Impact of soil texture on conidia movement and residual effect of entomopathogenic fungi applied through irrigation to control fruit-fly pupae in mango orchards

2021 ◽  
pp. 104559
Author(s):  
Carlos Alberto Tuão Gava ◽  
Jamille Cardeal da Silva ◽  
Welson Lima Simões ◽  
Beatriz Aguiar Jordão Paranhos
2000 ◽  
Vol 75 (1) ◽  
pp. 126-128 ◽  
Author(s):  
Rafael Diaz-Sobac ◽  
Laura Prez-Flores ◽  
Jaime Vernon-Carter
Keyword(s):  

Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 665 ◽  
Author(s):  
Charalampos Filippou ◽  
Inmaculada Garrido-Jurado ◽  
Nicolai Meyling ◽  
Enrique Quesada-Moraga ◽  
Robert Coutts ◽  
...  

The use of mycoviruses to manipulate the virulence of entomopathogenic fungi employed as biocontrol agents may lead to the development of novel methods to control attacks by insect pests. Such approaches are urgently required, as existing agrochemicals are being withdrawn from the market due to environmental and health concerns. The aim of this work is to investigate the presence and diversity of mycoviruses in large panels of entomopathogenic fungi, mostly from Spain and Denmark. In total, 151 isolates belonging to the genera Beauveria, Metarhizium, Lecanicillium, Purpureocillium, Isaria, and Paecilomyces were screened for the presence of dsRNA elements and 12 Spanish B. bassiana isolates were found to harbor mycoviruses. All identified mycoviruses belong to three previously characterised species, the officially recognised Beauveria bassiana victorivirus 1 (BbVV-1) and the proposed Beauveria bassiana partitivirus 2 (BbPV-2) and Beauveria bassiana polymycovirus 1 (BbPmV-1); individual B. bassiana isolates may harbor up to three of these mycoviruses. Notably, these mycovirus species are under distinct selection pressures, while recombination of viral genomes increases population diversity. Phylogenetic analysis of the RNA-dependent RNA polymerase gene sequences revealed that the current population structure in Spain is potentially a result of both vertical and horizontal mycovirus transmission. Finally, pathogenicity experiments using the Mediterranean fruit fly Ceratitis capitata showed no direct correlation between the presence of any particular mycovirus and the virulence of the B. bassiana isolates, but illustrated potentially interesting isolates that exhibit relatively high virulence, which will be used in more detailed virulence experimentation in the future.


2018 ◽  
Vol 53 (2) ◽  
pp. 144-151 ◽  
Author(s):  
Inana Xavier Schutze ◽  
Cléber Antonio Baronio ◽  
Morgana Mattiello Baldin ◽  
Alci Enimar Loek ◽  
Marcos Botton

Abstract: The objective of this work was to assess the lethal concentration and lethal time (LC and LT) of spinosad and spinetoram, combined with different food lures, and their residual effects on South American fruit fly (Anastrepha fraterculus). The toxic baits were offered in eight concentrations (2, 6, 14, 35, 84, 204, 495, and 1,200 mg L-1), combined with the following food lures: 7% sugarcane molasses, 3% Biofruit, 1.5% CeraTrap, 1.25% Flyral, 3% Samaritá Bait, and 3% Samaritá Tradicional; diluted food lures in water were used as controls. The residual effect of the formulations at 96 mg L-1 concentration were evaluated for 21 days and were compared with that of the commercial bait Success 0.02 CB. Both insecticides were toxic to adults of A. fraterculus, and mortality varied with the food lure used. The LC50and LT50ranged from 15.19 to 318.86 mg L-1and from 11.43 to 85.93 hours, respectively. Spinosad was 2 to 36 times as toxic as spinetoram when combined with different hydrolyzed proteins. Toxic baits formulated with spinosad and spinetoram (96 mg L-1) caused mortality equivalent to the one by Success 0.02 CB (90.2%), when assessed on the day of application. Toxic baits formulated with 3% Biofruit + spinosad and 3% Samaritá Bait + spinetoram are effective for managingA. fraterculusand provide up to seven days of residual effect in the absence of rain; however, only Success 0.02 CB caused more than 80% mortality for up to 21 days.


BMC Ecology ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ayoub Hallouti ◽  
Mohamed Ait Hamza ◽  
Abdelaziz Zahidi ◽  
Rachid Ait Hammou ◽  
Rachid Bouharroud ◽  
...  

Abstract Background Studying the ecology of biocontrol-agents is a prerequisite to effectively control medfly (Ceratitis capitata (Diptera: Tephritidae)) with entomopathogenic fungi. In this context, factors affecting the occurrence and distribution of medfly-associated entomopathogenic-fungi were studied. Soil samples (22) were collected from natural and cultivated areas of Souss-region Morocco. Results A total of 260 fungal isolates belonging to 22 species and 10 genera were obtained by using medfly pupae as bait. Medfly-associated fungi were detected in all studied soils and pupae infection percentages ranged from 3.33% to 48%. Two genera, Fusarium and Beauveria were the most frequent with 83 isolates (32%) and 50 isolates (19.23%) respectively. Pathogenicity test of isolated species against medfly pupae showed high mortality rates up to 91% for some strains. Principal component analysis (PCA) demonstrated a strong influence of origin, physical, and chemical properties of soil on the abundance of these fungi. In general, medfly-associated fungi were more abundant in soils with moderate pH (7.5 to 8) having high sand and organic content. High relative humidity negatively influenced the abundance of these fungi. Both factors directly affected the fungal infection percentages in pupae. The response of fungi to these parameters varied among species. According to principal component analysis (PCA), the soils of argan fields and forests were more suitable for the development of medfly-associated fungi than citrus orchards. Conclusions These results guide identifying suitable soils for the effective application of entomopathogenic fungi as biological control agents. In summary, isolated indigenous strains seem to be a promising option to control C. capitata.


Author(s):  
Adalton Raga ◽  
Ester Marques De Sousa ◽  
Léo Rodrigo Ferreira Louzeiro

Fruit flies (Diptera: Tephritidae) cause significant losses during the production and marketing of horticultural products. Brazilian growers usually adopt full-coverage insecticide spraying to control fruit flies, but toxic bait is a more strategic technique, because reach efficacy and the target surface is the foliage and branches. We provide information regarding the toxicity of spinetoram bait to two fruit fly species in the laboratory as an alternative to organophosphates and the specific spinosad formulation. We tested toxic baits in the laboratory, using commercial hydrolysed corn protein (10% v/v) plus 90 g, 120 g, 150 g and 180 g dilutions of spinetoram 250 WG (commercial product/1,000 litres of water). All toxic baits were compared with an untreated control (only protein) for the adults of females and males of Anastrepha obliqua (Macquart, 1835) and Ceratitis capitata (Wiedemann, 1824) up to 30 hours of exposure. Dry food for adults was included in all dilutions (5% w/v). In addition, we tested the residual effect of toxic baits applied to the leaves of mandarin seedlings. We used the same treatments of the earlier bioassay without dry food, collecting treated leaves and exposing them to C. capitata (medfly) females for 24 hours in the laboratory. Leaves were collected 1, 3, 7, 15 and 30 days after application. Overall, medfly adults were more susceptible to spinetoram baits than A. obliqua. All toxic baits resulted in 100% C. capitata mortality 24 hours after initial exposure, and the toxic bait at 150 g/1,000 L of water resulted in the maximum mortality (96%) in A. obliqua. Except for 90 g of spinetoram bait at 30 days after application, all spinetoram bait concentrations resulted in significantly, more dead C. capitata females than the control over all tested periods in the residual bioassay. At 30 days after application, spinetoram baits at 120 g, 150 g and 180 g resulted in 85%, 87% and 86% mortality in C. capitata, respectively. Spinetoram toxic baits have proven promising for long-term fruit fly management.


HortScience ◽  
1997 ◽  
Vol 32 (2) ◽  
pp. 275-277 ◽  
Author(s):  
W.R. Miller ◽  
R.E. McDonald

`Marsh' grapefruit (Citrus paradisi Macf.) produced in Florida must be certified for security against unwanted pests before entry into some domestic and export markets. Application of heat by hot water (HW) has been shown to cause severe injury to grapefruit; however, direct comparisons between forced vapor heat (VH) and HW have been lacking. Grapefruit preharvest-treated with gibberellic acid (GA) or not treated, were postharvest-treated with VH or HW such that the surfaces of fruit were exposed to the same rate of temperature increases and treatment durations. Condition and quality attributes were then compared with ambient air (AA) and ambient water (AW) controls after storage. After 4 weeks' storage at 10 °C plus 1 week at 20 °C, scald affected 5% of HW and 20% of VH-treated fruit. No scald developed on control fruit. At the end of storage, mass loss for HW and VH fruit was ≈5%. HW-treated fruit had a 5-fold higher incidence of aging than VH fruit; however, control fruit showed significantly more aging than all heat-treated fruit. Gibberellic acid (GA) and the heat treatments reduced decay relative to the control. GA-treated fruit remained greener during storage than control fruit. These findings indicate that VH and HW treatments at the temperatures and durations to control the Caribbean fruit fly (Anastrepha suspensa, Loew) will likely cause peel injury to `Marsh' grapefruit produced in Florida, regardless of treatment with GA.


2012 ◽  
Vol 86 (2) ◽  
pp. 275-284 ◽  
Author(s):  
Evangelos I. Beris ◽  
Dimitrios P. Papachristos ◽  
Anastasia Fytrou ◽  
Spyridon Α. Antonatos ◽  
Dimitrios C. Kontodimas

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