The influence of diurnal temperature variation on degree-day accumulation and insect life history.

Ectotherms, such as insects, experience non-constant temperatures in nature. Daily mean temperatures can be derived from the daily maximum and minimum temperatures. However, the converse is not true and environments with the same mean temperature can exhibit very different diurnal temperate ranges.

Using ecological indicators and a decision support system for integrated ecological assessment at two national park units in the mid-Atlantic region, USA.

We implemented an integrated ecological assessment using a GIS-based decision support system model for Upper Delaware Scenic and Recreational River (UPDE) and Delaware Water Gap National Recreation Area (DEWA)-national park units with the mid-Atlantic region of the United States. Our assessment examined a variety of aquatic and terrestrial indicators of ecosystem components that reflect the parks' conservation purpose and reference condition. Our assessment compared these indicators to ecological thresholds to determine the condition of park watersheds.

Estimating West Nile virus transmission period in Pennsylvania using an optimized degree-day model.

Abstract We provide calibrated degree-day models to predict potential West Nile virus (WNV) transmission periods in Pennsylvania. We begin by following the standard approach of treating the degree-days necessary for the virus to complete the extrinsic incubation period (EIP), and mosquito longevity as constants. This approach failed to adequately explain virus transmission periods based on mosquito surveillance data from 4 locations (Harrisburg, Philadelphia, Pittsburgh, and Williamsport) in Pennsylvania from 2002 to 2008.

Projecting insect voltinism under high and low greenhouse gas emission conditions.

We develop individual-based Monte Carlo methods to explore how climate change can alter insect voltinism under varying greenhouse gas emissions scenarios by using input distributions of diapause termination or spring emergence, development rate, and diapause initiation, linked to daily temperature and photoperiod. We show concurrence of these projections with a field dataset, and then explore changes in grape berry moth, Paralobesia viteana (Clemens), voltinism that may occur with climate projections developed from the average of three climate models using two different future emissions scenarios from the International Panel of Climate Change (IPCC). Based on historical climate data from 1960 to 2008, and projected downscaled climate data until 2099 under both high (A1fi) and low (B1) greenhouse gas emission scenarios, we used concepts of P.

Geographic variation in diapause induction: the grape berry moth (Lepidoptera: Tortricidae).

Diapause in insects occurs in response to environmental cues, such as changes in photoperiod, and it is a major adaptation by which insects synchronize their activity with biotic resources and environmental constraints. For multivoltine agricultural insect pests, diapause initiation is an important consideration in management decisions, particularly toward the end of the growing season. The grape berry moth, Paralobesia viteana (Clemens), is the main insect pest affecting viticulture, and this insect responds to postsummer solstice photoperiods to initiate diapause.

Carbaryl resistance in populations of grape berry moth (Lepidoptera: Tortricidae) in New York and Pennsylvania.

We collected grape berry moth, Endopiza viteana (Clemens) (from cultivated and wild Vitis along Lake Erie in Pennsylvania and New York), and measured carbaryl susceptibility in first instars. A model of susceptibility was based on the concentration-mortality curve of laboratory-maintained colonies originating from wild Vitis with no prior history of carbaryl exposure, and a noncommercial vineyard with modest previous exposure to carbaryl. We estimated LC50 and LC90 for susceptible grape berry moth larvae at 45.