NF04-594 Resistanct Management for YieldGard Rootworm™ \u3cem\u3eBt\u3c/em\u3e Corn

In 2003, the U.S. Environmental Protection Agency and Monsanto announced the registration of YieldGard Rootworm™ corn containing event MON863. These hybrids express a protein in the roots from the soil bacterium, Bacillus thuringiensis (Bt) that is toxic to larval corn rootworms. This NebFact discusses management requirements, refuge considerations, within-field configurations when using YieldGard Rootworm™

G80-521 Common Stalk Borer in Corn (Revised April 2000)

The life history and appearance of common stalk borers is described, along with information on damage they can cause, economic injury levels and ways to control them in corn. In the past, the common stalk borer, Papaipema nebris, has not been a major pest of corn in Nebraska. Stalk borer damage in corn commonly is confined to occasional plants in the first few rows near field margins, fence rows, grass terraces and waterways. In addition to attacking corn, this insect attacks over one hundred other species of plants, including ornamentals, broadleaf weeds and grasses. It may feed on soybeans as well, but is not an economically important pest of that crop. Understanding the common stalk borer life cycle and behavior is critical to selecting management practices to reduce its damage in corn

G80-521 Common Stalk Borer in Corn (Revised April 2000)

The life history and appearance of common stalk borers is described, along with information on damage they can cause, economic injury levels and ways to control them in corn. In the past, the common stalk borer, Papaipema nebris, has not been a major pest of corn in Nebraska. Stalk borer damage in corn commonly is confined to occasional plants in the first few rows near field margins, fence rows, grass terraces and waterways. In addition to attacking corn, this insect attacks over one hundred other species of plants, including ornamentals, broadleaf weeds and grasses. It may feed on soybeans as well, but is not an economically important pest of that crop. Understanding the common stalk borer life cycle and behavior is critical to selecting management practices to reduce its damage in corn

Massive quenched galaxies at z~0.7 retain large molecular gas reservoirs

The physical mechanisms that quench star formation, turning blue star-forming galaxies into red quiescent galaxies, remain unclear. In this Letter, we investigate the role of gas supply in suppressing star formation by studying the molecular gas content of post-starburst galaxies. Leveraging the wide area of the SDSS, we identify a sample of massive intermediate-redshift galaxies that have just ended their primary epoch of star formation. We present ALMA CO(2-1) observations of two of these post-starburst galaxies at z~0.7 with M* ~ 2x10^11 Msun. Their molecular gas reservoirs of (6.4 +/- 0.8) x 10^9 Msun and (34.0 +/- 1.6) x 10^9 Msun are an order of magnitude larger than comparable-mass galaxies in the local universe. Our observations suggest that quenching does not require the total removal or depletion of molecular gas, as many quenching models suggest. However, further observations are required both to determine if these apparently quiescent objects host highly obscured star formation and to investigate the intrinsic variation in the molecular gas properties of post-starburst galaxies.Comment: Accepted for publication in ApJ Letters (6 pages, 5 figures

Degree-Day Requirements for Alfalfa Weevil (Coleoptera: Curculionidae) Development in Eastern Nebraska

The alfalfa weevil, Hypera postica (Gyllenhal), is a serious, yet sporadic defoliator of alfalfa, Medicago sativa L., in Nebraska. A 2-yr study was conducted in 2005 and 2006 to test for variation in degree-day requirements by location in eastern Nebraska. Sampling took place along a latitudinal gradient in three regions of eastern Nebraska. Three fields were sampled in each region during the 2 yr of the study. Alfalfa weevil larval degree-day requirements were found to vary by latitude in eastern Nebraska. Alfalfa weevil larvae were discovered in southern regions after fewer developmental degree-days had accumulated than in fields in the northern regions. Alfalfa weevils may be more damaging to alfalfa in southern regions than in northern regions of eastern Nebraska because they emerge earlier relative to alfalfa growth. Management implications of this shift in alfalfa weevil phenology are discussed

Discovery of an introduced Florida Flagfish (\u3ci\u3eJordanella floridae\u3c/i\u3e) population in Coastal Mississippi

The recent discovery of Jordanella floridae (Florida Flagfish) in Harrison County, Mississippi represents the first known occurrence of the species in the state. Native along the Atlantic and Gulf Coasts of Florida from Jacksonville to Tallahassee, this species has been introduced outside of its range via aquarium introductions. We hypothesize that an aquarium introduction was also the source of the newly discovered population, which has persisted at the location since 2020. Multiple collections of the species have been taken from a small waterbody which has a direct connection to the Tchoutacabouffa River (25mm-47mm TL). While it is unknown if this represents the only population in the system, further surveys should be conducted to determine population numbers at the site of collection, the extent of the invasion within the Tchoutacabouffa, and the impact to the native fish fauna

Population structure drives cultural diversity in finite populations: A hypothesis for localized community patterns on Rapa Nui (Easter Island, Chile)

Understanding how and why cultural diversity changes in human populations remains a central topic of debate in cultural evolutionary studies. Due to the effects of drift, small and isolated populations face evolutionary challenges in the retention of richness and diversity of cultural information. Such variation, however, can have significant fitness consequences, particularly when environmental conditions change unpredictably, such that knowledge about past environments may be key to long-term persistence. Factors that can shape the outcomes of drift within a population include the semantics of the traits as well as spatially structured social networks. Here, we use cultural transmission simulations to explore how social network structure and interaction affect the rate of trait retention and extinction. Using Rapa Nui (Easter Island, Chile) as an example, we develop a model-based hypothesis for how the structural constraints of communities living in small, isolated populations had dramatic effects and likely led to preventing the loss of cultural information in both community patterning and technology