scholarly journals Early Infestations By Arthropod Pests Induce Unique Changes In Plant Compositional Traits And Leaf Reflectance

2021 ◽  
Author(s):  
Christian Nansen ◽  
Machiko Murdock ◽  
Rachel Purington ◽  
Stuart Marshall
Keyword(s):  
Leaf Reflectance ◽  
Arthropod Pests

scholarly journals Root-associated entomopathogenic fungi manipulate host plants to attract herbivorous insects

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Belén Cotes ◽  
Gunda Thöming ◽  
Carol V. Amaya-Gómez ◽  
Ondřej Novák ◽  
Christian Nansen
Keyword(s):  
Host Plant ◽  
Entomopathogenic Fungi ◽  
Host Plants ◽  
Near Infrared ◽  
Delia Radicum ◽  
Host Plant Selection ◽  
Herbivorous Insects ◽  
Herbivorous Insect ◽  
Insect Performance ◽  
Leaf Reflectance

AbstractRoot-associated entomopathogenic fungi (R-AEF) indirectly influence herbivorous insect performance. However, host plant-R-AEF interactions and R-AEF as biological control agents have been studied independently and without much attention to the potential synergy between these functional traits. In this study, we evaluated behavioral responses of cabbage root flies [Delia radicum L. (Diptera: Anthomyiidae)] to a host plant (white cabbage cabbage Brassica oleracea var. capitata f. alba cv. Castello L.) with and without the R-AEF Metarhizium brunneum (Petch). We performed experiments on leaf reflectance, phytohormonal composition and host plant location behavior (behavioral processes that contribute to locating and selecting an adequate host plant in the environment). Compared to control host plants, R-AEF inoculation caused, on one hand, a decrease in reflectance of host plant leaves in the near-infrared portion of the radiometric spectrum and, on the other, an increase in the production of jasmonic, (+)-7-iso-jasmonoyl-l-isoleucine and salicylic acid in certain parts of the host plant. Under both greenhouse and field settings, landing and oviposition by cabbage root fly females were positively affected by R-AEF inoculation of host plants. The fungal-induced change in leaf reflectance may have altered visual cues used by the cabbage root flies in their host plant selection. This is the first study providing evidence for the hypothesis that R-AEF manipulate the suitability of their host plant to attract herbivorous insects.

Identification of powdery mildew (Erysiphe graminis sp. tritici) and take-all disease (Gaeumannomyces graminis sp. tritici) in wheat (Triticum aestivum L.) by means of leaf reflectance measurements

2006 ◽  
Vol 1 (2) ◽  
pp. 275-288 ◽  
Author(s):  
Simone Graeff ◽  
Johanna Link ◽  
Wilhelm Claupein
Keyword(s):  
Powdery Mildew ◽  
Disease Severity ◽  
Near Infrared ◽  
Plant Stress ◽  
Stress Factors ◽  
Gaeumannomyces Graminis ◽  
Disease Assessment ◽  
Leaf Reflectance ◽  
Reflectance Measurements ◽  
Take All

AbstractThe ability to identify diseases in an early infection stage and to accurately quantify the severity of infection is crucial in plant disease assessment and management. A greenhouse study was conducted to assess changes in leaf spectral reflectance of wheat plants during infection by powdery mildew and take-all disease to evaluate leaf reflectance measurements as a tool to identify and quantify disease severity and to discriminate between different diseases. Wheat plants were inoculated under controlled conditions in different intensities either with powdery mildew or take-all. Leaf reflectance was measured with a digital imager (Leica S1 Pro, Leica, Germany) under controlled light conditions in various wavelength ranges covering the visible and the near-infrared spectra (380–1300 nm). Leaf scans were evaluated by means of L*a*b*-color system. Visual estimates of disease severity were made for each of the epidemics daily from the onset of visible symptoms to maximum disease severity. Reflectance within the ranges of 490780 nm (r2 = 0.69), 510780nm (r2 = 0.74), 5161300nm (r2 = 0.62) and 5401300 nm (r2 = 0.60) exhibited the strongest relationship with infection levels of both powdery mildew and take-all disease. Among the evaluated spectra the range of 490780nm showed most sensitive response to damage caused by powdery mildew and take-all infestation. The results of this study indicated that disease detection and discrimination by means of reflectance measurements may be realized by the use of specific wavelength ranges. Further studies have to be carried out, to discriminate powdery mildew and take-all infection from other plant stress factors in order to develop suitable decision support systems for site-specific fungicide application.

scholarly journals Synthetic acylsugars and their effects on the control of arthropod pests

2017 ◽  
Vol 41 (2) ◽  
pp. 201-208
Author(s):  
Anni Cristini Silvestri Gomes ◽  
Maria das Graças Cardoso ◽  
Juliano Vilela Resende ◽  
Sérgio Scherrer Thomasi ◽  
Luana Isac Soares ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Biological Effect ◽  
Sodium Acetate ◽  
Spectroscopic Techniques ◽  
Agricultural Pests ◽  
Wild Tomato Species ◽  
Tomato Species ◽  
Biological Tests ◽  
Arthropod Pests ◽  
Low Rate

ABSTRACT One of the main problems facing agriculture is the loss of production as a result of the attack of agricultural pests. Alternative ways to work around this problem are being sought. There are substances called acylsugars that are naturally produced by the wild tomato species S. pennellii and affect arthropod pests. The objectives of this work were to synthesize two acylsugars and assess the biological effect of these on the arthropod pests Bemissia tabaci and Tetranycus urticae. The syntheses were performed via the reactions of glucose and sucrose (saccharose) with acetic anhydride using sodium acetate as the catalyst. The products of these reactions were sucrose octa-acetate and glucose penta-acetate, the structures of which were confirmed by spectroscopic techniques. In a resistance test against the mite, a linear correlation between the concentration of the synthesized substances, and the dislocation of the mite was obtained. A delay in the hatching of the arthropod eggs was observed, causing a mortality rate of approximately 95% in the 1st instar larvae of mites that was confirmed in adults. In the biological tests with Bemisia tabaci, there was a low rate of hatching and emergence, and the effect on the nymphs was the deformation of the emergent adults.

scholarly journals Microbial control of arthropod pests of tropical tree fruits

2007 ◽  
Vol 36 (2) ◽  
pp. 161-179 ◽  
Author(s):  
Claudia Dolinski ◽  
Lawrence A. Lacey
Keyword(s):  
Microbial Control ◽  
Tropical Tree ◽  
Arthropod Pests ◽  
Tree Fruits

Changes in Photosystem II Activity and Leaf Reflectance Features of Several Subtropical Woody Plants Under Simulated SO2Treatment

2006 ◽  
Vol 48 (11) ◽  
pp. 1274-1286 ◽  
Author(s):  
Nan Liu ◽  
Chang-Lian Peng ◽  
Zhi-Fang Lin ◽  
Gui-Zhu Lin ◽  
Ling-Ling Zhang ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Woody Plants ◽  
Leaf Reflectance ◽  
Photosystem Ii Activity

Particle Films for Managing Arthropod Pests of Apple

2008 ◽  
Vol 101 (1) ◽  
pp. 145-150 ◽  
Author(s):  
N. J. Bostanian ◽  
G. Racette
Keyword(s):  
Arthropod Pests
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