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Almonds and pistachios are fed upon by a diverse assemblage of lepidopteran insects, several of which are economically important pests. Unfortunately, identification of these pests can be difficult, as specimens are frequently damaged during collection, occur in traps with non-target species, and are morphologically similar up to their third instar. Here, we present a quantitative PCR based melt curve analysis for simple, rapid, and accurate identification of six lepidopteran pests of almonds and pistachios: navel orangeworm (Amyelois transitella), peach twig borer (Anarsia lineatella), oriental fruit moth (Grapholita molesta), obliquebanded leafroller (Choristoneura rosaceana), raisin moth (Cadra figulilella), and Indian meal moth (Plodia interpunctella). In this approach, the dissociation (melt) temperature(s) of a 658 bp section of cytochrome c oxidase subunit 1 was determined using quantitative PCR (qPCR). Within these six species, the distribution and the number of melt peak temperatures provide an unambiguous species level identification that is reproducible when unsheared DNA can be extracted. The test is robust across a variety of sampling approaches including insects removed from sticky card traps, museum specimens, and samples that were left in the field for up to 7 days. The melt curves simplicity allows it to be performed in any basic molecular biology laboratory with a quantitative PCR.

Introduction Soybean aphid (Aphis glycines Matsumura) is a typical heteroecious aphid species that utilizes the primary host of various buckthorn trees for overwintering and soybean (Glycine max L. Merr.) as [...], Following its recent invasion of North America, the soybean aphid (Aphis glycines Matsumura) has become the number one insect pest of soybean (Glycine max L. Merr.) in the north central states of the USA. A few studies have been conducted on the population genetic structure and genetic diversity of the soybean aphid and the source of its invasion in North America. Molecular markers, such as simple sequence repeats (SSRs) are very useful in the evaluation of population structure and genetic diversity. We used 18 SSR markers to assess the genetic diversity of soybean aphid collections from the USA, South Korea, and Japan. The aphids were collected from two sites in the USA (Indiana and South Dakota), two sites in South Korea (Yeonggwang district and Cheonan city), and one site in Japan (Utsunomiya). The SSR markers were highly effective in differentiating among aphid collections from different countries. The level of differentiation within each population and among populations from the same country was limited, even in the case of the USA where the two collection sites were more than 1200 km apart. Key words: soybean aphid, genetic diversity, differentiation, simple sequence repeats. Suite a sa recente introduction en Amerique du Nord, le puceron du soya (Aphis glycines Matsumara) est devenu le plus important insecte ravageur chez le soya (Glycine max L. Merr.) dans les etats du centre-nord des Etats-Unis. Des etudes ont ete realisees pour caracteriser la structure de la population et la diversite genetique chez le puceron du soya et pour determiner la source de cette invasion en Amerique du Nord. Les marqueurs moleculaires, comme les microsatellites (SSR), sont tres utiles pour caracteriser la structure des populations et la diversite genetique. Les auteurs ont employe 18 marqueurs SSR pour mesurer la diversite genetique au sein de collections de pucerons du soya provenant des Etats-Unis, de la Coree du Sud et du Japon. Les pucerons ont ete preleves sur deux sites aux Etats-Unis (Indiana et Dakota du Sud), deux sites en Coree du Sud (district de Yeonggwang et ville de Cheonan) et un site au Japon (Utsunomiya). Les marqueurs SSR ont ete tres efficaces pour distinguer les collections de pucerons des differents pays. Le degre de differenciation au sein des populations et parmi celles provenant d'un meme pays etait cependant limite, meme aux Etats-Unis ou les deux sites de collecte etaient situes a plus de 1200 km l'un de l'autre. [Traduit par la Redaction] Mots-cles: puceron du soya, diversite genetique, differenciation, microsatellites.

Molecular dynamics (MD) simulation involves solving Newton's equations of motion for a system of atoms, by calculating forces and updating atomic positions and velocities over a timestep Δt. Despite the large amount of computing power currently available, the timescale of MD simulations is limited by both the small timestep required for propagation, and the expensive algorithm for computing pairwise forces. These issues are currently addressed through the development of efficient simulation methods, some of which make acceptable approximations and as a result can afford larger timesteps. We present MDLab, a development environment for MD simulations built with Python which facilitates prototyping, testing, and debugging of these methods. MDLab provides constructs which allow the development of propagators, force calculators, and high level sampling protocols that run several instances of molecular dynamics. For computationally demanding sampling protocols which require testing on large biomolecules, MDL includes an interface to the OpenMM libraries of Friedrichs et al. which execute on graphical processing units (GPUs) and achieve considerable speedup over execution on the CPU. As an example of an interesting high level method developed in MDLab, we present a parallel implementation of the On-The-Fly string method of Maragliano and Vanden-Eijnden. MDLab is available at http://mdlab.sourceforge.net. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010 [ABSTRACT FROM AUTHOR]