⚡ CHEAT SHEET

Ch.5: Mosquito Mgmt & Public Relations

What the exam tests on physical/biological/chemical control methods, larvicides, adulticides, and the components of effective public relations.

🎯 Top 5 Traps

Methoprene and other JH analogs do NOT kill larvae directly — they prevent development to ADULT. The larvae aren't immediately killed; their development is stopped, and physiological changes from malformation eventually cause death of the immature form. Marketed as Altosid.

Adulticide droplets must be 5 to 27 microns (average less than 17 microns). Distractors on the exam: 30 to 40 microns (too big — wouldn't impinge efficiently on mosquito body hairs) and 1 to 10 mm (that's mosquito-body size, not droplet size). Small droplets deliver minimum lethal dose to mosquitoes while sparing larger non-target insects.

Surface oils target LARVAE, not adults or eggs. Oils form a film on water that suffocates larvae and pupae trying to breathe at the surface. Common confusion — "oils" sound like an aerosol/adulticide, but they're a larvicide.

Gambusia affinis is a LARVAL predator — top-feeding minnow. Not effective against adults. South American native; tropical — usually requires re-stocking each spring in Michigan. Care must be taken to prevent escape into Michigan waterways (general predator, can disrupt native species).

Effective PR requires HONESTY about pluses AND minuses — not "only beneficial aspects." The manual is explicit that this is wrong. Pluses without minuses erodes trust.

🔢 Numbers You Must Know

Number

What It Represents

5 to 27 microns

Adulticide aerosol droplet size range — calibrated to impinge on mosquito body hairs and deliver a minimum lethal dose

less than 17 microns

Average adulticide droplet size

0.5 to 3 ounces per acre

Adulticide application rate

8 to 12 mph

Maximum wind speed for ground-equipment adulticide spraying — above this, droplets dissipate too rapidly

1 to 3 hours after sunset

Time after which most mosquito species become less active (some species are active most of the night)

up to 80 percent

Mermithid nematode parasitism rate of natural mosquito populations under ideal conditions

🔀 Easily Confused

Pair / Group

Distinguishing Feature

Source reduction vs Biological vs Chemical

Source reduction (physical): drainage, filling, water management — most permanent. Biological: pathogens (Bti, Bs), MGRs (methoprene), parasites, predators, sterile males. Chemical: larvicides and adulticides.

Bti vs Bs

Bacillus thuringiensis israelensis (Bti): VectoBac, Aquabac, Teknar — broadly used. Bacillus sphaericus (Bs): Vectolex — works especially well in richly organic systems (Culex). Both are bacterial, both target larvae, both must be ingested.

Methoprene vs Temephos

Methoprene (Altosid): mosquito growth regulator — mimics JH, prevents emergence to adult. Doesn't kill on contact. Non-toxic to vertebrates. Temephos: organophosphate larvicide — kills larvae through nervous-system toxicity. Both are EPA-registered MI larvicides.

Surface oils vs Monomolecular surface film

Both form a water-surface barrier that suffocates larvae and pupae. Oils are heavier, traditional. Monomolecular films use modern surfactant chemistry — thinner layer, less environmental persistence. Both target LARVAE, not adults.

Larvicides vs Adulticides

Larvicides: applied to water (Bti, Bs, temephos, oils, films, methoprene). Preventive — larvae confined and easier to kill. Adulticides: aerosol fog/mist on flying mosquitoes (malathion, chlorpyrifos, permethrin, resmethrin, sumithrin, fenthion). Reactive — only when surveys indicate need.

Sterile male technique vs Genetic manipulation

Sterile male: lab-rear, sterilize, release. Female mates only once and stores sperm in spermatheca — sterile mating yields infertile eggs. Limited MI use. Genetic manipulation: alter mosquito or its bacterial symbionts to block disease transmission or reproduction. Research stage, not in general use.

Honesty vs "Only beneficial aspects" (PR)

The exam baits with "Discussing only beneficial aspects to avoid confusing citizens" — this is the WRONG answer. Effective PR requires honesty about pluses AND minuses connected with pesticide use.

🌿 IMM Methods Quick Reference

Approach

Examples

Target Stage & Key Notes

Physical (source reduction)

Drainage, filling, water management; remove tires/containers/abandoned pools, clean gutters

Larval habitats. Most permanent reduction; high initial cost. MI wetland projects subject to Goemaere-Anderson Wetland Protection Act (DNRE jurisdiction).

Bacterial pathogens

Bti — VectoBac, Aquabac, Teknar; Bs — Vectolex

Larvae. Must be ingested. Granular or liquid formulations; standard spray equipment. Bs especially good in organic systems (Culex).

Mosquito growth regulators

Methoprene — Altosid (suspension, sand, pellets, briquets)

Larvae — prevents emergence to adult. Mimics JH; doesn't kill immediately. Non-toxic to vertebrates. Specific for mosquitoes and related Diptera.

Parasites

Mermithid nematodes

Larvae — up to 80% parasitism in ideal conditions. Cost-prohibitive for commercial use (must rear in live mosquitoes).

Predators

Gambusia affinis (top-feeding minnow); Toxorhynchites larvae; bird/bat houses (largely ineffective)

Larvae primarily. Gambusia tropical — usually requires re-stocking each spring; risk if escaped to MI waterways. Purple martins/bats: lack of evidence for control; bats may carry rabies.

Sterile males

Lab-reared, sterilized, released males

Adult reproduction. Female mates once; stores sperm in spermatheca; sterile mating yields infertile eggs. Limited use (cost effectiveness).

Larvicides (chemical)

Bti, Bs, temephos, oils, monomolecular surface film, methoprene

Larvae and pupae. Oils/films suffocate; chemicals act as toxicants or growth regulators. Larval control is preventive — focus here when possible.

Adulticides (chemical)

Malathion, chlorpyrifos, permethrin, resmethrin, sumithrin, fenthion

Adults flying. Aerosol fog/mist; droplets 5 to 27 microns; rate 0.5 to 3 oz/acre. Apply at dusk/early evening/dawn (changing light); wind under 8 to 12 mph. Aerial spraying for emergencies.

📣 Public Relations Do's & Don'ts

Don't

Honest about pluses AND minuses of pesticide use

Discuss only the beneficial aspects to "avoid confusing" citizens

Listen actively; plain language; focused, concise format

React emotionally; use technical jargon

Distribute educational materials (brochures reinforce verbal communication)

Rely solely on verbal explanations

Document everything; investigate complaints quickly; write reports promptly

Skip documentation; let problems linger

Stay current with technology; join professional organizations (management's responsibility)

Treat ongoing learning as cost-prohibitive

Practice PR regularly, not just in crisis

Wait until a complaint or incident to engage

💡 Memory Hooks

Larvae over adults: "Control where they sit, not where they fly." Larvae are confined to water and easier to control; adults are mobile. Larval control is preventive.

Methoprene: "Mimics JH — kids never grow up." MGR target is preventing metamorphosis, not direct kill. Larvae malformation eventually causes death of the immature form.

Gambusia: "Top-feeding minnow — eats larvae from the surface." LARVAL predator, not adult. Tropical — re-stock each spring.

Droplet size: "5 to 27 microns. Bigger is wasteful, smaller drifts." 30 to 40 microns is too big to impinge efficiently; 1 to 10 mm is absurd (mosquito-body size).

PR honesty: "Pluses AND minuses." Half-truths break trust. The exam baits with "only beneficial aspects" — that's always wrong.

🃏 Drill 7F flashcards

← Ch.4 All 7F chapters Ch.6 →