Oregon Grasshopper and Mormon Cricket
Survey Summary for 2013
Table of Contents
Introduction ------------------------------------------------------------------------------------------------------------------- 2
Areas of Special Mention -------------------------------------------------------------------------------------------------- 5
Fort Klamath Basin ------------------------------------------------------------------------------------------------- 5
Klamath Marsh National Wildlife Refuge ---------------------------------------------------------------------- 5
Lower Lake County ------------------------------------------------------------------------------------------------- 9
Malheur Wildlife Refuge ----------------------------------------------------------------------------------------- 10
Portland International Airport ----------------------------------------------------------------------------------- 10
Mormon Crickets ---------------------------------------------------------------------------------------------------------- 10
Tribal Lands ----------------------------------------------------------------------------------------------------------------- 11
Summary -------------------------------------------------------------------------------------------------------------------- 13
Figures
Fig. 1.
2013 estimated areas of surveyed showing three levels of infestation ------------------------ 3
Fig. 2
2013 survey locations and areas of economic infestation superimposed on ---------------- 3
counties ranked by economically infested acreage
Fig. 3
Millions of acres economically infested with grasshoppers in Oregon during --------------- 4
the recent past.
Fig. 4
Survey locations and estimated areas of grasshopper infestation in the
Fort Klamath basin ----------------------------------------------------------------------------------------- 5
Fig. 5
2013 nymphal grasshopper survey for the Klamath Marsh -------------------------------------- 6
Fig. 6
2013 treatment blocks on Klamath Marsh NWR including pre-treatment survey points -- 7
Fig. 7
2013 adult grasshopper survey for the Klamath Marsh ------------------------------------------- 8
Fig. 8
Areas of high grasshopper density across central and southern Lake County -------------- 9
Fig. 9
Grasshopper 2013 densities (GH / yd2) on and around the Malheur National ------------- 10
Wildlife Refuge
Fig. 10
Surveyed areas on CTUIR lands in north-central Oregon 2013. ------------------------------ 11
Fig. 11
Three locations where Mormon crickets (Anabrus sp.) were observed in north- --------- 12
central Oregon.
Table 1
Oregon Grasshopper Survey Statistics from 2005 through 2013. Economic
infestation  8 grasshoppers / yd2 ---------------------------------------------------------------------- 2
Table 2
A comparison of grasshopper (GH) infestation densities (/ yd2) adjusted for effort -------- 2
Appendix 1 Estimate of the acreage with economic levels of grasshopper infestation (8
grasshoppers / yd2) based on the 2013 survey --------------------------------------------------- 14
201312121053
Oregon Grasshopper and Mormon Cricket Survey Summary for 2013
Introduction
The 2013 Oregon grasshopper survey season, conducted by the Oregon Department of Agriculture
(ODA) in cooperation with the Oregon United States Department of Agriculture (USDA) Animal and
Plant Health Inspection Service (APHIS) Plant Protection and Quarantine (PPQ) office, showed that
the grasshopper population continues its decline from a high in 2011. Surveying began on 13 May
and ended on 22 August. Nymphal survey takes place early in the season and is used to locate
potential outbreak areas for the current year. Adult survey (this year 8 July - 22 August) is used by
APHIS to make predictions for the following season, estimating economic levels as 8 or more
grasshoppers per square yard. In 2013, a total of 1,489 sites were visited. Of the total stops 462
were during the period for nymphal grasshopper survey and 935 during the adult period (Table 1).
Approximately 0.87 million acres across 15 counties in eastern Oregon were estimated to be
economically infested (Fig. 1, Table 1). Thirteen of these counties had greater than 10,000
economically infested acres (Fig. 2; Appendix 1).
Table 1. Oregon Grasshopper Survey Statistics from 2005 through 2013. Economic infestation  8
grasshoppers / yd2.
Grasshopper Sites Surveyed
Year
Number
Counties
Infested
Acres of
Econ.
Infest.
Total
Nymph
Adult
Treatment
2013
2012
2011
2010
2009
2008
2007
2006
2005
15
17
18
12
11
12
13
14
9
869,857
1,178,872
2,888,455
1,910,222
151,974
1,129,820
798,358
97,399
64,751
1,489
1,135
3,139
1,905
998
2,722
1,585
1,368
859
462
387
1880
795
491
1116
706
750
306
935
748
914
750
507
1606
870
618
423
92
34
345
360
Samples
w/Econ
Density
Mean
GH /
yd2*
Number
of GH
Surveyors
280
526
1093
488
108
360
298
100
115
50
34
20
21
18
29
18
16
15
2.5
2.5
6
6
4
6
6 (+2)
6
5
*Mean of economically infested samples
Overall climatic conditions were again dry and warm this season.
Last year (2012) it was not clear if grasshopper population densities slightly lower than 2011 signaled
the start of an outbreak decline or were an artifact of having to scale back our survey effort. While the
survey resources are still down (Sites Surveyed, Table 1) it does appear that the densities found this
year indicate an end to the outbreak (Table 2, Fig. 3). When this year's areas of economic density
are adjusted for sampling effort the population decline from 2012 to 2013 is much greater than that
between 2011 and 2012 (Fig. 3).
Table 2. A comparison of grasshopper (GH) infestation densities (/ yd2) adjusted for effort.
Year
2013
2012
2011
Percent of Total Surveyed Acres
Economic
non-Econ
No GH
14.3
33.7
38.9
38.6
46.8
43.4
Total
47.1
19.6
17.7
6,093,999
3,503,235
7,422,908
2
Estimated Acres Surveyed
Economic
non-Econ
No GH
869,857
1,178,872
2,888,455
2,352,182
1,639,468
3,220,585
2,871,960
684,895
1,313,868
Fig. 1. 2013 estimated areas of surveyed showing three levels of infestation.
Fig. 2. 2013 survey locations and areas of economic infestation superimposed on counties
ranked by economically infested acreage.
3
3.0
2.5
Millions of Acres
% Sampled Acres Scaled to Maximum Season (2011)
2.0
1.5
1.0
0.5
0.0
2005
2006
2007
2008
2010
2011
2012
2013
Years
Fig. 3. Millions of acres economically infested with grasshoppers in Oregon during the
recent past. Brown bars indicate 2011 - 2013 values adjusted for sampling effort (% of
annual acreage sampled scaled to the economic acres surveyed in 2011).
This does not mean the pattern of decline is evident across all regions, nor that significant
grasshopper densities are not a problem at the local level. In addition to the areas discussed below,
where densities are still quite high and may even be on the increase, areas in central Baker and
Union counties also experienced a slight of increase during 2013.
4
Areas of Special Mention
Fort Klamath Basin.
Historically outbreaks have plagued the area around Fort Klamath. In 2010 a few of the basin's
private landowners made treatments. Since that time we have detected a slow density increase to
the point where 2013 levels suggest potential problems for 2014 (Fig. 4). Early monitoring and
preparation for suppression efforts are advised for 2014, especially in the northwest area.
Fig. 4. Survey locations and estimated areas of grasshopper infestation in the Fort Klamath basin.
Area ranchers considered a treatment program until their attention was diverted by the irrigation water
call back that occurred this summer. The dry range conditions and increasing grasshopper
population could lead to a larger problem next year. This area warrants a close look during
grasshopper hatch to see what develops.
Klamath Marsh National Wildlife Refuge (KMNWR).
Due to severe outbreaks of the clear-winged grasshopper, Camnula pelucida, in 2011 and 2012, we
focused a great deal of this year’s resources to intensive survey at the Klamath Marsh. We made
nearly weekly survey visits to the Marsh throughout the season (Fig. 5). The dense populations of
clear-winged grass hoppers and the dry climatic conditions in 2012 resulted in an extreme loss of
forage and economic impact to the private rangeland adjacent to the KMNWR. As a result, a meeting
was held between the KMNRW, private ranchers, and ODA/APHIS to coordinate control efforts in
2013.
5
Fig. 5. 2013 nymphal grasshopper survey for the Klamath Marsh.
The early June scouting on the KMNWR and surrounding private holdings indicated the southwest
area of the Marsh would again experience the high population densities it had in the previous three
seasons. ODA/APHIS participated in a suppression program at the Klamath Marsh in conjunction
with treatments done by neighboring ranches. At the request of the Fish and Wildlife Service (FWS)
APHIS, with assistance from ODA, treated approximately 312 acres with Dimilin applied at 1 oz/ac
using ground equipment (Fig. 6). Application was made in a 50% skip swath so that 624 acres were
6
protected. Neighboring landowners also treated in conjunction with efforts on the Refuge. It was
estimated 1,600 ac were protected on private land.
Fig. 6. 2013 treatment blocks on Klamath Marsh NWR including pre-treatment survey points.
The adult survey this year recorded much reduced grasshopper populations throughout the Klamath
Marsh compared with the past two years (Fig. 7). Survey in spring 2014 hopes to find the outbreak is
waning.
7
Fig. 7. 2013 adult grasshopper survey for the Klamath Marsh.
8
Lower Lake County.
Several locations in the central and south half of Lake County developed very high grasshopper
densities by the end of the season (Fig. 8). Across the southern area of this county, and certainly in
the vicinity of these survey areas, it would be wise to keep a close watch on the 2014 hatch and be
prepared for suppression activities if needed.
Fig. 8. Areas of high grasshopper density across central and southern Lake County.
9
Malheur Wildlife Refuge.
Grasshopper densities from 2009 and 2010 had suggested economic densities might be a problem in
and around the Malheur Wildlife Refuge in future years. 2013 densities in the immediate vicinity of
the Refuge are still of little concern, but further north, in the Burns area, there are pockets of
economic density (Fig. 9). Landowners in this region should be watchful during the spring hatch of
2014.
Fig. 9. Grasshopper 2013 densities (GH / yd2) on and around the Malheur National Wildlife Refuge.
Portland International Airport.
After successfully treating a problematic grasshopper population at the Portland International Airport
(PDX) with Dimilin in 2009 the Port of Portland continues to enjoy effects of that suppression. The
grasshopper outbreak was attracting birds to the airport grounds which created a dangerous situation
for aircraft. Even though grasshopper 2013 densities continue to be well under any level of economic
concern in relation to forage consumption, PDX has a goal of even lower grasshopper populations for
human/aircraft safety reasons. As a result a prophylactic Dimilin treatment was done on selected
airfield areas in early July.
10
Tribal Lands
The Survey intersected with tribal holdings (69,369 ac) at a few locations including Umatilla (CTUIR)
(45,235 ac), Warm Springs (23,452 ac) and Burns-Paiute (442 ac) lands. Only one area on the
CTUIR attained an economic density in the 8 - 15 grasshoppers / yd2 range (Fig. 10). This area may
warrant attention in 2014.
Fig. 10. Surveyed areas on CTUIR lands in north-central Oregon 2013.
11
Mormon Crickets
For the last few years Mormon Crickets have been on the decline. We did encounter the crickets at a
few locations in north-central Oregon this year (Fig. 11). These populations were at relatively low
density. Our survey found no bands of crickets in the usual areas of southern Malheur County.
Fig. 11. Three locations where Mormon crickets (Anabrus sp.) were observed in north-central
Oregon.
12
Summary
Given survey results from 2013 it appears our recent outbreak cycle peaked in 2011 and densities
are now returning to pre-outbreak levels of little economic concern, in most of eastern Oregon. That
is not to say, given the right conditions the trend cannot reverse, or that locally significant densities
cannot persist into the next few years. We cannot accurately predict where grasshopper outbreaks
will occur because they depend greatly on many factors at the time of hatch and early development,
variables that cannot be accurately forecast. However, we consider it likely that overall the pattern of
density decline (Fig. 3) will continue in 2014.
Even considering this promising trend we still encourage landowners, especially those in areas where
high or building populations persist, to be proactive in early 2014 if they are concerned about
grasshopper impacts to crops and rangeland. Control is most effective on young grasshoppers.
Contact us or your local Extension Office for advice, assistance, or to report grasshopper populations.
Paul Blom, Oregon Department of Agriculture, Salem, OR, 503-508-1253, [email protected]
Gary Brown, USDA-APHIS Portland, OR, 503-326-2814 (ext. 239), [email protected]
26 November 2013
Oregon’s grasshopper and Mormon cricket survey program:
http://www.oregon.gov/ODA/PLANT/IPPM/pages/gh_mc.aspx
Rangeland Grasshopper and Mormon cricket program:
http://www.aphis.usda.gov/plant_health/plant_pest_info/grasshopper/index.shtml
ARS resource page for grasshopper and Mormon Cricket:
http://www.sidney.ars.usda.gov/grasshopper/
13
Appendix 1. Estimate of the acreage with economic levels of grasshopper infestation (8 grasshoppers / yd2) based on
the 2013 survey
Ownership as a
Percentage of Area
Infested
County
Watershed
Acres
Baker
Hectares
Public Private Undet.
Burnt River
Clarks Creek-Burnt River
Love Creek-Powder River
North Fork Burnt River
Rock Creek-Powder River
Rock Creek-Snake River
Ruckles Creek-Powder River
Wolf Creek-Powder River
57,790
1,763
9,178
10,525
6,204
7,252
4,810
16,715
1,343
23,387
713
3,714
4,259
2,511
2,935
1,947
6,764
544
42.4
48.1
15.7
61.0
80.2
0.0
68.7
45.0
0.0
57.6
51.8
84.3
39.0
19.8
100.0
31.3
55.0
100.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Deschutes River-Charleton Creek
Upper Dry River
17,055
6,475
10,580
6,902
2,620
4,281
82.8
100.0
72.2
17.2
0.0
27.7
0.0
0.0
0.0
Bear Creek
Beech Creek
Big Creek-Middle Fork John Day River
Canyon Creek
Cottonwood Creek
Eight Mile Creek-Middle Fork John Day River
Fields Creek-John Day River
Grub Creek-John Day River
Laycock Creek-John Day River
Long Creek
Upper Silvies River
79,821
1,124
3,469
12,359
455
11,181
8,041
322
19,208
154
17,131
6,377
32,302
455
1,404
5,001
184
4,525
3,254
130
7,773
62
6,933
2,581
14.4
87.5
67.6
2.0
9.9
26.5
0.9
100.0
4.3
100.0
4.8
42.3
85.6
12.5
32.4
98.0
90.1
73.5
99.1
0.0
95.7
0.0
95.2
57.7
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Harney Lake-Malheur Lake
Home Creek-Garrison Lake
Kiger Creek-Diamond Canal
Lower Silvies River
Middle Donner und Blitzen River
North Basin
Sage Hen Creek
Upper Donner und Blitzen River
Walls Lake Reservoir
97,584
2,898
467
6,138
36,112
6,683
30,237
1,562
6,616
6,871
39,481
1,172
189
2,484
14,614
2,705
12,237
632
2,677
2,781
11.5
3.8
0.0
69.2
2.8
48.6
1.3
0.0
33.0
0.2
88.5
96.2
100.0
30.9
97.2
51.4
98.7
100.0
66.9
99.8
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Hood River
Mosier Creek-Columbia River
3,016
1,140
1,876
1,220
461
759
5.4
13.2
0.7
94.6
86.8
99.3
0.0
0.0
0.0
Antelope Creek
Muddy Creek-John Day River
Upper Trout Creek
10,350
315
5,367
4,669
4,189
128
2,172
1,889
1.5
0.0
2.7
0.2
98.5
100.0
97.3
99.8
0.0
0.0
0.0
0.0
Deschutes
Grant
Harney
Hood River
Jefferson
14
Appendix 1, continued.
Ownership as a
Percentage of Area
Infested
County
Watershed
Acres
Klamath
Hectares
Public Private Undet.
Big Springs Creek-Klamath Marsh
Crater Lake-Williamson River
Hog Creek-Williamson River
Jack Creek-Williamson River
Wood River
22,126
2,512
4,369
235
5,309
9,702
8,954
1,017
1,768
95
2,148
3,926
13.2
1.0
13.9
15.7
1.5
22.5
86.8
99.0
86.1
83.8
98.5
77.5
0.0
0.0
0.0
0.0
0.0
0.0
Alkali Lake
Anna River-Summer Lake
Crooked Creek
Deep Creek
Drews Creek
Lower Chewaucan River
Poverty Basin
Sand Canyon-Lake Albert
Thomas Creek
98,396
10,997
7,458
71
13,205
10,273
45,894
12
2,238
8,249
39,820
4,450
3,018
29
5,344
4,157
18,573
5
906
3,338
43.4
100.0
35.6
0.0
20.8
18.3
46.1
100.0
100.0
12.3
56.6
0.0
64.4
100.0
79.2
81.7
53.9
0.0
0.0
87.7
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Johnston Gulch Reservoir-Lower Malheur River
Little Malheur River
Middle Willow Creek
13,939
5,485
8,435
18
5,641
2,220
3,413
7
38.4
80.5
11.0
0.0
61.6
19.5
89.0
100.0
0.0
0.0
0.0
0.0
9,960
2,950
7,010
4,031
1,194
2,837
0.0
0.0
0.0
100.0
100.0
100.0
0.0
0.0
0.0
52,723
1,497
7,390
10,938
20,307
6,994
5,597
21,336
606
2,991
4,426
8,218
2,830
2,265
47.7
0.0
0.6
57.3
92.7
0.0
0.6
52.3
100.0
99.4
42.7
7.3
100.0
99.4
0.0
0.0
0.0
0.0
0.0
0.0
0.0
104,517
13,636
2,043
8,685
16,186
1,585
9,866
1,413
17,772
3,547
8,315
21,469
42,297
5,518
827
3,515
6,550
641
3,992
572
7,192
1,436
3,365
8,688
1.9
0.0
0.0
5.1
0.0
18.0
7.2
2.8
0.7
3.7
0.0
1.2
98.1
100.0
100.0
94.9
100.0
82.0
92.8
97.2
99.3
96.3
100.0
98.8
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Lake
Malheur
Morrow
Rhea Creek
Upper Willow Creek
Umatilla
Alkali Canyon-Umatilla River
Birch Creek
Lower Camas Creek
McKay Creek
Stage Gulch
Upper Butter Creek
Union
Cabin Creek-Grande Ronde River
Indian Creek-Grande Ronde River
Ladd Creek
Lower Catherine Creek
Lower Wallowa River
Meadow Creek
Minam River
Upper Catherine Creek
Upper Grande Ronde River
Willow Creek
Wolf Creek-Powder River
15
Appendix 1, continued.
Ownership as a
Percentage of Area
Infested
County
Watershed
Acres
Wallowa
Hectares
Public Private Undet.
Chesnimnus Creek
Grossman Creek-Grande Ronde River
Lower Big Sheep Creek
Lower Joseph Creek
Lower Wallowa River
Middle Wallowa River
Minam River
Mud Creek-Grande Ronde River
Upper Joseph Creek
Upper Wallowa River
83,980
2,050
33
11,205
4,298
28,949
208
841
8,206
19,233
8,958
33,985
830
13
4,534
1,739
11,715
84
340
3,321
7,783
3,625
8.7
0.3
0.0
0.0
81.8
4.5
0.0
6.9
0.6
12.2
0.0
91.3
99.7
100.0
100.0
18.2
95.5
100.0
93.1
99.4
87.8
100.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Antelope Creek
Bakeoven Creek
Buck Hollow Creek
Muddy Creek-John Day River
Upper Trout Creek
19,523
7,307
8,996
2,090
1,117
13
7,901
2,957
3,640
846
452
5
0.2
0.5
0.0
0.0
0.0
0.0
99.8
99.5
100.0
100.0
100.0
100.0
0.0
0.0
0.0
0.0
0.0
0.0
Butte Creek
Muddy Creek-John Day River
Thirtymile Creek
50,972
39,334
4,377
7,261
20,628
15,918
1,771
2,938
0.1
0.0
0.9
0.0
99.9
100.0
99.1
100.0
0.0
0.0
0.0
0.0
Wasco
Wheeler
16