Figure 2.— Detailed view of the sampling pole in use. Sighting 

 wires are being used to locate position for clipping a branch 

 with a hand pruning tool. 



Each square was pardoned into 169 smaller 

 squares measuring 0.5 by 0.5 foot, the outer 

 dimensions of the sampling pole. 



We used cluster sampling to select the sam- 

 pling units. In cluster sampling terminology, 

 the blocks are called primary units and the 0.5- 

 by 0.5-ft squares are the elementary sampling 

 units. 



We selected at random two secondary units in 

 each block, two tertiary units within each 

 selected secondary unit, and so on. Altogether 

 we selected 128 sampling units per block. 



In the plantation, the sampling pole was plac- 

 ed as close as possible to the sampling location 

 indicated on the map. The current year's foliage 

 within each vertical sampling unit was collected 

 and logged for later examination. The number of 

 eggs and egg clusters and the presence or 

 absence of foliage was recorded for each vertical 

 unit. 



RESULTS AND DISCUSSION 



In our sample, we found 28 egg clusters 

 ranging in size from 60 to 170 eggs, with a mean 

 size of 59.3 ± 6.28 eggs per cluster. The average 

 size of the egg clusters did not differ significant- 

 ly, nor is there any evidence that size of egg 

 cluster varied with density of egg clusters 

 (Table 1). 



However, there is evidence that egg clusters 

 higher in the tree were larger (Table 2). The 

 mid-crown mean differs little from the overall 

 mean. Lyons (1964) noted that the largest egg 

 clusters of N. sertifer are most often found in 

 the upper crowns of red pines. 



The number of egg clusters also varied with 

 height in the crown (Table 2). In this plantation, 

 the tree crowns extended to the ground, but 

 crown closure was nearly complete. The egg 



3 



