Description:
A study was made to determine the distribution of parasites of the larch casebearer, Coleophora laricelia, within crowns of western larch, Larix occidentalis. The most common parasites recovered in
order of their abundance, were: Agathis pumila (Ratz.), Diciadocerus sp. near westwoodii, Spilochalcis albifrons (Walsh), and MesopoZobus sp.
Parasitism by A. pumila was significantly higher in the outer limbs of the upper one-third of the crown. Diciadocerus sp. near westwoodii was highest on the inner branch portions regardless of crown level.
S. albifrons parasitized more casebearers on the lower-outer portion
of the crown. Parasitism by Mesopolobus sp. was uniform throughout the crown.