FIELDAND
FORAGE
CROPS
FIELD
The information and recommendations in this newsletter are applicable to
North Carolina
and may not apply in other areas.
With the upcoming arrival of the major July corn earworm (bollworm) moth flights in North Carolina, the egg stage becomes the principle area of focus. Threshold levels of eggs often are met within a week of significant increases in light or pheromone trap catches. At the onset of these moth flights, scouting twice per week is suggested until the threshold of 10 eggs per 100 terminals or 2 percent eggs on fruit is met. Eggs are mostly found in the terminals during the first 2 weeks of the moth flight, but can be deposited down in the plants later in the season or in dry weather.
Two pyrethroid treatments applied five days apart as an egg
threshold response has been effective for producers in North
Carolina for the past nine years, particularly in situations where
three or more applications are anticipated. In other situations,
notably in areas expecting lighter bollworm pressure, a single
application at the industry rate may be appropriate, followed by
subsequent scouting for bollworm larvae on squares or bolls. If
insecticide is applied by ground and six or more days may be
required to treat the cotton acreage at threshold, a single
treatment at the higher labeled rate is suggested. At this time of
year, a timely start is particularly important as cotton at our
latitude can compensate little for bolls lost to caterpillars in
August. After the initial application(s) of insecticide, base
further treatments on finding 3 percent or more bollworms on
squares or bolls.
Because insecticide treatment for bollworms and European corn
borers is expected to be minimal in Bollgard cotton, green and
brown stink bugs are expected to increase in numbers.
Stink bug
damage should be assessed during normal scouting for bollworm-
damaged bolls by cutting into questionable bolls with a sharp
knife. If the stink bug damaged bolls exceeds 2 percent, one of
the suggested stink bug scouting procedures should be followed (see
the
Cotton Insect Scouting Guide for details). If
treatment is indicated, use either one of the pyrethroids at the
industry rate or methyl parathion at 0.5 pound of active
ingredient per acre; a single application should suffice. Be wary
of the high mammalian toxicity of methyl parathion, and follow
label directions carefully.
The following cotton scouting schools have been scheduled for mid-July:
Lenoir-Greene-Craven-Jones-Onslow County area. July 16, 1996 at 7:00 p.m. King's Restaurant, Kinston. Contact either Curtis Fountain (919-633-1477) or Alan Harper (919-527-2191) for information.
Union-Stanley-Anson-Montgomery area. July 17, 1996 at 9:00 a.m. Contact Tom Pegram (919-704-3801) or Jim Monroe (704-983-3987) for information.
Northampton County. July 18, 1996 at 9:30 a.m. Northampton County Administration Building, Jackson. Contact David Fogarty (919-534- 2711) for information.
Halifax County. July 18, 1996 at 1:30 p.m. Halifax County Agricultural Building, Halifax. Contact Arthur Whitehead (919-583- 5161) for information.
Edgecombe County. July 19, 1996 at 9:30 a.m. Edgecombe County Administration Building, Tarboro. Contact Joe Dickens (919-641- 7815) for information.
Both indoor and field instruction are planned for each scouting
school. John Van Duyn, Extension Entomologist, Vernon G. James
Center, Plymouth, North Carolina, has arranged a series of similar
schools for the northeastern North Carolina cotton counties.
Scouting for bollworms, European corn borers, armyworms and stink
bugs in conventional and B.t. (Bollgard) cotton will be emphasized.
The new scouting guides will be distributed at the schools.
Web page last updated on 15 July 1996 by Stephen J. Toth, Jr..
