Larra bicolor Fabricius (Hymenoptera: Crabronidae): its distribution throughout Florida

We document the presence of Larra bicolor Fabricius (Hymenoptera: Crabronidae) in 46 of Florida's 67 counties. The species is represented by two stocks. The first (released in 1981) originated in Pará, Brazil, but was obtained from Puerto Rico, and became established in Broward County in southern Florida. The second (released in 1988) originated in Santa Cruz de la Sierra, Bolivia, and became established in Alachua County in northern Florida. The Bolivian stock, aided by additional satellite releases from Alachua County, is now widely distributed. The species probably occupies all counties in central and northern Florida, but may yet be absent from some southern counties. Introduction was made for classical biological control of invasive mole crickets

Potencial de producción de forraje durante el año en Puerto Rico y Santa Cruz

Forage production can vary substantially during the annual cycle in the tropical islands of Puerto Rico and St. Croix. Cool temperatures, low levels of solar radiation, and low rainfall in December and January have been hypothesized to cause decrease in forage growth. A forage growth model was used to simulate yield in different environments in order to examine these hypotheses quantitatively. Weather data were obtained over a period of three to six years from three locations in Puerto Rico and one location in St. Croix. Minimum temperatures were always near or above 20° C and, consequently, did not appear to cause serious losses in forage production. The forage model predicted a decrease in forage production during the winter months due to decreased levels of solar radiation; however, yields were estimated to be approximately 70 to 80% of summer yields. Whereas shallow rooting depth of 45 cm could cause decreased yields in some situations, inadequate rainfall could not explain large yield decreases in winter months. This research indicates that a factor in addition to the ones tested contributes to the loss in winter forage yield. It is speculated that short day lengths directly influence the regulation of plant growth such that forage yield is decreased in winter months. La producción de forraje puede variar substancialmente durante el ciclo anual en las islas tropicales de Puerto Rico y Santa Cruz. Se ha hipotetizado que las temperaturas frías, los bajos niveles de radiación solar, y la baja precipitación en diciembre y enero son los causantes de las disminuciones en el crecimiento del forraje. Para examinar cuantitativamente estas hipótesis se utilizó un modelo de crecimiento en forraje para simular el rendimiento bajo diferentes ambientes. Los datos climáticos por un periodo de tres a seis años se obtuvieron para tres localidades en Puerto Rico y una localidad en Santa Cruz. Las temperaturas mínimas estuvieron siempre cerca o por encima de los 20°C; por lo tanto, no parecieron causar serias pérdidas en la producción de forraje. El modelo de forraje predijo una reducción en la producción de forraje en los meses de invierno debido a una disminución en los niveles de radiación solar; sin embargo, los rendimientos estimados fueron un 70 a 80% de los rendimientos del verano. Si bien el enraizamiento superficial a una profundidad menor de 45 cm podría causar disminución de los rendimientos en algunas situaciones, la precipitación inadecuada no podría explicar las grandes disminuciones ocurridas en los meses de invierno. Esta investigación indica que un factor adicional a los evaluados contribuye a la pérdida en el rendimiento del forraje durante el invierno. Se especula que la corta duración del día influye directamente sobre la regulación del crecimiento de la planta de forma tal que el rendimiento de forraje disminuye en los meses de invierno

Photoperiod Response in Pensacola Bahiagrass

Photoperiod response has been found to influence the growth and development of \u3ePensacola\u27 derived bahiagrass (Paspalum notatum Flugge var. saure Parodi). Four selection cycles [\u3ePensacola= (Cycle 0), Cycle 4, \u3eTifton 9\u27 (Cycle 9) and Cycle 23] resulting from recurrent restricted phenotypic selection (RRPS) of spaced-plants, were field grown in 1999 and 2000, to study photoperiod sensitivity among genotypes. Two day-length treatments were imposed on the field grown plants. One treatment, used only natural light. The second treatment imposed an extended day-length treatment using Quartz-halogen lamps, installed in the field during the fall and winter, to extend day-length to15 hours. The top growth of individual plants was harvested three times during the fall and winter seasons and stolon spread was measured in mid February, 2000. Top growth was increased by the extended day-length treatment for Pensacola and RRPS Cycle 4 in all three harvest dates. Top growth of Tifton 9 was unaffected by the extended light for the September harvest, but increased in the late October and late January harvests. RRPS Cycle 23 plants grown under natural light, out-yielded the plants grown under extended light treatment, for the first two harvests. There were no differences in yields of RRPS Cycle 23 plants from extended or natural light from the January harvest. The later cycles, Tifton 9 and RRPS Cycle 23, were less sensitive to day-length, than RRPS Cycles 0 and 4. Extended daylength, for all cycles, dramatically reduced stolon spread by nearly half that of the plants grown under natural light. Results from this experiment demonstrate a high sensitivity in growth and development of Pensacola-derived bahiagrass to day-length

Using On-Farm Demonstrations to Evaluate Newly Developed Cool-Season Forages in the Southeastern USA

Multiple demonstration sites throughout Florida were designed to evaluate and provide hands-on producer and county faculty access to newly developed cool-season winter forage crops that can be grown in the southeastern United States. Research funding for these projects was provided by the Dairy Research and Education Project, supported through the Georgia/Florida Dairy Industry check-off dollars. Early adopter producers interested in evaluating forages were identified for this cooperation. Long-term goals are to have the early adopter producer aid in the trialing and dissemination of information about improved varieties. Cool-season forages for use on southeastern US livestock operations benefit the producer in providing highly nutritional greenchop or silage crop for livestock, winter cover to provide erosion and leaching protection on cultivated acreage, potentially recycle nutrients or remove significant nutrients from the forage system, and serve as a sentinel plots to help identify new or emerging pest problems related to forage production. We also focus developing forages for both low and high end input systems that address environmental issues related to N and P in the soils. In the southeastern U.S. particularly in Florida, nitrogen and phosphorus accumulate in many production fields and these nutrients impact surface and ground water resources. We participate with the Florida Department of Agriculture and the dairy and beef cattle industry to develop “best management practices” (BMPs) that guide producers to lessen their negative impacts on the environment and improve upon their operation’s sustainability and economic returns. This effort has led to the release of new cultivars from the University of Florida’s Forage Program. While we focus, primarily, on cool-season small grains and ryegrass, our program also includes breeding other subtropical forage species for adaptation to our environment and to improve adoption of BMPs

Nicotine, Carcinogen, and Toxin Exposure in Long-Term E-Cigarette and Nicotine Replacement Therapy Users:A Cross-sectional Study

BACKGROUND: Given the rapid increase in the popularity of e-cigarettes and the paucity of associated longitudinal health-related data, the need to assess the potential risks of long-term use is essential. OBJECTIVE: To compare exposure to nicotine, tobacco-related carcinogens, and toxins among smokers of combustible cigarettes only, former smokers with long-term e-cigarette use only, former smokers with long-term nicotine replacement therapy (NRT) use only, long-term dual users of both combustible cigarettes and e-cigarettes, and long-term users of both combustible cigarettes and NRT. DESIGN: Cross-sectional study. SETTING: United Kingdom. PARTICIPANTS: The following 5 groups were purposively recruited: combustible cigarette-only users, former smokers with long-term (≥6 months) e-cigarette-only or NRT-only use, and long-term dual combustible cigarette-e-cigarette or combustible cigarette-NRT users (n = 36 to 37 per group; total n = 181). MEASUREMENTS: Sociodemographic and smoking characteristics were assessed. Participants provided urine and saliva samples and were analyzed for biomarkers of nicotine, tobacco-specific N-nitrosamines (TSNAs), and volatile organic compounds (VOCs). RESULTS: After confounders were controlled for, no clear between-group differences in salivary or urinary biomarkers of nicotine intake were found. The e-cigarette-only and NRT-only users had significantly lower metabolite levels for TSNAs (including the carcinogenic metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol [NNAL]) and VOCs (including metabolites of the toxins acrolein; acrylamide; acrylonitrile; 1,3-butadiene; and ethylene oxide) than combustible cigarette-only, dual combustible cigarette-e-cigarette, or dual combustible cigarette-NRT users. The e-cigarette-only users had significantly lower NNAL levels than all other groups. Combustible cigarette-only, dual combustible cigarette-NRT, and dual combustible cigarette-e-cigarette users had largely similar levels of TSNA and VOC metabolites. LIMITATION: Cross-sectional design with self-selected sample. CONCLUSION: Former smokers with long-term e-cigarette-only or NRT-only use may obtain roughly similar levels of nicotine compared with smokers of combustible cigarettes only, but results varied. Long-term NRT-only and e-cigarette-only use, but not dual use of NRTs or e-cigarettes with combustible cigarettes, is associated with substantially reduced levels of measured carcinogens and toxins relative to smoking only combustible cigarettes. PRIMARY FUNDING SOURCE: Cancer Research UK

Effects of rhizoma peanut cultivars (Arachis glabrata Benth.) on the soil bacterial diversity and predicted function in nitrogen fixation

There is a growing awareness of the importance of soil microorganisms in agricultural management practices. Currently, much less is known about whether different crop cultivar has an effect on the taxonomic structure and diversity, and specific functions of soil bacterial communities. Here, we examined the changes of the diversity and composition and enzyme-encoding nitrogenase genes in a long-term field experiment with seven different rhizoma peanut cultivars in southeastern USA, coupling high-throughput 16S rRNA gene sequencing and the sequence-based function prediction with Tax4Fun. Of the 32 phyla detected (Proteobacteria class), 13 were dominant: Acidobacteria, Alphaproteobacteria, Actinobacteria, Betaproteobacteria, Bacteroidetes, Verrucomicrobia, Gammaproteobacteria, Deltaproteobacteria, Gemmatimonadetes, Firmicutes, Nitrospirae, Chloroflexi, and Planctomycetes (relative abundance >1%). We found no evidence that the diversity and composition of bacterial communities were significantly different among different cultivars, but the abundance of some dominant bacterial groups that have N-fixation potentials (at broad or fine taxonomic level) and predicted abundances of some enzyme-encoding nitrogenase genes showed significant across-cultivar differences. The nitrogenase genes were notably abundant in Florigraze and Latitude soils while remarkably lower in Arbook and UF_TITO soils when compared with other cultivars, indicating different nitrogen fixation potentials among different cultivars. The findings also suggest that the abundance of certain bacterial taxa and the specific function bacteria perform in ecosystems can have an inherent association. Our study is helpful to understand how microbiological responses and feedback to different plant genotypes through the variation in structure and function of their communities in the rhizosphere