Population Trends of the Sugarcane Borer (Lepidoptera: Crambidae) in Louisiana Sugarcane

2020 ◽  
Vol 49 (6) ◽  
pp. 1455-1461
Author(s):  
B E Wilson ◽  
W H White ◽  
R T Richard ◽  
R M Johnson
Keyword(s):  
First Generation ◽  
Total Precipitation ◽  
Weather Factors ◽  
Saccharum Spp ◽  
Sugarcane Borer ◽  
Winter Temperatures ◽  
Key Factor ◽  
Spring Temperatures ◽  
Overwintering Mortality ◽  
Linear Regressions

Abstract The sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), is the primary pest of sugarcane, Saccharum spp., in Louisiana. Spring populations are not considered economically damaging, but quantifying infestations can provide an indication of the spatial and temporal character of the damaging summer populations. Statewide surveys quantified the density of sugarcane tillers killed by D. saccharalis (deadhearts) from sugarcane fields across the state in spring from 2003 to 2020. Deadheart density varied greatly among years with a high of 1,318/ha in 2003 to a low of 0/ha in 2018. Linear regressions of the 3-yr rolling average showed declines in spring D. saccharalis populations and the percentage of acreage treated with insecticides over 17 yr. Weather factors including minimum winter temperatures and average spring temperatures were poor predictors of D. saccharalis populations. Only total precipitation in the month of April was positively correlated with numbers of deadhearts per hectare. Results suggest overwintering mortality is not a key factor influencing populations of the first generation of D. saccharalis in Louisiana. Total precipitation in the month of July was positively associated with percentage of treated acreage. Spring deadheart density was directly related to percentage of acreage treated with insecticides during the summer. Quantifying first-generation D. saccharalis populations by recording deadheart density can aid in predicting pest pressure later in the growing season.

scholarly journals Global warming leads to more uniform spring phenology across elevations

2017 ◽  
Vol 115 (5) ◽  
pp. 1004-1008 ◽  
Author(s):  
Yann Vitasse ◽  
Constant Signarbieux ◽  
Yongshuo H. Fu
Keyword(s):  
Global Warming ◽  
Mountain Forest ◽  
European Alps ◽  
Spring Phenology ◽  
Winter Temperatures ◽  
Spring Temperatures ◽  
Plant Animal Interactions ◽  
Tree Leaf ◽  
And Function ◽  
Phenological Shift

One hundred years ago, Andrew D. Hopkins estimated the progressive delay in tree leaf-out with increasing latitude, longitude, and elevation, referred to as “Hopkins’ bioclimatic law.” What if global warming is altering this well-known law? Here, based on ∼20,000 observations of the leaf-out date of four common temperate tree species located in 128 sites at various elevations in the European Alps, we found that the elevation-induced phenological shift (EPS) has significantly declined from 34 d⋅1,000 m−1 conforming to Hopkins’ bioclimatic law in 1960, to 22 d⋅1,000 m−1 in 2016, i.e., −35%. The stronger phenological advance at higher elevations, responsible for the reduction in EPS, is most likely to be connected to stronger warming during late spring as well as to warmer winter temperatures. Indeed, under similar spring temperatures, we found that the EPS was substantially reduced in years when the previous winter was warmer. Our results provide empirical evidence for a declining EPS over the last six decades. Future climate warming may further reduce the EPS with consequences for the structure and function of mountain forest ecosystems, in particular through changes in plant–animal interactions, but the actual impact of such ongoing change is today largely unknown.

Dormancy cycling is accompanied by changes in ABA sensitivity in Polygonum aviculare seeds

2020 ◽  
Vol 71 (19) ◽  
pp. 5924-5934 ◽  
Author(s):  
Natalia Verónica Laspina ◽  
Diego Batlla ◽  
Roberto Luis Benech-Arnold
Keyword(s):  
Molecular Mechanisms ◽  
Hormone Metabolism ◽  
Polygonum Aviculare ◽  
Primary Dormancy ◽  
Aba Sensitivity ◽  
Winter Temperatures ◽  
Spring Temperatures ◽  
Aba Content ◽  
Dormancy Induction ◽  
Endogenous Aba

Abstract Polygonum aviculare seeds show high levels of primary dormancy (PD). Low winter temperatures alleviate dormancy and high spring temperatures induce seeds into secondary dormancy (SD), naturally establishing stable seedbanks cycling through years. The objective of this work was to elucidate the mechanism(s) involved in PD expression and release, and in SD induction in these seeds, and the extent to which abscisic acid (ABA) and gibberellins (GAs) are part of these mechanisms. Quantification of endogenous ABA both prior to and during incubation, and sensitivity to ABA and GAs, were assessed in seeds with contrasting dormancy. Expression analysis was performed for candidate genes involved in hormone metabolism and signaling. It was found that endogenous ABA content does not explain either dormancy release or dormancy induction; moreover, it does not seem to play a role in dormancy maintenance. However, dormancy modifications were commonly accompanied by changes in ABA sensitivity. Concomitantly, induction into SD, but not PD, was characterized by a increased PaABI-5 and PaPYL transcription, and a rise in GA sensitivity as a possible counterbalance effect. These results suggest that dormancy cycling in this species is related to changes in embryo sensitivity to ABA; however, this sensitivity appears to be controlled by different molecular mechanisms in primary and secondary dormant seeds.

scholarly journals Comparison of the Spatiotemporal Variability of Temperature, Precipitation, and Maximum Daily Spring Flows in Two Watersheds in Quebec Characterized by Different Land Use

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Ali A. Assani ◽  
Raphaëlle Landry ◽  
Christophe Kinnard ◽  
Ouassila Azouaoui ◽  
Christine Demers ◽  
...  
Keyword(s):  
Land Use ◽  
Temporal Variability ◽  
Agricultural Watershed ◽  
Spatiotemporal Variability ◽  
Forested Watershed ◽  
Total Precipitation ◽  
Forested Watersheds ◽  
Spring Temperatures ◽  
Maximum Temperatures ◽  
Over Time

We compared the spatiotemporal variability of temperatures and precipitation with that of the magnitude and timing of maximum daily spring flows in the geographically adjacent L’Assomption River (agricultural) and Matawin River (forested) watersheds during the period from 1932 to 2013. With regard to spatial variability, fall, winter, and spring temperatures as well as total precipitation are higher in the agricultural watershed than in the forested one. The magnitude of maximum daily spring flows is also higher in the first watershed as compared with the second, owing to substantial runoff, given that the amount of snow that gives rise to these flows is not significantly different in the two watersheds. These flows occur early in the season in the agricultural watershed because of the relatively high temperatures. With regard to temporal variability, minimum temperatures increased over time in both watersheds. Maximum temperatures in the fall only increased in the agricultural watershed. The amount of spring rain increased over time in both watersheds, whereas total precipitation increased significantly in the agricultural watershed only. However, the amount of snow decreased in the forested watershed. The magnitude of maximum daily spring flows increased over time in the forested watershed.

A comparison of sweet sorghum and maize as first-generation bioethanol feedstocks in Greece

2014 ◽  
Vol 153 (5) ◽  
pp. 853-861
Author(s):  
C. E. VLACHOS ◽  
N. A. MARIOLIS ◽  
G. N. SKARACIS
Keyword(s):  
Sweet Sorghum ◽  
Fossil Fuels ◽  
First Generation ◽  
Raw Material ◽  
Bioethanol Production ◽  
Material Source ◽  
Key Factor ◽  
Crop Sustainability ◽  
The Eu ◽  
Ghg Savings

SUMMARYAccording to the EU 28/2009 directive, member states are mandated to substitute 10% of fossil fuels used in transportation with biofuels by the year 2020. Bioethanol production is expected to contribute significantly towards fulfilling Greece's obligations. First-generation bioethanol, produced from amylaceous and sugar crops, is the most important biofuel globally. Maize (Zea mays L.) is the main feedstock for production worldwide, while sweet sorghum (Sorghum bicolor L. Moench), although a promising raw material source, has not yet enjoyed substantial commercial exploitation due to the high seasonality of the crop. Sustainability criteria set by the EU constitute a key factor in the characterization and future use of biofuels. A 3-year study including 20 maize and 4 sweet sorghum varieties was conducted in order to compare these two crops in terms of emitted greenhouse gases (GHG) during the cultivation phase as well as regarding emission savings by substituting bioethanol for petrol/gasoline. Both crops demonstrated promising bioethanol yields reaching 5235·7 and 6443·7 l/ha/yr for maize and sweet sorghum, respectively, and showed that they could be employed towards first-generation bioethanol production in Greece. Sweet sorghum varieties produced higher bioethanol yields per hectare coupled with lower emissions during the cultivation phase and better overall GHG savings compared to maize.

scholarly journals Evolutionary Pathways to Statehood: Old Theories and New Data

2018 ◽  
Author(s):  
Peter Turchin ◽  
Harvey Whitehouse ◽  
Andrey Korotayev ◽  
Pieter Francois ◽  
Daniel Hoyer ◽  
...  
Keyword(s):  
Social Stratification ◽  
First Generation ◽  
Wealth Status ◽  
Territorial Expansion ◽  
Face To Face ◽  
Administrative Organization ◽  
Social Scale ◽  
Key Factor ◽  
Negative Effect ◽  
Governance Institutions

Over the past 10,000 years, human societies evolved from “simple”—small egalitarian groups, integrated by face-to-face interactions—to “complex”— societies of millions, characterized by great differentials in wealth, status, and power, extensive division of labor, and elaborate governance structures. At the heart of this transformation was the rise of the state; a politically centralized territorial polity with an internally specialized administrative organization. But what drove the emergence and evolution of specialized governance is broadly contested. Here we use Seshat: Global History Databank to empirically test predictions from a variety of theories. One set of explanations proposes social scale (polity population and territory, population of the largest settlement) as the primary factor favoring the evolution of specialized governance institutions. Other theories focus on alternative mechanisms, such as social stratification or the provisioning of public goods. Still others point to the importance of sophisticated information and money systems as potential preconditions for the evolution of bureaucracy. Our analysis identifies polity population size as the main evolutionary driver of state-formation. Although information systems also play a role, stratification has no detectable impact, once polity population is included in the model; and, while territorial expansion may be a key factor in the emergence of certain first-generation or primary states, the territorial extent of polities actually has a negative effect on the evolution of sophisticated governance, once polity population is included in the model.

scholarly journals Plasticity of cold hardiness in the eastern spruce budworm, Choristoneura fumiferana

2021 ◽  
Author(s):  
Skye Butterson ◽  
Amanda D Roe ◽  
Katie Elizabeth Marshall
Keyword(s):  
Phenotypic Plasticity ◽  
Local Adaptation ◽  
Cold Hardiness ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Cold Temperatures ◽  
Eastern Spruce Budworm ◽  
Winter Temperatures ◽  
Overwintering Mortality ◽  
Overwintering Survival

High latitude insect populations must cope with extreme conditions, particularly cold temperatures. Insects use a variety of cold hardiness mechanisms to withstand this temperature stress, and these can drive geographic distributions through overwintering mortality. The degree of cold hardiness can be altered by two evolved responses: phenotypic plasticity and local adaptation. Phenotypic plasticity can occur within or between generations (transgenerational plasticity; TGP), and local adaptation can evolve through directional selection in response to regional climatic differences. We used the eastern spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae) as a model to explore the role that variable winter temperatures play in inducing two aspects of plasticity in cold hardiness: TGP and local adaptation in phenotypic plasticity. This species is one of the most destructive boreal forest pests in North America, therefore accurately predicting overwintering survival is essential for effective management. While we found no evidence of TGP in cold hardiness, there was a long-term fitness cost to larvae that experienced repeated cold exposures. We also found evidence of local adaptation in both seasonal and short-term plasticity of cold hardiness. These findings provide evidence for the importance of phenotypic plasticity and local adaptation when modelling species distributions.

Alfalfa Weevil (Coleoptera: Curculionidae) Phenology with its Host Crop and Parasitoids in Virginia

2001 ◽  
Vol 36 (4) ◽  
pp. 352-365 ◽  
Author(s):  
Thomas P. Kuhar ◽  
Roger R. Youngman ◽  
Curtis A. Laub
Keyword(s):  
First Generation ◽  
Adult Emergence ◽  
Activity Period ◽  
Alfalfa Weevil ◽  
Winter Climate ◽  
Larval Parasitoid ◽  
Shenandoah Valley ◽  
Winter Temperatures ◽  
Adult Parasitoid ◽  
Microctonus Aethiopoides

Alfalfa weevil, Hypera postica (Gyllenhal), phenology is influenced by winter climate. In 1997 we initiated a 2-yr study of alfalfa weevil phenology with respect to its host crop and parasitoids in three geographically distinct locations of Virginia: the central Piedmont, Shenandoah Valley, and southwestern region. Alfalfa weevil populations from nine fields were sampled regularly from November until first harvest in each season. Eggs laid in December and January resulted in alfalfa weevil larval infestations in March and April at all locations. Because of warmer winter temperatures, eggs developed faster in the Piedmont compared with the higher elevations, and resulted in larval populations attacking alfalfa earlier in the season, when the crop was at an earlier growth stage. The adult parasitoid, Microctonus aethiopoides Loan, was synchronized poorly with alfalfa weevil populations in Virginia. At all locations studied, adult emergence of first generation M. aethiopoides occurred in April and early May, when few overwintering alfalfa weevil adults were present in fields. Emergence of the second generation of the parasitoid occurred in late May to June after many of the fields had been harvested. The larval parasitoid, Bathyplectes anurus (Thomson), was well synchronized with its host in Virginia. The activity period of the parasitoid overlapped the peak occurrence of alfalfa weevil larvae at all locations.

scholarly journals Onset of Flowering in Biennial and Perennial Garden Plants

2012 ◽  
pp. 85-132
Author(s):  
F. T. Last ◽  
A. M.I Roberts
Keyword(s):  
Late Winter ◽  
Base Temperature ◽  
Early Winter ◽  
Species Trees ◽  
Air Temperatures ◽  
Winter Temperatures ◽  
Soil Temperatures ◽  
Significant Temperature ◽  
Spring Temperatures ◽  
Delayed Flowering

Observations were made weekly over a period of 30 years of 208 species (trees, shrubs, herbaceous plants and geophytes) from more than 1,000 growing in a garden located 18km east of the Royal Botanic Garden Edinburgh (RBGE), Scotland (lat. 55º 56ʹN: long. 3º 09ʹW). Of these species, 27 were British native or naturalised.The First Flowering Dates (FFD) of 67 species were without significant temperature association with variable weather; the FFDs of the other 141 species reflected, in contrast, the net outcome of ‘major’ associations with late winter/spring temperatures and smaller impacts of autumn/early winter temperatures. Increases in late winter and spring temperatures advanced the onset of flowering in the current year; in contrast, increases in autumn and early winter temperatures tended to be associated with delayed flowering in the following year.With stepwise regression, penalised signal regression and thermal-time models, it was possible to identify species with ‘strong’ associations with both air and soil temperatures and species with ‘weak’ associations with either air or soil temperatures.Thermal-time models for each of 120 species, whose FFDs were associated with temperature, enabled the characterisation of (1) base temperatures, Tb(°C), at, and above which, development towards open flowers is possible; and (2) thermal constants (degree days accumulated between the start of development and the onset of flowering). Together these attributes suggested that each base temperature cohort has species with widely different degree-day requirements. Between 1978 and 2007 mean air temperatures significantly increased by 0.080°C, 0.044°C and 0.026°C yrˉ¹ in the first, second and third quarters; soil temperatures increased by 0.060ºCyrˉ¹in the first quarter. Over the 30-year period, the trends in flowering showed the early (February/March) flowering species flowering c. 24 days sooner; the later flowering species (April/May) advanced by only c. 12 days.

scholarly journals The influence of weather conditions on breeding dates of the common gull (Larus canus) in the south of Western Siberia

2021 ◽  
Vol 16 (3) ◽  
pp. 8-18
Author(s):  
M. Yu. Garyushkina ◽  
A. K. Yurlov
Keyword(s):  
Air Temperature ◽  
Large Scale ◽  
Climatic Factors ◽  
Weather Conditions ◽  
Egg Laying ◽  
Weather Variables ◽  
Weather Factors ◽  
Spring Temperatures ◽  
The Common ◽  
Using Data

Aim. The purpose of this research was to find out what local weather factors influence the nesting timing of the common gull (Larus canus). Material and Methods. The time of egg laying by the common gull was determined using data obtained during regular surveys over 8 years (1996‐1998, 2002‐2003, 2006‐2008) on the islands of Lake Bolshie Chany. Weather and climatic factors were assessed using open‐access databases. Results. It was been established that the start of egg‐laying in the colony of the common gull is determined by wind strength, the number of rainy days, the associated atmospheric pressure during the second decade of April, and the air temperature – the transition date at which the average daily air temperature rose above 0°C. In years with unstable spring temperatures, a relationship was revealed between the air temperature and the intensity of egg laying by the common gulls by day. In years when temperatures rise evenly, precipitation and wind speed become the main factors.Conclusion. We conclude that the egg‐laying dates of the common gull is influenced by weather variables during the whole nesting season and not predominantly by early season variables. We also show the importance of large‐scale climatic phenomena such as the EAWR in explaining variability in timing of the nesting of the common gull in Siberia. We suggest that future studies should focus on the effects of extremes in weather variables and global climatic phenomena.

scholarly journals Detection of homogeneous precipitation regions at seasonal and annual time scales, northwest Iran

2017 ◽  
Vol 8 (4) ◽  
pp. 701-714 ◽  
Author(s):  
Mohammad Arab Amiri ◽  
Mohammad Saadi Mesgari ◽  
Christian Conoscenti
Keyword(s):  
Time Scales ◽  
Time Scale ◽  
Homogeneous Precipitation ◽  
Total Precipitation ◽  
Spatial And Temporal Patterns ◽  
Study Region ◽  
Key Factor ◽  
Northwestern Iran ◽  
And Cluster Analysis ◽  
Annual Time

Abstract Detection of homogeneous climate areas is a challenging issue, which can be affected by different criteria. One of the most prominent factors is choosing the time scale, which can lead to different spatial and temporal patterns. Total precipitation is a key factor in climatological studies, and studying its distribution is of utmost importance. The combination of principal components analysis and cluster analysis is used for homogeneous precipitation areas' detection. Hence, the spatial pattern of total precipitation was investigated in northwestern Iran during the past two decades (1991–2010) on seasonal and annual time scales. The results of clustering on each time scale were validated, and well-defined clusters were investigated and compared with each other. Two homogeneous sub-regions were recognized in spring, the best period for depicting homogeneous precipitation clusters at seasonal resolution. The annual pattern of precipitation delineated three clusters in the study region. Finally, the characteristics of the well-clustered maps reveal the importance of time scale in detection of homogeneous precipitation sub-zones.

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