C
Damaged
1 inch boll
Under the Radar, Deep in the Canopy
Brown Stink Bugs in Arizona Cotton
Peter C. Ellsworth, Lydia Brown & Ayman Mostafa
The Brown Stink Bug (Euschistus servus) (BSB) (A) is rarely
damaging in Arizona cotton, but at high densities, they can reduce
yield and quality. BSBs pierce bolls to feed on developing seeds;
young bolls (<10 d old) (B) may shed when these are the only sizes
available to the bugs (C). BSB can cause carpel and seed injury
(D), stain lint, lower yields and quality, and encourage boll rot
organisms. Successfully attacked bolls will have callus warts (E) on
the interior of the carpel wall or brown stains on lint (F) and seeds.
An externally visible small brown pockmark on the boll surface
does not necessarily mean the boll interior is damaged; bolls
must be opened to determine if injury has occurred.
D
Brown Stink
Bug (BSB)
Damage to young
bolls causes shed
s
A
Warts form inside
the carpel wall
E
There is no recent Arizona-specific information available for
monitoring or decision-making. We must rely on information from
Stained lint
the Southeastern U.S. Stink bug action thresholds are based on the
percentage of internally damaged bolls (bolls with any internal
Tracer 0.07
Tracer 0.06
0.07
injury). Collect at least 25 1-inch bolls from each field, avoiding
Intrepid
Tracer 0.06
0.07
FDenim
Intrepid
field edges. The boll sample must consist of properly sized bolls,
0.0125
Tracer 0.06
0.07
Intrepid
Denim
0.0125
Tracer
0.07
which give easily when squeezed and are 0.9–1.1 inches in
Intrepid
0.06
Denim 0.0125
diameter. Crack and inspect bolls for internal injury. If any warts
Intrepid
0.06
Intruder
0.05
Denim
0.0125
Intruder
0.05
or stained lint are present, count that boll as injured. Chemical
PhillipsProvado
2-4
DAT
field
Denim
0.0125
0.047
Intruder
0.05
2-4
DAT(0.05)
field
control may be warranted when 20% or more of the boll sample PhillipsProvado
0.047
Centric
Centric 0.05
Intruder
0.05
2-4
DAT(0.05)
field
Provado
0.047
Centric
Centric
0.05
have warts or stained lint and stink bugs are present in the field. Phillips
Intruder
PhillipsProvado
2-4 DAT(0.05)
field
0.047
Centric
Centric
0.05
The Southeast has developed dynamic thresholds for stink bugs,
Provado
0.047
Endigo
(4-5.5
oz)
Leverage
0.0634
Centric
(0.05)
Centric
0.05
because cotton’s susceptibility to stink bugs varies. Very early and
Endigo
(4-5.5
oz)
Leverage
0.0634
Centric
0.05
Leverage
0.0634
Endigo
(4-5.5
oz)
very late in the season, stink bugs do not pose as much of a threat
Ammo
0.06
Leverage
0.0634
Endigo
(4-5.5
oz)
and higher percentages of injured bolls can be tolerated, up to 50% Karate
Ammo
0.06
Leverage
0.0634
(0.025-0.032)
Karate
0.03
Ammo
with warts or stained lint. Maturing bolls are relatively safe from Karate (0.025-0.032)
Karate 0.06
0.03
Baythroid
0.04
Ammo 0.06
Karate
0.03
stink bug feeding injury starting at 25 days of age or once they are KarateBaythroid
(0.025-0.032)
0.04
Ammo
0.06
Fury
0.0445
Karate
0.03
KarateBaythroid
(0.025-0.032)
≥1.25 inches in diameter; internal injury to lint is unlikely.
0.04
Fury
0.0445
Karate
0.03
Research in Arizona as far back as the 1950s confirms that stink
bugs are not caught in representative numbers in standard
sweep net sampling, because they drop rapidly from plants and are
frequently located on the plant below the range of a normal net
stroke. Do NOT rely on sweep net sampling alone, except to
confirm BSB presence in the field. Small boll sampling is
required to schedule and to assess chemical controls.
There have been no BSB specific chemical control studies since
the early 1960s, when BSB was often associated with alfalfa
production. So we must rely on the Southeast; however, even there,
most chemicals are screened against a complex of unrelated stink
bugs (Green Stink Bug & Southern Green Stink Bug). Lab bioassay results for BSB show that Bidrin is highly effective (Fig. 1).
Though a standard there, this old organophosphate is not registered
for use in Arizona. Bidrin is significantly more effective on
Euschistus spp. than bifenthrin (Capture), but not more so than
acephate (Orthene). Acephate at the full label rate of 1 lb ai / A may
provide control of BSB. Belay is an option for helping suppress
stink bug populations in general but should not be relied on as a
rescue tool. Few other products are effective.
8/2012!
Any products, services, or organizations that are mentioned, shown, or indirectly implied in this publication
do not imply endorsement by the University of Arizona.
Shed bolls
B
Others
Others
Others
Others
Others
Neonicotinoids
Neonicotinoids
Neonicotinoids
Neonicotinoids
Neonicotinoids
Pyrethroid
*
mixture
Pyrethroid
mixture
Pyrethroids
Pyrethroids
Pyrethroids
Pyrethroids
Pyrethroids
Capture
(0.05-0.10)
Capture
0.06
Baythroid
0.04
Fury
0.0445
Capture
(0.05-0.10)
Capture
0.06
Baythroid
0.04
Fury 0.0445
Capture
0.06
Capture
(0.05-0.10)
Fury
0.0445
Curacron
0.75
Capture
0.06
Capture
(0.05-0.10)
Curacron
0.75
Capture0.773
0.06
Malathion
Organophosphates
Curacron0.773
0.75
Malathion
Orthene
(0.75-1.0)
Orthene
0.5
Curacron
0.75
Malathion
0.773
Organophosphates
Orthene
0.5
Orthene
(0.75-1.0)
Curacron
0.75
Orthene
(0.5)
Orthene
Malathion
0.773
Organophosphates
Orthene
0.5
Orthene
(0.75-1.0)
Orthene
0.75
Orthene
(0.5)
Malathion
0.773
Bidrin
(0.05)
Bidrin
0.5
Organophosphates
Orthene
0.5
Orthene
(0.75-1.0)
Orthene
0.75
Orthene
(0.5)
Bidrin
0.5
Bidrin
(0.05)
Organophosphates
Orthene
UTC
Orthene
0.75
Orthene
(0.5)
Bidrin
0.5
Bidrin
(0.05)
UTC
Orthene
0.75
10 20 30 40 50 60 70 80 90 100
Bidrin
0.5 0
Bidrin
(0.05)
UTC
0BSB
10
20
40
50 (%
60at 24
70hr)
80
90(%)100
Contact
Lab 30
Efficacy,
24-hr
Corrected
Mortality
0.5
Figure Bidrin
1. Topical
lab insecticide
efficacy
in Arkansas
UTC
0 Contact
10
20
30
40 Georgia
50 Corrected
60
70 Euschistus
80 90(%)100
Lab
Efficacy,
24-hr
Mortality
(bars) & Field
efficacy
(%
2–4
DAT)
in
against
UTC
0 Contact
10 20
40 24-hr
50 Corrected
60 70 Mortality
80 90(%)100
Lab 30
Efficacy,
spp. (dots ± SEM);
from
Greene
et50
al. 2005,
Beltw.
0 adapted
10 20
40 24-hr
60 Proc.
70 Mortality
80
90(%)100
Contact
Lab 30
Efficacy,
Corrected
Cotton Proceedings Contact
& P. Roberts,
unpubl.24-hr
data.Corrected
*Endigo Mortality
at 4–5.5 (%)
oz.!
Lab Efficacy,
0.9" Boll sizes for
stink bug
sampling
1.1" Also see:
Bacheler, J. et al. 2010. http://ipm.ncsu.edu/cotton/insectcorner/pdf/AG_730_WPrint-NC.pdf
Herbert, A. et al. 2010. http://pubs.ext.vt.edu/444/444-390/444-390_pdf.pdf
Also
Bache
co
Co
ht
Herbe
So