scholarly journals Rearing technique and demographic parameters of Tetrastichus giffardianus Silvestre (Hymenoptera: Eulophidae)

2019 ◽  
Vol 40 (5Supl1) ◽  
pp. 2201 ◽  
Author(s):  
Elania Clementino Fernandes ◽  
Mariana Macêdo Souza ◽  
Maria Itala Alves Souza ◽  
Antonio Gabriel Nunes Felipe ◽  
Elton Lucio Araujo
Keyword(s):  
Ceratitis Capitata ◽  
Intrinsic Rate ◽  
Population Increase ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Demographic Parameters ◽  
Laboratory Conditions ◽  
Arid Conditions ◽  
Brazilian Semiarid ◽  
Rearing Methods

Tetrastichus giffardianus Silvestri (Hymenoptera: Eulophidae) is a gregarious koinobiont endoparasitoid of frugivorous dipterans. In recent years, T. giffardianus has been detected parasitizing Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in different Brazilian semiarid sites. Thus, T. giffardianus has potential to be used in the biological control of C. capitata in semi-arid conditions. However, one of the factors limiting the use of this parasitoid is the lack of detailed information on rearing methods and bioecological aspects. Therefore, the main objectives of this study were to demonstrate a rearing technique for T. giffardianus and to determine the increase in population under laboratory conditions. Specimens of T. giffardianus were obtained in the field through of the collection of fruits infested with C. capitata. The specimens obtained were used to adapt a rearing methodology for T. giffardianus under laboratory conditions. Information on demographic parameters for a T. giffardianus population was obtained using the same methodology. Based on the parameters evaluated, we found that the intrinsic rate of population increase of T. giffardianus was 0.34, the average time of one generation was 19.7 days, the population doubling time was 2.03 days and the finite rate of population increase (?) was 1.41. The demographic parameters obtained demonstrated that, with the rearing technique used, it is possible to maintain populations of T. giffardianus and enable them to multiply under laboratory conditions.

Fertility life table and biology of Tetrastichus giffardianus (Hymenoptera: Eulophidae) in the larvae of Ceratitis capitata (Diptera: Tephritidae)

2020 ◽  
pp. 1-8
Author(s):  
Elania Clementino Fernandes ◽  
Mariana Macedo Souza ◽  
Dori Edson Nava ◽  
Janisete Gomes Silva ◽  
Elton Lucio Araujo
Keyword(s):  
Life Table ◽  
Ceratitis Capitata ◽  
Intrinsic Rate ◽  
Mass Rearing ◽  
Population Increase ◽  
Intrinsic Rate Of Increase ◽  
Rate Of Increase ◽  
Males And Females ◽  
The Mean ◽  
Time Required

Abstract Tetrastichus giffardianus is a gregarious koinobiont endoparasitoid of tephritids, including Ceratitis capitata, which is one of the most important fruit pests worldwide. The objective of this study was to evaluate the effect of constant temperatures on the biology and development of the egg-adult period of T. giffardianus in larvae/pupae of C. capitata to construct a fertility life table. The study was carried out in climatic chambers at constant temperatures of 15, 20, 25, 30, and 35 ± 1°C, 70 ± 10% relative humidity and a photophase of 12 h. Complete egg and larval development occurred only at temperatures of 20, 25, and 30°C. The mean longevity of males and females was inversely proportional to temperature. The time of development of the pre-imaginal period was influenced by temperature and ranged from 41 days at 20°C to 11 days at 25°C. The best T. giffardianus performance occurred at 25°C when the intrinsic rate of increase was 0.21, the mean generation time was 20.43 days, the time required to double the population was 3.33 days, and the finite rate of population increase (λ) was 1.23. The results of this study provided information for the establishment of mass rearing and an evaluation of the adaptability of T. giffardianus to different environments, which is necessary for the use of this parasitoid in the biological control of tephritid pests, particularly C. capitata.

Developmental and reproductive biology of Scirtothrips perseae (Thysanoptera: Thripidae): a new avocado pest in California

2002 ◽  
Vol 92 (4) ◽  
pp. 279-285 ◽  
Author(s):  
M.S. Hoddle
Keyword(s):  
Reproductive Biology ◽  
Adult Development ◽  
Intrinsic Rate ◽  
Population Doubling ◽  
Intrinsic Rate Of Increase ◽  
Adult Longevity ◽  
Average Lifetime ◽  
Population Doubling Time ◽  
Developmental Threshold ◽  
Rate Of Increase

AbstractThe developmental and reproductive biology of a new avocado pest, Scirtothrips perseae Nakahara, was determined in the laboratory at five constant temperatures, 15, 20, 25, 27.5 and 30°C. At 20°C, S. perseae exhibited greatest larval to adult survivorship (41%), and mated females produced a greater proportion of female offspring at this temperature when compared to 15, 25, 27.5 and 30°C. Average lifetime fecundity and preoviposition period was greatest at 15°C at 39.6 eggs per female and 17.6 days, respectively. Jackknifed estimates of net reproduction (Ro), capacity for increase (rc), intrinsic rate of increase (rm), and finite rate of increase (λ) were all significantly greater at 20°C than corresponding values at 15, 25 and 27.5°C. Population doubling time (Td) was significantly lower at 20°C, indicating S. perseae populations can double 33–71% faster at this temperature in comparison to 15, 25 and 27.5°C. Mean adult longevity decreased with increasing temperature, from a maximum of 52.4 days at 15°C to a minimum of 2.4 days at 30°C. Developmental rates increased linearly with increasing temperatures for eggs and rates were non-linear for development of first and second instar larvae, propupae, pupae, and for egg to adult development. Linear regression and fitting of the modified Logan model to developmental rate data for egg to adult development estimated that 344.8 day degrees were required above a minimum threshold of 6.9°C to complete development. An upper developmental threshold was estimated at 37.6°C with an optimal temperature of 30.5°C for egg to adult development. Unmated females produced only male offspring confirming arrhenotoky in S. perseae.

scholarly journals Reproduction, longevity and life table parameters of Monosteira unicostata (Hemiptera: Tingidae) at constant temperatures

2018 ◽  
Vol 15 (4) ◽  
pp. e1012 ◽  
Author(s):  
Ismael Sánchez-Ramos ◽  
Susana Pascual ◽  
Cristina E. Fernández ◽  
Manuel González-Núñez
Keyword(s):  
Mediterranean Basin ◽  
Natural Increase ◽  
Population Increase ◽  
Effect Of Temperature ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Mortality Pattern ◽  
Lace Bug ◽  
The Mediterranean ◽  
The Mediterranean Basin

Information on the effect of temperature on biological parameters of phytophagous insects is one of the tools in IPM programs, as it allows prediction of risk situations in the field. This work reports the effect of temperature on reproductive parameters and longevity of one of the most important current pests of almond orchards in the Mediterranean basin, the poplar lace bug, Monosteira unicostata (Mulsant & Rey) (Hemiptera: Tingidae). The temperatures tested were 22, 25, 28, 31, 34 and 37ºC, always at 60 ± 10% relative humidity and under a L16:D8 photoperiod. Extreme temperatures had an adverse effect on preoviposition period, total fecundity and daily fecundity while increasing values of oviposition period and adults longevity were registered for decreasing temperatures. Male longevity was higher than female longevity, and mortality pattern differed between sexes for all temperatures but 37ºC. The nonlinear Lactin model described accurately the effect of temperature on the intrinsic rate of natural increase of M. unicostata populations and predicted the optimum temperature for population increase at 34.1ºC, at which the population doubling time is 3.6 days. Produced values of lower and upper thresholds for M. unicostata populations were 14.8 and 38.8ºC, respectively. This characterizes the poplar lace bug as a very important pest in the Mediterranean basin, with an increasing potential risk in a global warming scenario.

Plant Resistance in Some Modern Soybean Varieties May Favor Population Growth and Modify the Stylet Penetration of Bemisia tabaci (Hemiptera: Aleyrodidae)

2021 ◽  
Author(s):  
Mauricélia F Almeida ◽  
Clébson S Tavares ◽  
Euires O Araújo ◽  
Marcelo C Picanço ◽  
Eugênio E Oliveira ◽  
...  
Keyword(s):  
Population Growth ◽  
Bemisia Tabaci ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Genetically Engineered ◽  
Population Increase ◽  
Net Reproductive Rate ◽  
Bt Toxin ◽  
Demographic Performance

Abstract Complaints of severe damage by whiteflies in soybean fields containing genetically engineered (GE) varieties led us to investigate the role of transgenic soybean varieties expressing resistance to some insects (Cry1Ac Bt toxin) and to herbicide (glyphosate) on the population growth and feeding behavior of Bemisia tabaci (Gennadius) MEAM1 (Hemiptera: Aleyrodidae). In the laboratory, the whiteflies reared on the GE Bt soybeans had a net reproductive rate (R0) 100% higher and intrinsic rate of population increase (rm) 15% higher than those reared on non-GE soybeans. The increased demographic performance was associated with a higher lifetime fecundity. In electrical penetration graphs, the whiteflies reared on the GE soybeans had fewer probes and spent 50% less time before reaching the phloem phase from the beginning of the first successful probe, indicating a higher risk of transmission of whitefly-borne viruses. Data from Neotropical fields showed a higher population density of B. tabaci on two soybean varieties expressing glyphosate resistance and Cry1Ac Bt toxin. These results indicate that some GE soybean varieties expressing insect and herbicide resistances can be more susceptible to whiteflies than non-GE ones or those only expressing herbicide resistance. Most likely, these differences are related to varietal features that increase host-plant susceptibility to whiteflies. Appropriate pest management may be needed to deal with whiteflies in soybean fields, especially in warm regions, and breeders may want to consider the issue when developing new soybean varieties.

scholarly journals Expansion and characterization of bone marrow derived human mesenchymal stromal cells in serum-free conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samatha Bhat ◽  
Pachaiyappan Viswanathan ◽  
Shashank Chandanala ◽  
S. Jyothi Prasanna ◽  
Raviraja N. Seetharam
Keyword(s):  
Bone Marrow ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Population Doubling ◽  
Seeding Density ◽  
Population Doubling Time ◽  
Differentiation Potential ◽  
Serum Free ◽  
Safety Issues ◽  
Free Media

AbstractBone marrow-derived mesenchymal stromal cells (BM-MSCs) are gaining increasing importance in the field of regenerative medicine. Although therapeutic value of MSCs is now being established through many clinical trials, issues have been raised regarding their expansion as per regulatory guidelines. Fetal bovine serum usage in cell therapy poses difficulties due to its less-defined, highly variable composition and safety issues. Hence, there is a need for transition from serum-based to serum-free media (SFM). Since SFM are cell type-specific, a precise analysis of the properties of MSCs cultured in SFM is required to determine the most suitable one. Six different commercially available low serum/SFM with two different seeding densities were evaluated to explore their ability to support the growth and expansion of BM-MSCs and assess the characteristics of BM-MSCs cultured in these media. Except for one of the SFM, all other media tested supported the growth of BM-MSCs at a low seeding density. No significant differences were observed in the expression of MSC specific markers among the various media tested. In contrary, the population doubling time, cell yield, potency, colony-forming ability, differentiation potential, and immunosuppressive properties of MSCs varied with one another. We show that SFM tested supports the growth and expansion of BM-MSCs even at low seeding density and may serve as possible replacement for animal-derived serum.

scholarly journals Effect of Inflammation on Gingival Mesenchymal Stem/Progenitor Cells’ Proliferation and Migration through Microperforated Membranes: An In Vitro Study

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
M. Al Bahrawy ◽  
K. Ghaffar ◽  
A. Gamal ◽  
K. El-Sayed ◽  
V. Iacono
Keyword(s):  
Pore Size ◽  
Progenitor Cells ◽  
Cellular Migration ◽  
Gingival Tissue ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Electron Microscopic ◽  
Healthy Human ◽  
Membrane Pores ◽  
Scanning Electron

Background. In the field of periodontal guided tissue regeneration, microperforated membranes have recently proved to be very promising periodontal regenerative tissue engineering tools. Regenerative periodontal approaches, employing gingival mesenchymal stem/progenitor cells in combination with these novel membranes, would occur mostly in inflamed microenvironmental conditions intraorally. This in turn entails the investigation into how inflammation would affect the proliferation as well as the migration dynamics of gingival mesenchymal stem/progenitor cells. Materials and Methods. Clones of human gingival mesenchymal stem/progenitor cells (GMSCs) from inflamed gingival tissues were characterized for stem/progenitor cells’ characteristics and compared to clones of healthy human GMSCs (n=3), to be subsequently seeded on perforated collagen-coated poly-tetra-floro-ethylene (PTFE) membranes with a pore size 0.4 and 3 microns and polycarbonic acid membranes of 8 microns pore size in Transwell systems. The population doubling time and the MTT test of both populations were determined. Fetal bovine serum (FBS) was used as a chemoattractant in the culturing systems, and both groups were compared to their negative controls without FBS. Following 24 hours of incubation period, migrating cells were determined on the undersurface of microperforated membranes and the membrane-seeded cells were examined by scanning electron microscopy. Results. GMSCs demonstrated all predefined stem/progenitor cell characteristics. GMSCs from inflamed gingival tissues showed significantly shorter population doubling times. GMSCs of inflamed and healthy tissues did not show significant differences in their migration abilities towards the chemoattractant, with no cellular migration observed in the absence of FBS. GMSCs from healthy gingival tissue migrated significantly better through larger micropores (8 microns). Scanning electron microscopic images proved the migratory activity of the cells through the membrane pores. Conclusions. Inflammation appears to boost the proliferative abilities of GMSCs. In terms of migration through membrane pores, GMSCs from healthy as well as inflamed gingival tissues do not demonstrate a difference in their migration abilities through smaller pore sizes, whereas GMSCs from healthy gingival tissues appear to migrate significantly better through larger micropores.

Characterization of a newly established uterine carcinosarcoma cell line featuring the sarcomatous phenotype of the tumor in vitro

2008 ◽  
Vol 18 (2) ◽  
pp. 339-344 ◽  
Author(s):  
H.-J. Schulten ◽  
J. Wolf-Salgó ◽  
C. Gründker ◽  
B. Gunawan ◽  
L. FÜZESI
Keyword(s):  
Cell Line ◽  
Hormone Receptors ◽  
Tumor Biology ◽  
Growth Factor Receptor ◽  
Population Doubling ◽  
Established Cell Line ◽  
Population Doubling Time ◽  
Uterine Carcinosarcoma ◽  
Specific Staining

We describe the newly established cell line CS-99 derived from a uterine carcinosarcoma retaining features of the sarcomatous phenotype in vitro. CS-99 cells exhibit a mesenchymal morphology with predominantly spindle-shaped cells at nonconfluence turning to pleomorphic appearance at confluence. The mesenchymal phenotype was evidenced immunohistochemically by strong vimentin and moderate SM-actin, which was similar to the sarcomatous component of the primary tumor. P53 was overexpressed in a subset of CS-99 cells. Epithelial membrane antigen was moderately expressed whereas other markers including pan CK, CK 5/6, CK 34, epidermal growth factor receptor, desmin, carcinoembryonic antigen, S100, KIT, ERBB2, and the hormone receptors, estrogen receptor and progesterone receptor revealed either weak or no specific staining in CS-99 cells. High self-renewal capacity corresponded to the population doubling time of 23 h in high passage. CS-99 cells were able to develop three-dimensional tumor spheroids in vitro. Cytogenetic analysis and multicolor fluorescence in situ hybridization of CS-99 demonstrated an almost stable karyotype including numerical changes +8, +18, and +20 and translocations, amongst others der(1)t(1;2), der(1)t(1;7), der(2)t(2;19), der(5)t(5;8), and der(5)t(5;14). Taken together, the cell line CS-99 exhibits strong growths dynamics and a complex but stable karyotype in higher passages, and can be further a useful in vitro model system for studying tumor biology of carcinosarcomas.

Influence of temperature on life history traits of the free-living, bacterial-feeding nematode Panagrolaimus sp. strain NFS-24

Nematology ◽  
2013 ◽  
Vol 15 (8) ◽  
pp. 939-946 ◽  
Author(s):  
Farhana Ayub ◽  
Olaf Strauch ◽  
Laurent Seychelles ◽  
Ralf-Udo Ehlers
Keyword(s):  
Intrinsic Rate ◽  
Analysis Data ◽  
Natural Increase ◽  
Population Doubling ◽  
Food Density ◽  
Hanging Drop ◽  
Free Living ◽  
Single Male ◽  
Different Temperatures ◽  
Hanging Drop Method

Life cycle analysis data of the free-living, bacterial-feeding Panagrolaimus sp. strain NFS 24-5 were assessed at different temperatures using a hanging drop method with single male and female individuals and a food density of 3 × 109 Escherichia coli cells ml−1. Lifespan at the moment when the first egg was laid was 5.7 days at 21°C and 4 days at 25, 27 and 29°C. The intrinsic rate of natural increase () was 0.53 at 21°C, 0.81 at 25°C, 0.93 at 27°C and 0.81 at 29°C, corresponding to population doubling times () of 1.3, 0.9, 0.7 and 0.9 days, respectively. Over 200 offspring per female were produced at 27°C. All other temperatures yielded fewer offspring. When females were kept without males, the life span was 49 days, whereas the last reproductive female (hanging drop with male individual) died after 16.5 days. These data will contribute to the interpretation of nematode population dynamics recorded in liquid culture.

scholarly journals Sulodexide reduces glucose induced senescence in human retinal endothelial cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Gericke ◽  
K. Suminska-Jasińska ◽  
A. Bręborowicz
Keyword(s):  
Endothelial Cells ◽  
High Glucose ◽  
Glucose Concentration ◽  
Chronic Exposure ◽  
Replicative Senescence ◽  
Population Doubling ◽  
Population Doubling Time ◽  
High Glucose Concentration ◽  
Retinal Endothelial Cells

AbstractChronic exposure of retinal endothelium cells to hyperglycemia is the leading cause of diabetic retinopathy. We evaluated the effect of high glucose concentration on senescence in human retinal endothelial cells (HREC) and modulation of that effect by Sulodexide. Experiments were performed on HREC undergoing in vitro replicative senescence in standard medium or medium supplemented with glucose 20 mmol/L (GLU) or mannitol 20 mnol/L (MAN). Effect of Sulodexide 0.5 LRU/mL (SUL) on the process of HREC senescence was studied. Glucose 20 mmol/L accelerates senescence of HREC: population doubling time (+ 58%, p < 0.001) β-galactosidase activity (+ 60%, p < 0.002) intracellular oxidative stress (+ 65%, p < 0.01), expression of p53 gene (+ 118%, p < 0.001). Senescent HREC had also reduced transendothelial electrical resistance (TEER) (− 30%, p < 0.001). Mannitol 20 mmol/L used in the same scenario as glucose did not induce HREC senescence. In HREC exposed to GLU and SUL, the senescent changes were smaller. HREC, which became senescent in the presence of GLU, demonstrated higher expression of genes regulating the synthesis of Il6 and VEGF-A, which was reflected by increased secretion of these cytokines (IL6 + 125%, p < 0.001 vs control and VEGF-A + 124% p < 0.001 vs control). These effects were smaller in the presence of SUL, and additionally, an increase of TEER in the senescent HREC was observed. Chronic exposure of HREC to high glucose concentration in medium accelerates their senescence, and that process is reduced when the cells are simultaneously exposed to Sulodexide. Additionally, Sulodexide decreases the secretion of IL6 and VEGF-A from senescent HREC and increases their TEER.

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