Natural Mosquito Control

Summer might not be just around the corner, but once gardens are in full bloom safe insect and pest control will become a necessity. As a NY green contractor that specializes in green roofs and gardens it’s part of our job to ensure that the spaces we create can be enjoyed to their fullest potential.

Mosquitoes and other bugs will exist naturally within any green space and it is important to be able to control their populations. The best option is to use safe and natural methods so as to reduce diseases spread by mosquitoes and maintain a clean and healthy setting. It’s much easier for our clients to enjoy their urban landscape when they are free from worry regarding insects and pests.

With this article we aim to provide a deeper understanding of how one of the most annoying and dangerous pests, mosquitoes, finds a host and the current scientific advancement in safe pesticide production and application.

The focus here is on the mosquito species Aedes Aegypti AKA the Asian Tiger mosquito; most well known for being a royal nuisance but also very importantly responsible for spreading yellow fever. When mosquitoes hunt for a meal they detect a number of chemicals, including carbon dioxide, lactic acid, ammonia, and octenol.

Octenol, in particular, is emitted by all mammals and is a carbon-based compound that has a molecular structure that can take on a “right-handed” or “left-handed” form. Both the right and left forms are a mirror image of the other and the “handedness” of either form determines how its molecular bonds are assembled.

A test performed by Agricultural Research Service (ARS) entomologists concluded that mosquitoes are more likely to be attracted to the right-handed form of octenol emitted by mammals. Information regarding compounds that most attract mosquitoes can be crucial in determining effective pesticide and repellent use.

Traditionally, a variety of man-made chemicals are applied to the body or a garden to repel insects. These chemicals are known to have harsh smells and negative health effects especially when applied directly to the skin. Folk and homeopathic remedies have long been used by indigenous cultures and many are coming under current scientific review.

The USDA and their chief scientific research agency the ARS along with a few collaborators have recently found that the ancient Pacific folk remedy of using breadfruit (Artocarpus altilis) to repel mosquitoes actually holds scientific weight.

Three chemicals within male inflorescences of breadfruit have been identified as being more effective at repelling mosquitoes than the leading repellent known as DEET. These chemicals – Capric, undecanoic and lauric acids (or C10, C11, and C12 saturated fatty acids) – have been recorded as being entirely successful in repelling the malaria carrier.

A separate study that examined the effectiveness of a variety of saturated and unsaturated fatty acids as mosquito repellent found that participants wearing a cloth treated with these compounds were protected against mosquito bites. Dried clusters of the flowers can be burned, as is done in native pacific cultures, to release the chemicals and stave off harmful mosquitoes as well. This is the first scientific research validating the effectiveness of the folk remedy.

In the same respect, ARS scientists studied the effectiveness of the Indian and African method of burning Jatropha curcas seed oil to repel insects. Jatropha curcas is a versatile plant with all parts having homeopathic functions.

In an effort to validate the folk remedy, Natural Products Utilization Research Unit (NPURU) chemist Charles Cantrell extracted the smoke from the plant and analyzed its repellent properties concluding that the free fatty acids and triglycerides present were effective at preventing mosquitoes from biting. Fatty acids have previously been observed to have mosquito repelling properties, but this study is the first to include triglycerides in its findings.

Folk remedies are regarded as safer methods of repelling mosquitoes due to the toxicity of modern pesticides. Chemical pesticides often have a strong negative impact on humans due to the similarity in physiological systems shared by humans and pests.

In further scientific advancement, ARS scientists have tested a new form of mosquito control that they have concluded to be safe for humans, yet detrimental to insect populations. This nonchemical approach involves using a molecular pesticide technology that prevents mosquitoes from producing essential proteins necessary for their survival. The protein present in this pesticide is a nucleic acid such as DNA or RNA that interrupts specific genes within pests.

Due to the gene technology involved, this method can be designed to target a specific pest species and is even effective against species that are resistant to certain chemical pesticides. It is important to use caution with any technological advancement, however this alternative to modern pest control is reported by the USDA to negatively affect only the species towards which the method is directed. This new, nonchemical approach to preventing mosquito bites could serve as a model system for developing new, safer pesticides.

When enjoying your days and evenings in your Brooklyn green roof or garden you probably won’t be using natural pesticides like jatropha curcas seed oil or breadfruit to stave off pesky mosquitoes. But we are looking at these ingredients and many more as possible natural mosquito control. We’ll be sure to keep you posted as our research continues!

Removing Lead From New York Gardens

Here are two articles relevant to lead remediation in New York garden soil. Eco Brooklyn gets a lot of calls from clients with a child on the way and a recently purchased house. They intelligently tested the soil in the garden to be sure it is safe for toddlers and to their dismay they often find it has lead in it.

Our solution is usually to remove the top layer of soil, add a protective root barrier and then bring in new soil. We then landscape the garden using salvaged bricks or bluestone to create a patio and native plantings  area free of lead contaminated soil.

Garden Soil Remediation

This garden was barren with lead soil when we got to it. We removed the top layer of soil and brought in a layer of rich compost. We then landscaped with all salvaged materials – bluestone, deck, planter, border. We then planted. The ground was planted with ecological grass which takes a season to grow in. 

Removing the soil is costly however. So recently we have started to look into stay-in-place solutions. The most common one is to simply dilute the existing soil with certain kinds of material.

The best options we have found so far are to load the soil up with rich compost, which is full of iron, manganese, phosphorous and organic matter. These elements reduce the uptake of lead in humans and plants. The iron and manganese bind with the lead and thus make it less accessible. The phosphorous and organic matter increase the soil PH, which reduces the availability of lead uptake.

Some studies have found that doing this actually renders vegetables grown in the contaminated soil safe to eat. Getting the soil to be safe for toddlers is more of a challenge but we are becoming increasingly more confident with this new process. We aren’t completely there yet but we are working towards a solution that involves simply adding specific kinds of compost to the soil. This would reduce the remediation time and cost considerably.

As a New York green contractor and landscaper we feel that remediating NY gardens is a crucial part of making our city safe. There is no point in building a beautiful garden if the soil is toxic. Along with building healthy homes, the garden is a top priority for the safety of our children.

The following two articles are very interesting and worth reading:
Cornell U.
Biosolids

Natural Mosquito Repellent

Brooklyn’s beautiful summer days coax us outdoors to converse and lounge in our parks, backyards, and porches. In the heat of the summer, water features are a welcome cooling sight and draw the abundance of people looking to maximize their free time. However, these same water features are also home to pesky mosquitoes, diminishing the quality of our outdoor experiences.

At Eco Brooklyn, we are developing natural methods of mosquito control. These methods aim to diminish the mosquito’s presence while maintaining the balance of our fragile local ecosystems. We have a mosquito-repellant service with several components and options, which we make available to the community in an attempt to combat the mosquito problem on a larger scale.

Our service uses three main tools to reduce mosquitoes:

1. Landscaping Mosquito repellent plants – yards, pots and living walls.

2. Water features for mosquito predators – Fish and Dragonfly ponds.

3. Natural oils applied to the skin and garden area surfaces.

New York and Brooklyn were originally full of marshes, rivers and wetlands, which most probably had lots of mosquitoes. The difference now is that those areas are gone, and so are all the creatures and plants that kept mosquitoes at bay.

Now, with little left but clogged gutters and putrid waterways like the Gowanus Canal, there are few predators to the mosquito. Add to that the introduction of non-native mosquitoes from Asia that have even less predators here, and you have a real mosquito heaven (for the mosquito that is. Not for us humans).

Mosquitoes are a problem worldwide.  A wide variety of defenses have been put into effect to reduce the impact of the insect, some with more success than others.

Many of these methods have negative affects on the surrounding environment and may in fact be simultaneously attacking the mosquito’s natural predators. Broad-spectrum insecticides such as the organic pesticide Pyrethrum may kill mosquitoes and other insect pests, but they also kill beneficial pest-controlling insects such as ladybugs and lacewings.

Any attempt to reduce mosquito numbers must be founded in the natural lifecycle of the mosquito itself. The mosquito lays its eggs in standing water and hatches as larva before changing into pupae, then emerging and taking flight. Any standing water greater than a bottle cap’s full can serve as a mosquito-breeding site.

As such it is very important to eliminate small containers that have the potential to fill with rainfall and remain inactive. The elimination of all rainwater collection sites, however, is far from necessary. Slightly larger ponds can be effective methods of mosquito control by acting as habitats for the mosquito’s natural predators.

Some of the mosquito’s natural predators are dragonflies, damselflies, bats, and numerous fish species. While bats do consume mosquitoes, they are at most 5% of their diet. Extensive bat preservation policies, while beneficial to the bat, may not in fact greatly diminish the inhabiting mosquito population. Many fish will consume mosquitoes, but some are better adapted to the task than others.

Fish

The highly touted mosquitofish Gambusia affinis can consume 42-167% of its body weight in mosquitoes per day.  Its mouth is faced upwards towards the sky, allowing for more efficient consumption of mosquito larvae. It can tolerate various temperature changes in the water, salinity, decreased food supply, and organic pollutants and is compatible with goldfish, koi, and karp.

A nonnative species, it was first introduced to New York’s waters as a biological control for mosquitoes. However, mosquitofish were found to be ill-adapted to the cooler waters. Most importantly, it is not compatible with native species and very few instances of coexistence exist.

As such EcoBrooklyn does not recommend the introduction of mosquitofish into existing garden ponds. If your brownstone garden already includes a fish pond, we recommend finding a hardy native fish species that can reproduce in the local climate, such as the fathead minnow.

Dragonflies and Damselflies

Fish are not the only mosquito predator reliant on a pond source. Dragonflies and damselflies lay their eggs in foliage above or below the waterline of a pond. They then hatch as aquatic predators, consuming mosquito larva to feed and grow.

Depending on the species, this stage of life takes 1-2 months to 5 years. The larva then climb out of the pond via a plant stalk or rock and seek protection in nearby foliage before taking flight and attacking mosquito adults.

The life cycle of dragonflies and damselflies therefore shadows that of the mosquito, but the predator-prey relationship remains the same effectively controlling mosquito populations. Adult dragonflies and damselflies return to water features to feed and sun themselves, and eventually lay eggs in the pond.

Eco Brooklyn offers a dragonfly pond building service as a component of its mosquito solutions. Dragonfly ponds are a beautiful addition to a brownstone garden, and the insects provide welcome entertainment on a summer’s eve.

15% of North America’s 307 dragonfly species are in danger of extinction, and a new dragonfly habitat can help the graceful insects to reestablish themselves while also providing a welcome solution to the mosquito problem!

A dragonfly pond by Carole A. Brown

A dragonfly pond should vary in depth, with a segment around 2 ft in depth and flat rocks such as slate on the shallow side. Water plants should be included in the deeper parts of the pond to serve as nurseries, with perching sedges and rushes on the side for adults. It is also recommended that a small wildflower grassland be planted on the side of the pond.

The pond should include erect and submerged plants to allow for dragonflies and damselflies at all stages of the life cycle. A small pump can be included to keep the water clean and oxygenated, although this is not necessary for larger ponds. While the best dragonfly ponds are 20 feet wide, this width is not practical for a NY lot nor is it necessary to maintaining a healthy population.

In fact, adapted whiskey barrels, fountain basins, and earthen or plastic lined ponds can all provide welcome habitats as long as there are sloped sides and varying depths. The dragonfly larvae like to hide in the depths of the water to escape predation, but sufficient plant cover may substitute for that in the case of shallower ponds.

A simple stake in the pond can substitute for erect perching plants. It is very important that the pond be 70% in the sun and that no fish are added to the water.

Fish consume dragonfly larva as well as mosquito larva and are therefore incompatible, unless we design the pond to have two sections so there are safe places for the larvae to escape.

Once the pond is built we jumpstart it with a few spadefulls of soil from a nearby pond with a known dragonfly population.

The following plants work well in a dragonfly pond:

Deepwater -submerged plants

Curly pondweed – Potomogeton crispus

Water Starwort – Callitriche spp

Hornwort – Ceratophyllum demersum

Spiked Water Milfoil – Myrophyllum spicatum

Deeper water Floating Plants

Stiff-leaved Water Crowfoot – Rannunculus circinatus

Frogbit – Hydrocharis morus-ranae

Broad-leaved pondweed – Potomegetum natans

Amphibious Bistort – Polygonum amphibium

Yellow Waterlily – Nurphar lutea

Fringed Waterlily – Nymphoides pelatata

Shallow water emergent plants

Flowering Rush – Butomus umbellatus

Water Horsetail – Equisetum fluviatile

Bur-reed – Sparganium erectum

Water Plantain – Alisma plantago-aquatica

Common Spike Rush – Eleocharis palustris

Bog Bean  – Menyanthes trifoliate

Plants

EcoBrooklyn also installs plants as  a direct means of mosquito control. We offer several plant-based services:

-vertical frames planted with mosquito repellant plants, to be hung on the walls of porches, balconies, and other outdoor activity areas. The frames are made of cedar or pine as both of these woods repel mosquitoes.

-plant troughs filled with mosquito repellant plants, placed near outdoor activity areas

-herbal oil concoctions designed to specifically repel mosquitoes; these can be applied directly to the skin or sprayed on the surfaces of an outdoor activity area

-dried mosquito-repellant plants placed into sachets to be hung in desired locations

Below we have organized known mosquito repellant plants into two categories: native and nonnative species. Edible plants are subcategorized. We work with clients to offer aesthetically pleasing plant combinations.




Once planted, it is advised that plants be brushed before engaging in outdoor activities in order to release some of the scent. The compounds citronellal, geraniol, geranial, and pulegone are all known to repel mosquitoes. Plants containing these compounds are the most effective.

It is important to note that the plants themselves will not repel mosquitoes, it is the oil within their leaves that acts as a repellent. This is why brushing the leaves (resulting in small breaks) helps to repel mosquitoes. Our plant troughs and vertical installations  are meant to be a reliable supplier of leaves for your own herbal concoctions while also aesthetically ameliorating your home.

We highly recommend troughs consisting of edible mosquito repellent plants, which provide the additional ecosystem service of providing food.

Herbal solutions

While there are many variations of mosquito repellant liquids, they are made similarly.

The first method uses actual plant leaves from mosquito repellant plants. These are steeped in water, strained, and then the liquid is added to isopropyl alcohol.  Any combination of plants works well as well as using a single plant per batch.

The second method involves mixing 2 ½ teaspoons of any combination of essential oils (basil, cedarwood, cinnamon, citronella, juniper, lemon, myrrh, palmarosa, pine, rose geranium, rosemary) with 1 cup of 190-proof grain alcohol. These concoctions can be applied directly to the skin or used in a spray bottle. If applied to the skin, it may take some experimentation to determine what combination of oils works best with one’s body chemistry.

As described by the above overview, there are many natural means of combating the mosquito problem in Brooklyn. EcoBrooklyn is constantly improving its services through experimentation in the Green Show House and offers its solutions to the community.

These solutions aim to repel mosquitoes, add to the aesthetic value of Brooklyn brownstones, and support native species and the local ecosystem.

Biophilia in Brooklyn

As I was walking to the subway after work today, I passed a man who was leaving a few belongings on the sidewalk in front of his house. He is moving to DC tomorrow and, instead of just throwing the stuff away he couldn’t bring with him, he was leaving it out for passerbys to take. There were a few books, some old records, half broken appliances, but the prize giveaway was this massive pot of aloe vera plants.

ny green builder

I quickly grabbed the plant and continued to the subway. As I was riding the J train out to Bushwick, everyone in my car was eying my plant. People were pointing and whispering. When I got off the train and commenced the two block walk to my apartment, I kid you not, everyone on the street stopped to tell me how beautiful my plant was.

A young latino man who was working outside an appliance repair shop stopped me to talk about my plant and asked if he could take one of the baby aloe vera shoots extending from the mother plant. I happily gifted him a young sprout.

I continued walking and was again stopped by a group of Jamaican men who were barbecuing outside their newly opened thrift and clothing store next to my building. They too asked for a shoot, which I gladly relinquished.

Just outside my apartment I was stopped yet again by a young woman. She saw that I had given the two men a sprout and she asked if she could have one too. She didn’t know what kind of plant it was or how to care for it so I taught her a bit about both. She walked away thrilled.

Now the plant, which is still quite sizable, is sitting on my balcony overlooking the J train where commuters can easily look out and see it.

I felt compelled to write about this because I was so impressed by how a green action like donating items instead of throwing them away led to a whole chain reaction of community engagement. It’s incredible that a mere plant can stir up so much intrigue among city dwellers! This especially struck me because earlier in the day I was reading about E. O. Wilson’s Biophilia Hypothesis. Biophilia is a love for living things. The Biophilia Hypothesis suggests that there is an instinctive bond between humans and living systems (i.e. plants and animals). Wilson suggests that as humans were evolving we developed a love for nature because it sustained us and because our love for nature sustained it.

After my experience today, I have no doubt that Wilson was on to something.

 

By Malone Matson

How Our Soul Connects to the Earth

I spent the day in the Eco Brooklyn garden with seven interns today hauling salvaged blue stone around and working on the natural swimming pool. Typically we are working around the pool so they have their shoes off.

Adding the final touches to the natural swimming pool

But today I had them wear shoes to protect them from the heavy stones they were hauling.

I know the garden very well and can navigate the many native plants and stones with my eyes closed. For the most part the interns have been pretty good at where they put their bare feet as well, even if it is more to protect their virgin feet than to protect the garden.

But today they were like a herd of elephants. Carried away with their work, they forgot what was beneath their shoes. And asking them to be more aware didn’t lessen the damage.

Considering they were so intelligent in other areas I expected a much higher level of awareness from them and I found myself getting frustrated. And it wasn’t like they didn’t care or had physical disabilities. These college level athletes were mortified when I pointed out the damage their feet were doing.

It made me think about intelligence in general and how different societies value different things. In mainstream North America intelligence is measured in college test exams. In the Jungles of the Amazon intelligence is measured in whether you step on a snake or not.

But more importantly I had this profound realization that these seven intelligent college grads had spent the vast majority of their lives walking on dead materials – concrete, tile, car carpet, varnished wood – with shoes. They were completely illiterate when it comes to talking to the alive earth with their feet.

99% of the time they don’t need to be aware of where they are stepping. They have to navigate dead objects like getting out of a car, running on a track or walking up stairs but these things are all standardized – hard, flat, lifeless – so the process requires minimal awareness. The worst that can happen is they step in dog crap and never do they worry about killing anything.

The Eco Brooklyn back yard, however, is full of life and far from standard. There are little piles of stones to be toppled, plants of all sizes to be trampled, snails and bugs to be crushed, and all sorts of other life forms like mushrooms, moss, lichen, and berries that a Nike shoe easily kills.

Bees from the roof drinking water from moss in the Eco Brooklyn show house pond.

This lack of connection between our feet and the soil is powerful. I saw these kids with great intentions slowly trampling their surroundings and it brought up in me much more emotions than what was at hand. It reminded me of the many times I see environmental destruction due to a lack of awareness of and connection with the earth.

People are good. But disconnect them from their surroundings and they become killer monkeys.

This was a real learning experience for me as I work with them as a mentor. I have extra wide feet because I spent most of my summers as a boy barefoot. I remember crying from the pain of trying to put my feet into shoes at the end of summer for school. Maybe this gives me good connection between my feet and the soil. It isn’t much compared with so many people on this planet who live closely with nature but in NYC’s concrete jungle I’m an exception.

It drove home in me that more important than understanding the ecology of a natural pool or eco garden is having the awareness of where we step, both physically and metaphorically. An awareness of ourselves as we move on this planet and impact other life forms is the height of environmentalism. This has been a valuable lessen for me both in my own life and in my teaching.

Bus Roots on Bus Routes

Interactive designer Marco Castro has recently developed an innovative idea about how to efficiently increase green space in overcrowded urban settings through an interesting new reinterpretation of the term “green vehicle”.  The “Bus Roots” project is working to establish rooftop gardens atop buses in New York City and around the country so as to counteract the negative impacts of an environment warmed by cities lined entirely with asphalt, concrete and steel.

Castro has developed his first Bus Roots prototype with a garden topped bus known as the Bio Bus displaying a 15 ft2 green roof weighing a total of 225lbs (the estimated weight of one NYC public transit passenger).  With 4,500 buses in New York City’s Metropolitan Transport Authority (MTA) Fleet, Castro estimates a potential 35 acres of garden space lies atop New York City buses alone.

Bus Roots aims not only to beautify the city but to concurrently utilize green roof buses to reduce rising temperatures and increase CO2 and storm water capture. With this project Bus Roots aims to stimulate the conversation on urban planting, nomadic agriculture and environmental remediation that is imperative to the future of urban planning.   Since Ecobrooklyn is a New York green roof installer we appreciate and support this concept.

Digital mockup of a bus-top garden (Image: Marco Castro Cosio)

More information about Bus Roots is available at their website.