Abstract
The broom twig miner, Leucoptera spartifoliella (Hübner) is a highly specific biological control agent for the Scotch broom, Cytisus scoparius (L.). Cytisus scoparius has become a major invasive weed spreading in North America, South America, Australia and both the South and North Island of New Zealand, causing a major disturbance to the ecology of the area where it has been established. Currently, there is no tool available to monitor the population density, dispersal, and establishment of L. spartifoliella . This work was undertaken to identify the sex pheromone of L. spartifoliella and develop a monitoring tool for this biological control agent. Analysis of the extract of the female sex pheromone gland by gas chromatography/mass spectrometry and chemical ionization identified a single compound in the extract. Using the mass spectral data and synthesis of candidate compounds, this compound was identified as 5-methylheptadecane. In a field trapping trial, testing various doses (0.01, 0.1 and 1 mg) of 5-methylheptadecane and virgin females as a positive control, the highest male catch obtained was in traps baited with the 1 mg dose. When testing two releasing substrates for the pheromone (i.e. a glass vial containing a cotton ball and another containing white septum), the male catch in a trap baited with a glass vial with the cotton ball was significantly higher than in a trap baited with a white septum. The identification of the sex pheromone of L. spartifoliella will help to detect and determine population densities, distribution, and dispersal of L. spartifoliella .