Bill Stanuszek, Director
Saginaw County Mosquito Abatement
Commission
Saginaw, Michigan
Concern with Catch Basins
 Source of mosquito vectors of WNv and SLE.


Culex pipiens, Cx. restuans - Michigan
Cx. quinquefasciatus
 Components of complex storm water management
systems.
 Approach 1000/sq. mile in urban setting.
 Account for majority of public health larviciding efforts
in Michigan.
Importance of sampling Catch
Basins
 Mosquito populations
 Vector species
 Public Health
 Thresholds
 Product efficacy
 Cost savings
 Environmental impacts
Catch Basin Variety
Saginaw County, Michigan
816 sq. miles
Where Art Thou Catch Basins?
 Roadside
 Backyard drainage
 Subdivisions
 Field drainage
 Schools & parks
 Parking lots
0.5 sq. miles
Saginaw’s Recent Catch Basin
Treatment History
Larvicide Selection
 Methoprene
 Biologicals
 Spinosad
 Bacillus sphaericus
 Bacillus thuringiensis
israelensis
 Temephos
 Monomolecular film
Application Method
 Trucks
 Foot crew
 Mopeds
 Bikes - 2017
Traditional Catch Basin Sampling
Traditional sampling of involves:
 Lifting/removal of cover for sampling
 Sampling with a dipper
 Reproducible
Doug Allen
Doug Allen
Concerns with Traditional Sampling
 Need specialized tools
 Safety – lifting, securing, hazard
 “Stuck” lids
 Larval recovery
 Uncomfortable
 Time consuming
Doug Allen
“No Lift” method for Catch Basin
Sampling
 Catch basin cover is not removed
 Improved safety
 Easy to use
 Expedites sampling
 Reproducible
Suitable for a Variety of Catch
Basins
Sampling the Catch Basin
 Sample in “Figure 8” motion
 Ensure net remains open, do
not double back
 Distance (d) from grate to
water will dictate Area (A)
sampled.
 >d = >A
 Can collect organic matter
“Figure 8 “sampling
Processing the Sample
• Rinse net and collection into container.
• Separate larvae from organics.
• Record and collect mosquito larvae.
What’s Needed
 Aquarium net
 PVC Pole – ½ inch diameter, 8




- 10 feet
Water and flush bottle – e.g.
Nalgene
Collection container
Larval collection supplies
Additional samplers prevent:
o Contamination of study
controls
o Larvicide cross-contamination
Customizable
 Pole length – cut to needs
 Net size, e.g. 4 or 2 inch
 Net mesh size, minnow (fine)
or plankton (very fine)
 Net security– e.g. duct tape
 Note lengths – depth
measurements
Plankton
Minnow
Negatives
 Early instars may escape through mesh.
 Variable water volume sampled, catch basin specific.
 Does not access all catch basin covers.
 Restrictor plates, solid covers, etc.
 Can collect “junk”, may not get through solid mats.
Catch Basin Surveillance Utility Saginaw
 Vector populations
 Treatment thresholds
 Larvicide efficacy
 Application efficacy
 Rainfall impacts
Culex pipiens Populations
Larvicide Efficacy & Thresholds
Treat Threshold
Environmental Impacts - Rainfall
Parting Thoughts
 Catch basin sampling is necessary –
vector populations, product efficacy.
 “No lift” method allows for safe,
consistent, quick sampling of catch
basins.
 Resources needed for constructing are
inexpensive and readily available.
 Customizable to fit a variety of Catch
basin needs.
Alternative Sampling Method?