Nucleation is a stochastic process, most accurately represented by a probability distribution. Obtaining sufficient data to define this probability distribution is a laborious process. Here, we describe a novel instrument capable of the automated determination of hydrate nucleation probability under non-equilibrium conditions for a range of natural gas mixtures at pressures up to 10MPa. The instrument is based on the automated lag time apparatus (ALTA) which was developed to study the stochastic nature of nucleation in ambient pressure systems [1].We demonstrate that the probability distribution represents a robust and reproducible tool for the quantitative evaluation of hydrate formation risk under pseudo-realistic pressure conditions.

Brown marmorated stink bug, Halyomorpha halys (Stål), is a crossover pest impacting agriculture and invading urban environments. Studies were conducted to better understand the management of the bug through its physiology, behavior and susceptibility to insecticidal intervention. Halyomopha halys exhibit great variability in overwintering site selection with choices including manmade structures and tree bark. Because of these diverse sites, the bug must have the ability to withstand varying conditions throughout the overwintering cycle. We were able to determine that H. halys is chill intolerant and capable of adapting its tolerance to temperatures by season, sex, and location of acclimation. The mean supercooling point (± SEM) in the winter in Minnesota was -17.06°C ± 0.13° and in Virginia was -13.90°C ± 0.09°. Laboratory experiments conducted in Blacksburg, VA were able to determine baseline lethal high temperatures over time against H. halys adults. To achieve 100% mortality, temperatures fell between 45°C and 50°C, 40°C and 45°C, and 42°C and 45°C, over 15-min, 1-h, and 4-h, respectively. Moving forward, we were able to utilize this information to develop heat treatment guidelines for export shipping cargo infested with overwintering H. halys. In a controlled field experiment, we determined that exposing the coldest areas of an infested vehicle to temperatures greater than 50°C for a minimum of 15 minutes resulted in 100% mortality of overwintering BMSB adults. In 2012 and 2013, citizen scientists were recruited through Virginia Cooperative Extension to assist in evaluating several in home light traps designed to help eradicate overwintering H. halys adults in homes. Over the course of the two year study, fourteen houses participated in the study with 72% of those houses having stink bug activity. It was found that the most effective trap was an aluminum foil pan trap. In 2013, the trap was 19 times more effective at catching stink bug adults than any other trap tested. In September of 2014, a near-field experiment was conducted to determine the residual efficacy of several recommended and labeled insecticides for treatment of homes against invading H. halys adults. This study used constructed window screen bags that were dipped in insecticide solution. After the initial treatment, bugs were exposed to the bags for 24h weekly, up to 54 days after treatment (DAT). It was determined that 2 DAT all insecticides had activity except for indoxacarb. All insecticides lost efficacy after 29 DAT except for lambda-cyhalothrin, beta-cyfluthrin, beta-cyfluthrin + imidacloprid, lambda-cyhalothrin + thiamethoxam, and dinotefuran, which had some measureable activity even after 40 DAT. Each of these insecticides contained a pyrethroid alone or in combination with a neonicotinoid. Laboratory bioassays were conducted to determine the LC50 values of clothianidin, dinotefuran, imidacloprid, and thiamethoxam against H. halys nymphs using a systemic application method. Those LC50 values were found to be 0.077, 0.013, 0.068, and 0.018 ppm, respectively. Field experiments conducted in Virginia in 2012 and 2013 showed a significant reduction of stink bug damage using two soil applications of neonicotinoid insecticides in pepper and tomato. In North Carolina, a single drip irrigation application significantly reduced stink bug damage in 2012 and 2014 using dinotefuran or imidacloprid. / Ph. D.