scholarly journals Persistence of Foliar-Applied Insecticides for Elm Leaf Beetle Control, Trial Two, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 370-371
Author(s):  
D. Casey Sclar ◽  
Whitney S. Cranshaw

Abstract The mortality of elm leaf beetle larvae to foliar-applied insecticides sprayed on different dates was assessed. Three different insecticides were examined for differences in performance. Siberian elm foliage was treated with foliar-applied insecticides on each of 4 different dates. Treatments were applied with a pump-mister sprayer to the point of run-off. All foliage was collected and bagged on 24 Jul. In the laboratory, 10 larvae were placed in a petri dish and treated foliage was introduced for consumption. Mortality was assessed at 48 and 96 h after exposure by counting the number of dead, live, moribund and pupated larvae present in a petri dish at a given time interval. A few larvae in the petri dishes became infected with the fungus Beauvaria bassiana (Balsamo) Vuillemin and subsequently died during the course of the experiment. For this reason, only dead, uninfected larvae were used to calculate percent mortality estimates. The experiment was analyzed as a CRD with 8 replications per treatment.

1995 ◽  
Vol 20 (1) ◽  
pp. 329-329
Author(s):  
E. Guerrero-Rodriguez ◽  
S. Davalos-Luna ◽  
J. Corrales-Reynaga

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.


1998 ◽  
Vol 23 (1) ◽  
pp. 372-372
Author(s):  
Nihat Demirel ◽  
Whitney Cranshaw

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.


1995 ◽  
Vol 20 (1) ◽  
pp. 349-349
Author(s):  
J. F. Brunner ◽  
M. D. Doerr ◽  
L. O. Smith

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).


1995 ◽  
Vol 20 (1) ◽  
pp. 328-328
Author(s):  
Thomas B. Eckberg ◽  
Whitney Cranshaw ◽  
D. Casey Sclar

Abstract Field collected fall webworm larvae in approximately Instar III-IV were exposed to either of the neem-derived insecticides Azatin EC or Margosan-O. Treatments included either a direct application of the insecticide to the body of the insect or feeding it chokecherry foliage sprayed to point of run-off. Larvae that received topical applications and larvae that were included as the water check were fed non-treated foliage. Larvae and foliage were sprayed August 30. Rates of Azatin used were 16 fl oz/100 gal; Margosan-O was applied in a 1:240 dilution. Larvae were separated into groups of approximately 10/petri dish, with 6 groups per treatment. Mortality was assessed over a 21 day period following exposure.


1994 ◽  
Vol 19 (1) ◽  
pp. 369-369
Author(s):  
R. L. Horsburgh ◽  
J. R. Warren

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.


1995 ◽  
Vol 20 (1) ◽  
pp. 333-333
Author(s):  
Rick J. Zimmerman ◽  
Terri Randolph ◽  
Whitney Cranshaw

2004 ◽  
Vol 50 (3) ◽  
pp. 221-224 ◽  
Author(s):  
Christopher F Green ◽  
Pasquale V Scarpino ◽  
Paul Jensen ◽  
Nancy J Jensen ◽  
Shawn G Gibbs

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.


1995 ◽  
Vol 20 (1) ◽  
pp. 351-351 ◽  
Author(s):  
J. F. Brunner ◽  
M. D. Doerr ◽  
L. O. Smith

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.


2016 ◽  
Vol 44 (2) ◽  
pp. 466-471 ◽  
Author(s):  
Melih YILAR ◽  
Yusuf BAYAN ◽  
Abdurrahman ONARAN

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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