Aquatic, Right-of-Way, Industrial/Structural and Public Health Pest Control
Aquatic Pest Control
Scope
Aquatic pest control covers algae, submerged, floating and emergent weeds, and noxious vegetation in ponds, lakes, streams, canals and irrigation systems. Only products registered for aquatic use may be applied to water; a terrestrial product with the same active ingredient is not legal for that use. Know the water-use designations on the label - drinking water, irrigation, livestock watering, swimming, fishing - and the waiting periods that follow treatment.
Technique
Methods include subsurface injection, drop nozzles, weighted granules, and wick or hand application for small areas. Treat in sections, because killing too much vegetation at once depletes dissolved oxygen and can kill fish. Remember that surfactants and carriers can be more toxic to fish than the herbicide itself, and that copper products are a special concern in trout waters. In Vermont, work in waters of the state also involves state permits and notice, so coordinate before the first tank is mixed.
Traps
Ignoring irrigation restrictions on treated water; treating a whole pond in one pass; using an ester formulation or a terrestrial surfactant; and failing to identify the plant before choosing an algicide instead of an aquatic herbicide.
Rule of thumb
One acre-foot is about 325,851 gallons, and 1 ppm in one acre-foot requires about 2.72 lb of active ingredient. Worked example: 2 acre-feet at 2 ppm = 2 x 2 x 2.72 = 10.9 lb of active ingredient. Convert that to product using the label's active ingredient percentage, then split the dose across several treatment blocks.
Right-of-Way Pest Control
Scope
Right-of-way work keeps roadsides, railroads, utility corridors, pipelines and fence lines safe and accessible. Know the vegetation programs: bareground (total vegetation control), grass-only selective programs, brush control, and low-growing growth regulators. Understand the difference between contact and residual products, and why residuals near trees, wells or crop fields are risky.
Technique
Methods include broadcast and banded spraying, directed spray with shields, basal bark, cut-stump, stem injection for tall trees, and wicking. Calibrate for band width: treating a 4-ft band on 12-ft centers uses one-third of the broadcast rate per treated acre. Plan around environmental sensitive areas - streams, wetlands, wells, schools, gardens, and neighboring sensitive crops such as grapes and tomatoes. Wind, inversions and droplet size drive off-target movement more than product choice does.
Traps
Using a bareground product where grass cover is wanted; failing to account for root uptake of soil residuals by nearby trees; spraying when a sensitive crop is downwind; and neglecting sprayer cleanout between sites.
Rule of thumb
Band rate = broadcast rate x (band width / row spacing). Worked example: a 4 qt per acre broadcast rate applied in a 4-ft band on 12-ft spacing is 4 x (4/12) = 1.3 qt per treated acre. Confirm the label allows banded application and states the rate basis before you mix.
Industrial/Structural and Public Health Pest Control
Scope
Industrial, structural and public health work covers cockroaches, ants, bed bugs, stored product pests, rodents, termites and other wood-destroying insects, wasps, and mosquitoes and ticks of public health concern. Know the application types - crack and crevice, spot, void, broadcast, baiting and fumigation - and know that each label defines how much and where you may treat.
Rules
Read the site list precisely: an outdoor-labeled product cannot be moved indoors, and a product labeled for food-handling establishments has specific limits around food and food-contact surfaces. Rodenticide work requires tamper-resistant bait stations where children and pets can reach, plus careful placement and recordkeeping. Reentry and notification requirements protect occupants. Public health mosquito and tick programs rely on source reduction and larviciding before adulticiding, along with resistance management. In Vermont, structural pest control is a commercial category, so both the applicator and the business must be licensed.
Traps
Substituting a spot treatment for a crack and crevice label; over-applying bait so pests avoid it; placing rodenticide where pets can reach it; treating a food-preparation surface; and fogging where the label calls for a directed application.
Rule of thumb
Ounces of concentrate = (desired % / concentrate %) x gallons x 128. Worked example: to make 2 gallons of 0.06% solution from a 2% concentrate, (0.06 / 2) x 2 x 128 = 7.7 fl oz. Mix only what you will use in a day.