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Aerial application of Btk is the preferred method for eradicating and suppressing gypsy
moth populations that are widespread. There are several important advantages of using this
method over other forms of treatment.
- Safe - Foray 48B (Btk) is harmless to non-target organisms (other than some
species of caterpillars) especially humans. Because there are minimal health risks and it
does not harm the environment, Foray 48B can be applied over populated areas without any
buffers for water bodies.
- Effective - Aerial sprays have been proven over several decades of use to be
highly effective at achieving the desired level of control of gypsy moth and other forest
pests.
- Fast - treatment can be completed in only a few hours vs. ground applications
which may take several days to treat a much smaller area. The majority of droplets will be
have reached the ground within 10 minutes of application.
- Complete coverage - droplets are evenly spread throughout the target area and,
most importantly, are able to penetrate crowns of trees no matter how high they are.
Ground application of Btk is limited by access, terrain, and the height and density of the
target vegetation.
- Cost effective - aerial application has the lowest cost per hectare of any
effective treatment.
There is one technical disadvantage:
- Weather limitations - rain and wind are the most important factors limiting the
application of Btk aerially. Spraying can be done in moderate winds but low to no wind is
preferred. A period of 2 hours without precipitation after spraying is required to allow
adequate adherence of the Btk to foliage.
Aerial application of Foray 48B (Btk) will
usually:
- be conducted during a period between April
1 to June 30 (specific dates are unknown as they are dependent on both
the development rate of the gypsy moth and the weather)
- start between dawn (approximately 5 AM)
and 7:30 AM in April and between dawn to 7 AM in May and June
- be completed in about 1.5 hours on each
day of application
- have three applications of Foray 48B
ideally spaced 10 days apart but the actual time between sprays will
probably vary by several days depending on weather conditions and insect
development
- have a public notice provided at least 24
hours in advance of any spray through radio, TV, and this web site. A
toll-free information line will also be open during the hours of 8:30 AM
to 4:30 PM to provide answers to any questions regarding the spray. This
number will be posted on this site and advertised when it becomes
operational.
- have written notification given to all
schools and hospitals at least 24 hours before a spray is to be done [Note: If 24 hours notice is given, the
spray may actually take place any time after the 24 hour period due to weather and other
uncontrollable factors]
- be conducted by highly trained spray
specialists using multi-engined aircraft. All necessary safety
precautions will be taken to ensure that there is minimal risk to the
public and the applicators. All activities will be closely monitored by
the project team.
- be applied by aircraft flying as low as
150 feet above ground level so it is likely that the public will hear
aircraft noise in the early morning hours.
Detailed Information on Aerial Application
Methods
Click here
for more specific information on aerial application methods for
gypsy moth eradication.
Gypsy
Moth Homepage > Management Options
> Description of the Eradication Strategy
> monitoring > Selecting
a Treatment > Aerial Spraying with Btk > Detailed
Information on Aerial Spraying > Ground
Spraying > Alternative Treatments >
public involvement
Source: Fraser, B.D. and Agriculture
and Agri-Food Canada. 1994. Draft Management Plan for the North American
Gypsy Moth in British Columbia. 35 pp.
Contact Tim Ebata
if you have comments on the presentation of this information.
BC Ministry of Forests and Range
Forest Practices Branch
P.O. Box 9513 Stn. Prov. Gov.
Victoria, BC
V8W 9C2
Section phone: (250) 387-8739
Section fax: (250) 387-2136
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