Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Life tables for the Nantucket pine tip moth, Rhyacionia frustrana (Comstock), and the pitch pine tip moth, Rhyacionia rigidana (Fernald) (Lepidoptera: Tortricidae).

Abstract

Life tables were constructed for 6 generations of Rhyacionia frustrana (Comst.) and 1 generation of R. rigidana (Fern.) in a 2- to 3-year-old plantation of loblolly pine (Pinus taeda) in Georgia, USA, in 1978 and 1979. Overlapping stage-density trend curves were estimated for each generation by a schedule of 2-stage cluster samples. Population models were applied to these curves to estimate stage recruitments for the life tables. Important mortality occurred during the egg and pupal stages. Egg mortality was high and perhaps density-dependent. Trichogramma sp. caused much egg mortality in the 2nd and 3rd generations, but an unknown factor caused most egg mortality in the 1st generation. Fifth-instar larvae were heavily parasitised by Lixophaga mediocris Aldr., but this mortality was constant and not a key factor. Some pupal mortality was caused by parasites (of which lists are presented). However, the sources of most pupal mortality were not identified. The pattern of survivorship for R. rigidana was similar to that for R. frustrana, except for high 1st-instar mortality, apprently due to resin from feeding wounds on pine shoots. Sex ratios and fecundities were also examined.