The Tools:
The Trap:
Growers and the public alike may be curious about the plastic, yellow-green
fluorescent traps that are highly visible around cotton fields during the
main eradication phase. Initially these traps may be placed from 100 to
250 feet apart around the edge of every cotton field. After eradication,
the cotton is monitored with 1 trap for every 10 acres to alert managers
to any reinfestation. The size, shape, and color of the trap have been
proven attractive to the weevil through years of careful research. The
trap is an inverted cup, topped with a cone-shaped wire mesh screen. A
capture chamber on top of the cone contains a dispenser for boll weevil
attractant. A chip with insecticide is added to prevent weevils from escaping.
The interchangeable parts make the trap economical.
The Pheromone:
The pheromone is a chemical called grandlure, a laboratory version
of the weevil's own attractant, used by the insects to call each other
together for mating. Fresh 10-mg doses of grandlure are placed in traps
every 14 days. As the weevil population is reduced, the pheromone becomes
increasingly effective at "calling" weevils to the trap. Armed with information
on weevil populations provided by the baited traps, officials know when
and where to apply necessary treatments. Continuous trapping helps determine
the treatment efficacy. At very low population levels, the trap also serves
as a control device, ridding a field of the last few pests. Trapping with
grandlure can detect weevils at lower levels than visual surveys. Producers
should continue scouting their cotton for other pests, however, because
the eradication program will treat for boll weevil only. Growers will continue
to be responsible for control of other cotton pests.
The Insecticide:
The program begins with fall treatments in areas where significant
numbers of weevils have been found over winter. These treatments are applied
every 7 to 14 days, depending on temperature and plant growth, as well
as trap counts. In succeeding years, a field is treated only if a threshold
number of weevils is trapped. The insecticide used in the eradication program
is selected by the OBWEO. The organization contracts with a chemical company
and aerial applicators on an annual basis. Eligible insecticides must be
approved by the Environmental Protection Agency as environmentally safe
for use on cotton. The program uses only short-lived materials that will
not carry over in the soil from one season to the next. Malathion was used
last season; it is commonly used in home-and-garden preparations and many
mosquito-abatement efforts.
Cultural Practices:
Growers are encouraged to follow good cultural practices that will
limit early and late food sources for the weevil: