Monitoring Spruce Budworm with Light Traps: The Effect of Trap Position

Figure 2

Relationships between numbers of adult spruce budworms captured at light traps deployed in tree canopies and forest clearings (-axis) and the density of eggs (-axis) at nine locations in New Brunswick, Canada, in the 1970s. Regressions based on captures in tree canopies were statistically significant for both males (, , and ) and females (, , and) (solid lines). Regressions based on captures in forest clearings were not significant for either sex (males: , , and ; females: , , and ) (dotted lines). Data were subjected to logarithmic transformations to reduce heterogeneity of variance.