) following identification of olfactory sensilla. The third objective was to test the attraction of T. fuscum to linalool in field trapping experiments. We observed nine different morphological types of sensilla on the antennae of T. fuscum: three types of sensilla chaetica (SC), sensilla trichodea (ST), two types of sensilla basiconica (SB), grooved peg sensilla (GP), thick-walled sensilla (TW), and Böhm bristles (BB). Males and females did not differ significantly in number or distribution of any morphological sensilla types except for SC1. Based on ultrastructure, SC1 were proposed to be contact chemoreceptors, and SB and ST were determined to be the olfactory receptors. Single sensillum recordings were obtained from 102 sensilla and grouped into 49 physiological types based on the compounds that elicited a response. The male-produced aggregation pheromone, fuscumol, accounted for 25% of all responses on its own, and 43% of all responses total. Males and females did not differ significantly in the number of sensilla that responded to fuscumol, either alone or with other compounds. There were no clear distinctions between sensilla that responded to host volatiles (HVs) and those that responded to non-host volatiles (NHVs) as has been observed in other insects. Linalool elicited responses in the greatest number of physiological sensilla types. Despite the number of sensilla that responded to linalool, racemic linalool and (R)-(-)-linalool did not significantly increase trap catch either on their own or in combination with the standard T. fuscum trapping lure. There have been very few SSR studies done on cerambycids, and our investigation was the first to test pheromone components as well as HVs and NHVs.

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https://scholar.acadiau.ca/islandora/object/theses:270