Greenhouse and Laboratory Evaluation of The Efficiency of Green Silicon Dioxide Nanoparticles Against Tetranychus urticae (Koch)

Abstract Fungi are a promising source for bioactive secondary metabolites against various agricultural pests. Soil samples were collected from the rhizosphere of various plants at El-Khatatba, Egypt, in May 2016. Sixty-two fungal isolates were locally isolated and screened against Tetranychus urticae Koch (Acari: Tetranychidae). Four fungal strains, showed potent control activities, were morphologically identified. Laboratory evaluation of the crude extracts of the selected strains, Aspergillus melleus, A. terreus, Emericella nidulans, and Chaetomium globosum, exhibited LC50 values of 10.27, 33.05, 14.68, and 22.40 mg/ml against females of T. urticae, respectively. Correspondent LC50 values that exhibited on eggs were 8.81, 23.17, 11.66, and 11.05 mg/ml. Consequently, secondary metabolites of A. melleus were separated by liquid chromatography/mass spectrometry. Compounds separated from the active fraction were identified as mellamide, ochratoxin C, nodulisporic acid, 7-Oxocurvularin, and 6-(4′-hydroxy-2′-methyl phenoxy)-(−)-(3R)-mellein. Obtained secondary metabolites are promising sources for biopesticides to be used in bio-rationale control of T. urticae.

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Tomato Carrying MI-1.2 Gene as a Host-Plant to the Two-Spotted Spider Mite (Tetranychus urticae Koch): Results of Laboratory Evaluation

Vegetable Crops Research Bulletin ◽

10.2478/v10032-010-0002-2 ◽

2010 ◽

Vol 72 (1) ◽

pp. 15-24 ◽

Cited By ~ 2

Author(s):

Monika Godzina ◽

Małgorzata Kiełkiewicz ◽

Katarzyna Szymczykiewicz

Keyword(s):

Host Plant ◽

Tetranychus Urticae ◽

Spider Mite ◽

Reproductive Potential ◽

Laboratory Evaluation ◽

Population Parameters ◽

Tomato Plants ◽

Two Spotted Spider Mite ◽

Short Time ◽

Tetranychus Urticae Koch

Tomato CarryingMI-1.2Gene as a Host-Plant to the Two-Spotted Spider Mite (Tetranychus urticaeKoch): Results of Laboratory EvaluationMi-1.2gene contributes to the resistance of tomato plants against some species of herbivores (i.e. nematodes, aphids) that are sap-feeders. In this study, two genotypes of tomato (Solanum lycopersicumL. syn.Lycopersicon esculentumMill.) plants with dominant (Motelle cv) and recessive (Moneymaker cv)Mi-1.2alleles were evaluated as a host-plant to the two-spotted spider mite (Tetranychus urticaeKoch, Acari: Tetranychidae). Plants were grown under glasshouse conditions. The effect of tomato genotypes onT. urticaebionomy was estimated on cut leaflets in controlled photoperiod, temperature and humidity (L/D=16/8 h; D/N temp.=23/20°C; RH=70%). Results of laboratory evaluation showed that both the bionomy and population parameters ofT. urticaereached a very similar or even higher value on plants with dominantMi-1.2allele than on plants with recessive one. A relatively high value ofT. urticaeparameters on plants resistant to root knot nematodes indicates that the mite has potential to develop rapidly. This allows the mite population to reach the density causing marked damage to plant in a short time. It is concluded that the presence ofMi-1.2gene product in tomato plants does not significantly affect the reproductive potential ofT. urticae.Therefore,Mi-1.2gene cannot be a satisfying source of plant resistance to this mite-herbivore generalist.

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