Trapping is the first line of attack in boll weevil eradication
operations. Trapping identifies the location of boll weevil
populations and measures their densities.
The boll weevil trap has three parts: a body, a molded screen
cone and a collection chamber. The yellow-green trap body mimics the
plants the boll weevil lives in and feeds on.
artificial pheromone contained in a polyvinyl-chloride dispenser is
placed in the collection chamber to attract weevils along with an
insecticide strip to kill weevils that enter the trap.
Weevils attracted to the trap land on the outside of the body and
crawl to the inside of the cone. An opening in the top of the cone
allows the weevils to enter the collection chamber.
Traps are placed around fields at the rate of one trap every
tenth of a mile. However, the density may be doubled to two traps
per one-tenth of a mile alongside any overwintering habitat areas
such as brush, grass, shrubs, weeds, etc. In the latter stages of a
program, trap density is reduced.
Traps between two adjacent cotton fields are spaced at one trap per
one-tenth of a mile by alternating trap positions and assignments
between the two fields.
Traps are placed around the perimeter of all cotton fields on a
four-foot long, wooden stake driven into the ground. Each trap is
set on a nail halfway driven into the top of the stake to hold the
trap upright in high winds or other disturbances.
Traps are placed as near to the cotton field as possible but in a
position that avoids the regular path of field equipment or other
traffic. This keeps the traps from being damaged and maintains a
high level of trap effectiveness.
Also, the trap is positioned in as open an area as possible, free
from weeds, brush or other obstacles that may obstruct trap
visibility or interfere with free airflow to and from the traps.
The work unit number, field number and trap number are marked on the
outside of the trap body. Each trap is identified with a unique
number to precisely pinpoint the location of each trap capture. Trap
numbering begins with No. 1 at the northeast corner of each field,
moving counterclockwise around the field with subsequent trap
numbers 2, 3, 4 etc.
Note: The traps used in the eradication program are important to
the program’s success. Cotton producers are asked to take care when
working around the traps to ensure the traps are not damaged or
destroyed. Growers are encouraged to work with their field unit
Traps are inspected once a week.
lure is replaced every two weeks. The date of lure replacement is
indicated on the lure by marking the date on the lure with a
permanent marker pen.
Insecticide strips are replaced once a month. Insecticide strip
replacement is indicated by marking “I.S.” next to the
trap-servicing date on the trap body.
Trappers also check the current crop stage in the field next to each
trap and report the most advanced stage.
bar-code system is a crucial part of the boll weevil
trapping program. The bar code for each trap is unique, associating
the data from a particular trap to a computerized map location.
Each time a trap is inspected a hand-held scanner is used to read
the bar code. The time and date of inspection as well as the
sequence in which the traps are serviced are automatically recorded.
Trappers also record crop stage, number of weevils found in the
trap, replacement of pheromone and insecticide dispensers and trap
Quality control ensures program guidelines for boll weevil
trapping are being properly implemented and is conducted throughout
the season. A minimum of 15 percent of all fields in each work unit
are randomly selected on a weekly basis. Quality control consists
Visual Inspection -- A supervisor inspects ttraps and reports on
whether the traps have been properly mapped, placed at the correct
density and properly positioned. The inspecting supervisor also
checks to be sure the lure and insecticide strips have been properly
replaced and whether the proper information has been recorded on the
Spiking -- The inspecting supervisor will plant a known number
of weevils or tokens in a percentage of the fields selected for
quality control that week.
Information gathered by the supervisor is entered into the computer
and subsequently compared with the relevant daily trapping report
when it is submitted. This comparison verifies that the spiked
weevils were recovered and allows Foundation personnel to determine
how many weevils were actually captured in the trap.
Trappers who fail to retrieve spiked weevils or tokens or report
false data are subject to disciplinary action, including