Disease Prevention

Brian FeldhakeMMCD

Special Thanks:

Excuse my absence:

Rural to Urban Conditions

• Habitat varies to a slight degree across Cass County

• Generally large rural areas surrounding isolated communities and some urban mosquito habitat

• Extreme impact from drainage ditches and road ditches that channel water

• Flood prone even in summer• Slow drainage creates problems everywhere• Culex tarsalis is the main vector species

Other known vectors

• Most commonly identified as nuisance species, some vector potential, but can justify applications:– Culiseta inornata- WEE, SLE– Aedes trivitattus- dog hear worm– Culex pipiens/restuans

Control Methodologies

• Adult Mosquito Surveillance & Control– Trap Collections – Vector identification– Adult Control Applications

• Larval Surveillance and Pesticide Control– Standard two prong attack in high human population

areas: larval and adult control – 70% : 30% – Rural – low human populations: only adult control

fiscally possible • Mechanical Control– Storm Water Control Structure Construction Techniques

Adult Mosquito Surveillance & Control

• High Human Population Areas: – Daily NJLT Trap Collections – Approx. 22 Static

Locations– Weekly/Semiweekly CO2 Collections – 6 Locations

(static and mobile) • Vec Test on WNV species, other disease vectors

monitored and contribute to risk assessment-

– Gravid traps as needed and warranted by conditions– Significant vector species counts can trigger

applications of adulticide

Additional Adult Control

• Adult Control in High Human Populations Assesment:– (Adult Culex Threshold) + (Environmental Conditions)

x (Current Human Risk) = (Wide Spread “Urban” ULV Applications) or (No Adult Control Action)

• WNV risk has historically been significant enough to warrant preventative barrier applications in public spaces and in wood lots

Larval Control Methodology

• Significant overlap of site types:

Majority of sites have flood water and standing water features including culverts, sloughs, manmade structures, and the like.

Multiple brood – Floodwater/Culex sites:

“Standard” Culex sites:

Manmade & Artificial structures :

Larval Control Methodology

• “Standard” culex larviciding principals- – 30 day residual and 180 day residual treatments

• GIS data – integrate larval culex identification into breeding site attributes– often very little site trait distinction, identification of samples key for

justification of residuals

• Multiple brood habitat – Sites produce floodwater species initially– Water sits and stagnates providing abundant Culex

tarsalis habitat – Try and mitigate with residuals• Manmade & Artificial structures- Affect most sites

Mechanical Control

• Due to very flat terrain, below ground storm water management is highly specified within city limits.

• Important to discuss mosquito with public works officials to promote or adopt these standards

Mechanical Control• Continued monitoring of storm control

facilities that do not follow local storm sewer BMP’s is still important– Private parking lots etc.– Larval control tactics when conditions warrant– Generally populations maintained by adult

applications- ULV still a major aspect of prairie programs due to economics of rural mosquito control

Above Ground Storm Water Mitigation• Poor• Unavoidable and necessary on a “dried” lake bed

Multiple brood – Floodwater/Culex sites:

“Standard” Culex sites:

Manmade & Artificial structures :

• Miles of ditches, county drains, and other water channeling structures require repeated inspection and treatment

• Resources are unavailable to larvicide enough footprint to end adult control