G86-774 Western Corn Rootworom Soil Insecticide Treatment Decisions Based on Beetle Numbers

This NebGuide describes how counting western corn rootworm beetles throughout the summer can be used to determine the need for insecticide applications the following spring. Western corn rootworms are one of Nebraska\u27s most serious insect pests of corn. Eggs laid in the soil from late July through September overwinter and begin hatching in late May or early June. Larvae feed on corn roots, causing plants to lodge, and may reduce grain yields. The greatest injury usually occurs from late June to mid-July, when all corn roots may be destroyed if infestations are heavy. Fully grown larvae pupate in the soil and change into the adult beetle. Beetles emerge from pupae in the soil and are present in cornfields from early July until frost. Counting beetles in the cornfield throughout the summer will help you decide whether or not you need to use a soil insecticide if corn is to be planted in that field the following spring

Exploring new physics frontiers through numerical relativity

The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

G87-838 Management of Greenbugs in Sorghum (Revised May 1994)

This NebGuide describes the identification, biology and management options for greenbugs in Nebraska sorghum. The greenbug is the most important insect pest of grain and forage sorghums in Nebraska. Although numbers fluctuate from year to year, greenbugs are a limiting factor to sorghum yield in most years. Their management is complicated by the fact that greenbugs have been able to evolve populations capable of overcoming plant resistance and organophosphate insecticides, so best management practices continue to change over time. Another common aphid found in sorghum is the corn leaf aphid. Corn leaf aphids are often mistaken for greenbugs; however, they normally do not cause serious damage to sorghum, and controls for them are rarely justified in Nebraska

Field evaluation of an attract and kill strategy against western corn rootworm larvae

The larvae of the invasive maize pest Diabrotica virgifera virgifera (Coleoptera; Chrysomelidae, western corn rootworm) hatch in the soil in spring and search for maize roots following CO2 gradients. CO2 is one cue that might be used as an attractant towards soil insecticides, a mechanism already shown in laboratory experiments. This study compared the efficacy of several combinations of in or between-row applications of different rates of CO2-emitting capsules and/or soil insecticides (here tefluthrin) aimed at preventing root damage by the pest larvae under field conditions. CO2 emission of the capsules in the soil lasted up to 28 days with a peak after 21 days coinciding with the first larval hatch. The pest density in the soil was not high enough to cause root damage above the economic threshold. Furthermore all tefluthrin applications, regardless of whether at full, half or quarter rates effectively prevented root damage; thus CO2 did not significantly further increase this efficacy. In-row applications of tefluthrin with or without CO2-emitting capsules prevented root damage to a much larger extent (59-77 % on the node injury scale) than the between-row applications of tefluthrin with or without capsules (17-31 %). In conclusion, further research on belowground orientation and movement of D. v. virgifera larvae, as well as tests with combinations of CO2-emitting capsules and lower rates of soil insecticide are needed to potentially develop attract and kill strategies as a management option against this maize pest.Syngenta Crop Protection AG, Basel, Switzerlan