scholarly journals A fractional-order fall armyworm-maize biomass model with naturally beneficial insects and optimal farming awareness

2021 ◽  
Vol 12 ◽  
pp. 100209
Author(s):  
Salamida Daudi ◽  
Livingstone Luboobi ◽  
Moatlhodi Kgosimore ◽  
Dmitry Kuznetsov
Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Shouzong Liu ◽  
Mingzhan Huang ◽  
Juan Wang

In this paper, the bifurcation control of a fractional-order mosaic virus infection model for Jatropha curcas with farming awareness and an execution delay is investigated. By analyzing the associated characteristic equation, Hopf bifurcation induced by the execution delay is studied for the uncontrolled system. Then, a time-delayed controller is introduced to control the occurrence of Hopf bifurcation. Our study implies that bifurcation dynamics is significantly affected by the change of the fractional order, the feedback gain and the extended feedback delay provided that the other parameters are fixed. A series of numerical simulations is performed, which not only verifies our theoretical results but also reveals some specific features. Numerically, we find that the Hopf bifurcation gradually occurs in advance with the increase of the fractional order, and there exist extreme points for the feedback gain and the extended feedback delay which can minimize the bifurcation value.


Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 121
Author(s):  
Michael Hilary Otim ◽  
Stella Adumo Aropet ◽  
Moses Opio ◽  
Dalton Kanyesigye ◽  
Henry Nakelet Opolot ◽  
...  

The fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) has successfully invaded Africa, where it has significantly impacted maize and sorghum production. Management of FAW in Africa predominantly relies on synthetic insecticides, which are expensive, and negatively impact the environment and beneficial insects. We, therefore, conducted field surveys in Uganda in 2017 and 2019 to identify egg and larval parasitoids of FAW for possible use in integrated pest management (IPM) programs. Parasitoids were identified by their mitochondrial DNA cytochrome c oxidase subunit 1 (mtCOI) gene sequences. We identified 13 parasitoid species belonging to three families of Hymenoptera: Platygastridae, Braconidae and Ichneumonidae, as well as one Dipteran family (Tachinidae). Coccygidium spp. and Chelonus bifoveolatus were the most abundant and widely distributed parasitoids. Overall, parasitism averaged 9.2% and ranged from 3.1% to 50% in 2017, and 0.8% to 33% in 2019. Parasitism by Sturmiopsis parasitica, Diolcogaster sp., and Cotesia flavipes on FAW in maize crops are reported for the first time. Our results suggest high biological diversity of FAW parasitoids, which should be exploited in the IPM of the FAW in Uganda.


2013 ◽  
Vol 40 (2) ◽  
pp. 277-293 ◽  
Author(s):  
R. A. Galbreath ◽  
P. J. Cameron

The introduction of the eleven-spotted ladybird Coccinella undecimpunctata to New Zealand in 1874 has been widely quoted as the first importation of an insect for biological control in New Zealand and one of the first anywhere. However, searches of historical records show no evidence that such an introduction was made or attempted. Instead, there is clear evidence that the presently accepted record arose by a process of cumulative misreporting. An account of discussions in the Entomological Society of London in December 1873 about possible introductions of various beneficial insects to New Zealand was misreported by the American entomologist C. V. Riley, and several subsequent authors restated his version with further modifications and additions. This created the record of the introduction of C. undecimpunctata to New Zealand in 1874 that has been accepted and repeated ever since.


2018 ◽  
Vol 29 (5) ◽  
pp. 213-214 ◽  
Author(s):  
Graham Matthews

The author introduces the next three articles on the invasion of Fall Army Worm into Sub-Saharan Africa and Asia describing how the pest spreads, the damage it causes and approaches to its control.


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