Canadian Forest Service Publications
Solution separation and maximum likelihood density estimates of hemlock looper (Lepidoptera: Geometridae) eggs in moss. 1972. Shepherd, R.F.; Gray, T.G. The Canadian Entomologist 104: 751-754.
Issued by: Pacific Forestry Centre
Catalog ID: 18869
Availability: Not available through the CFS (click for more information).
Counting hemlock looper (Lambdina fiscellaria lugubrosa) eggs attached to moss samples is tedious and inaccurate. Moss samples treated with a 0.5% NaOH solution for 1 minute releases the eggs, which can be washed and filtered out of the moss. Other debris can be separated through differential flotation with 15% NaC1 solution. Three such washings provide data for analysis with the maximum likelihood method, producing density estimates with low-standard errors.