Recommendations for sampling and extracting the eggs of the western hemlock looper, <i>Lambdina fiscellaria lugubrosa</i>, (Lepidoptera: Geometridae)


  • T. L. Shore Forestry Canada Pacific Forestry Centre 506 W. Burnside Road Victoria, BC V8Z 1M5


No significant differences were found in the numbers of both new and old western hemlock looper eggs per 100 grams of lichen between three crown levels. Representative samples may be collected from lower crown levels with pole pruners, rather than from upper crown levels, which usually involves tree felling. Hot water is more efficient than 2% chlorine bleach for extracting the eggs from the lichen on which they are laid. However, the bleach method is non-destructive and allows the eggs to be reared in order to assess parasitism and fertility. These characteristics can also be identified through egg color using the hot water method , but the parasitoid species cannot be identified. It is recommended that the hot water method be used for forecasting population trends and the bleach method for specific information about parasitoids.