scholarly journals Direct and Indirect Effect of Myzus Persicae Infestation on Buildup of Whitefly (Bemisia tabaci) in Tomato Crop under Laboratory Conditions

2020 ◽  
pp. 1-8
Author(s):  
Khadija Javed ◽  
Humayun Javed ◽  
Dewen Qiu
Keyword(s):  
Bemisia Tabaci ◽  
Indirect Effect ◽  
Myzus Persicae ◽  
Green Peach Aphid ◽  
Tomato Crop ◽  
Aphid Infestation ◽  
Tomato Plants ◽  
Factors Affecting ◽  
Whitefly Population ◽  
Negative Effect

The tomato crop is affected by a number of pests in the world as well as in China and Pakistan. The whitefly (Bemisia tabaci) is considered a very serious and damaging pest of tomato crop along with many other vegetables and field crops. Population buildup of whitefly is affected by many factors, including biotic and a biotic. One of the factors affecting the whitefly population in the tomato crop is green peach aphid (Myzus persicae) infestation before the whitefly attack. This project designed to note the direct and indirect effect of Myzus persicae infestation on the population setup of whitefly in tomato crops. The results revealed that whitefly prefers tomato plants without having aphids on them (choice) and can be settled on the tomato plants also when there are aphids present (no choice). The period after aphid infestation have a negative effect on the whitefly population, and the density of aphids/leaf has also influenced the whitefly population.

Green peach aphid and potato leafroll virus: transmission and control

2020 ◽  
Author(s):  
R.A. Bagrov ◽  
◽  
V.I. Leunov
Keyword(s):  
Myzus Persicae ◽  
Green Peach Aphid ◽  
Virus Transmission ◽  
Potato Leafroll Virus ◽  
Factors Affecting ◽  
Potato Viruses ◽  
Tuber Necrosis ◽  
Aphid Vectors ◽  
Leafroll Virus ◽  
And Control

The mechanisms of transmission of potato viruses from plants to aphid vectors and from aphids to uninfected plants are described, including the example of the green peach aphid (Myzus persicae, GPA). Factors affecting the spreading of tuber necrosis and its manifestation on plants infected with potato leafroll virus (PLRV) are discussed. Recommendations for PLRV and GPA control in the field are given.

scholarly journals The green peach aphid Myzus persicae perform better on pre-infested Chinese cabbage Brassica pekinensis by enhancing host plant nutritional quality

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
He-He Cao ◽  
Hui-Ru Liu ◽  
Zhan-Feng Zhang ◽  
Tong-Xian Liu
Keyword(s):  
Chinese Cabbage ◽  
Myzus Persicae ◽  
Green Peach Aphid ◽  
Marker Genes ◽  
Plant Leaves ◽  
Resistance Level ◽  
Aphid Infestation ◽  
Phloem Sap ◽  
Brassica Pekinensis ◽  
Plant Nutritional Quality

Abstract The green peach aphid, Myzus persicae Sulzer, is a notorious pest on vegetables, which often aggregates in high densities on crop leaves. In this study, we investigated whether M. persicae could suppress the resistance level of Chinese cabbage Brassica pekinensis. M. persicae performed better in terms of weight gain (~33% increase) and population growth (~110% increase) when feeding on previously infested (pre-infested) Chinese cabbage compared with those on non-infested plants. However, when given a choice, 64% of the aphids preferred to settle on non-infested leaves, while 29% of aphids chose pre-infested leaves that had a 2.9 times higher concentration of glucosinolates. Aphid feeding significantly enhanced the amino acid:sugar ratio of phloem sap and the absolute amino acid concentration in plant leaves. Aphid infestation significantly increased the expression levels of salicylic acid (SA) marker genes, while it had marginal effects on the expression of jasmonate marker genes. Exogenously applied SA or methyl jasmonate had no significant effects on M. persicae performance, although these chemicals increased glucosinolates concentration in plant leaves. M. persicae infestation increase amino acid:sugar ratio and activate plant defenses, but aphid performed better on pre-infested plants, suggesting that both nutrition and toxics should be considered in insect-plant interaction.

scholarly journals Greenhouse Screening of Capsicum Accessions for Resistance to Green Peach Aphid (Myzus persicae)

HortScience ◽  
2004 ◽  
Vol 39 (6) ◽  
pp. 1332-1335 ◽  
Author(s):  
James D. Frantz ◽  
Jeffrey Gardner ◽  
Michael P. Hoffmann ◽  
Molly M. Jahn
Keyword(s):  
Myzus Persicae ◽  
Green Peach Aphid ◽  
Resistance Mechanism ◽  
Cotton Aphid ◽  
Sources Of Resistance ◽  
Leaf Pubescence ◽  
Aphid Infestation ◽  
Greenhouse Screening ◽  
Damage Tolerant ◽  
Considerable Damage

A greenhouse screen for resistance to green peach aphid (GPA) [Myzus persicae (Sulzer)] was done using 50 pepper (Capsicum spp.) accessions. There were significant differences among accessions for damage rating, number of aphids per plant and number of aphids per leaf. Leaf pubescence, the basis of a reported nonpreference resistance mechanism to green peach aphid infestation, failed to protect pepper accessions from GPA colonization and damage. Sources of resistance and tolerance to cotton aphid [Aphis gossypi (Glover)] supported high levels of green peach aphid infestation and exhibited considerable damage. Although no accessions provided strong resistance to aphid colonization evident by significantly reduced numbers of aphids, several commercial varieties and sources of virus resistance exhibited strong tolerance to GPA, evident as reduced damage. Tolerant varieties could be an important component in integrated pest management of green peach aphid.

scholarly journals Spatial distribution of the Barbary Partridge (Alectoris barbara) in Sardinia explained by land use and climate

2021 ◽  
Vol 67 (4) ◽  
Author(s):  
Gianpasquale Chiatante ◽  
Marta Giordano ◽  
Anna Vidus Rosin ◽  
Oreste Sacchi ◽  
Alberto Meriggi
Keyword(s):  
Land Use ◽  
Conservation Status ◽  
Distance Sampling ◽  
Strong Relationship ◽  
European Population ◽  
Factors Affecting ◽  
Brood Rearing ◽  
Management Actions ◽  
Negative Effect ◽  
Study Sites

AbstractMore than half of the European population of the Barbary Partridge is in Sardinia; nonetheless, the researches concerning this species are very scarce, and its conservation status is not defined because of a deficiency of data. This research aimed to analyse the habitat selection and the factors affecting the abundance and the density of the Barbary Partridge in Sardinia. We used the data collected over 8 years (between 2004 and 2013) by spring call counts in 67 study sites spread on the whole island. We used GLMM to define the relationships between the environment (topography, land use, climate) both the occurrence and the abundance of the species. Moreover, we estimated population densities by distance sampling. The Barbary Partridge occurred in areas at low altitude with garrigue and pastures, avoiding woodlands and sparsely vegetated areas. We found a strong relationship between the occurrence probability and the climate, in particular, a positive relation with temperature and a negative effect of precipitation, especially in April–May, during brood rearing. Furthermore, dry crops positively affected the abundance of the species. We estimated a density of 14.1 partridges per km2, similar to other known estimates. Our findings are important both because they increase the knowledge concerning this species, which is considered data deficient in Italy, and because they are useful to plan management actions aimed to maintain viable populations if necessary.

scholarly journals The effects of current unsatisfactory performance and evaluative approach on improvement expectancy and commitment to improvement

2021 ◽  
Vol 45 (2) ◽  
pp. 159-170
Author(s):  
Adam Abdulla ◽  
Ruth Woods
Keyword(s):  
High School Students ◽  
Indirect Effect ◽  
School Students ◽  
Satisfactory Performance ◽  
Cognitive Behavioural ◽  
Negative Effect ◽  
Mediation Hypothesis ◽  
Positive Direct ◽  
Conditional Indirect Effects ◽  
Solution Focused

AbstractThis study investigated the effects of current unsatisfactory performance (CUP) on improvement expectancy (IE) and commitment to improvement (CTI). 118 high school students were randomly assigned to consider either current satisfactory performance (CSP) or CUP. In addition, students within each group were randomly assigned to one of two evaluative approaches: (1) dichotomous present-focused evaluation (“Are you succeeding in this area? Or not?”), or (2) historical success scaling (“What is the highest level of success that you have reached in this area?”). It was hypothesised that (relative to CSP) CUP has a negative effect on improvement expectancy (IE). This hypothesis was supported. In addition, the data were consistent with an inconsistent mediation hypothesis according to which CUP has a positive direct effect on CTI but a negative indirect effect through reduced IE. The indirect effect of CUP on CTI was expected to be less negative amongst students engaging in historical success scaling than amongst students engaging in dichotomous present-focused evaluation. Although this was indeed the case, a test of moderated mediation indicated that the conditional indirect effects did not differ statistically. The study helps to illuminate the conflicting effects of CUP on CTI. Findings also have important implications for cognitive-behavioural and solution-focused approaches, both of which champion “scaling.”

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