Effects of elevated CO2 leaf diets on gypsy moth (Lepidoptera: Lymantriidae) respiration rates.

Elevated levels of CO2 affect plant growth and leaf chemistry, which in turn can alter host plant suitability for insect herbivores. We examined the suitability of foliage from trees grown from seedlings since 1997 at Aspen FACE as diet for the gypsy moth (Lymantria dispar L.) Lepidoptera: Lymantriidae: paper birch (Betula papyrifera Marshall) in 2004-2005, and trembling aspen (Populus tremuloides Michaux) in 2006-2007, and measured consequent effects on larval respiration.

Laboratory performance of two polyphagous invasive weevils on the predominant woody plant species of a northern hardwood community.

A complex of invasive weevils that consume roots as larvae and foliage as adults have become established in northern hardwood forests in North America. We evaluated adults of the two most prominent species, Phyllobius oblongus and Polydrusus sericeus, for longevity, foliage consumption, and egg production on several putative hosts commonly found in this ecosystem. Adult pairs were monitored in no-choice laboratory assays for the duration of their lifespans on basswood, Tilia americana, ironwood, Ostrya virginiana, sugar maple, Acer saccharum, raspberry, Rubus spp.

Application of semiochemicals to assess the biodiversity of subcortical insects following an ecosystem disturbance in a sub-boreal forest.

From 2000 through 2003 we used semiochemical-baited traps in northeastern Minnesota, USA, to assess changes in assemblages of subcortical forest insects after a catastrophic wind storm in 1999 and subsequent (1999-2000) fuel-reduction activities (salvage-logging and prescribed-burning). We determined the regional efficacy of fifteen semiochemical blends (pheromones and kairomones) as attractants for target and non-target subcortical insect species (Coleoptera: Anthribidae, Buprestidae, Cerambycidae, Cleridae, Cucujidae, Curculionidae, Histeridae, Nemonychidae, Salpingidae, Scolytidae, Tenebrionidae, and Hymenoptera: Siricidae). During the four summers, we trapped 86,471 subcortical insects (143 species) in baited and unbaited Lindgren funnel traps, and 500 beetles (44 species) in baited and unbaited pitfall traps.

Legacy effects of low N diets on a vernal folivore: deprivation leads to gluttony.

We tested for legacy effects of low-N diets offered to newly emerged second-instar spruce budworm (Choristoneura fumiferana) larvae for a duration of either one or two full instars on their growth and nutritional physiology in the sixth instar. The experimental design evaluated the effects of initial diet, final diet, and sex on energy consumption, assimilation, retention, and growth rates. Legacy effects were apparent after two instars of low-N diet exposure and were manifested by elevated ( approximately 10%) consumption rates (RCRs) coupled to elevated ( approximately 10%) growth rates (RGRs) and elevated ( approximately 3%) body energy densities, i.

Biology and management of insect pests in North American intensively managed hardwood forest systems.

Increasing demand for wood and wood products is putting stress on traditional forest production areas, leading to long-term economic and environmental concerns. Intensively managed hardwood forest systems (IMHFS), grown using conventional agricultural as well as forestry methods, can help alleviate potential problems in natural forest production areas. Although IMHFS can produce more biomass per hectare per year than natural forests, the ecologically simplified, monocultural systems may greatly increase the crop's susceptibility to pests.

The role of insects in the dynamics of cone production of red pine.

The mortality of red pine cones was studied for several consecutive years using life tables in eight different stands in the northern Great Lakes States. Usually less than 20% of a cohort of female flowers survived to maturity. Insects were the main source of mortality and were primarily responsible for annual fluctuations in the abundance of mature cones.