scholarly journals A Model for Pest Control using Integrated Approach: Impact of Latent and Gestation Delays

Author(s):  
M. H. Noor ◽  
Fahad Al Basir

Abstract In this article, we have established a mathematical model using impulsive differential equations for the dynamics of crop pest management in the presence of a pest with its predator and bio-pesticides. The pest population is divided into two subpopulations, namely, the susceptible pests and the infected pests. In this control process, bio-pesticides (generally virus) infect the susceptible pest through viral infection within the pest and make it infected so that predators can consume it quickly. We assume that pest controlling, using this integrated approach, is a delayed process and thus incorporated latent time of susceptible pest and gestation delay of predator in the model as time delay parameters. The system dynamics have been analyzed using qualitative theory: the existence of the equilibrium points and their stability properties has been derived. Hopf bifurcation of the coexisting equilibrium point is presented for both the delayed and non-delayed system. Detail numerical simulations are performed in support of analytical results and illustrate the different dynamical regimes observed in the system. We have observed that the system becomes free of infection when the latent time of the pest is large. Coexisting equilibrium exists for the lower value of latent delay, and it can change the stability properties from stable to unstable when it crosses its critical value. In contrast, gestation delay affects the stability switches of coexisting equilibrium only. The combined effect of the two delays on the system is shown numerically. Also, viral replication rate, infection rate (from virus to pest) is also significant from the pest management perspective. In summary, both the delay is essential for crop pest management, and pest control will be successful with tolerable delays.

Weed Science ◽  
1982 ◽  
Vol 30 (S1) ◽  
pp. 46-47
Author(s):  
Donald Penner

Integrated Pest Management (IPM) has been defined as an interdisciplinary science (3). IPM has become popular this past decade; however, integrated pest management has been practiced by farmers and growers for decades. As nonfarming agricultural professionals become more specialized they tend to become “reductionists” or ever-narrower in their perspective base. From this evolution into disciplines has arisen the necessity to redirect thought and effort to addressing the total or whole such as is commonly done by the farmer or grower. IPM has been considered an effort in this direction, although unanimity in definition of IPM has been notably absent. Some have considered it synonymous with integrated pest control; in contrast, others have viewed it as a means to reduce the use of pesticides. Nevertheless, IPM has received considerable attention in the pest-related disciplines. Its implementation has been addressed in Presidential messages to Congress in 1977 and 1979 (7, 8).


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254193
Author(s):  
Carlos Balsa ◽  
Albino Bento ◽  
Francesco Paparella

In recent years, the Asian gall wasp Dryocosmus kuriphilus has invaded chestnut trees and significantly affected the Portuguese chestnut production. Studies in other countries, such as Japan or Italy, have shown that the parasitoid Torymus sinensis can successfully achieve biological control of D. kuriphilus. Mathematical models help us to understand the dynamics of the interaction between the pest D. kuriphilus and its parasitoid T. sinensis and, consequently, they can help to implement measures that enhance crop pest management. In this work, the evolution of the density of D. kuriphilus and T. sinensis across time and space is studied through the numerical solution of models that include parameters based on observations made in Portugal. Simultaneous releases of the parasitoid are simulated at various locations and at different times. The results indicate that, in the case of a small and homogeneous orchard, biological control can be effective, but, in the case of extensive domains, the pest control is much more difficult to achieve. In order for biological control to be efficient, it is necessary to implement, in each chestnut-producing region, a collective strategy based on the annual monitoring of infestation levels.


2018 ◽  
Vol 26 (02) ◽  
pp. 339-372 ◽  
Author(s):  
D. PAL ◽  
G. S. MAHAPATRA ◽  
G. P. SAMANTA

In this work, a fuzzy prey–predator system with time delay is proposed. The model consists of two preys and one predator. The biological coefficients/parameters are considered as imprecise in nature and quantified by triangular fuzzy numbers. We have studied the effect of gestation delay on the stability of the system in fuzzy environment. The signed distance method for the defuzzification of the proposed fuzzy prey–predator system is adopted. For the underlying fuzzy model, we have provided a solution procedure to find all possible equilibrium points and studied their stabilities in the fuzzy sense. It is observed that there are stability switches, and Hopf-bifurcation occurs when the delay crosses some critical value in fuzzy sense. Numerical illustrations are provided in crisp as well as fuzzy environment with the help of graphical presentations to support our proposed approach.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
A. Farajzadeh ◽  
M. H. Rahmani Doust ◽  
F. Haghighifar ◽  
D. Baleanu

The study of the dynamics of predator-prey interactions can be recognized as a major issue in mathematical biology. In the present paper, some Gauss predator-prey models in which three ecologically interacting species have been considered and the behavior of their solutions in the stability aspect have been investigated. The main aim of this paper is to consider the local and global stability properties of the equilibrium points for represented systems. Finally, stability of some examples of Gauss model with one prey and two predators is discussed.


2020 ◽  
Vol 117 (32) ◽  
pp. 19245-19253 ◽  
Author(s):  
Soumyadip Sahu ◽  
Zhenzhen Wang ◽  
Xinfu Jiao ◽  
Chunfang Gu ◽  
Nikolaus Jork ◽  
...  

Regulation of enzymatic 5′ decapping of messenger RNA (mRNA), which normally commits transcripts to their destruction, has the capacity to dynamically reshape the transcriptome. For example, protection from 5′ decapping promotes accumulation of mRNAs into processing (P) bodies—membraneless, biomolecular condensates. Such compartmentalization of mRNAs temporarily removes them from the translatable pool; these repressed transcripts are stabilized and stored until P-body dissolution permits transcript reentry into the cytosol. Here, we describe regulation of mRNA stability and P-body dynamics by the inositol pyrophosphate signaling molecule 5-InsP7(5-diphosphoinositol pentakisphosphate). First, we demonstrate 5-InsP7inhibits decapping by recombinant NUDT3 (Nudix [nucleoside diphosphate linked moiety X]-type hydrolase 3) in vitro. Next, in intact HEK293 and HCT116 cells, we monitored the stability of a cadre of NUDT3 mRNA substrates following CRISPR-Cas9 knockout ofPPIP5Ks(diphosphoinositol pentakisphosphate 5-kinases type 1 and 2, i.e.,PPIP5KKO), which elevates cellular 5-InsP7levels by two- to threefold (i.e., within the physiological rheostatic range). ThePPIP5KKO cells exhibited elevated levels of NUDT3 mRNA substrates and increased P-body abundance. Pharmacological and genetic attenuation of 5-InsP7synthesis in the KO background reverted both NUDT3 mRNA substrate levels and P-body counts to those of wild-type cells. Furthermore, liposomal delivery of a metabolically resistant 5-InsP7analog into wild-type cells elevated levels of NUDT3 mRNA substrates and raised P-body abundance. In the context that cellular 5-InsP7levels normally fluctuate in response to changes in the bioenergetic environment, regulation of mRNA structure by this inositol pyrophosphate represents an epitranscriptomic control process. The associated impact on P-body dynamics has relevance to regulation of stem cell differentiation, stress responses, and, potentially, amelioration of neurodegenerative diseases and aging.


Meccanica ◽  
2021 ◽  
Author(s):  
Dóra Patkó ◽  
Ambrus Zelei

AbstractFor both non-redundant and redundant systems, the inverse kinematics (IK) calculation is a fundamental step in the control algorithm of fully actuated serial manipulators. The tool-center-point (TCP) position is given and the joint coordinates are determined by the IK. Depending on the task, robotic manipulators can be kinematically redundant. That is when the desired task possesses lower dimensions than the degrees-of-freedom of a redundant manipulator. The IK calculation can be implemented numerically in several alternative ways not only in case of the redundant but also in the non-redundant case. We study the stability properties and the feasibility of a tracking error feedback and a direct tracking error elimination approach of the numerical implementation of IK calculation both on velocity and acceleration levels. The feedback approach expresses the joint position increment stepwise based on the local velocity or acceleration of the desired TCP trajectory and linear feedback terms. In the direct error elimination concept, the increment of the joint position is directly given by the approximate error between the desired and the realized TCP position, by assuming constant TCP velocity or acceleration. We investigate the possibility of the implementation of the direct method on acceleration level. The investigated IK methods are unified in a framework that utilizes the idea of the auxiliary input. Our closed form results and numerical case study examples show the stability properties, benefits and disadvantages of the assessed IK implementations.


2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Changtong Li ◽  
Sanyi Tang ◽  
Robert A. Cheke

Abstract An expectation for optimal integrated pest management is that the instantaneous numbers of natural enemies released should depend on the densities of both pest and natural enemy in the field. For this, a generalised predator–prey model with nonlinear impulsive control tactics is proposed and its dynamics is investigated. The threshold conditions for the global stability of the pest-free periodic solution are obtained based on the Floquet theorem and analytic methods. Also, the sufficient conditions for permanence are given. Additionally, the problem of finding a nontrivial periodic solution is confirmed by showing the existence of a nontrivial fixed point of the model’s stroboscopic map determined by a time snapshot equal to the common impulsive period. In order to address the effects of nonlinear pulse control on the dynamics and success of pest control, a predator–prey model incorporating the Holling type II functional response function as an example is investigated. Finally, numerical simulations show that the proposed model has very complex dynamical behaviour, including period-doubling bifurcation, chaotic solutions, chaos crisis, period-halving bifurcations and periodic windows. Moreover, there exists an interesting phenomenon whereby period-doubling bifurcation and period-halving bifurcation always coexist when nonlinear impulsive controls are adopted, which makes the dynamical behaviour of the model more complicated, resulting in difficulties when designing successful pest control strategies.


2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Dahlia Khaled Bahlool ◽  
Huda Abdul Satar ◽  
Hiba Abdullah Ibrahim

In this paper, a mathematical model consisting of a prey-predator system incorporating infectious disease in the prey has been proposed and analyzed. It is assumed that the predator preys upon the nonrefugees prey only according to the modified Holling type-II functional response. There is a harvesting process from the predator. The existence and uniqueness of the solution in addition to their bounded are discussed. The stability analysis of the model around all possible equilibrium points is investigated. The persistence conditions of the system are established. Local bifurcation analysis in view of the Sotomayor theorem is carried out. Numerical simulation has been applied to investigate the global dynamics and specify the effect of varying the parameters. It is observed that the system has a chaotic dynamics.


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