West Chester Borough residents request free larvicide here. Other municipalities: please do similarly to help cut down on mosquito populations without harming other species.
Non-toxic methods
WEST CHESTER BOROUGH MOSQUITO ABATEMENT ACTION PLAN
In May 2019, West Chester Borough officially adopted a well-conceived mosquito abatement plan relying on controlling stagnant water and larviciding where needed. The text can be downloaded here in official form and also is copied below:
Regarding the spread of disease, such as West Nile Virus, through mosquitos, the Borough of West Chester has tasked the Public Works Department to implement the following action plan which replaces all other mosquito/West Nile Virus plans:
• The attainment of Larvicide Applicator Certification by at least two Public Works employees.
• Continue to store adequate quantity of dunks at its facility to be made available to Borough residents at their request.
• Elimination of all sumps from existing inlets inspected and found to facilitate ponding.
• Re-double its efforts to keep inlets clean and clear of debris that might inhibit proper drainage.
• Establish GIS mapping of current low-lying areas that are deemed susceptible to water ponding.
• Identify locations within the Borough that are potential “hot spots” for mosquito breeding for additional investigation by the Public Works Department.
• All activities must be consistently coordinated in concert with Chester County Health Department (CCHD) protocol.
• Constant communication must be kept with the CCHD as this will further enable the Public Works Department to be pro-active with on-going responses, by their ability to provide more detailed inspection and identification of potential breeding grounds.
• Direct residents who observe standing water on properties to call Building, Housing & Code Enforcement at 610-696-1773.
Q&A: What can we do to reduce the mosquito population?
Updated May 9, 2021. Short version: dump standing water; larvicide water that can’t be dumped.
Here is the enemy: 
But that photo shows mosquito larvae, which don’t bite.
Right, but once larvae hatch, they are harder to control. One female mosquito, with a protein infusion from blood, lays 100+ eggs. The eggs hatch into larvae, which fly away as adults in a few days. Continue reading
Petition to your public officials to end mosquito spraying from Beyond Pesticides
See background write-up and sign the petition here. The Don’t Spray Me! board has approved signing on as an organization; please add your individual signature as well. The text of the petition is below. The URL at the very end downloads the pdf of “PUBLIC HEALTH MOSQUITO MANAGEMENT STRATEGY For Decision Makers and Communities,” a very thorough summary of issues related to mosquito control and spraying.
Mosquito spray programs, which target flying mosquitoes with highly toxic organophosphate or synthetic pyrethroid insecticides, are ineffective and endanger our health. These pesticides, which are generally applied as ultra-low-volume (ULV) formulations, will float in the air longer than usual because of their small droplet size, but will eventually land on lawns, gardens, and anything that is outside. That droplet size also allows them to be carried deeper into the lungs. These pesticides can cause a wide range of health effects in humans, including exacerbating respiratory illness like Covid-19, and harm our environment.
Symptoms of organophosphate poisoning in humans include numbness, tingling sensations, headache, dizziness, tremors, nausea, abdominal cramps, sweating, incoordination, blurred vision, difficulty breathing, slow heartbeat, loss of consciousness, incontinence, convulsions, and death. Some organophosphates have been linked to birth defects, cancer, and brain effects. Symptoms of synthetic pyrethroid poisoning include dermatitis and asthma-like reactions, eye and skin irritation, and flu-like symptoms. Synthetic pyrethroids are endocrine disruptors and have been linked to breast and prostate cancer. People with asthma and pollen allergies should be especially cautious. Exposure has resulted in deaths from respiratory failure.
Naled, an organophosphate commonly used for mosquito control, affects a variety of non-target animals, including fish, insects, aquatic invertebrates, and honey bees. Naled is moderately acutely toxic to mammals, moderately to very highly toxic to freshwater fish and birds, highly toxic to honey bees, and very highly toxic to freshwater aquatic invertebrates, and estuarine fish and invertebrates. Elevated mortality rates among honey bees have been documented after nighttime aerial ULV applications of naled. Synthetic pyrethroids are highly toxic to fish and honey bees, even in low doses. Beneficial insects, including mosquito predators like dragonflies, will be killed by synthetic pyrethroids and organophosphates.
In addition to the dangers, spraying to kill adult mosquitoes (adulticiding) is the least effective mosquito control method. Close to 99.9% of sprayed chemicals goes off into the environment where they can have detrimental effects on public health and ecosystems, leaving 0.10% to actually hit the target pest. In addition, efforts to control the transmission of mosquito-borne diseases are encountering a big, though predictable, problem—mosquitoes are developing resistance to insecticides.
There are better ways to manage mosquito problems. Outbreaks of disease-carrying mosquitoes often result from habitat disturbance, such as deforestation, impairing wetlands, and spraying insecticides. Restoring the health of ecosystems helps keep mosquitoes under control. Native minnows, for example, can provide effective control of mosquito larvae breeding in standing water. Where water cannot be emptied from containers, the bacterial larvicide Bacillus thurigiensis israelensis is a least-toxic option. A better mosquito management plan protects public health and the environment. Please tell our local and state health departments to abandon spraying and adopt a mosquito management plan that does not depend on toxic chemicals: bp-dc.org/mosquito-mgmt.
Thank you for your consideration of my concerns.
DIY Lemon Eucalyptus Bug Repellent
From Kimberton Whole Foods. If you try it, please leave a comment to let us know results!
It’s the time of year when we need to begin considering protecting ourselves from the elements, especially pestering insects. The Center for Disease Control has listed Lemon Eucalyptus has an effective active ingredient for long-lasting protection against mosquitoes. Essential oils are powerful bug deterrents when diluted and applied correctly. Here’s an easy recipe with safe, natural ingredients that you can make at home!
See the recipe at Kimberton Whole Foods . And remember, there is a big difference between repellents with and without toxic ingredients. this one is non-toxic; mosquitoes just don’t like its smell.
Bti for Mosquito Control
Good advice on larviciding from the US EPA. It’s so much easier to get rid of larvae that can’t escape than winged adults that fly where they wish! And right now is the time to dispatch all possible larvae, before numbers start to multiply.
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1. What is Bti?
Bti is a biological or a naturally occurring bacterium found in soils. (Bti is short for Bacillus thuringiensis subspecies israelensis.) It contains spores that produce toxins that specifically target and only affect the larvae of the mosquito, blackfly and fungus gnat. EPA has registered five different strains of Bti found in 48 pesticide products that are approved for use in residential, commercial and agricultural settings primarily for control of mosquito larvae.
2. Does Bti pose health risks to humans?
No. Bti has no toxicity to people and is approved for use for pest control in organic farming operations. It has been well tested by many studies on acute toxicity and pathogenicity (ability to cause disease) for Bacillus thuringiensis including studies specifically on Bti. Based on these studies, EPA has concluded that Bti does not pose a risk to humans.
3. Where has Bti been used for mosquito control?
Bti is used across the United States for mosquito control. Bti is approved for aerial spraying, which has taken place in Massachusetts, Pennsylvania, Maryland and Michigan, among other states. Bti can be sprayed over waterbodies such as ponds, lakes, rivers and streams. Bti is used to kill developing mosquito larvae by being applied to standing water where those larvae are found. Bti can be used around homes in areas and containers where water can collect, such as flower pots, tires, and bird baths. Bti can also be used to treat larger bodies of water like ponds, lakes and irrigation ditches.
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4. Will Bti work to control mosquito larvae?
Yes, Bti has been shown to be effective in reducing mosquito larval populations and could be effective in controlling mosquitos carrying Zika, dengue and chikungunya in places like Puerto Rico and other areas where these diseases have been identified.
5. Are insects becoming resistant to Bti?
No. There is no documented resistance to Bti as a larvicide. A recent study (Tetreau et al. 2013) confirmed previous research showing a lack of Bti resistance in mosquito populations that had been treated for decades with Bti.
6. Are there special precautions to be taken during Bti spraying?
No special precautions are needed for applying Bti. A number of Bti products are sold as “homeowner” products and are easy and safe to use. People do not need to leave areas being treated. However, as is the case with many microbial pesticides, some commercial use Bti products may require applicators to wear a dust/mist filtering mask.
7. How will I know if aerial spraying is going to take place?
Decisions about where and when to spray will be made by local officials. Listen for announcements in your community with the dates, times and locations of upcoming sprayings on social media sites, newspapers or radios.
8. Does Bti pose risk to crops or water supplies?
No. Bti has no toxicity to people, so it can be applied safely to mosquito habitat without a detrimental impact on food crops or water supplies. In fact, Bti can be used for pest control in organic farming operations. It is important to follow the label for any Bti product to ensure that the product is being used correctly. There are multiple Bti products and some are allowed to be used on certain drinking water (e.g., cisterns) while others are not intended for that use.
9. Is Bti harmful to wildlife including honey bees?
Studies indicate Bti has minimal toxicity to honey bees. Bti produces toxins that specifically affect the larvae of only mosquitoes, black flies and fungus gnats. These toxins do not affect other types of insects including honey bees.
10. Is there a medical test to show whether I’ve been exposed to Bti?
Since Bti has no toxicity to humans, a medical test to show exposure to the active ingredient has not been developed.
11. What other measures should be taken to control mosquitoes besides aerial spraying?
Eliminate any standing water (even tiny amounts) to prevent infected mosquitoes from laying their eggs (breeding) in standing water.
Use window and door screens to block infected mosquitoes from entering your home, workplace or children’s schools.
Use EPA-registered insect repellents to prevent getting bitten. EPA-registered means the product works and is safe when you follow the directions.
Dress in light-colored clothing, long pants, and long sleeves and try to avoid areas where mosquitoes are present.
Blackberry Leaves Decompose to Thwart Mosquito Breeding
Beyond Pesticides, December 21, 2019)
A study at the University of Maine (UMaine) finds that adding blackberry leaf litter in stormwater catch basins creates an “ecological trap,” enticing mosquito females to lay eggs in sites unsuitable for larvae survival. Employing this new and incredibly viable “attract-and-kill’ tool for mosquito control shows potential for preventing the breeding of mosquitoes that may carry insect-borne diseases, especially in urban environments. Stormwater catch basins regularly accumulate leaf litter, which serve as habitat for the mosquito species Culex pipiens (Cx. Pipiens) that may carry West Nile virus.
Previous University of Maine research discovered decomposing leaf litter from Amur honeysuckle (Lonicera maackii) and common blackberry (Rubus allegheniensis) produces chemical compounds that attracts and stimulates Cx. Pipiens female to oviposit, or lay eggs.
Investigating the attractiveness and lethality of varying catch basin conditions to mosquitoes, researchers hypothesized that blackberry leaf litter could be shown to be lethal to developing mosquito larvae, and, therefore, act as a natural ecological trap for Cx. Pipiens….
read more at Beyond Pesticides
To larvicide or not to larvicide?
Larviciding is widely considered the prime means of reducing mosquito populations. Killing larvae is much easier than killing adults, because the larvae are in limited areas of water, whereas adults can be flying around anywhere in the air up to a height of something like 20 feet or sheltering in or under plants, in tree hollows, under porches and basement entryways, and in other areas where airborne spray may not penetrate well.
Furthermore, larvicides are not chemical toxins and affect only mosquitoes and some other species of insect pests, whereas airborne pesticides have collateral damage, killing many non-targeted insects and possibly harming other species.
The larvicide you can buy in the hardware store is the bacteria-based Bti “dunks.” According to the PA DEP, “Bti produces toxins that specifically affect the larvae of only mosquitoes, black flies and fungus gnats. These toxins do not affect other types of insects including honey bees.”
Another widely-used larvicide, methoprene is a growth regulating “juvenile hormone” that prevents insect larvae from maturing into adults.
PA West Nile website home page extols the benefits of larviciding. Indeed, larval control is an important part of the Chester County Health Department’s 2018 application for a grant from PA DEP (download here: DEP DH contract for 2018:
So wouldn’t we expect that the County would be regularly larviciding in West Chester Borough, which the Health Department has been regularly identifying as having high “Vector Indexes” (likely from breeding in storm drains)? Unfortunately not. In fact, the County has conducted only ten larvicide events in the Borough in the last 4 years! See the locationsn black on this map constructed by the 2018 Don’t Spray Me! / Sierra Club intern Kyle Erisman on the basis of geographical coordinates obtained by a Right To Know request to the PA DEP:
We hope that the Borough will, as planned, successfully take larviciding into its own hands beginning in 2019.
We’re all for larviciding
But wouldn’t a canoe be cheaper and more environment-friendly? From PA DEP (you have to keep refreshing the URL in your browser to find this photo and commentary):
Who says storm drains are a big mosquito problem?
The PA Department of Environmental Protection, that’s who!
We usually call them “storm drains” but others use the term “catch basins” or “inlets.” In any case, that’s where runoff from streets goes through a grill and disappears from our sight. But then were does it go? It should drain by gravity though a pipe system and eventually flow into a stream. That’s a problem for the stream, because street runoff can be polluted, e.g, by car and animal wastes.
But when water is able to remain standing in the storm drain, it provides an ideal habitat for mosquitoes to breed! Then those storm drains need to be “treated” (with a larvicide like Bti) to keep larvae from maturing there into adult mosquitoes. Here’s what PA DEP says (you have to keep refreshing the URL in your browser to find this photo and commentary):
dontsprayme 