Root and Root Collar Insects in Forestry. North America

1990

S. 232-241

36 Lit. Ang.

Unselbständiges Werk

200085814

Root and collar insectes in North America include several long-lived species, characterized by patchy distribution, often high densities, and in several cases cyclic populations. Certain weevils and white grubs continue to be damaging in nurseries and plantations. At the same time, new evidence increasingly implicates various root insects as contributors to complex conifer diseases, such as "red pine pocket decline", "black stain root disease", and "spruce-fir decline". Under nursery conditions, prevention and control largely employ organophosphate and carbamate insecticides, while in the field, cultural controls relying onsite amelioration, tree species considerations or timing aspects are providing choices. The use of nematodes for biological control is a promising innovation.