scholarly journals Evaluation of linear and nonlinear models for temperature driven development of Spodoptera litura (Fabricius) on soybean crop

2021 ◽  
Vol 23 (2) ◽  
pp. 169-175
Author(s):  
Y.G. PRASAD ◽  
M. GAYATHRI ◽  
V. SAILAJA ◽  
M. PRABHAKAR ◽  
G.RAMACHANDRA RAO ◽  
...  
Keyword(s):  
Spodoptera Litura ◽  
Linear Models ◽  
Nonlinear Models ◽  
Pupal Stage ◽  
Economic Losses ◽  
Temperature Threshold ◽  
Optimum Temperature ◽  
Developmental Threshold ◽  
Threshold Temperatures ◽  
Phenology Model

The tobacco caterpillar, Spodoptera litura, a major pest of soybean in India is under surveillance in all soybean growing areas in Maharashtra in order to issue alerts to farmers and prevent economic losses. In this context, two linear models were fitted to developmental data of S. litura life stages reared on soybean at five constant temperatures viz. 15, 20, 25, 30 and 35°C through laboratory experiments. Optimum temperature for development (Topt) and upper temperature threshold (Tmax) were estimated from three nonlinear models by additionally including developmental response at >35°C. Topt estimates for the total immature development were 34.5°C (Lactin-2), 33.7°C (Briere-1) and 33.2°C (Simplified Beta type function) while Tmax estimates were in the range of 38 to 40°C. Application of a thermodynamic non-linear model (Optim SSI) gave estimate ofintrinsic optimum temperature (Tφ) for development of egg (28.3°C), larva (27.5°C) and pupal stage (30.3°C). The phenology model of S. litura on soybean based on estimated developmental threshold temperatures and thermal constants was validated using available field surveillance data to facilitate informed pest management decisions.

scholarly journals Nonlinear models for describing development and fecundity of the pseudococcid predators Nephus includens and Nephus bisignatus

2017 ◽  
Vol 21 (1) ◽  
pp. 13 ◽  
Author(s):  
Dimitrios Ch. Kontodimas
Keyword(s):  
Mathematical Models ◽  
Goodness Of Fit ◽  
Nonlinear Models ◽  
Planococcus Citri ◽  
Temperature Threshold ◽  
Optimum Temperature ◽  
Biological Features ◽  
Lower Temperature Threshold ◽  
Lower Temperature

Among several mathematical models used to describe the development or the fecundity of insects the equations of Enkegaard, Analytis, Bieri 1 and Bieri 2 could describe both biological features. In the current study these equations used to describe the development and fecundity of two pseudococcid predators [Nephus includens (Kirsch) and Nephus bisignatus (Boheman) (Coleoptera: Coccinellidae)] preying on Planococcus citri (Risso) (Hemiptera: Pseudococcidae) at constant temperatures (15oC - 35oC). All models have goodness of fit to data especially for development [R2 adj, RSS and AIC ranged 0.9908-0.9996, 0.0019-89.1752 (x10-4), and (-75.43) – (-31.07) respectively]. Optimum temperature (Topt) and upper threshold (Tmax) were calculated accurately by all models (Topt ranged 32.6-34.0oC for N. includens and 30.0-30.6oC for N. bisignatus and Tmax ranged 35.0-38.8oC for N. includens and 33.1-36.0oC for N. bisignatus, respectively). Lower temperature threshold (Tmin) was calculated accurately by Bieri-1 model (11.0 and 10.0oC for N. includens and N. bisignatus respectively) whereas Analytis model underestimated it (8.0 and 4.9oC). As far as fecundity is concerned the respective values were better fitted near the optimum temperature (25oC) [R2 adj, RSS and AIC ranged 0.8246-0.9704, 9.2729-24.0736 and (-246.82) – (-115.34) respectively]. Conclusively, from the tested models the Bieri-1 equation was proved as the most appropriate for the reason that could estimate correctly all the requested parameters concerning the development (Tmin, Topt, Tmax) as well as it could describe sufficiently the fecundity trend of the two predators.

scholarly journals Evaluation of non-linear models to describe development and fertility of codling moth at constant temperatures

2017 ◽  
Vol 20 (1) ◽  
pp. 3 ◽  
Author(s):  
H. Ranjbar Aghdam ◽  
Y. Fathipour ◽  
D. C. Kontodimas
Keyword(s):  
Goodness Of Fit ◽  
Linear Models ◽  
Information Criterion ◽  
Developmental Rate ◽  
Codling Moth ◽  
Coefficient Of Determination ◽  
Temperature Threshold ◽  
Optimum Temperature ◽  
Non Linear ◽  
Lower Temperature

Developmental rate of immature stages and age-specific fertility of females of codling moth at constant temperatures was modeled using non-linear models. The equations of Enkegaard, Analytis, and Bieri 1 and 2 were evaluated based on the value of adjusted R2 (R2adj) and Akaike information criterion (AIC) besides coefficient of determination (R2) and residual sum of squares (RSS). All models have goodness of fit to data especially for development [R2, R2adj, RSS and AIC ranged 0.9673-0.9917, 0.8601-0.9861, 0.08-6.7x10-4 and (-75.29) – (-46.26) respectively]. Optimum temperature (Topt) and upper threshold (Tmax) were calculated accurately (Topt and Tmax ranged 29.9-31.2oC and 35.9-36.7oC) by all models. Lower temperature threshold (Tmin) was calculated accurately by Bieri-1 model (9,9-10,8oC) whereas Analytis model (7,0-8,4oC) underestimated it. As far as fertility is concerned the respective values were better fitted near the optimum temperature (in 30oC) [R2 ,R2adj, RSS and AIC ranged 0,6966-0,7744, 0,5756-0,6455, 2,44-3,33 x10-4 and (-9,15)-7,15 respectively].

scholarly journals Temperature dependent development of Phenacoccus solenopsis under laboratory conditions

2017 ◽  
Vol 21 (1) ◽  
pp. 25 ◽  
Author(s):  
Sanjeev Kumar ◽  
Ch. Kontodimas
Keyword(s):  
Nonlinear Models ◽  
Thermal Constant ◽  
Temperature Threshold ◽  
Critical Temperatures ◽  
Phenacoccus Solenopsis ◽  
Developmental Threshold ◽  
Cotton Mealybug ◽  
Lower Temperature Threshold ◽  
Lower Temperature ◽  
The Relationship

Cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is an important cotton pest in Punjab, India. Development of the immature stages (four instars in female and five in male) of P. solenopsis was observed at nine constant temperatures (15, 18, 20, 25, 30, 34, 35, 38, 40°C). Using the linear model, the lower temperature threshold (tmin) for development was estimated to be 4.93 and 2.95°C and the thermal constant (K) was 333.33 and 454.54 degree days for female and male, respectively. In addition, three nonlinear models (Lactin, Bieri-1 and 3rd order polynomial) were tested to describe the relationship between temperature and development rate and to estimate the upper developmental threshold (tmax) and the optimum temperature for development (topt). Our results proved that the Bieri-1 and Lactin models and provided the best fit (r2 = 93,4 – 99,9%) and estimated accurately all the three critical temperatures, ranged tmin = 5.06 – 5.25°C, topt = 33.55 – 33.60°C, tmax = 39.99 – 40.00°C, for the total development of females and tmin = 2.82 – 3.16°C, topt = 34.01 – 34.04°C, tmax =40.00 – 40.10°C, for the total development of males.

scholarly journals Temperature driven development of the rice brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae)

2021 ◽  
Vol 21 (2) ◽  
pp. 131-140
Author(s):  
JHANSILAKSHMI VATTIKUTI ◽  
V. SAILAJA ◽  
Y.G. PRASAD ◽  
P.M.CHIRUTKAR ◽  
G. RAMACHANDRA RAO ◽  
...  
Keyword(s):  
Linear Models ◽  
Brown Planthopper ◽  
Nilaparvata Lugens ◽  
Coefficient Of Determination ◽  
Temperature Threshold ◽  
Life Stages ◽  
Thermal Constants ◽  
Non Linear ◽  
Nilaparvata Lugens Stål ◽  
Phenology Model

Temperature driven development of rice brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) population (biotype 4) was examined at seven constant temperatures (15, 18, 20, 25, 30, 32 and 35°C). Complete development of BPH from egg to adult was observed at constant temperatures ranging from 15 to 32°C with linear development observed till 30°C. Total immaturedevelopmental duration decreased from 74.4 days at 15°C to 22.4 days at 30°C. Linear and non-linear models fitted to describe developmental rates of life stages as a function of temperature, gave estimates of bioclimatic thresholds (lower, optimum and upper temperature thresholds). Thermal constants estimated from Campbell linear model for egg, nymph and cumulative immature development to adult were, 198.8, 275.5 and 473.9 degree days, respectively. Among empirical non-linear models, Lactin 2 model was selected for estimates of upper temperature threshold at 35°C based on higher coefficient of determination. Application of thermodynamic SSI model explained the observed nonlinear relationship of development of BPH life stages at temperatures higher than 30°C. The estimated thermal constants and bioclimatic thresholds were used in developing temperature dependent phenology model based on Campbell equation. Phenology model predicted closely the occurrence of different life stages of BPH with those observed under field conditions. 

Estimating development and temperature thresholds of Ephestia kuehniella: toward improving a mass production system

2018 ◽  
Vol 109 (4) ◽  
pp. 435-442
Author(s):  
H. Pakyari ◽  
M. Amir-Maafi ◽  
Z. Moghadamfar ◽  
M. Zalucki
Keyword(s):  
Linear Models ◽  
Rapid Development ◽  
Ephestia Kuehniella ◽  
Thermal Constant ◽  
Temperature Threshold ◽  
Optimal Temperature ◽  
Thermal Thresholds ◽  
Stage Of Development ◽  
Threshold Temperatures ◽  
Non Linear

AbstractThe development of the Mediterranean flour moth, Ephestia kuehniella (Zeller), was evaluated at 10, 15, 17.5, 20, 22.5, 25, 27.5, 30 and 32.5°C with no lighting. None successfully completed development at 10 and 32.5°C. The total development time from egg to adult emergence was 164, 140, 98, 76, 61, 62 and 50 days, respectively, at the remaining temperatures. The developmental rate of E. kuehniella was described by the common linear model and six non-linear models. The lower temperature threshold for the immature stages and the thermal constant for E. kuehniella were 9°C and 1111 degree-days (DD) to complete development from egg to newly emerged adult. Non-linear models estimated the lower and upper thermal thresholds (Tmin and Tmax) and optimal temperature (Topt). The values of Tmax calculated by three nonlinear models ranged from 34°C to 46°C; Topt for each stage of development varied from 24 and 31°C, consistent with the temperature (30°C) at which the most rapid development occurred. Information on the threshold temperatures for development and thermal requirements can be utilized to predict E. kuehniella population dynamics and phenology and to evaluate optimal temperature conditions for mass rearing in stored products.

scholarly journals Thermal energy requirement for tobacco caterpillar Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) development on artificial diet

2021 ◽  
Vol 23 (2) ◽  
pp. 236-241
Author(s):  
SUBHASH CHANDER ◽  
MAZHAR HUSAIN ◽  
GUNDAPPA BARADEVANAL
Keyword(s):  
Spodoptera Litura ◽  
Artificial Diet ◽  
Energy Requirement ◽  
Adult Emergence ◽  
Thermal Constant ◽  
Optimum Temperature ◽  
Developmental Duration ◽  
Developmental Threshold ◽  
Larval Instars ◽  
Tobacco Caterpillar

Development and survival of tobacco caterpillar Spodoptera litura larvae and pupae were studied at each of seven constant temperatures, 15±1, 18±1, 21±1, 24±1, 27±1, 30±1 and 33±1°C, in incubators. Oviposition, in-cubation, larval and pupal periods were recorded at each of the temperatures. The survival from 1st instar to adult emergence ranged between a maximum of 60% at 24°C and 30% at each of 18°C and 33°C. Developmental duration of different larval instars and pupae declined with an increase in temperature from 15 to 33°C. The optimum temperature for larval and pupal survival in S .litura on artificial diet was observed to be 24°C. On the other hand, optimum temperature range for oviposition was observed to be 27-33°C.The relationship between temperature (T) and development rate (r) was established using linear regression to estimate the thermal constant (K) and development threshold (T0).Thermal constant for 1st to 6th larval instars were computed as 76.9, 90.9, 125, 83.3, 62.5, 90.9 and 200 degree days (DD), respectively, with corresponding development thresholds as 12.8, 11.7, 9.8, 10.3, 10, 10.9 and 13.2oC. Single developmental threshold for larval stage was computed as 13°C.These thermal constants and development thresholds can be used in developing mechanistic population simulation model, which in turn will facilitate the assessment of climate change impact on the pest.

Turbofan Engine Robust H-∞ Dynamical Output Feedback Control Design Based on LMI Method

2005 ◽  
Author(s):  
Xi Wang ◽  
Daoliang Tan ◽  
Tiejun Zheng
Keyword(s):  
Output Feedback ◽  
Linear Models ◽  
Nonlinear Models ◽  
Design Method ◽  
State Space Model ◽  
Output Feedback Control ◽  
Linear Matrix ◽  
Turbofan Engine ◽  
Engine Simulation ◽  
Linear State

This paper presents an approach to turbofan engine dynamical output feedback controller (DOFC) design in the framework of LMI (Linear Matrix Inequality)-based H∞ control. In combination with loop shaping and internal model principle, the linear state space model of a turbofan engine is converted into that of some augmented plant, which is used to establish the LMI formulations of the standard H∞ control problem with respect to this augmented plant. Furthermore, by solving optimal H∞ controller for the augmented plant, we indirectly obtain the H∞ DOFC of turbofan engine which successfully achieves the tracking of reference instructions and effective constraints on control inputs. This design method is applied to the H∞ DOFC design for the linear models of an advanced multivariate turbofan engine. The obtained H∞ DOFC is only in control of the steady state of this turbofan engine. Simulation results from the linear and nonlinear models of this turbofan engine show that the resulting controller has such properties as good tracking performance, strong disturbance rejection, and satisfying robustness.

scholarly journals On the Wave Spectrum Generated by Tropical Heating

2011 ◽  
Vol 68 (9) ◽  
pp. 2042-2060 ◽  
Author(s):  
David A. Ortland ◽  
M. Joan Alexander ◽  
Alison W. Grimsdell
Keyword(s):  
Linear Models ◽  
Nonlinear Models ◽  
Wave Spectrum ◽  
Convective Heating ◽  
Temperature Structure ◽  
Mean Flow ◽  
Quasi Biennial Oscillation ◽  
Wave Response ◽  
Zonal Wavenumber ◽  
The Mean

Abstract Convective heating profiles are computed from one month of rainfall rate and cloud-top height measurements using global Tropical Rainfall Measuring Mission and infrared cloud-top products. Estimates of the tropical wave response to this heating and the mean flow forcing by the waves are calculated using linear and nonlinear models. With a spectral resolution up to zonal wavenumber 80 and frequency up to 4 cpd, the model produces 50%–70% of the zonal wind acceleration required to drive a quasi-biennial oscillation (QBO). The sensitivity of the wave spectrum to the assumed shape of the heating profile, to the mean wind and temperature structure of the tropical troposphere, and to the type of model used is also examined. The redness of the heating spectrum implies that the heating strongly projects onto Hough modes with small equivalent depth. Nonlinear models produce wave flux significantly smaller than linear models due to what appear to be dynamical processes that limit the wave amplitude. Both nonlinearity and mean winds in the lower stratosphere are effective in reducing the Rossby wave response to heating relative to the response in a linear model for a mean state at rest.

Temperature thresholds of shoot elongation in provenances of Pinus contorta

2001 ◽  
Vol 31 (8) ◽  
pp. 1444-1455 ◽  
Author(s):  
Isabelle Chuine ◽  
Sally N Aitken ◽  
Cheng C Ying
Keyword(s):  
Pinus Contorta ◽  
Growth Parameters ◽  
Shoot Elongation ◽  
Total Elongation ◽  
Genotype By Environment Interaction ◽  
Temperature Threshold ◽  
Environment Interaction ◽  
Growth Responses ◽  
Temperature Thresholds ◽  
Threshold Temperatures

Periodicity of shoot elongation in seedlings of Pinus contorta Dougl. ex Loud. was assessed during one growing season in two extremely different environments (Cowichan Lake, and Red Rock, British Columbia) for 109 provenances sampled range wide. Analysis of variance of total elongation and growth parameters showed significant differences among geographic regions and among provenances within each region. Our study also revealed tremendous genotype-by-environment interaction for growth and phenological traits. The response of growth to temperature of each provenance was assessed from their growth curve using an original methodology. The estimated temperature threshold of the provenance growth responses (i.e., the temperature for which the response reaches half of its maximum) varied between 4.1 and 6.5°C among regions. Threshold temperatures showed less variation than total elongation, and only the northern provenances showed thresholds significantly different from the other regions. Our results show that, across highly contrasting environments, relationship between phenology and growth may not be as important as the relationship between growth and number of internode priomordia. This tempers the results of studies, carried out in one or few similar environments, that have shown that phenological differences were important in determining total height growth in lodgepole pine.

scholarly journals Optimal Attack against Autoregressive Models by Manipulating the Environment

2020 ◽  
Vol 34 (04) ◽  
pp. 3545-3552
Author(s):  
Yiding Chen ◽  
Xiaojin Zhu
Keyword(s):  
Predictive Control ◽  
Linear Models ◽  
Nonlinear Models ◽  
Linear Quadratic Regulator ◽  
Black Box ◽  
Combine System ◽  
Linear Quadratic ◽  
Time Series Forecast ◽  
Forecast Models ◽  
Adversarial Attack

We describe an optimal adversarial attack formulation against autoregressive time series forecast using Linear Quadratic Regulator (LQR). In this threat model, the environment evolves according to a dynamical system; an autoregressive model observes the current environment state and predicts its future values; an attacker has the ability to modify the environment state in order to manipulate future autoregressive forecasts. The attacker's goal is to force autoregressive forecasts into tracking a target trajectory while minimizing its attack expenditure. In the white-box setting where the attacker knows the environment and forecast models, we present the optimal attack using LQR for linear models, and Model Predictive Control (MPC) for nonlinear models. In the black-box setting, we combine system identification and MPC. Experiments demonstrate the effectiveness of our attacks.

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