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

Development of a Bahiagrass \u3cem\u3ePaspalum Notatum\u3c/em\u3e Flugge With Increased Short-Day Biomass

Low herbage productivity of subtropical grasses during the short-day winter months of October through to March can place a severe burden on livestock producers in Southeastern U.S. Researchers at the University of Florida (Sinclair et al., 2001) hypothesised that the decrease in forage production might result from physiological dormancy induced by short day length. A study using artificial lights to extend the day length demonstrated that maintaining the day length at 15 hr during the short-day length period increased \u27Pensacola\u27 bahiagrass P. notatum Flugge saure Parodi forage yield 122% when compared with normal photoperiod (Mislevy et al., 2001). A Pensacola-derived bahiagrass population was selected for increased vegetative growth under short-day length using restricted recurrent phenotypic selection for three cycles (UF Cycle 3) to increase forage yield. Plants that comprise this population were less sensitive to short photoperiod and produced increased forage mass during the short days. The objective of this clipping study was to evaluate forage production and forage nutritive value of UF Cycle 3 compared with selected standard entries during short and long day length periods

Seasonal expression of apospory in bahiagrass

This paper was presented at the 22nd International Grassland Congress, Sydney, Australia, 15−19 September 2013. Its publication in Tropical Grasslands – Forrajes Tropicales is the result of a co-publication agreement with the IGC 2013 Organizing Committee. Except for adjustments to the journal’s style and format, the text is essentially the same as that published in: Michalk LD; Millar GD; Badgery WB; Broadfoot KM, eds. 2013. Revitalising Grasslands to Sustain our Communities. Proceedings of the 22nd International Grassland Congress, Sydney, Australia, 2013. New South Wales Department of Primary Industries, Orange, NSW, Australia. p. 258–259.Fil: Rios, Esteban Fernando. University Of Florida; Estados Unidos de América; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina;Fil: Blount, Ann. University Of Florida; Estados Unidos de América;Fil: Kenworthy, Kevin E.. University Of Florida; Estados Unidos de América;Fil: Acuña, Carlos Alberto. Universidad Nacional del Nordeste; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina;Fil: Quesenberry, Kenneth H.. University Of Florida; Estados Unidos de América

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

Seasonal Expression of Apospory in Bahiagrass

Flowering plants can reproduce sexually (outcrossing and/or selfing) and/or asexually. Sexual reproduction implies the successful completion of meiosis and double fertilisation for the formation of both the embryo and the endosperm. In contrast, gametophytic apomixis is an asexual mode of reproduction through seeds that involves parthenogenetic embryo development from a cytologically unreduced egg cell (2n). Apospory is the process by which unreduced gametophytes are formed after a series of mitotic divisions of somatic cells (2n) in the ovary. This occurs independently from the sexual meiotic process; and therefore, both sexual and apomictic pathways may coexist simultaneously. Apospory is inherited in bahiagrass (Paspalum notatum) as a single dominant Mendelian factor with distorted segregation (Martínez et al. 2001), and its degree of expression was reported to vary throughout the flowering season in P. cromyorrhizon, a close relative of bahiagrass (Quarin 1986). Bahiagrass is a perennial warm-season grass widely used for forage and utility turf in the south-eastern US due to its persistence in sandy, infertile soils. Diploid races reproduce sexually and are highly self-incompatible (Acuña et al. 2007), while polyploids are classified as pseudogamous apomicts (pollination is required) (Quarin 1999). Sexual tetraploid genotypes have been experimentally created (Quesenberry and Smith 2003; Quesenberry et al. 2010) and successfully used in crosses (Acuña et al. 2009). Cytoembryological analysis has been used to determine the mode of reproduction in bahiagrass (Martínez et al. 2001; Acuña et al. 2007). At anthesis, sexual plants produce spikelets having only a single Polygonum type meiotic embryo sac (SES), characterised by bearing the egg apparatus close to the micropyla, a large binucleated central cell and a group of antipodal cells at the chalazal end (Figure 1a). Highly apomictic plants produce ovules having single or multiple aposporous embryo sacs (AES), which present the egg apparatus and a central cell with 2 polar nuclei, and no antipodal cells (Figure 1b). Some tetraploid bahiagrass races are also able to produce ovules that have the sexual meiotic megasporocyte together with one or more aposporous sacs (AES+SES), and these plants are classified as facultative apomictic. The objective of this study was to characterise the reproductive mode of 5 wild dwarf bahiagrasses, a highly apomictic hybrid (Acuña et al. 2009) and the cultivar ‘Argentine’ at different times during the flowering season and under different nitrogen (N) fertiliser rates

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

Approaches toward Sustainable Forage-Livestock Systems: Strip-Planting a Legume into a Warm-Season Perennial Grass Pasture

Despite the demonstrated potential of rhizoma peanut (Arachis glabrata Benth.; RP) for grazing in the southeastern USA (Ortega-S. et al. 1992), high establishment cost and removal of land from production during establishment have limited its use to primarily hay production systems. The premise of this experiment is that strip-planting RP in existing bahiagrass (Paspalum notatum Flügge) pastures offers the opportunity to use grass forage during the legume establishment phase so that land need not be totally removed from grazing, while allowing successful establishment of the legume

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

Impact of investigational microbiota therapeutic RBX2660 on the gut microbiome and resistome revealed by a placebo-controlled clinical trial

BACKGROUND: Intestinal microbiota restoration can be achieved by complementing a subject\u27s perturbed microbiota with that of a healthy donor. Recurrent Clostridioides difficile infection (rCDI) is one key application of such treatment. Another emerging application of interest is reducing antibiotic-resistant genes (ARGs) and organisms (AROs). In this study, we investigated fecal specimens from a multicenter, randomized, double-blind, placebo-controlled phase 2b study of microbiota-based investigational drug RBX2660. Patients were administered either placebo, 1 dose of RBX2660 and 1 placebo, or 2 doses of RBX2660 via enema and longitudinally tracked for changes in their microbiome and antibiotic resistome. RESULTS: All patients exhibited significant recovery of gut microbiome diversity and a decrease of ARG relative abundance during the first 7 days post-treatment. However, the microbiome and resistome shifts toward average configurations from unperturbed individuals were more significant and longer-lasting in RBX2660 recipients compared to placebo. We quantified microbiome and resistome modification by RBX2660 using a novel transplantation index metric. We identified taxonomic and metabolic features distinguishing the baseline microbiome of non-transplanted patients and taxa specifically enriched during the process of transplantation. We elucidated the correlation between resistome and taxonomic transplantations and post-treatment dynamics of patient-specific and RBX2660-specific ARGs. Whole genome sequencing of AROs cultured from RBX2660 product and patient samples indicate ARO eradication in patients via RBX2660 administration, but also, to a lesser extent, introduction of RBX2660-derived AROs. CONCLUSIONS: Through shotgun metagenomic sequencing, we elucidated the effects of RBX2660 in the microbiome and resistome. Antibiotic discontinuation alone resulted in significant recovery of gut microbial diversity and reduced ARG relative abundance, but RBX2660 administration more rapidly and completely changed the composition of patients\u27 microbiome, resistome, and ARO colonization by transplanting RBX2660 microbiota into the recipients. Although ARGs and AROs were transmitted through RBX2660, the resistome post-RBX2660 more closely resembled that of the administered product-a proxy for the donor-than an antibiotic perturbed state. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02299570 . Registered 19 November 2014 Video Abstract