Peter Silk, Don Ostaff, and Edward Kettela
Natural Resources Canada, Canadian Forest Service

SERG Project #2006/04
Year of Project: 2005
Report Received: 2005




In a process of insect collection, sex pheromone gland excision and extraction, female volatile collection, EAD (electroantennographic detection), GC/MS (gas chromatography/mass spectrometry) analysis, chemical synthesis and field trapping, we have identified Z,Z-6,9-nonadecadiene and Z,Z,Z-3,6,9-nonadecatriene as pheromone components for the pale-winged gray, Iridopsis ephyraria (Wlk.). Triene hydrocarbons were not originally detected in gland extracts or volatiles by GC/MS, but this year’s analysis (2005), in which larger numbers and better quality insect material was analyzed, has lead to the identification of these two components in sex pheromone gland material. Epoxides were not detected, but cannot be precluded because of interferences in the analysis.

The Z,Z,6,9-19:H and Z,Z,Z-3,6,9-19:H’s are highly EAD-active, and confirm their presence in the sex pheromone gland of this insect.

In field trapping, clearly the Z,Z 6,9-19:H + Z,Z,Z-3,6,9-19:H combination (double blue lure #9) at 100 μg was active in capturing a significant number of male I. ephyraria. Also significant is the combination of Z,Z-6,9-19:H with 10 μg each of the Z6–9,10-epoxy-19:H’s (both enantiomers), which also caught significant numbers. In contrast, Z,Z-6,9-19:H and Z9-6,7-epoxy-19:H combinations (either enantiomer) in 2004 caught few moths. The CMEs of Z,Z-6,9 and Z,Z,Z-3,6,9-19, 20 and 21:H’s were entirely unsuccessful in capturing moths, as were the Z,Z,Z-3,6,9-20 and 21:H’s as individual components. Z,Z,Z-3,6,9-19:H did, however, capture a significant number of moths when used alone (double yellow lure # 6).

A dose–response test with lure # 9 is highly warranted, based on this data set, but epoxides clearly can not be discarded at this point as pheromone components.