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Mosquito close-up

Field Guide · Herbal Shield

Mosquitoes
Aedes albopictus & Culex pipiens

Mosquito control is 90% water management. By eliminating standing water, applying Bti larvicide where water can't be dumped, and using botanical repellent sprays at the perimeter, we dramatically reduce biting pressure without synthetic fogging.

Standing WaterBotanical RepellentLarvicideHabitat Reduction
Care Card
Identification & Behavior
Asian Tiger Mosquito (Aedes albopictus)
Black with bold white stripes on legs and body. Small (~5 mm). Daytime biter — most aggressive in morning and late afternoon shade. Dominant mid-Atlantic species. Flight range only ~300 feet, so breeding sites are almost always on or immediately adjacent to the property. Breeds in tiny containers — bottle caps, plant saucers, folded tarps.
Common House Mosquito (Culex pipiens)
Uniform light brown, medium-sized (~6 mm). Dusk and dawn biter — enters homes through open doors and torn screens. Flight range 1+ miles, making source reduction harder. Breeds in stagnant water — clogged gutters, storm drains, abandoned pools, birdbaths, and tree holes. Primary vector for West Nile virus in Maryland.
Breeding Requirements
Any standing water that persists for more than 7 days can produce mosquitoes — females lay 100–200 eggs per cycle. Aedes eggs survive drought on container walls and hatch when re-wetted months later. A single clogged gutter or forgotten bucket can produce hundreds of adults per week throughout the season.
Disease Risk
West Nile virus (Culex — present in Maryland every year), Eastern Equine Encephalitis (rare but severe), and Zika (Aedes — low current risk in MD). Herbal Shield botanical sprays reduce biting but do not provide disease-level personal protection. Always recommend EPA-registered personal repellents (DEET, picaridin, IR3535, or oil of lemon eucalyptus) in disease-active areas.
Pressure Indicators

Field call: how much pest pressure is on the property. Determines urgency, treatment intensity, and whether botanical alone is enough or whether escalation-consent should be discussed.

Low
Intermittent yard activity, no confirmed breeding site.
Moderate
Daily activity, one standing-water source identified.
Heavy
Multiple bites during service, multiple breeding sources, may include neighbor property — set source-reduction expectations honestly.
IPM Action Steps
1
Survey the Property for Standing Water
Walk the entire property — front, back, side yards, roofline, garage, shed, driveway edges. Check every container, depression, and drainage feature. Common culprits: plant saucers, tires, tarps, buckets, toys, wheelbarrows, clogged gutters, bird baths, grill covers, AC drip pans, corrugated drain pipes.
2
Eliminate All Containers
Dump, drain, or flip anything holding water. Remove or drill drain holes in permanent items. Empty plant saucers weekly. Store unused pots upside down. Tighten tarp covers to prevent pooling. This single step eliminates 80–90% of Aedes tiger mosquito breeding on the property.
3
Larvicide Water That Can't Be Dumped
Place Bti (Bacillus thuringiensis israelensis) dunks in birdbaths, rain barrels, ornamental ponds, storm drain catch basins, French drain endpoints, and any permanent water feature. One dunk treats 100 sq ft of surface water for 30 days. Bti is a biological larvicide — it kills mosquito larvae on contact but poses minimal risk to fish, birds, pets, and beneficial insects.
4
Botanical Repellent Perimeter Spray
Apply cedar oil or peppermint oil spray to shaded resting areas: under decks, along fence lines, in dense shrub beds, and around seating areas. Mosquitoes rest in cool, shaded vegetation during the day. Botanical sprays repel adults from these harbor zones, reducing biting pressure in the yard. Reapply every 7–10 days or after rain.
5
Habitat Modification
Grade low spots in the yard to eliminate standing water. Clean and repair gutters — clogged gutters are the #1 Culex breeding site on most properties. Extend downspouts away from the foundation. Thin dense shrub plantings to improve airflow (mosquitoes avoid wind). Remove leaf litter from garden beds and yard edges.
6
Evaluate & Follow Up
Check Bti dunks monthly — replace when dissolved or after 30 days. Re-survey for new standing water sources after storms. Reapply perimeter spray on schedule. Client should notice a significant reduction in biting within 7–10 days of a thorough source-reduction visit. Full seasonal control requires repeat visits every 3–4 weeks.
Prevention & Cultural Controls
Water Management — The 90% Solution
Eliminating standing water is the single most effective mosquito control measure. Walk the property weekly during mosquito season (May–Oct in Maryland). Dump saucers, empty birdbaths every 5 days, tighten tarps, store containers upside down. Drill drain holes in tire swings and permanent outdoor items.
Gutter Maintenance
Clean gutters at least twice per year (spring and fall). Clogged gutters with organic debris are ideal Culex breeding habitat — invisible from the ground. Install gutter guards where feasible to prevent leaf accumulation. Ensure all downspouts drain freely and direct water at least 4 feet from the foundation.
Landscaping for Airflow
Mosquitoes are weak fliers and avoid even light breezes. Thin dense shrub plantings, especially near patios and seating areas, to improve airflow. Remove ground-level leaf litter. Trim low branches. Reduce shaded, humid micro-environments where mosquitoes rest during the heat of the day.
Application Techniques
Bti Dunk Placement — Biological Larvicide
  1. Identify all permanent water sources that cannot be dumped: birdbaths, rain barrels, ornamental ponds, catch basins, tree holes, French drain endpoints.
  2. Break dunks into quarters for small containers (birdbaths, plant bases). Use a full dunk for 100 sq ft of surface water.
  3. Place dunk pieces directly in the water — they float and release Bti slowly.
  4. For rain barrels: anchor a dunk piece in a mesh bag at the water surface.
  5. Replace every 30 days throughout mosquito season (May through October in Maryland).
  6. Bti poses minimal risk to fish, birds, pets, and beneficial insects — it targets only mosquito and black fly larvae.
Cedar / Lemongrass Oil Perimeter Spray
  1. Target shaded resting areas where adult mosquitoes harbor: under decks, along fence lines, dense shrub beds, ground-level ivy, woodpile perimeters, and around seating areas.
  2. Use a pump sprayer to apply cedar oil or peppermint oil spray to foliage, undersides of deck boards, fence slats, and ground-level vegetation.
  3. Spray in the morning or evening when mosquitoes are most likely to be resting in these zones.
  4. Reapply every 7–10 days or after any significant rain. Botanicals degrade in UV and weather faster than synthetics.
  5. Shake product well before each application. Test on a small area of any painted or finished surface first.
Garlic Barrier Application
  1. Mosquito Barrier (garlic juice concentrate) is applied as a perimeter and yard-wide broadcast spray.
  2. Dilute per label — typically 1 part concentrate to 10 parts water in a pump or backpack sprayer.
  3. Apply to lawn, shrubs, ground cover, fence lines, and under decks. The sulfur compounds in garlic repel mosquitoes for up to 3–4 weeks.
  4. Strong garlic odor dissipates for humans within 24–48 hours but remains effective to mosquito olfactory receptors for weeks.
  5. Apply in the evening for best adhesion (no UV degradation overnight). Avoid application immediately before rain.
  6. Safe for lawns, gardens, pets, and children once dry.
Recommended Products
Mosquito Dunks (Bti)
Bacillus thuringiensis israelensis — biological larvicide. One dunk treats 100 sq ft of standing water for 30 days. Break into quarters for small containers. Safe for fish, birds, pets, and beneficial insects. The single most important product for residential mosquito control.
Bti / Larvicide
Mighty Mint / Cedar Oil Spray
Concentrated peppermint or cedar oil in water base. Apply to shaded resting areas and perimeter vegetation. Repels adult mosquitoes from treated harbor zones. Reapply every 7–10 days. Safe for families and pets once dry. Not a substitute for source reduction.
Botanical / Repellent
Mosquito Barrier (Garlic Juice)
Concentrated garlic extract broadcast spray. Repels mosquitoes from treated yard areas for up to 3–4 weeks. Strong garlic odor fades for humans in 24–48 hours. Dilute per label and apply with pump sprayer to lawn, shrubs, and perimeter. Safe for gardens and pets.
Garlic / Area Repellent
Gutter Guards
Mesh or micro-screen guards prevent leaf accumulation and standing water in gutters — a top Culex breeding site. Recommend professional installation for multi-story homes. Reduces long-term maintenance burden and eliminates a hidden breeding source most homeowners overlook.
Exclusion / Habitat Reduction
▶Training Videos
Larvicide Application
How to Use Mosquito Dunks — Proper Placement
Breaking dunks for small containers, placement in rain barrels and birdbaths, and replacement schedule for season-long control.
Search: How to Use Mosquito Dunks Bti Placement
Species ID
Asian Tiger Mosquito vs. Common House Mosquito
Visual identification of Aedes albopictus and Culex pipiens — body markings, behavior, and bite timing differences.
Search: Asian Tiger Mosquito Identification Maryland
Source Reduction
Residential Mosquito Source Reduction Walkthrough
Step-by-step property survey identifying every standing water source — containers, gutters, tarps, and hidden breeding sites.
Search: Mosquito Source Reduction Property Walkthrough
Garlic Barrier
Mosquito Barrier Garlic Spray — Application Demo
Dilution ratio, pump sprayer technique, yard broadcast coverage, and reapplication timing for maximum repellency.
Search: Mosquito Barrier Garlic Spray Application
Warnings & Herbal Shield Standards
No Synthetic Pyrethroid Fogging: Herbal Shield does not use bifenthrin, permethrin, or other synthetic pyrethroid misting or fogging systems. These products kill beneficial pollinators, contaminate waterways, and provide only short-lived knockdown without addressing breeding sources. Our approach targets the root cause — standing water and larval habitat.
Bti Safety: Bacillus thuringiensis israelensis (Bti) is a naturally occurring soil bacterium, not a chemical pesticide. It produces proteins toxic only to mosquito and black fly larvae. It poses minimal risk to fish, birds, pets, bees, butterflies, and humans. Approved for use in organic farming and certified by the EPA, WHO, and NSF for use in drinking water.
Botanical Sprays ≠ Disease Protection: Cedar oil, peppermint, and garlic repellent sprays reduce mosquito biting in treated yard areas, but they do NOT provide personal protection against mosquito-borne diseases. In areas with active West Nile or other mosquito-borne disease advisories, always recommend clients use EPA-registered personal repellents (DEET, picaridin, IR3535, or oil of lemon eucalyptus) when outdoors, especially at dusk and dawn.
Client Script — Managing Expectations: "Our treatment focuses on two things: eliminating breeding sources on your property and applying botanical repellents to the areas where you spend time outdoors. You should notice a significant reduction in mosquito activity within 7–10 days. However, yard treatments reduce biting pressure — they don't create a 100% mosquito-free zone. Mosquitoes can still drift in from neighboring properties. For the best protection during peak hours, we recommend using a personal repellent like picaridin or oil of lemon eucalyptus when you're outdoors."
Client Script — Why Not Fog: "You may have seen companies that offer pyrethroid fogging or misting systems. We don't use those because they kill bees, butterflies, and other beneficial insects along with mosquitoes — and the effect only lasts a few hours. Mosquitoes breed so quickly that fogging without removing standing water is like mopping the floor with the faucet running. Our approach targets the water where mosquitoes breed, which gives you much longer-lasting results and protects your yard's ecosystem."

Have mosquitoes in your Maryland home?

Call and walk us through what you're seeing. We'll tell you what we can treat, what we can't, and what it costs — and if it falls outside our license, we'll say so and point you to someone who holds it.

Call (443) 228-6070 Request a callback

Greater Baltimore & the DC-metro counties · MDA Categories 7A + 7D licensed · what we do & don't do