Does Citronella Work for Mosquitoes?
Citronella offers minimal protection — at most 20 minutes under ideal conditions. The 2002 NEJM study found DEET lasts 301 minutes versus ≤20 minutes for all citronella sprays tested. Wristbands averaged just 12–18 seconds. The CDC does not recommend citronella. In New Hampshire, where EEE and West Nile Virus circulate, citronella is not a safe substitute for EPA-registered repellents.
At a Glance
- Short Answer: Barely — provides at most 20 minutes of protection
- Key Fact: DEET lasts 301 min vs. ≤20 min for citronella (Fradin & Day, NEJM 2002)
- NH Relevance: CDC does not recommend citronella — EEE and WNV risk in NH makes this critical
- Action Needed: Use EPA-registered repellent (DEET, picaridin, or OLE) instead
Does Citronella Work for Mosquitoes — The Numbers
≤20 min
Citronella spray protection
301 min
DEET 23.8% protection
12–18 sec
Citronella wristband protection
2
FTC enforcement actions vs. citronella brands
The Full Picture
Citronella sounds appealing — a natural, pleasant-smelling plant extract that keeps mosquitoes away. But the peer-reviewed evidence is consistent and damning: citronella products offer only minutes of protection under the best conditions, dramatically underperform EPA-registered repellents, and are legally exempt from federal efficacy review. The CDC does not recommend them for disease protection.
What the Landmark NEJM Study Actually Found
The most-cited independent comparison is Fradin & Day (2002), published in the New England Journal of Medicine.
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In controlled arm-in-cage testing with Aedes aegypti mosquitoes, 23.8% DEET spray provided a mean complete protection time (CPT) of approximately 301 minutes — roughly 5 hours. All citronella-based sprays tested, ranging from 0.05% to 12% concentration, protected for 20 minutes or less. Citronella wristbands averaged just 12–18 seconds of protection. A follow-up comparison by Müller et al. (2008) in the Journal of the American Mosquito Control Association found 5% citronella candles offered only 29% repellency, versus 71% for linalool and 85% for geraniol. Rodriguez et al. (2017) in the Journal of Insect Science found a burning citronella candle had no statistically significant effect in wind-tunnel testing — mosquitoes flew toward the host at nearly the same rate (about 91%) whether the candle was burning or not.
Candles, Sprays, and Live Plants: What Each Form Actually Does
Citronella candles can reduce bites by 0–42% within a 3–5 foot radius on a calm night — but Lindsay et al. (1996) showed that plain unscented candles alone reduced bites by approximately 24%, meaning much of the candle effect comes from heat and convective disruption of odor plumes, not from citronella itself.
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Citronella topical sprays (5–12%) offer at most 20 minutes of protection per Fradin & Day. Citronella wristbands provide essentially no protection — Consumer Reports tested citronella and geraniol bands and concluded they 'did not protect against bug bites.' Live citronella plants (typically Pelargonium citrosum, a scented geranium) have no peer-reviewed support: volatile oils are only released when leaves are crushed, and University of Guelph trials cited by both Rutgers Extension and Colorado State Extension found the plant did not reduce bites when growing in a garden. Colorado State's PlantTalk is direct: 'None of them will repel mosquitoes by merely growing in a landscape.'
EPA, CDC, and FTC: The Regulatory Picture
Oil of citronella is classified under EPA FIFRA Section 25(b) as a 'minimum-risk' pesticide active ingredient — meaning products using it are exempt from federal registration and from any EPA efficacy review.
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Manufacturers are not required to prove their citronella products actually work before selling them. The CDC's recommended repellent list includes DEET, picaridin, IR3535, oil of lemon eucalyptus/PMD, and 2-undecanone. Citronella is not on that list and is not recommended for disease protection. The FTC has taken enforcement action against companies overstating citronella efficacy: Aromaflage received a 2018 FTC consent order (20-year compliance) for claiming essential-oil products were 'as effective as 25% DEET over 2.5 hours' and repelled Zika and dengue mosquitoes. Viatek 'Mosquito Shield Bands' paid a $300,000 penalty in 2015 for deceptive claims about citronella wristbands creating a '5-foot vapor barrier.'
What to Use Instead in New Hampshire
In New Hampshire, where EEE, West Nile Virus, and Jamestown Canyon Virus all circulate, the stakes of using ineffective repellents are real.
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NH DHHS and the CDC recommend EPA-registered actives: DEET (20–30%) for 5+ hours of protection, picaridin (20%) for 8–14 hours, IR3535 (20%) for 7–10 hours, and oil of lemon eucalyptus/PMD (30%) for roughly 6 hours. Consumer Reports consistently finds 25–30% DEET products as top performers, with 30% OLE as the best DEET-free option. These products have been independently tested and proven — citronella has not.
Bottom line — Citronella is a pleasant ambient scent that may reduce bites very slightly at close range on a still night — but it is not protection. On a typical NH summer evening with any breeze, it provides essentially nothing. For a state with confirmed EEE fatalities, do not substitute citronella for an EPA-registered repellent.
Why This Matters for New Hampshire Residents
New Hampshire has 48 mosquito species and three confirmed mosquito-borne diseases: EEE, West Nile Virus, and Jamestown Canyon Virus. A Hampstead, Rockingham County resident died of EEE in 2024 — NH's first EEE fatality in a decade. NH DHHS does not recommend citronella for protection against mosquito-borne disease. The NH mosquito season runs April through first hard frost, with peak EEE and WNV risk in late August and September. Using ineffective repellents during this window is a genuine health risk.
Key Local Data
NH's 2024 EEE fatality occurred in late summer — the exact window when people most commonly rely on citronella candles at backyard gatherings. EEE has a case-fatality rate of approximately 30% and no specific treatment.
We serve these communities
Service Area Map
Southern New Hampshire
Seasonal Mosquito Activity in NH
Jan
Off-season
Feb
Off-season
Mar
Off-season
Apr
Season starts
May
Use repellent outdoors
Jun
Use repellent outdoors
Jul
Peak activity — repellent critical
Aug
Peak WNV risk
Sep
EEE peak — repellent critical
Oct
Winding down
Nov
Off-season
Dec
Off-season
DIY vs. Professional Treatment
An honest comparison to help you choose the right approach for your situation.
DIY Methods
What you can do yourself
High — 301 min CPT (Fradin & Day 2002, NEJM)
CDC top recommendation; safe for adults and children over 2 months
High — 8–14 hours protection
Odorless; safe for fabrics; CDC-recommended
High — ~6 hours protection
Best DEET-free option per Consumer Reports; not for children under 3
Low — 0–42% at 3–5 feet on calm nights only
Mostly heat/convection effect; degraded by any breeze; not for disease protection
Professional Treatment
Licensed applicators
85-90%
Reduction
21 days
Per treatment
$75–150
Per visit
Professional barrier sprays treat the resting sites where mosquitoes spend 90% of their time — vegetation, shaded shrubs, and woody groundcover
85–90% reduction in Aedes mosquitoes for approximately 21 days (Stoops et al. 2019)
Licensed NH applicators can identify and treat breeding sites homeowners commonly miss
Professional programs can combine adulticide barrier spray with In2Care larviciding stations for broader population reduction
Applicators using bifenthrin or lambda-cyhalothrin provide protection across the property, not just within 3–5 feet of a candle
No obligation · Same-day service available
Our Honest Recommendation
Skip citronella products entirely for disease-protection purposes. For personal protection outdoors, use an EPA-registered topical repellent. For yard-wide protection, professional barrier spray with pyrethroid adulticide or a botanical alternative provides measurably better results than any citronella product on the market.
How Long Does Each Method Last?
Longer bars = longer protection from a single application.
Fradin & Day 2002, NEJM — essentially zero protection; Consumer Reports confirmed
Fradin & Day 2002 — all citronella sprays tested protected for 20 min or less
Lindsay et al. 1996: plain unscented candles cut bites ~24% vs. 42% for citronella — mostly heat/convection effect
Fradin & Day 2002 NEJM gold-standard comparison; CDC top recommendation
EPA-registered; CDC-recommended; best DEET-free option per Consumer Reports
EPA-registered; CDC-recommended; significantly outperforms citronella
EPA-registered; CDC-recommended; odorless alternative to DEET
85–90% Aedes reduction (Stoops et al. 2019); targets resting adults in vegetation
Prevention Checklist
Consistent prevention is the most effective long-term strategy. Follow these steps to break the breeding cycle on your property.
7
Action Items
15 min
Weekly check
Same-day service available · No obligation
Use EPA-registered repellents containing DEET (20–30%), picaridin (20%), IR3535 (20%), or OLE/PMD (30%) — these are CDC-recommended and independently proven
Apply topical repellent per label — cover all exposed skin and reapply after swimming or sweating
Do not rely on citronella candles for protection in disease-risk areas; use them as ambiance only
Eliminate standing water weekly — this reduces mosquito populations far more than any repellent or candle
Install a patio fan — 75% landing reduction (Hoffmann & Miller 2003) and completely safe for all pets and pollinators
Check the NH DHHS arbovirus risk map in late August and September — escalate protection when risk is elevated
Avoid citronella wristbands — Consumer Reports and peer-reviewed studies confirm they do not protect against mosquito bites
Want protection that actually works?
Our barrier spray treatments use EPA-registered active ingredients proven to reduce mosquitoes by 85–90% for up to 21 days.
Our Approach
Property Inspection
We identify every breeding source — gutters, downspouts, catch basins, and hidden standing water most homeowners miss.
Barrier Spray Treatment
85-90% mosquito reduction for up to 21 days. EPA-registered products applied to resting areas around your home.
Source Reduction
We treat standing water with Bti larvicide and recommend permanent fixes for chronic breeding sites.
Ongoing Protection
6-8 treatments per NH season (May-October). Each visit includes re-inspection and treatment adjustment.
Why Anchor Pest Services
Free inspection · No obligation · Same-day available
Frequently Asked Questions
Citronella Isn't Enough — Get Proven Protection
Our barrier spray treatments use EPA-registered bifenthrin and lambda-cyhalothrin proven to reduce Aedes mosquitoes by 85–90% for up to 21 days. Applied by licensed NH professionals.
Sources & References
This article is based on publicly available data from the CDC, EPA, NH DHHS, and peer-reviewed entomological research. All sources are independently verifiable.
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Editorial disclaimer: This content is provided for informational purposes only and does not constitute medical or pest control advice. Every property is unique — consult a licensed pest control professional for guidance specific to your situation. Anchor Pest Services is licensed in New Hampshire (#782664).
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