COMPARISON OF LEAF DISC AND PETRI DISH ASSAYS FOR THE ASSESSMENT OF DICOFOL RESISTANCE IN POPULATIONS OF EUROPEAN RED MITE FROM SOUTHERN ONTARIO

1989 ◽  
Vol 121 (9) ◽  
pp. 771-776 ◽  
Author(s):  
D.J. Pree ◽  
K.J. Cole ◽  
P.A. Fisher
Keyword(s):  
Leaf Disc ◽  
Petri Dish ◽  
Wild Populations ◽  
Low Frequencies ◽  
Southern Ontario ◽  
Leaf Discs ◽  
Field Type ◽  
European Red Mite ◽  
Petri Dishes

AbstractTwo bioassay methods using leaf discs and Petri dishes as the treated medium were compared. Resistance levels were approximately 11-fold with the leaf disc method and 7-fold using the Petri dish assay. Comparisons of the two methods on six wild populations indicated that the Petri dish assay was more sensitive in identifying low frequencies of resistance. Advantages of the Petri dish assay over the previously used leaf disc method for rapid, field-type surveys are discussed.Surveys of populations from the Simcoe and Niagara areas, using the Petri dish assay, indicated resistance to dicofol in 11 of 22 samples. Resistance was generally correlated with sites where dicofol had been used at least once a year for 2–3 consecutive years. The data indicate a resurgence of dicofol resistance since 1984 when resistance was detected at 4% of the surveyed sites.

FIELD BIOASSAY METHODOLOGIES FOR THE DETECTION OF RESISTANCE TO ACARICIDES IN POPULATIONS OF EUROPEAN RED MITE (ACARI: TETRANYCHIDAE)

2000 ◽  
Vol 132 (1) ◽  
pp. 69-80 ◽  
Author(s):  
D.J. Pree ◽  
L.A. Bittner ◽  
K.J. Whitty
Keyword(s):  
Resistance Management ◽  
Petri Dish ◽  
Leaf Disk ◽  
Panonychus Ulmi ◽  
Field Bioassay ◽  
Laboratory Procedure ◽  
Reliable Technique ◽  
European Red Mite ◽  
Petri Dishes ◽  
Leaf Disks

AbstractThe toxicity of dicofol, pyridaben, formetanate HCl, and abamectin to European red mite, Panonychus ulmi (Koch), was determined using either a Petri dish or leaf dip bioassay (as potential field assay procedures) and was compared with results from a standard laboratory procedure that requires a Potter spray tower to treat leaf disks. Abamectin and pyridaben were the most toxic acaricides tested, and dicofol and pyridaben were more toxic when applied to Petri dishes than to leaf disks. Formetanate HCl was the least toxic acaricide tested by either leaf disk or leaf dip procedures. Diagnostic concentrations of pyridaben were determined as 5 mg active ingredient per litre (a.i./L) with the Petri dish assay and 15 mg a.i./L with the leaf disk assay. Mortality of European red mites to pyridaben at diagnostic concentrations was consistently 100% with the leaf disk assay and > 90% with the Petri dish assay. Residues of pyridaben on Petri dishes stored at 4 °C in a refrigerator were stable for at least 21 d. For dicofol, both leaf disk and Petri dish assays gave similar results, and 25 mg a.i./L, previously used as the diagnostic concentration in the Petri dish assay, resulted in > 99% mortality of the standard susceptible strain. This technique identified resistant individuals in all of the field populations tested. Abamectin applied at 2 mg a.i./L to leaf disks consistently gave 98–100% mortality, but results at 2 mg a.i./L with the Petri dish assay gave variable results and this was not a reliable technique for monitoring resistance. Concentrations of formetanate HCl required for the leaf dip assay were too high to be useful in field assays; however, all populations of European red mite tested using the leaf disk assay appeared susceptible. For the ovicide, clofentezine, mortality of eggs tested by the leaf disk assay at 100 or 500 mg a.i./L ranged from 89 to 100%. Results with the leaf dip procedure, using a 350 mg a.i./L suspension consistently resulted in > 96% mortality of eggs from susceptible field populations. These procedures are a useful tool in the development of resistance management programs for acaricides used in integrated pest management (IPM) systems for tree fruits.

scholarly journals Response of Mexican Corn Rootworm to Insecticides, 1991

1995 ◽  
Vol 20 (1) ◽  
pp. 329-329
Author(s):  
E. Guerrero-Rodriguez ◽  
S. Davalos-Luna ◽  
J. Corrales-Reynaga
Keyword(s):  
Petri Dish ◽  
Mortality Data ◽  
Corn Rootworm ◽  
Field Corn ◽  
Paper Towel ◽  
Percent Mortality ◽  
Petri Dishes ◽  
Mexican Corn Rootworm ◽  
Corn Plants ◽  
Commercial Field

Abstract Populations of MCR of commercial field corn from Arenal, Jalisco were exposed to nine insecticides of organophosphorous (OP), cabamate, organo chlorinated and pyrethroid groups. Larvae were collected from the roots of corn plants daily, and confined in polyethylene black bags of two kg capacity with humidity and germinated corn as food for larvae. Insects were taken to the laboratory of Sanidad Vegetal in Guadalajara, Jalisco. Dilutions of the insecticides tested were prepared using acetone from 500 to 5000 ppm (6 to 9 dosage/product). For this study 20 larvae of last instar were selected and 1 u, liter of the solution was placed topically on the thorax, after this, each larva was placed in a petri dish with a moistened paper towel and the petri dishes confined in a cardboard box to eliminate light. Mortality counts were carried out at 24 hours. Percent mortality was corrected by Abbott’s formula. The mortality data were analyzed by probit to obtain LC50 and LC,5 values for each insecticide.

scholarly journals Laboratory Bioassay of Beauveria Bassiana, Spinosad, Garlic, and Neem-Derived Products for Control of Grasshoppers

1998 ◽  
Vol 23 (1) ◽  
pp. 372-372
Author(s):  
Nihat Demirel ◽  
Whitney Cranshaw
Keyword(s):  
Beauveria Bassiana ◽  
Petri Dish ◽  
Neem Oil ◽  
Laboratory Bioassay ◽  
Neem Extract ◽  
Late Instar ◽  
Petri Dishes

Abstract Trials were conducted with adult, field collected migratory grasshoppers to determine susceptibility to ingestion expo sure to Beauveria bassiana Strain GHA (BotaniGard WP), spinosad (Conserve SC) a garlic-derived insecticide/repellent (Garlic Barrier), neem oil (Tril ogy) and a neem extract (BioNeem). Field collected late instar grasshoppers were confined, 8 per petri dish (100 mm X 15 mm), with 6 petri dishes usetl per treatment. Treatments involved dipping alfalfa leaves into the insecticide solutions and allowing them to air dry before feeding these to the grasshop pers. After the originally treated foliage were consumed, untreated foliage was used to maintain grasshoppers in all treatments. Mortality was assessed a 24, 48, 96, and 192 h after exposure.

scholarly journals Bioassay, Laboratory Tests of Beauveria Bassiana, Bacillus Thuringiensis, and a Feeding Stimulant on Leafroller Larvae, 1994

1995 ◽  
Vol 20 (1) ◽  
pp. 349-349
Author(s):  
J. F. Brunner ◽  
M. D. Doerr ◽  
L. O. Smith
Keyword(s):  
Beauveria Bassiana ◽  
Petri Dish ◽  
Larval Survival ◽  
Wetting Agent ◽  
Food Storage ◽  
Storage Container ◽  
Feeding Stimulant ◽  
Petri Dishes ◽  
Extension Center ◽  
Leaf Disks

Abstract Beauveria bassiana (Naturalis-L), two B. thuringiensis products (Dipel and Troy Bt), and a feeding stimulant (Konsume) combined with a B. thuringiensis product were evaluated using a leaf-dip bioassay method for their effect on PLR and OBLR larvae. Treatments were prepared by diluting the appropriate amt of product (see table) in 500 ml water in a glass beaker. The Konsume treatments received a constant 1X rate of Dipel and 4X-0.25X rates of Konsume. A small amt (about 2 ml) of wetting agent, X-77®, was added to each treatment. An untreated control was prepared using water plus the wetting agent only. Untreated apple leaves were collected from ‘Red Delicious’ trees at the WSU Tree Fruit Research and Extension Center, Wenatchee. Leaves were dipped, then allowed to dry. Two punches (2.3 cm diameter) were taken from each leaf. Four punches were placed in a petri dish (Falcon 1006, 50 × 9 mm). Petri dishes were chosen randomly, and five 1- to 2-d-old leafroller larvae were placed on the leaf disks. The petri dish lid was put in place and dishes were placed inside a food storage container and kept at 75°F (± 2°F) constant temperature and a photoperiod of 16:8 (L:D) h. Petri dishes were examined after 7 d and larval survival recorded. Ten dishes were used for each treatment (50 larvae per treatment).

scholarly journals Apple, Insecticide DIP Test (Tabm vs. Insecticides), 1993

1994 ◽  
Vol 19 (1) ◽  
pp. 369-369
Author(s):  
R. L. Horsburgh ◽  
J. R. Warren
Keyword(s):  
Filter Paper ◽  
Room Temperature ◽  
Petri Dish ◽  
Spray Application ◽  
Water Control ◽  
Poor Control ◽  
Laboratory Bioassay ◽  
The Third ◽  
Petri Dishes ◽  
Dip Test

Abstract A large commercial apple grower reported failure in attempts to control TABM with airblast applications of Penncap M (2 pt/acre) combined with methomyl (3 pt/acre). At the time of the grower applications larval hatch had begun and most larvae were in the first or second instar. By the time larvae were entering the third instar (10 days after spray application) it was apparent that commercially acceptable control had not been achieved. In 1992 this grower also had poor control when Penncap M was applied to suppress redbanded leafroller and experiments showed that tolerance of Penncap M was present in the resident RBLR population (Horsburgh et al. 1992). This laboratory bioassay was begun on 3 Sep to determine tolerance of the TABM population to Penncap M and other insecticides. Seven treatments (including a water control) were selected and rates calculated on the basis of 300 gal of spray being applied per acre. The appropriate dosage of pesticide for each treatment was mixed with 1 gallon of 77°F water in clean 1 gallon battery jars. Twenty plastic petri dishes containing moistened filter paper were prepared and served as individual cages for twenty 3rd instars per treatment. The larvae, on single leaves, were immersed in the appropriate solutions for five seconds and the leaf placed on the moist filter paper. The petri dish cover was put in place and the cages held at room temperature (80°F) for the duration of the test. All larvae were examined at 24 hour intervals and mortality was recorded. Death of larvae was assumed when no movement was observed when the larvae were gently prodded with a blunt steel probe.

Disinfection of selected Aspergillus spp. using ultraviolet germicidal irradiation

2004 ◽  
Vol 50 (3) ◽  
pp. 221-224 ◽  
Author(s):  
Christopher F Green ◽  
Pasquale V Scarpino ◽  
Paul Jensen ◽  
Nancy J Jensen ◽  
Shawn G Gibbs
Keyword(s):  
Aspergillus Fumigatus ◽  
Aspergillus Flavus ◽  
Fungal Spores ◽  
Petri Dish ◽  
Testing Unit ◽  
Ultraviolet Germicidal Irradiation ◽  
Airborne Fungal Spores ◽  
Agar Surface ◽  
Petri Dishes ◽  
Higher Doses

Aims: The efficacy of ultraviolet germicidal irradiation (UVGI) and the UVGI dose necessary to inactivate fungal spores on an agar surface for cultures of Aspergillus flavus and Aspergillus fumigatus were determined. Methods and results: A four-chambered UVGI testing unit with a 9-W, Phillips, low pressure, mercury UVGI lamp in each chamber was used in this study. An aperture was adjusted to provide 50, 100, 150, and 200 µW/cm2 of uniform flux to the surfaces of the Petri dish, resulting in a total UVGI dose to the surface of the Petri dishes ranging from 12 to 96 mJ/cm2. The UVGI dose necessary to inactivate 90% of the A. flavus and A. fumigatus was 35 and 54 mJ/cm2, respectively. Conclusions: UVGI can be used to inactivate culturable fungal spores. Aspergillus flavus was more susceptible than A. fumigatus to UVGI. Significance and impact of the study: These results may not be directly correlated to the effect of UVGI on airborne fungal spores, but they indicate that current technology may not be efficacious as a supplement to ventilation unless it can provide higher doses of UVGI to kill spores traveling through the irradiated zone.Key words: Aspergillus, ultraviolet germicidal irradiation, fungi.

RELATIONSHIP OF SPATIAL DENSITY OF SPRAY DROPLET TO FREQUENCY OF CONTACT BY EUROPEAN RED MITE (ACARINA: TETRANYCHIDAE)

1973 ◽  
Vol 105 (7) ◽  
pp. 999-1001
Author(s):  
R. W. Fisher ◽  
D. R. Menzies
Keyword(s):  
Adult Female ◽  
Spatial Density ◽  
Spray Droplet ◽  
Leaf Discs ◽  
European Red Mite ◽  
Frequency Of Contact ◽  
Relationship Of ◽  
The Relationship ◽  
Individual Adult

AbstractThe behaviour of individual adult female European red mites was observed on peach leaf discs sprayed with different numbers of 200 micron droplets of nigrosine dye solution, nigrosine plus Carzol miticide, and nigrosine plus dicofol. On nigrosine and Carzol deposits, the relationship between the number of contacts and the number of stains was linear, but the addition of Carzol reduced the slope of the line. Tests of stains containing dicofol were intermediate to those of nigrosine and Carzol.

Resistance of Solanaceous and non-Solanaceous species to Peronospora tabacina as shown by necrotrophic reactions

1971 ◽  
Vol 11 (48) ◽  
pp. 94 ◽  
Author(s):  
M Mandryk
Keyword(s):  
Leaf Disc ◽  
Peronospora Tabacina ◽  
Nicotiana Species ◽  
Leaf Discs ◽  
Solanaceous Species ◽  
Wide Range ◽  
Disc Area ◽  
Susceptibility Status

A necrotrophic reaction in leaf discs of a wide range of Nicotiana and other Solanaceous and non-Solanaceous species following infection by Peronospora tabacina Adam is described.With a few exceptions, species resistant to the pathogen developed water-soaking or gave no reaction, whereas susceptible species showed necroses affecting 60-100% of the leaf disc area. The degree if necrotrophic reaction is related to the resistance-susceptibility status of Nicotiana species, and it may be extended to detect susceptibility to the pathogen in Petunia, Capsicum, Lycopersicon, Hyoscyamus, Schizanthus, and other genera related ti Nicotiana.

scholarly journals Bioassay, Effect of Field-Aged Residue Degradation of Basillus Thuringiensis, 1994

1995 ◽  
Vol 20 (1) ◽  
pp. 351-351 ◽  
Author(s):  
J. F. Brunner ◽  
M. D. Doerr ◽  
L. O. Smith
Keyword(s):  
Constant Temperature ◽  
Petri Dish ◽  
Larval Survival ◽  
Apple Orchard ◽  
Food Storage ◽  
Storage Container ◽  
Tree Fruit ◽  
Petri Dishes ◽  
Extension Center ◽  
Neonate Larvae

Abstract Using a leaf-disk bioassay, B. thuringiensis products were evaluated for residue effects on PLR and OBLR neonate larvae. The test was conducted in an apple orchard at the Tree Fruit Research and Extension Center. The trees were 15-yr-old spur type ‘Red Delicious’ on dwarfing roots. The treatments were applied on 22 Sep at the recommended rate with a handgun sprayer at 300 psi to the point of drip, simulating a dilute spray of approximately 400 gal/acre. Each treatment was replicated three times with one tree in each. Ten leaves were collected from the interior canopy of each tree at 1, 4, 6 and 8 DAT. Two punches (2.3 cm diameter) were taken from each leaf. Four punches were placed in a petri dish (Falcon 1006, 50 × 9 mm), keeping the leaves from each replication separate. Petri dishes were chosen randomly, and five 1- to 2-d-old leafroller larvae were placed on the leaves. Five petri dishes were prepared for each tree and each leafroller species (75 larvae per treatment). The petri dishes were placed inside a food storage container and kept at 20°C constant temperature and a photoperiod of 16:8 (L:D) h. Petri dishes were examined after 7 d and larval survival recorded.

scholarly journals Chemical Composition and Antifungal Effects of Vitex agnus-castus L. and Myrtus communis L. Plants

2016 ◽  
Vol 44 (2) ◽  
pp. 466-471 ◽  
Author(s):  
Melih YILAR ◽  
Yusuf BAYAN ◽  
Abdurrahman ONARAN
Keyword(s):  
Chemical Composition ◽  
Essential Oil ◽  
Essential Oils ◽  
Plant Pathogens ◽  
Petri Dish ◽  
Myrtus Communis ◽  
Mycelium Growth ◽  
Agnus Castus ◽  
Petri Dishes

The purpose of this study was to assess the effectiveness of essential plant oils from Vitex agnus-castus L. (VAC) and Myrtus communis L. against the plant pathogens, Fusarium oxysporum f. sp. radicis-lycopersici (Sacc.) W.C. Synder & H.N. Hans, Rhizoctonia solani J.G. Kühn., Sclerotinia sclerotiorum (Lib.) de Bary and Verticillium dahliae Kleb., and to determine the chemical composition of the compounds in these essential oils. GC/MS analysis was identified 25 different compounds in VAC essential oil, while the main compounds were determined as Eucalyptol (17.75%), β-Caryophyllene (13.21%) and Spathulenol (10.41%). On the other hand, the essential oil of M. communis, consisted of 16 different compounds which were Eucalyptol (49.15%), Myrtenol (19.49%) and α-Pinene (8.38%) being its main compounds. An assessment of antifungal activity was performed under in vitro conditions. Plant pathogens were inoculated onto Petri dishes (60 mm) containing PDA medium (10 mL/Petri-1), and plant essential oils were applied at concentrations of 0.5, 1, 1.5, 2, 5 and 10 (μL/Petri-1) into the 5 mm diameter wells opened on the Petri dish surface. After that, the Petri dishes incubated at 22±2 °C. The results of this study, the essential oil of M. communis, at a dose of 10 μL/ Petri, inhibited the 100% mycelium growth of V. dahliae, S. sclerotiorum and R. solani. The highest dose of VAC essential oil was also 100% inhibited V. dahliae and S. sclerotiorum. The LC50 and LC90 values of M. communis and VAC essential oil calculated for V. dahliae, FORL, S. sclerotiorum and R. solani. This plant extracts were shown by in vitro conditions to be potential antifungal agents.

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