Deer Flat National Wildlife Refuge

Summary of Mosquito Activity and Pesticide Use Record for 2015

To fulfill the conditions of the SUP (Special Use Permit) for mosquito abatement activity on Deer Flat

National Wildlife Refuge (Lake Lowell Sector), the Canyon County Mosquito Abatement District is

submitting the following year-end report that reflects all mosquito abatement activity: adult mosquito

surveillance and arbovirus disease testing; mosquito larvae surveillance; action threshold levels;

larvicide treatment record and pesticide use report.

Mosquito abatement activity started the first week of March with documented larvae activity on March

2. A two person inspection team conducted inspections and reported activity to the District Director on

a regular basis. An action threshold level of 5 mosquitoes/dip larvae density using industry standard

inspection technique of 10 dip average/350 ml. mosquito dipping cup was used. When threshold

levels were met on a particular inspection site then the decision was made to consider mosquito larval

control operations, either by limited ground applications, wide area aerial or no action. Most ground

applications were limited in scope to under 10 acres or in designated “no fly zones” because of nesting

bald eagles. CCMAD contracted with Frankie’s Aerial Application, Nampa, ID to conduct aerial

applications. Frankie’s Aerial Application’s personnel are licensed in Public Health Pest Control.

Non-target organism surveys as a baseline were conducted starting in March and throughout the season

on selected treated areas within 48 hours after treatment. Measurement surveys were conducted on

non-target organisms utilizing the same 10 dip sampling method as described above. There were no

incidents of non-target organism population suppression after Bti applications.

CCMAD applys Bti (Bacillus thuringiensis israelensis) products only under the brand names:

Aquabac G (EPA reg. no. 62637-3), Teknar CG (EPA reg. no.73049-19), Vectobac GR (EPA reg. no.

73049-486) FourStar CRG Bti (EPA reg. no.85685) and VectoMax FG (EPA reg. no. 73049-429, active

ingredient Bacillus thuringiensis israelensis and Bacillus sphaericus). Products were used at the

application rate of 8 to 10 lbs. per acre.

Figure 1: Lake Lowell Water Levels

Low water level in Lake Lowell contributed heavily to the low mosquito year experienced on Deer Flat

National Wildlife Refuge after July 31.

Adult Mosquito Surveillance and West Nile Virus Testing:

CCMAD designated 14 adult mosquito surveillance sites deploying 10 to 12 CDC CO2 baited light

traps on Deer Flat National Wildlife Refuge (Figure 1: Trap Site Map). Adult mosquito surveillance

began the week of May 19 and ended September 8 when mosquito activity declined to low population

numbers. The Canyon County Mosquito Abatement District has the capability to conduct West Nile

Virus testing on collected mosquitoes utilizing the R.A.M.P. (Rapid Analyte Measurement Platform).

Mosquitoes are collected from traps each morning, frozen, separated into species pools and tested for

West Nile Virus. Results are obtained within 6 hours after traps are collected and mosquito control

management decisions are quickly made. CCMAD conducted 81 West Nile Virus tests on Culex

species vectors on Deer Flat National Wildlife Refuge compared to 116 tests in 2014. No traps tested

positive for the disease. (Table 1: Weekly Mosquito Surveillance Data)

Figure 2: DFNWR CDC CO2 Trap Site Location

Table 1: DFNWR Weekly Adult Surveillance Data

Adult mosquito surveillance commenced on May 20 deploying CDC CO2 baited light traps. Traps

were set out in late afternoon before sunset and retrieved the next morning. Mosquito samples were

frozen, separated by species and cataloged. Vector species (Culex tarsalis, pipiens, and

erythrothorax) were separated into test pools of 50 mosquitoes or less and tested for West Nile virus.

Test results were available within 6 hours after mosquitoes were collected from the field.

CDC CO2 baited light trap

Figure 3: WNV Vector Tracking Data (Adult Female)

Analysis of Figure 2 West Nile Virus Species Tracking Data:

The three species tracked are compared above. The Western Equine Encephalitis mosquito

(Culex tarsalis) was the dominate species tracked. Species populations peaked early in the

season on May 30.

Culex tarsalis numbers dropped after July 17 because of low water in Lake Lowell and aerial

larvicide applications conducted through May and June. (see pesticide use report) One trap

located on Access 1 tested positive for WNV on July 16. The trap contained 216 Culex

tarsalis.

Other vector species (Culex pipiens and Culex erythrothorax) never reached significant

numbers. Culex erythrothorax species of mosquito primarily feeds on nesting migratory

birds.

Northern House Mosquito (Culex pipiens) numbers remain relatively low. Culex pipiens is

a more urban mosquito and low population numbers is expected.

Figure 4: Non-Vector Adult Mosquito Tracking Data (Adult Female)

Analysis of Non-Vector Mosquito Surveillance Data (Adult):

Most dominate species tracked: Inland Floodwater Mosquito Aedes vexans (Ae vx.)

This species “yo-yoed” through the season probably as a response to “off refuge” irrigation

practices on bordering agriculture.

Anopheles freebornii (Western Malaria Mosquito) peaked in early June and again in early

July. This is a permanent water species with primary habitat being marsh areas and irrigation

ditches. (An free)

Culiseta inornata (Winter Marsh Mosquito) population peaked in May. This species is a

“cold water” mosquito, is one of the first to hatch out in the spring and primary habitat are

marsh areas. (Cs in)

Aedes nigromaculis (Irrigated Pasture Mosquito) population responds to off refuge

irrigation of agricultural crops and stays relatively steady through the season. Peaking twice,

early June and late June. (Ae ni.)

Note: No specific abatement activities are conducted on “Non-Vector” species unless numbers

reach a level of economic importance or high nuisance levels.

Figure 5: Adult Female Mosquito Population Comparison May 19-August 25

Analysis of Adult Mosquito Population Comparison:

Culex tarsalis: Most dominate species collected: 32% of all species sampled.

Aedes vexans second most sampled species: 22% of all species sampled.

Primary West Nile Virus Vectors: Culex tarsalis, Culex pipiens, and Culex erythrothorax

combined totals make up 35% of all species sampled.

Early Culex tarsalis population spikes are more than likely a response to high water levels

and warm water temperatures in May.

Surveillance activity ended September 8 because of below normal water levels in Lake

Lowell.

Figure 6: DFNWR WNV Vector Sample Comparison 2014-2015

Culex WNV carries sample numbers were up 44% over 2014 numbers. Possible Causes:

Warmer than normal winter temperatures led to an increase in population of overwinter Culex

species. (Culex over winter as adult mosquitoes.)

Warm spring weather led to an early increase in vector species

High water levels of Lake Lowell: Culex species are permanent water species.

Pesticide Use Report:

The decision to conduct pesticide application (larvicide treatments) on DFNWR are determined by

using Integrated Pest/Mosquito Management principles (IPM) utilizing surveillance both adult

mosquito and larvae surveillance as the driving force. The action threshold of 5 mosquito larvae per

dip by standard dipping methods is used to determine any action level which includes:

1. Limited ground applications.

2. Aerial treatments on large acreage sites.

3. No action. Sometimes the larval count density does not warrant a treatment but may

include monitoring only.

Figure 7: DFNWR LARVICIDE SITE LOCATIONS

Table 2: DFNWR Pesticide Application Log (Threshold Levels >5 larvae/dip) Date Site Product Amount Acres Treated

3/27 Access 6 VectoMax FG 20 lbs. 2.0

3/31 Access 7 Fourstar Bti CRG 130 lbs. 13.0

3/31 Access 5-7 Aquabac 200G 1600 lbs. 200*

4/15 NY Canal inflow VectoMax FG 40 lbs. 4.0

4/17 Tio Ln. Access VectoMax FG 30 lbs. 3.0

4/20 Orchard Ringneck VectoMax FG 10 lbs. 1.0

4/22 Shaeffer ditch (Tio ln.) VectoMax FG 20 lbs. 2.0

4/23 Access 2-7 Aquabac 200G 2800 lbs. 350*

4/30 NY Canal inflow VectoMax FG 65 lbs. 6.5

5/1 Access 2-7 Vectobac GR 2800 lbs. 350*

5/5 East Marsh (Tio Access) VectoMax FG 80 lbs. 8.0

5/8 Tio Access-East Marsh Aquabac 200G 1600 lbs. 160*

5/8 Access 00 (eagle nest area) FourStar Bti CRG 175 lbs. 17.5

5/15 Access 2-7 Aquabac 200G 2000 lbs. 200*

5/22 Access 2-7 Aquabac 200G 2000 lbs. 200*

5/18 Orchard-Ringneck VectoMaxFG 20 lbs. 2.0

5/22 Upper Embk Marsh VectoMaxFG 40 lbs. 4.0

5/22 Access 00(eagle nest area) VectoMaxFG 20 lbs. 2.0

5/27 Access 1 VectoMaxFG 20 lbs. 2.0

5/27 NY Canal inflow Vectomax FG 80 lbs. 8.0

5/29 Access 4 VectoMaxFG 15 lbs. 1.5

5/29 Access 2 VectoMaxFG 50 lbs. 5.0

6/1 Tio Ln-Gotts Pt. VectoMaxFG 15 lbs. 1.5

6/3 Access 00(eagle nest area) VectoMaxFG 25 lbs. 2.5

6/4 Access 2-7 Aquabac 200G 3200 lbs. 400*

6/4 Access 7 VectoMaxFG 5 lbs. 0.5

6/5 Orchard-Ringneck VectoMaxFG 5 lbs. 0.5

6/5 Upper Embk Marsh VectoMaxFG 3 lbs. 0.3

6/11 Tio Ln. Access VectoMaxFG 10 lbs. 1.0

6/12 NY Canal inflow VectoMaxFG 30 lbs. 3.0

6/15 Access 00 (eagle nest area) VectoMaxFG 35 lbs. 3.5

6/19 Access 6-7, Tio Ln, E.Marsh, Uppr Embk Marsh Aquabac 200G 1280 lbs. 220*

6/16 Access 4 VectoMaxFG 5 lbs. 0.5

6/24 NY Canal inflow VectoMaxFG 20 lbs. 2.0

6/26 Access 2 VectoMaxFG 15 lbs. 1.5

6/30 Upper Embk Marsh VectoMaxFG 8 lbs. 0.8

6/30 Tio ln. Access VectoMaxFG 5 lbs. 0.5

7/2 East Marsh VectoMaxFG 25 lbs. 2.5

7/7 Access 00 (eagle nest area) VectomaxFG 3.0 lbs. 0.3

7/16 East Marsh VectoMaxFG 5.0 lbs. 0.5

7/16 Access 3 VectoMaxFG 20 lbs. 2.0

7/21 New York Canal inlet Vectobac 12AS 8 gal. 2.7

7/21 New York Canal inlet VectoMaxFG 105 lbs. 10.5

* Indicates Aerial Applications by Frankie’s Aerial Application Service

Pesticide Use Summary 3/27-7/21

Ground Applications:

Product EPA Reg. No. QTY UOM Acres 2014 Comparison

FourStar Bti 85685-4 305.0 Lbs. 30.0 n/a

VectoBac 12AS 73049-38 8.0 Gals. 2.8 n/a

VectoMax FG 73049-10 849.0 Lbs. 85.0 184 lbs. 17.8 acres Note: 2014 ground use included 82 lbs Vectobac GR on 8.4 acres

Aerial Applications:

Product EPA Reg. No. QTY UOM Acres 2014 Comparison

Aquabac200G 53263-28 14,480 Lbs. 1780 4500 lbs. 525 acres

Vectobac GR 73049-486 2,800 Lbs. 350 1000 lbs. 125 acres

Figure 7:

Aerial larvicide suppression affecting Vector Species (Culex species) Adult Population

Table 3: DFNWR IPM Mosquito Larvae and Non Target Aquatic Insect Inspection Log Date Site Location Mosquito

Species

Ave.

Dip Ct.

Ave. Dip Count

Non-target insects.

Water

Temp (ºF) Comments

3/2 Access 1-5 Culiseta 1 13 43º

3/4 NY Canal inlet x x 21 45º

3/5 Upr. Embkmt Marsh x x 24 48º

3/5 Orchard-Ring Neck x x 11 45º

3/6 Access 4-6 x x 16 48º

3/9 Access 4/6 x x 24 48º

3/10 Access 1-3 x x 18 48º

3/11 Tio Ln. and East Marsh x x 0 (dry) x

3/13 Access 6-8 x x 38 51º

3/16 Access 4-5 x x 15 50º

3/16 Tio Ln. Access-Gotts Pt. x x 12 53º

3/17 Tio Ln. Access Rd. Anph/Culiseta <1 15 55º

3/17 Access 3 x x 9 51º

3/18 Access 6-7 Aedes 12 25 54º

3/19 Access 4-5 x x 53 51º

3/20 Tio Ln. Main Access An. free 12 7 51º

3/20 Upper Embk. Marsh Culiseta <1 29 51º

3/25 Access 7 Aedes <1 30 45º

4/6 Access 5-7 Culex <1 40 50 º aerial treatment 3/31

4/10 Access 0 (eagle nests area) x x 20 45º

4/13 Access 1-2 Culex/Aedes <1 53 58º

4/16 Tio Ln. Access Aedes 5 30 58º

4/16 East Marsh Aedes <1 20 48º

4/21 Access 2-4 Aedes 5 50 66º

4/22 Orchard-Ring Neck Culex 1 34 65º

4/23 Upper Embkmt Marsh Culiseta 1 31 50º

4//29 Access 2-7 Culex <1 40 53º aerial treatment 4/23

4/29 Tio ln. Access Aedes <1 40 66º

5/1 Access 0 (eagle nests area) Culex 1 60 50º

5/4 Access 2-7 Culex <1 68 60º aerial treatment 5/1

5/6 Schaffers Access Tio Ln. Culex 3 34 60º

5/12 Tio Ln-East Marsh-Gotts Pt. 0 larvae 0 54 60º aerial treatment 5/8

5/12 Access 2-7 Culex 4 85 61º *reached threshold 24 hrs. later

5/19 Access 2-7 Culex 2 84 62º aerial treatment 5/15

5/20 Access 8 Culex <1 86 61º

5/21 Access 0 (Eagle nests area) Aedes/An free. 5 60 62º

5/21 New Canal inflow Aedes <1 60 62º

5/26 NY Canal-Access7 Culex 3 70 60º

5/28 Tio Ln. East Marsh Culex 1 40 67º

5/28 Access 2-4 Culex/Aedes 4 80 65º * reached threshold 24 hrs. later

6/1 East Marsh-Tio Access Aedes 1 60 65º

6/5 Upper Embkmt marsh Culex/Aedes 4 48 65º

6/9 Access 2-7 Culex <1 89 70º aerial treatment 6/4

6/10 East Marsh-Tio Ln Access Culex, Aedes 3 60 74º

6/11 Gotts Pt. 0 larvae x 60 69º

6/11 NY Canal inlet Culex/Aedes 1 70 78º

6/11 Tio Ln. Access Culex, Aedes 4 80 72º

6/12 Access 7 0 larvae x 40 70º

6/16 Access 5-6 Culex,Aedes 6 85 70º

6/18 Access 7-Orchard-Ring Neck 0 larvae x 50 70º

6/22 Tio ln.-East Marsh-Shaeffers Culex-Aedes <1 55 69º aerial treatment 6/19

6/22 Upper Embk Marsh Culex-Aedes <1 52 69º aerial treatment 6/19

6/23 Access 5 Culex <1 50 80º

6/24 Access 0(eagle nest area-Access 6 Culex <1 77 83º

6/25 Tio Ln Access-Gotts Pt. 0 larvae x 10 75º note: area drying up

6/25 Orchard-Ring Neck 0 larvae x 67 77º

6/26 Access 2 Culex-Aedes 3 90 65º

6/29 East Marsh-Tio Ln Culex-Aedes 6 40 79º

7/1 Access 4, 5, 7 Culex <1 90 70º

7/6 Access 4-6 Aedes 1 80 70º

7/7 Access 1- NY Canal inlet Culex 2 80 74º

7/15 East Marsh-Tio Ln. Access Culex 4 50 70º

7/15 Upper Embkmt Marsh Culex-An free 1 60 70º

Table 3 (cont’): DFNWR IPM Mosquito Larvae and Non-Target Aquatic Organism Inspection Log Date Site Location Mosquito

Species

Ave.

Dip

Ct.

Ave. Dip Count

Non-Target

Species

Water

Temp (º F ) Comments

7/16 Access 5 No larvae 0 70 73º

7/16 East Marsh-Tio Ln. Access Culex 4 50 70 reached threshold level 24

hrs.later

7/22 Access 1-Access 4 Culex <1 60 73º

7/31 East Marsh Culex <1 20 70º

7/31 Tio Ln Main Access-Gotts Pt. Culex <1 24 71º

8/17 Upper Embkmt Marsh Culex <1 28 78º

8/17 East Marsh-Tio ln. Access Rd-Gotts

Point

No larvae

0

29

60º

9/3 Access 1-5 Culex <1 60 58º

Pesticide Use Summary

1. Threshold levels met 33 times between March 27 and September 3. (2014: 20 times)

2. Acres treated: 30% more than 2014.

3. Aerial larvicide applications: 2015: 8 applications on 2130 acres (2014: 3 application 650

acres) 4. Ground larvicide applications: 2015: 35 applications on 118. (2014: 15 applications on

26.2 acres)

Summary and Conclusion:

Above average winter temperatures and high spring water levels resulted in early

mosquito activity. Abatement operations started on March 27

Above average water levels and above average temperatures in May resulted in high

Culex (WNV vector species in late May.

Arbovirus disease activity detected on July 16 when 216 trapped Culex tarsalis tested

+WNV.

Pesticide use was up by 77% over 2014.

CCMAD wishes to thank the U.S. Fish and Wildlife Service for their cooperation in helping us

provide mosquito abatement services on Deer Flat National Wildlife Refuge in 2015.

Respectfully submitted,

Ed Burnett,

District Director

Canyon County Mosquito Abatement District

DEER FLAT NATIONAL WILDLIFE REFUGE

APPENDIX

DFNWR Cost Analysis

Maps of Aerial Larvicide Applications

Labels of Pesticides (larvicide) used

Deer Flat National Wildlife Refuge

2015 Mosquito Abatement Cost Analysis

Adult Mosquito Surveillance and Disease Testing

Labor: $3000

Trap processing and disease testing: $3275

Pesticide Applications (Bti) Mosquito Larvae Control

Total acres treated: 2248

Acres treated by air: 2130

Total pounds of Bti (Bacillus thuringiensis israelensis):

Cost of Pesticides:

Vectobac GR: 2,800 lbs. @ $ 1.87/lb. = $5,236

Aquabac 200 G: 14480 lbs. @ $1.64/lb. = $23,747.20

VectoMax FG: 849 lbs. @$8.60 /lb. = $7,301.40

Fourstar Bti CRG: 305 lbs. @$14.30 = $ 4,361.50

Vectobac 12 AS: 8 gals. @ $35.76 = $286.09

Labor Costs (inspections and treatments): $ 15000

Contracted Aerial Applicator: $25,560

Total costs for mosquito abatement operations: $87,767.19

Aerial Applications Maps:

3/31: Access 5-Access 7

4/23, 5/1, 5/15, 5/22, 6/4: Access 2-Access 7

5/8: Tio Lane to Gott’s Point

6/19: Access 6-7, East Marsh to Tio Ln, Upper Embankment Marsh

MOSQUITO LARVICIDE LABELS