scholarly journals Effect of elevated temperature on the population dynamics of fall armyworm, Spodoptera frugiperda

2021 ◽  
Vol 42 (4(SI)) ◽  
pp. 1098-1105
Author(s):  
K. Ashok ◽  
◽  
V. Balasubramani ◽  
J.S. Kennedy ◽  
V. Geethalakshmi ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Life Table ◽  
Spodoptera Frugiperda ◽  
Elevated Temperatures ◽  
Fall Armyworm ◽  
Developmental Time ◽  
Fecundity Rate ◽  
Temperature Regimes ◽  
Custom Made ◽  
Increasing Temperature

Aim: The present study was conducted to determine the growth, survival, fecundity and mortality rate of Spodoptera frugiperda in maize at elevated temperature. Methodology: Biology and life table experiments were carried out in custom made Open Top Chambers (4m x 4m x 4m size) fitted with SCADA under increasing temperature regimes viz., 32˚C, 33˚C, 34˚C, 35˚C and 36˚C. Each stage of the insects was examined daily and the fertility and life-table parameters were calculated by using TWOSEX-MS chart. Results: The overall developmental time for egg, larva, pupa and adult stages (total lifespan) at different elevated temperatures were in the order of 32˚C > 33˚C > 34˚C > 35˚C > 36˚C. The fecundity rate of S. frugiperda at different elevated temperatures were in the order of 34˚C > 33˚C > 32˚C > 35˚C > 36˚C. Interpretation: The current study confirms that the elevated temperature regimes had a positive correlation with fecundity rate upto 34˚C and negative correlation with the survival rate of S. frugiperda.

Residual Fracture Toughness of Concrete Subject to Elevated Temperatures

2011 ◽  
Vol 488-489 ◽  
pp. 743-746
Author(s):  
Jiang Tao Yu ◽  
Ke Quan Yu ◽  
Zhou Dao Lu
Keyword(s):  
Fracture Toughness ◽  
Experimental Investigation ◽  
Weight Loss ◽  
Elevated Temperature ◽  
Significant Influence ◽  
Elevated Temperatures ◽  
Uniform Size ◽  
Increasing Temperature ◽  
The Relationship ◽  
Wedge Splitting

This paper presents an experimental investigation on the variation of residual fracture toughness of concrete after being exposed to elevated temperatures. A total of 60 specimens, with a uniform size of 200x200x230mm and precast notches of 80mm in height, were heated to constant temperatures of 65°C, 120°C, 200°C, 300°C, 350°C, 400°C, 450°C, 500°C and 600°C respectively. After cooling, standard wedge splitting tests, according to the corresponding Chinese Specification, were employed. The results indicate that the elevated temperature has significant influence on the residual fracture toughness of concrete. The magnitude of fracture toughness decreases drastically with increasing temperature. Additionally the relationship between residual fracture toughness and weight loss of specimens with respect to temperatures is also investigated.

scholarly journals Biostatistics of fall armyworm Spodoptera frugiperda in maize plants in Bogor, West Java, Indonesia

2021 ◽  
Vol 22 (6) ◽  
Author(s):  
WANDA RUSSIANZI ◽  
Ruly Anwar ◽  
HERMANU TRIWIDODO
Keyword(s):  
Life Cycle ◽  
Life Table ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Egg Laying ◽  
Reproduction Rate ◽  
West Java ◽  
Mating Activity ◽  
Male And Female ◽  
Maize Plants

Abstract. Russianzi W, Anwar R, Triwidodo H. 2021. Biostatistics of fall armyworm Spodoptera frugiperda in maize plants in Bogor, West Java, Indonesia. Biodiversitas 22: 3463-3469. Fall Armyworm (FAW) Spodoptera frugiperda (J.E. Smith) is an invasive species that has become important pest of maize in Indonesia since 2019. This research was aimed to study the biology and demographic statistics of FAW in maize at Bogor. Daily observations of 132 FAW individuals from egg to death were carried out as the basis for compiling biology and life table. The demographic statistics of FAW were calculated using the Jackknife approach from the basic life table data. ImagoFAW actives at night. Mating activity occurs between 06.00 pm – 04.00 am, while egg-laying activity occurs between 06.00 pm-10.00 pm. Most hatching occurs between 00.00 am - 02.00 am. FAW has 6 larvae instars and there is no difference in stage between larvae that develop into male and female, which is around 15 days. The male pupae stage was longer than the female pupae, 8.78 ± 0.12 days and 7.81 ± 0.15 days. Male and female imagoes have the same life cycle, which is about 10 days. The life cycle of FAW was 32.26 ± 0.41 days, with a preoviposition period of 2.56 ± 0.45 days. Fecundity of FAW reaches 1012.62 ± 99.12 eggs per female imago. The population of FAW in Bogor has an intrinsic growth rate of 0.154 ± 0.001 individuals/day, with gross reproduction rate of 0.154 ± 0.001 individuals per generation, and net reproduction rate of 104.781 ± 0.155 individuals per imago per generation and a generation time of 30.114 ± 0.002 days.

scholarly journals Performance of Two Trichogrammatid Species from Zambia on Fall Armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 859
Author(s):  
Jia-Wei Sun ◽  
Hong-Ying Hu ◽  
Phillip O. Y. Nkunika ◽  
Peng Dai ◽  
Wei Xu ◽  
...  
Keyword(s):  
Spodoptera Frugiperda ◽  
Morphological Characteristics ◽  
Fall Armyworm ◽  
Developmental Time ◽  
Egg Parasitoid ◽  
Management Approach ◽  
Parasitoid Species ◽  
Test Species ◽  
Trichogrammatoidea Lutea ◽  
Trichogramma Mwanzai

The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a noctuid moth native to the tropical and subtropical Americas that has successfully invaded Africa and Asia, where it is has become a serious threat to food security as a pest of cereals and other crops. Biological control is an environmentally friendly means of combating the pest and contributes to an integrated pest management approach. In our study, two egg parasitoid species (Trichogramma mwanzai and Trichogrammatoidea lutea) found in parasitized fall armyworm eggs in Zambia were identified by using a combination of both molecular and morphological characteristics. To evaluate their potential and efficiency on 0- to 2-day-old fall armyworm eggs, we compared their parasitism capabilities with three Trichogramma species native to China (T. ostriniae, T. leucaniae and T. japonicum) under laboratory conditions. The results showed that both parasitoid species would accept 0-, 1- and 2-day-old fall armyworm eggs, and complete their development successfully. Trichogramma mwanzai and T. lutea preferred parasitizing 0- and 1-day-old eggs over 2-day-old eggs. Trichogrammatoidea lutea females supplied with fall armyworm eggs produced the highest parasitism rate of host eggs among the five tested species, while T. mwanzai had the shortest developmental time on all test age eggs. In general, T. lutea was the best performing of the five species when reared on fall armyworm eggs, while T. japonicum was the worst. There were no significant differences, however, in percent emergence in the five test species when reared on fall armyworm eggs.

scholarly journals Effect of Elevated Ambient Temperature on Simulator-Derived Oscillometric Blood Pressure Measurement

2020 ◽  
Author(s):  
Jennifer S Ringrose ◽  
Michael D Kennedy ◽  
Jalisa Kassam ◽  
Omar Mouhammed ◽  
Sangita Sridar ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Elevated Temperature ◽  
Ambient Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Blood Pressure Measurement ◽  
Ambient Temperatures ◽  
Oscillometric Blood Pressure Measurement ◽  
Increasing Temperature ◽  
Relative Differences

Abstract BACKGROUND Oscillometric blood pressure (BP) devices are typically labeled for use up to 40 °C. Many geographic regions have ambient temperatures exceeding 40 °C. We assessed the effect of increased ambient temperature (40–55 °C) on simulator-derived oscillometric BP measurement. METHODS Three Omron BP769CAN devices, 3 A&D Medical UA-651BLE devices, and accompanying cuffs were used. A custom heat chamber heated each device to the specified temperature. A noninvasive BP simulator was used to take 3 measurements with each device at differing temperatures (22, 40, 45, 50, and 55 °C) and BP thresholds: 80/50, 100/60, 120/80, 140/90, 160/110, and 180/130 mm Hg. Using each device as its own control (22 °C), we determined the relative differences in mean BP for each device at each temperature and BP setting, assessed graphical trends with increasing temperature, and examined variability. RESULTS Graphical trends of mean simulator-subtracted BP differences from room temperature showed no discernable pattern, with differences clustered around zero. Overall mean difference in BP (combined elevated temperatures minus room temperature) was −0.8 ± 2.1 (systolic ± SD)/1.2 ± 3.5 (diastolic ± SD) mm Hg for the A&D device and 0.2 ± 0.4 (systolic ± SD)/−0.1 ± 0.1 (diastolic ± SD) mm Hg for the Omron. All individual elevated temperature differences (elevated temperature minus room temperature) except A&D diastolic BP at 50 °C were within 5 mm Hg. CONCLUSIONS In this simulator-based study assessing within-device differences, higher ambient temperatures resulted in oscillometric BP measurements that were comparable to those performed at room temperature.

Assessing fitness costs of the resistance of Spodoptera frugiperda (Lepidoptera: Noctuidae) to pyramided Cry1 and Cry2 insecticidal proteins on different host plants

2022 ◽  
pp. 1-9
Author(s):  
Cínthia G. Garlet ◽  
Dionei S. Muraro ◽  
Daniela N. Godoy ◽  
Gisele E. Cossa ◽  
Manoela R. Hanich ◽  
...  
Keyword(s):  
Spodoptera Frugiperda ◽  
High Capacity ◽  
Fall Armyworm ◽  
Developmental Time ◽  
Adult Survival ◽  
Bt Cotton ◽  
Fitness Costs ◽  
Bt Maize ◽  
Insecticidal Proteins ◽  
Resistant Genotypes

Abstract Fall armyworm (FAW), Spodoptera frugiperda (Smith), is one of the major pests targeted by transgenic crops expressing insecticidal proteins from Bacillus thuringiensis (Bt) Berliner. However, FAW presents a high capacity to develop resistance to Bt protein-expressing crop lines, as reported in Brazil, Argentina, Puerto Rico and the southeastern U.S. Here, FAW genotypes resistant to pyramided maize events expressing Cry1F/Cry1A.105/Cry2Ab2 (P-R genotype) and Cry1A.105/Cry2Ab2 (Y-R genotype) from Brazil were used to investigate the interactions between non-Bt hosts (non-Bt maize, non-Bt cotton, millet and sorghum) and fitness costs. We also tested a FAW genotype susceptible to Bt maize and F1 hybrids of the resistant and susceptible genotypes (heterozygotes). Recessive fitness costs (i.e., costs affecting the resistant insects) were observed for pupal and neonate to adult survival of the P-R genotype on non-Bt cotton; larval developmental time of the P-R genotype on millet and sorghum; larval and neonate-to-adult developmental time of the Y-R genotype on non-Bt cotton and sorghum; the fecundity of the Y-R genotype on non-Bt cotton; and mean generation time of both resistant genotypes. However, on non-Bt cotton and non-Bt maize, the P-R genotype had a higher fitness (i.e., fitness benefits), displaying greater fecundity and rates of population increases than the Sus genotype. Non-recessive fitness costs (i.e., costs affecting heterozygotes) were found for fecundity and population increases on millet and sorghum. These findings suggest that, regardless of the disadvantages of the resistant genotypes in some hosts, the resistance of FAW to Cry1 and Cry2 Bt proteins is not linked with substantial fitness costs, and may persist in field conditions once present.

Elevated Temperature Fatigue Life Investigation of Aluminium Alloy based on the Predicted S-N Curve

2013 ◽  
Vol 63 (1) ◽  
Author(s):  
K. A. Zakaria ◽  
S. Abdullah ◽  
M. J. Ghazali
Keyword(s):  
Fatigue Life ◽  
Elevated Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Fatigue Tests ◽  
Maximum Temperature ◽  
Stress Control ◽  
Temperature Regimes ◽  
Engine Mount ◽  
Load Sequence

This paper discusses a methodology used to predict the stress-life (S-N) curve at elevated temperatures based on the normal S-N curve. Fatigue tests were performed under stress control at room temperature in accordance with the ASTM E466 standard to obtain a normal S-N curve. In addition, the tests were performed at both room and elevated temperatures using constant-amplitude, high-to-low sequence, and low-to-high sequence loadings to investigate the effect of the load sequence at elevated temperatures on fatigue life. Three elevated temperature regimes at 70 to 250°C were chosen based on the maximum temperature of the engine mount bracket and the cylinder head that can be reached during normal service. The results show that the fatigue lives were significantly affected by the load sequences at both room and elevated temperatures. Furthermore, the existing fatigue data obtained at elevated temperatures can be used to predict the corresponding S-N curves. 

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