Use of an Attractantbaited Barrier Line at the Stephens Landing Condominium

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Use of an Attractant-baited Barrier Line at the
Stephens Landing Condominium
Jeff Stivers Maria Eggett Adrian Salinas
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Study Objectives
Continue barrier line study
Test with people in protected area
Develop new target
Test new octenol injector
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Target Components Lids from 5 gal. Buckets
Plastic shade cloth Eye bolt for hanging
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Surveillance Traps 4 outside barrier 4
inside barrier Collected daily CO2
200ml/min Octenol wick out
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Processing of Collections
Daily collections returned to the laboratory Air
dried for 24 hours Sample weight recorded Sub
sample separated for ID Greater of 10 of sample
or 1 gram Sub sample identified as Aedes
taeniorhynchus All others
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Location of Pipeline and Surveillance Traps
Pipeline
Inside traps
Outside traps
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Test Dates for Stevens Landing in 1998
Line Off 1 July 21 - August 4
Line On 1 August 5 - August 18
Line Off 2 August 19 - August 26
Line On 2 August 27 - September 3
Line Off 3 September 4 - September 10
Line On 3 September 11 - September 23
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Analysis of the Residents Journal Entries
The question Are the mosquitoes tolerable today?
Answer
Line Off
Line On
Totals
Yes
63
101
164
No
77
18
95
Totals
140
119
259
Test Statistic Value
df
Probability
YES!
Pearson Chi-square 44.034
1.000 0.000
The answer
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Inside/Outside Ratios for Aedes taeniorhynchus At
Stevens Landing, 1998
Line Off
Line On
Ratio
Collection Date
Mann-Whitney Rank Sum Test comparing Line Off and
Line On Ratios indicates a significant difference
at P lt 0.001
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Conclusions

• The residents feel that the system provided
  them with relief

• Statistical analysis indicates that the system
  is effective

• The new target design is much better than the
  old design

• The octenol injection system still needs
  improvement

• Permethrin is not an acceptable substitute for
  lambda-cyhalothrin