Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Nitrogen, leaf toughness and the population dynamics of Paropsis atomaria Olivier (Coleoptera: Chrysomelidae) - a hypothesis.

Abstract

Field and laboratory studies were carried out in Australia to determine the effects of foliar nitrogen levels and leaf toughness in Eucalyptus blakelyi on the population dynamics of the chrysomelid Paropsis atomaria. The levels of nitrogen in field collected foliage ranged between 2.44 and 1.38% dry weight. The results of the studies suggested that leaf toughness rather than nitrogen levels were limiting to the 1st-generation larvae. The relationship between nitrogen concentrations and fecundity of the chrysomelid was dose dependent. It is suggested that nitrogen and leaf toughness influence populations of the chrysomelid since during years when new foliage is plentiful and there are high nitrogen levels in the leaves there is high egg production. Survival of the hatched eggs would also be high. The reverse would happen in years of drought and poor growth.