Spray deposition and persistence of a Bacillus thuringiensis formulation (Foray® 76B) on spruce foliage, following aerial application over a northern ontario forest

1996 ◽  
Vol 31 (4) ◽  
pp. 763-813 ◽  
Author(s):  
A. Sundaram ◽  
K. M. S. Sundaram ◽  
L. Sloane
Keyword(s):  
Bacillus Thuringiensis ◽  
Spray Deposition ◽  
Aerial Application ◽  
Northern Ontario

MORTALITY, FEEDING INHIBITION, AND RECOVERY OF SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE) LARVAE FOLLOWING AERIAL APPLICATION OF A HIGH-POTENCY FORMULATION OF BACILLUS THURINGIENSIS SUBSP. KURSTAKI

2000 ◽  
Vol 132 (4) ◽  
pp. 505-518 ◽  
Author(s):  
Kees van Frankenhuyzen ◽  
Carl Nystrom ◽  
John Dedes ◽  
Vern Seligy
Keyword(s):  
Bacillus Thuringiensis ◽  
Spray Deposition ◽  
Larval Mortality ◽  
Lethal Dose ◽  
Spruce Budworm ◽  
Limiting Factor ◽  
Larval Feeding ◽  
Spray Application ◽  
Aerial Application ◽  
Feeding Inhibition

AbstractA larval population of spruce budworm, Choristoneura fumiferana (Clemens), was monitored for 5 d following aerial application of a commercial formulation of Bacillus thuringiensis Berliner subsp. kurstaki to investigate dose acquisition and expression (larval mortality, recovery, feeding, and growth) in relation to spray deposition and persistence of spray deposits. The main objective was to test if previous laboratory observations on how B. thuringiensis affects feeding and dose ingestion by spruce budworm larvae hold true under field conditions. About 40% of the treated population ingested a lethal dose within 1 d after spray application. Lethally dosed larvae died without further feeding upon transfer from treated foliage to (untreated) artificial diet. Resumption of feeding by larvae that survived the treatment was delayed relative to larvae from the control population during 3 d following spray application; during that time, normal feeding activity and larval weight gain were suppressed. Inhibited feeding by survivors appeared to prevent further dose uptake because the proportion of lethally dosed larvae in daily collections did not increase despite significant residual spray deposits in budworm feeding sites. Restoration of "normal" recovery times by the fourth day coincided with a 65–85% reduction in persistence of the pathogen on the foliage and did not result in further lethal dose acquisition, as treatment-induced mortality dropped to about 20% on the 4th and 5th days. The observations are consistent with previous laboratory observations of how B. thuringiensis affects larval feeding and with the hypothesis that feeding inhibition may be a limiting factor in the acquisition of a lethal dose.

scholarly journals Spray Deposition on Weeds (Palmer Amaranth and Morningglory) from a Remotely Piloted Aerial Application System and Backpack Sprayer

Drones ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 59
Author(s):  
Daniel Martin ◽  
Vijay Singh ◽  
Mohamed A. Latheef ◽  
Muthukumar Bagavathiannan
Keyword(s):  
Spray Deposition ◽  
Tap Water ◽  
Application Rate ◽  
Palmer Amaranth ◽  
Test Results ◽  
Herbicide Application ◽  
Aerial Application ◽  
Spray Droplet ◽  
Application System ◽  
Leaf Surfaces

This study was designed to determine whether a remotely piloted aerial application system (RPAAS) could be used in lieu of a backpack sprayer for post-emergence herbicide application. Consequent to this objective, a spray mixture of tap water and fluorescent dye was applied on Palmer amaranth and ivyleaf morningglory using an RPAAS at 18.7 and 37.4 L·ha−1 and a CO2-pressurized backpack sprayer at a 140 L·ha−1 spray application rate. Spray efficiency (the proportion of applied spray collected on an artificial sampler) for the RPAAS treatments was comparable to that for the backpack sprayer. Fluorescent spray droplet density was significantly higher on the adaxial surface for the backpack sprayer treatment than that for the RPAAS platforms. The percent of spray droplets on the abaxial surface for the RPAAS aircraft at 37.4 L·ha−1 was 4-fold greater than that for the backpack sprayer at 140 L·ha−1. The increased spray deposition on the abaxial leaf surfaces was likely caused by rotor downwash and wind turbulence generated by the RPAAS which caused leaf fluttering. This improved spray deposition may help increase the efficacy of contact herbicides. Test results indicated that RPAASs may be used for herbicide application in lieu of conventional backpack sprayers.

The effects on small-mammal populations of aerial applications of Bacillus thuringiensis, fenitrothion, and Matacil® used against jack pine budworm in Ontario

1989 ◽  
Vol 67 (5) ◽  
pp. 1318-1323 ◽  
Author(s):  
Duncan G. L. Innes ◽  
James F. Bendell
Keyword(s):  
Bacillus Thuringiensis ◽  
Small Mammal ◽  
Pinus Banksiana ◽  
Jack Pine ◽  
Pitfall Traps ◽  
Pitfall Trapping ◽  
Northern Ontario ◽  
Limited Impact ◽  
Choristoneura Pinus ◽  
Jack Pine Budworm

In late June 1985, both operational and experimental aerial spraying was conducted against an outbreak of jack pine budworm (Choristoneura pinus) in northern Ontario. We report the effects of the insecticides Bacillus thuringiensis, fenitrothion, and Matacil® on populations of rodents and shrews in young (20 years) and medium-aged (40 years) jack pine (Pinus banksiana) plantations. Live, snap, and pitfall traps were used to monitor small-mammal populations from early June to late August on four sprayed plots and two control plots. We found no statistically significant differences in abundances that could be attributed to an insecticide. However, pitfall trapping suggested that the abundance of shrews was altered by the fenitrothion spray. Both the pattern and magnitude of shrew captures was different relative to a control and two other treatment plots. This difference may have resulted from the lack of available prey (arthropods) on the fenitrothion plot. With the exception of fenitrothion, our results agree with other studies which suggest that standard applications of insecticides to control forest insects have no detectable or only limited impact on small mammals.

Aerial Application Methods for Increasing Spray Deposition on Wheat Heads

2007 ◽  
Vol 23 (6) ◽  
pp. 709-715 ◽  
Author(s):  
B. K. Fritz ◽  
W. C. Hoffmann ◽  
D. E. Martin ◽  
S. J. Thomson
Keyword(s):  
Spray Deposition ◽  
Aerial Application ◽  
Application Methods

Developing the USDA ARS Spray Nozzle Models for Rotary Wing Applications

2017 ◽  
Vol 33 (5) ◽  
pp. 631-640
Author(s):  
W Clint Hoffmann ◽  
Bradley K Fritz
Keyword(s):  
Droplet Size ◽  
User Interfaces ◽  
Computational Models ◽  
Spray Deposition ◽  
Orientation Angle ◽  
Spray Drift ◽  
Product Label ◽  
Aerial Application ◽  
Nozzle Orifice ◽  
Rotary Wing

Abstract. Optimizing aerial spray applications requires proper setup of the sprayer system, particularly with respect to nozzle selection and operation, which significantly affects spray deposition, product efficacy, and spray drift. Droplet size from an aerial application is a function of the combination of nozzle type, nozzle orifice size, spray pressure, orientation angle, and airspeed of the aircraft. A set of computational models for 14 commonly-used aerial application nozzles were developed and released for use by applicators. These models allow applicators to determine the droplet size characteristics associated with their specific nozzle and operational setup, determining the proper combination of orifice, pressure, orientation, and airspeeds from 22 to 54 m/s (50 to 120 mph), which are commonly-associated with applications made from rotary wing aircraft (i.e., helicopters). Both spreadsheet and smartphone user interfaces are available for applicators to use to ensure that their application conforms to the legal droplet size requirements specified on an agrochemical product label. Keywords: Aerial application, Atomization, Droplet size, Droplet size models, Spray nozzles.

Effects of the insecticide Bacillus thuringiensis on Sorex cinereus (masked shrew) populations, diet, and prey selection in a jack pine plantation in northern Ontario

1992 ◽  
Vol 70 (3) ◽  
pp. 505-510 ◽  
Author(s):  
M. I. Bellocq ◽  
J. F. Bendell ◽  
B. L. Cadogan
Keyword(s):  
Population Structure ◽  
Bacillus Thuringiensis ◽  
Pinus Banksiana ◽  
Prey Selection ◽  
Jack Pine ◽  
Adult Males ◽  
Northern Ontario ◽  
Treated Area ◽  
Lepidopteran Larvae ◽  
Sorex Cinereus

A simulated operational spray with Bacillus thuringiensis in a jack pine (Pinus banksiana) plantation near Gogama, Ontario, showed effects of the insecticide on the population structure, diet, and prey selection of the masked shrew, Sorex cinereus. During the pretreatment period, the abundance and population structure of S. cinereus were similar in the control and experimental areas. Although the total abundance of shrews was also similar after spraying, there were fewer adult males and more juveniles in the treated area than in the control. The emigration of adult males was apparently increased after spraying. Lepidopteran larvae and Araneae were the most abundant items in the diet. After spraying, more lepidopteran larvae were eaten on the control than on the treated area. Juveniles and adult females but not adult males shifted from lepidoptran larvae to alternative prey in the treated area. Generalist insectivores such as S. cinereus are more likely to control the abundance of arthropods and less likely to be impacted negatively by selective insecticides such as B. thuringiensis.

AERIAL APPLICATION METHODS FOR INCREASING SPRAY DEPOSITION ON WHEAT HEADS

2006 ◽  
Vol 22 (3) ◽  
pp. 357-364 ◽  
Author(s):  
B. K. Fritz ◽  
I. W. Kirk ◽  
W. C. Hoffmann ◽  
D. E. Martin ◽  
V. L. Hofman ◽  
...  
Keyword(s):  
Spray Deposition ◽  
Aerial Application ◽  
Application Methods

Does aerial spraying of Bacillus thuringiensis subsp. kurstaki (Btk) pose a risk to nontarget soil microarthropods?

2006 ◽  
Vol 36 (6) ◽  
pp. 1610-1620 ◽  
Author(s):  
Janet A Addison ◽  
Imre S Otvos ◽  
Jeffrey P Battigelli ◽  
Nicholas Conder
Keyword(s):  
Bacillus Thuringiensis ◽  
Selective Reduction ◽  
Diversity Indices ◽  
Total Abundance ◽  
Aerial Application ◽  
Soil Microarthropods ◽  
Bacillus Thuringiensis Subsp ◽  
Surface Dwelling ◽  
Time Of Year ◽  
Mite Communities

This field study was carried out to investigate whether application of an aerial spray containing Bacillus thuringiensis subsp. kurstaki (Btk) to control the western spruce budworm (Choristoneura occidentalis Freeman, 1967) had any measurable effects on aspects of the abundance, distribution, diversity, and feeding behaviour of nontarget soil microarthropods. Although total abundance and species richness (N0) of Collembola declined significantly in samples taken 3 weeks after spraying, this decline occurred in the control plots as well as in plots sprayed with Btk. Values for the diversity indices N1 and N2 were not affected by the treatment. Correspondence analysis did not identify changes in collembolan communities following the aerial application of Btk. Total abundance of mites and populations of different suborders (Prostigmata, Mesostigmata, and Oribatida) were not significantly affected by application of Btk, or by the time of year that the samples were collected. There was no evidence of a selective reduction in the surface-dwelling portions of the collembolan and mite communities following exposure to Btk. Similarly, the experimental spray did not cause a decline in the abundance of the guild of Collembola known to feed on bacteria, and the proportion of bacteria in the diet of these Collembola following application of Btk was also unchanged.

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