scholarly journals Hunting Billbug (Coleoptera: Curculionidae) Life Cycle and Damaging Life Stage in North Carolina, With Notes on Other Billbug Species Abundance

2012 ◽  
Vol 105 (6) ◽  
pp. 2045-2051 ◽  
Author(s):  
J. P. Doskocil ◽  
R. L. Brandenburg
Paleobiology ◽  
2018 ◽  
Vol 44 (4) ◽  
pp. 783-797 ◽  
Author(s):  
Kelly E. Cronin ◽  
Gregory P. Dietl ◽  
Patricia H. Kelley ◽  
Stewart M. Edie

AbstractLife span bias potentially alters species abundance in death assemblages through the overrepresentation of short-lived organisms compared with their long-lived counterparts. Although previous work found that life span bias did not contribute significantly to live–dead discordance in bivalve assemblages, life span bias better explained discordance in two groups: longer-lived bivalve species and species with known life spans. More studies using local, rather than global, species-wide life spans and mortality rates would help to determine the prevalence of life span bias, especially for long-lived species with known life spans. Here, we conducted a field study at two sites in North Carolina to assess potential life span bias between Mercenaria mercenaria and Chione elevata, two long-lived bivalve species that can be aged directly. We compared the ability of directly measured local life spans with that of regional and global life spans to predict live–dead discordance between these two species. The shorter-lived species (C. elevata) was overrepresented in the death assemblage compared with its live abundance, and local life span data largely predicted the amount of live–dead discordance; local life spans predicted 43% to 88% of discordance. Furthermore, the global maximum life span for M. mercenaria resulted in substantial overpredictions of discordance (1.4 to 1.6 times the observed live–dead discordance). The results of this study suggest that life span bias should be considered as a factor affecting proportional abundances of species in death assemblages and that using life span estimates appropriate to the study locality improves predictions of discordance based on life span compared with using global life span estimates.


2020 ◽  
Vol 10 (2) ◽  
pp. 63-75
Author(s):  
Muhammad Nauman Khan ◽  
Sajjad Ali ◽  
Tabassum Yaseen ◽  
Sami Ullah ◽  
Akhtar Zaman ◽  
...  

Background: The study of species diversity, its conservations and extinction can be done by using systematics in plant biodiversity. Poaceae is a very diverse grass family with great economic importance as it contains crops like rice, maize, oats, wheat, etc. Objectives: The current study was undertaken in district Charsadda during 2017-18 in flowering season to collect different grass species from the area. Methodology: Grass specimens were gathered, preserved, mounted and then identified from the available literature/native flora (Flora of Pakistan). Ecological parameters like habitat, class, life cycle and biological spectra were determined. A total of 51 taxa comprised of 34 genera, 5 subfamilies and 11 tribes of grasses were collected from the District Charsadda. The subfamily Panicoideae was the leading family with highest number of genera, taxa and tribes, followed by Pooideae. Results: The biological spectrum showed that in the life-form class, therophyte had the highest number of species 32 (62.74%), followed by hemicryptophyte having 13 species (25.49%). In the Leaf size class, microphylls were dominant with 24 species (47.05%) followed by nanophylls having 14 species (27.45%). The adaptational survival of plants showed that 32 species (62.74%) were terrestrial and 19 species (37.25%) were amphibious in our study. The Life-cycle class depicted that 33 species (64.70%) were annual, 17 species (33.33%) were perennial and 1 species (1.960%) was annual or perennial. The Palatability class showed that 35 species (68.62%) were highly palatable, followed by less-palatable 11 species (21.56%), non-palatable 2 species (3.921%) and moderately palatable 3 species (5.882%). The Abundant class were determined through species rating scale in ecology Acfor (Abundant Common Frequent Occasional Rare) scale to describe species abundance in a given area; 26 species (50.98%) were occasional, 12 species (23.52%) were frequent, 7 species (13.72%) were rare, 5 species (9.803%) were common and only 1 species cynodon dactylon (1.960%) was abundant in the whole area and present everywhere in the research area in every season. Conclusion: It has been concluded from the study that unwise collection, over-grazing, over-exploitation, over-consumption and overutilization are major biotic factors, which affect the diversity of the grasses in the area and affect the populations’ sustainability on the earth crust. Therefore, the study aims to document and explore wild grasses from the area, which might help in future researches. This survey will be helpful in identifying plant wealth and status for their exploitation on systematic approaches and scientific basis.


2020 ◽  
Vol 110 (10) ◽  
pp. 1704-1712 ◽  
Author(s):  
Lijiang Liu ◽  
Li Qin ◽  
Zhuqing Zhou ◽  
Wilhelmina G. H. M. Hendriks ◽  
Shengyi Liu ◽  
...  

As a soilborne protist pathogen, Plasmodiophora brassicae causes the devastating clubroot disease on Brassicaceae crops worldwide. Due to its intracellular obligate biotrophic nature, the life cycle of P. brassicae is still not fully understood. Here, we used fluorescent probe-based confocal microscopy and transmission electron microscopy (TEM) to investigate the infection process of P. brassicae on the susceptible host Arabidopsis under controlled conditions. We found that P. brassicae can initiate the primary infection in both root hairs and epidermal cells, producing the uninucleate primary plasmodium at 1 day postinoculation (dpi). After that, the developed multinucleate primary plasmodium underwent condensing and cytoplasm cleavage into uninucleate zoosporangia from 1 to 4 dpi. This was subsequently followed by the formation of multinucleate zoosporangia and the production of secondary zoospores within zoosporangium. Importantly, the secondary zoospores performed a conjugation in the root epidermal cells after their release. TEM revealed extensive uninucleate secondary plasmodium in cortical cells at 8 dpi, indicating the establishment of the secondary infection. The P. brassicae subsequently developed into binucleate, quadrinucleate, and multinucleate secondary plasmodia from 10 to 15 dpi, during which the clubroot symptoms appeared. The uninucleate resting spores were first observed in the cortical cells at 24 dpi, marking the completion of a life cycle. We also provided evidence that the secondary infection of P. brassicae may represent the diploid sexual life stage. From these findings, we propose a refined life cycle of P. brassicae which will contribute to understanding of the complicated infection biology of P. brassicae.


BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Si-Qi Tao ◽  
Bin Cao ◽  
Emmanuelle Morin ◽  
Ying-Mei Liang ◽  
Sébastien Duplessis

Abstract Background Gymnosporangium spp. are fungal plant pathogens causing rust disease and most of them are known to infect two different host plants (heteroecious) with four spore stages (demicyclic). In the present study, we sequenced the transcriptome of G. japonicum teliospores on its host plant Juniperus chinensis and we performed comparison to the transcriptomes of G. yamadae and G. asiaticum at the same life stage, that happens in the same host but on different organs. Results Functional annotation for the three Gymnosporangium species showed the expression of a conserved genetic program with the top abundant cellular categories corresponding to energy, translation and signal transduction processes, indicating that this life stage is particularly active. Moreover, the survey of predicted secretomes in the three Gymnosporangium transcriptomes revealed shared and specific genes encoding carbohydrate active enzymes and secreted proteins of unknown function that could represent candidate pathogenesis effectors. A transcript encoding a hemicellulase of the glycoside hydrolase 26 family, previously identified in other rust fungi, was particularly highly expressed suggesting a general role in rust fungi. The comparison between the transcriptomes of the three Gymnosporangium spp. and selected Pucciniales species in different taxonomical families allowed to identify lineage-specific protein families that may relate to the biology of teliospores in rust fungi. Among clustered gene families, 205, 200 and 152 proteins were specifically identified in G. japonicum, G. yamadae and G. asiaticum, respectively, including candidate effectors expressed in teliospores. Conclusions This comprehensive comparative transcriptomics study of three Gymnosporangium spp. identified gene functions and metabolic pathways particularly expressed in teliospores, a stage of the life cycle that is mostly overlooked in rust fungi. Secreted protein encoding transcripts expressed in teliospores may reveal new candidate effectors related to pathogenesis. Although this spore stage is not involved in host plant infection but in the production of basidiospores infecting plants in the Amygdaloideae, we speculate that candidate effectors may be expressed as early as the teliospore stage for preparing further infection by basidiospores.


Author(s):  
William Rasdorf ◽  
Ali Almalki

This paper is about highway asset deterioration rates. Typically, these are difficult to determine. However, using a data collection method adopted in North Carolina (and the resulting data obtained over a 5-year timespan), an approach was developed to determine accurate deterioration rates for several highway assets. This was not previously done, and thus, deterioration was not included as a factor in estimating future maintenance needs for these assets despite the ready availability of the necessary data. This paper focuses on unpaved shoulders and outlines how their deterioration rates were obtained and how such rates can also be obtained for other assets. The resulting deterioration rates are presented and compared over various road systems and geographical regions. With this new knowledge, deterioration rates can now be included in life cycle asset analysis, resulting in more accurate condition predictions and maintenance budgeting. The paper focuses on highway assets and does not address bridge or pavement maintenance.


2010 ◽  
Vol 92 (1) ◽  
pp. 1-11 ◽  
Author(s):  
HARRI VEHVILÄINEN ◽  
ANTTI KAUSE ◽  
HEIKKI KOSKINEN ◽  
TUIJA PAANANEN

SummarySurvival from birth to a reproductive adult is a challenge that only robust individuals resistant to a variety of mortality factors will overcome. To assess whether survival traits share genetic architecture throughout the life cycle, we estimated genetic correlations for survival within fingerling stage, and across egg, fingerling and grow-out stages in farmed rainbow trout. Genetic parameters of survival at three life cycle stages were estimated for 249 166 individuals originating from ten year classes of a pedigreed population. Despite being an important fitness component, survival traits harboured significant but modest amount of genetic variation (h2=0·07–0·27). Weak associations between survival during egg-fry and fingerling periods, between early and late fingerling periods (rG=0·30) and generally low genetic correlations between fingerling and grow-out survival (mean rG=0·06) suggested that life-stage specific survival traits are best regarded as separate traits. However, in the sub-set of data with detailed time of death records, positive genetic correlations between early and late fingerling survival (rG=0·89) showed that during certain years the best genotypes in the early period were also among the best in the late period. That survival across fingerling period can be genetically the same, trait was indicated also by only slightly higher heritability (h2=0·15) estimated with the survival analysis of time to death during fingerling period compared to the analysis treating fingerling survival as a binary character (h2=0·11). The results imply that (1) inherited resistance against unknown mortality factors exists, but (2) ranking of genotypes changes across life stages.


2016 ◽  
Vol 35 (4) ◽  
pp. 357-366 ◽  
Author(s):  
Joke Anthonissen ◽  
Wim Van den bergh ◽  
Johan Braet

Bituminous pavement can be recycled – even multiple times – by reusing it in new bituminous mixtures. If the mechanical properties of the binder get worse, this reclaimed asphalt is often used in the sub-structure of the road. Apparently, up till now, no end-of-life phase exists for the material. Actually, defining the end-of-life and the end-of-waste stage of a material is important for life cycle assessment modelling. Various standards and scientific studies on modelling life cycle assessment are known, but the crucial stages are not yet defined for reclaimed asphalt pavement. Unlike for iron, steel and aluminium scrap, at this moment, no legislative end-of-waste criteria for aggregates are formulated by the European Commission. More research is necessary in order to develop valuable end-of-life criteria for aggregates. This contribution is a mini-review article of the current regulations, standards and studies concerning end-of-life and end-of-waste of reclaimed asphalt pavement. The existing methodology in order to define end-of-waste criteria, a case study on aggregates and the argumentation used in finished legislative criteria are the basis to clarify some modelling issues for reclaimed asphalt material. Hence, this contribution elucidates the assignment of process environmental impacts to a life cycle stage as defined by EN15804, that is, end-of-life stage (C) and the supplementary information Module D with benefits and loads beyond the system boundary.


2020 ◽  
Author(s):  
José M. Ranz ◽  
Pablo M. González ◽  
Bryan D. Clifton ◽  
Nestor O. Nazario ◽  
Pablo L. Hernández-Cervantes ◽  
...  

ABSTRACTThe monarch butterfly epitomizes insect biodiversity decline. Understanding the genetic basis of the adaptation of the monarch to a changing environment requires genomic and transcriptomic resources that better reflect its genetic diversity while being informative about gene functionality during life cycle. We report a reference-quality genome assembly from an individual resident at a nonmigratory colony in Mexico, and a new gene annotation and expression atlas for 14,865 genes, including 492 unreported long noncoding RNA (lncRNA) genes, based on RNA-seq data from 14 larval and pupal stages, plus adult morphological sections. Two thirds of the genes show significant expression changes associated with a life stage or section, with lncRNAs being more finely regulated during adulthood than protein-coding genes, and male-biased expression being four times more common than female-biased. The two portions of the heterochromosome Z display distinct patterns of differential expression between the sexes, reflecting that dosage compensation is either absent or incomplete –depending on the sample– in the ancestral but not in the novel portion of the Z. This study represents a major advance in the genomic and transcriptome resources available for D. plexippus while providing the first systematic analysis of its transcriptional program across most of its life cycle.


2019 ◽  
Author(s):  
Priscila Karla Ferreira Santos ◽  
Maria Cristina Arias ◽  
Karen M. Kapheim

AbstractDiapause is a physiological arrest of development ahead of adverse environmental conditions and is a critical phase of the life cycle of many insects. In bees, diapause has been reported in species from all seven taxonomic families. However, they exhibit a variety of diapause strategies. These different strategies are of particular interest since shifts in the phase of the insect life cycle in which diapause occurs has been hypothesized to promote the evolution of sociality. Here we provide a comprehensive evaluation of this hypothesis with phylogenetic analysis and ancestral state reconstruction of the ecological and evolutionary factors associated with diapause phase. We find that social lifestyle, latitude, and voltinism are significant predictors of the life stage in which diapause occurs. Ancestral state reconstruction revealed that the most recent common ancestor of all bees likely exhibited developmental diapause and shifts to adult or reproductive diapause have occurred in the ancestors of lineages in which social behavior has evolved. These results provide fresh insight regarding the role of diapause as a prerequisite for the evolution of sociality in bees.


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