Discrimination of Anoplophora glabripennis (Coleoptera: Cerambycidae) host and non-host tree species by antennally active volatiles

Anoplophora glabripennis (Asian Longhorned Beetle, ALB) is a phytophagous, wood-boring pest of many economically and ecologically important hardwood tree species. ALB is a major pest in its native Asia, and potential economic damage of invasive ALB in North America is estimated in excess of 600 billion dollars. The need to improve the capture rate of current pheromone-based monitoring traps may be addressed by improving kairomone blends. Polyphagous, phytophagous insects must differentiate diverse host from non-host plant species and the ratios of specific host volatiles are a potential cue.  We hypothesized that ALB recognizes its broad host range using a ratio of commonly produced host volatiles that differs from that of non-hosts. To identify this blend, volatiles from several known hosts (Acer mono, A. pensylvanicum, A. saccharum and Aesculus hippocastanum) and non-hosts (Acer mandshurica, Ailanthus altissima, Fraxinus mandshurica, Pyrus calleryana, and Quercus mongolica) were collected by field aeration on Porapak Q in North America and China. GC-EAD was used to determine which host compounds were antennally active. GC-MS was used to determine the relative proportion of each antennally active compound in each sample of volatiles. In a multivariate discriminate analysis, antennally active compounds were used as variables with individual values derived from the proportion of each compound in each sample; samples were coded as host or non-host. The contribution of each antennally active compound to host/non-host discrimination was used to construct a host blend for field assays.