There's a sucker born every minute

A paranoid man is a man who knows a little about what's going on.  
-- William S. Burroughs 

A new disease is making the rounds, and much like swine flu, bird flu, ebola, AIDS, SARS, and pretty much every other "newly discovered" disease that has gone before it, the Zika virus is bringing with it not only real pathology, but also the imagined kind. 
As Zika does pose some actual (though relatively minor) dangers related to infectious disease, and those dangers can be mitigated by proper gardening hygiene, now seems like the perfect opportunity to revisit some thoughts on mosquito control vis-à-vis permaculture.
 First off, a little primer on this "Zika" business. The Zika Virus is a species in the Flavivirus genus, which includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, zika virus and several other viruses which may cause encephalitis. This makes it a relative of some of the nastier mosquito-borne tropical diseases, though as of October of 2015, the outbreak of Zika in the Americas had resulted in fewer than 200 cases, and zero deaths. Its potential for fatality is at present unknown, though it has been theoretically linked to a higher probability of encephalopathy and microcephaly (lack or malformation of brain tissue) in pregnancies where an expectant mother had the infection during the first trimester. Research on this question is still sketchy, owing to the newness of the disease, but it makes sense, even if both the causation and quantification are neither clear nor overwhelming. 
As with all mosquito borne illnesses, most folk have a relatively sketchy understanding of exactly when and where they danger really lay. For starters, Zika (much as with West Nile) is associated with only one particular species of mosquito, the daytime-active Aedes aegypti mosquito, which (as its name suggests) originated in Africa, but has migrated to every tropical and subtropical environment in the world. 
Unlike the vectors for West Nile (Culex pipiens in the Eastern and Northern United States, Culex tarsalis in the Midwest and West, and Culex quinquefasciatus in the South), Aedes aegypti is a year-round pest, though there are some limiting factors. They most commonly bite at dusk and dawn, indoors, in shady areas, or when the weather is cloudy, although the Centers for Disease Control warn "they can bite and spread infection all year long and at any time of day." West Nile mosquitoes, on the other hand, are typically nighttime active, and require heat and humidity in order to breed, meaning that they are most dangerous from late Spring to early Autumn. 
CDC recommends the use of repellents with DEET (N, N-diethylmetatoluamide, 20% to 30% concentration, but not more), and this advice has been the guiding principle for several decades now. Unfortunately, a 2013 study has suggested that, while mosquitoes do, in fact, hate the smell of DEET, they have learned to adapt. A non-genetic modification to mosquito behavior suggests that they are collectively capable of overcoming their revulsion to chemical aversion in much the same way that beer-goggles make barflies more attractive to each other at last call in pubs around the world. Quite simply, if everyone in your backyard is wearing DEET (or if you are there by yourself), the mosquito thinks "Oh, well. Sure, she stinks, but she's the best blood-on-the-hoof I'm gonna be able to exsanguinate." 
Myrtle, of course, never passes up a chance to say "I told you so" (what can we say, chickens are cantankerous, crotchity and opinionated).  DEET is seldom fatally toxic, but numerous studies have associated it with various rashes, irritations, and inflammations, in addition to insomnia, ill-effects on mood (especially for those who already suffer from mood disorders) and, as with most manufactured chemical additions to one's personal environment, passes across most membrane barriers and combines with numerous other chemical additives in increasingly unpredictable ways. 
As with practically everything else, fully studying DEET is virtually impossible. The fact that so few regulatory agencies throughout the world can agree on what concentrations to call "safe" -- coupled with the fact that it is becoming increasingly less effective over time -- suggests that a different method of mosquito control ought to be our response to the increase in mosquito-borne diseases. 
There are, as luck would have it, natural means of disrupting the interaction of all mosquitoes (whether one of the Culex species, or one of the Aedes blighters), and some simple prevention measures which make mosquito-to-human transmission of viruses less likely. We have discussed some of these strategies before, but they are well worth revisiting. 
Typical Bti "dunk"
First and foremost, an understanding of mosquito ecology is essential. Removing or properly treating standing water is near the top of practically every municipal mosquito control checklist; there is some validity to this, as mosquitoes lay their eggs in water, where the larval stage of the insects develop. However, there is significant misunderstanding of which bodies of water are most to blame for the spread of mosquitoes.  Ironically, the larger the body of water, the less likely it is to be your villain. The reason is fairly simple -- the natural predators of mosquito larvae are likely to live in ponds, ditches, slow-moving creeks, etc. They are not likely to live in spare tires, buckets left standing open-end-skyward, clogged drainage gutters, or any other containers or non-draining surfaces. For those of us who hate mosquitoes, there are few sounds as joyous as the incessant din of amphibian romance. A frog gone a' courtin' is a human's best friend. Dogs are a distant second. But tadpoles don't live in gutters, so make sure yours are clear. Search your property high and low for puddles and other forms of standing water. This is especially true from May to October regarding West Nile, but now with Zika, we must be more vigilant in Winter, as well (and, to be honest, we at Myrtle's place have historically been lax at the end of "West Nile Season"… well, no longer). 
For larger bodies of water (ponds, fountains, etc.), mosquito dunks ought to be used. These are floating donut-shaped formulations used to spread a bacteria known as Bacillus thuringiensis serotype israelensis (Bti). This bacteria has the happy habit of feeding on the larval stages of mosquitoes, fungus gnats, and blackflies, but ignoring other organisms. This is especially fortuitous, as other serotypes of Bacillus thuringiensis do, in fact, harm other creatures, most notably bees and butterflies. The use of dunks has two major advantages therefore -- first, it helps control mosquitoes, and second (and almost as importantly), the spread of Bti takes away an ecological niche which would otherwise be filled with harmful species. 
For controlled bodies of water (rainwater collection ponds, fountains, or aquaponic tanks), several predatory species can be grown which are great at mosquito control:  mosquitofish (Gambusia affinis), some cyprinids (carps and minnows), killifish, and tilapia all love to chow down on mosquito larvae. None of these predators ought to be introduced to the wild, of course, as they are invasive exospecies, but for contained environments, they work wonders. 
The next component of ecological mosquito control relates to the habitat of the full grown mosquito. No matter how careful we are about monitoring mosquito breeding habitats, some will grow to maturity. And adult mosquitoes don't live in the water, though few people stop to consider where they do live. So... "Okay, Myrtle, where do adult mosquitoes live?" Glad you asked. They live in tall grass, leaf piles, piles of rotting debris, under stacks of lumber, behind boxes in outdoor sheds... pretty much anywhere dark and moist. 
That includes in mulch in your garden, by the way. 
Where adult mosquitoes hang out
So, unless you are willing to poison anything and everything which comes into contact with any and all of those hidey-holes (and we strongly recommend that you not do so), some other mitigation strategy is necessary for dealing with adult mosquitoes. Happily (particularly vis-à-vis mulch in your garden), there is an extremely simple, low-maintenance method of dealing with the full grown mosquito, and it is hinted at by why the DEET-only strategy has become less effective. Essentially, relying on DEET means there is only one tier of deterrence for the mosquito to overcome. But we know (based on the studies explaining DEET's effectiveness at grossing them out with its particularly mosquito-unfriendly-rankness) that mosquitoes will avoid certain smells, if at all possible. 
The only thing left to do is to figure out which smells they naturally avoid, and then layer our outdoor habitation with as many of those smells as possible. 
And as luck would have it, you really ought to be growing a lot of these plants, anyway. They are all the "smelly herbs" and the more of them you have, growing in as random an array and in as many different places on your property as possible, the better. Catnip, mint, basil (all varieties), oregano, rosemary, lavender, fennel, oregano (all varieties), thyme, honeysuckle, trumpet vine, cilantro, parsley, anise, bay laurel, borage, fenugreek, chives, onions, leeks, garlic, ginger, horseradish, hyssop, marjoram... anything you have ever picked up at the farmer's market and thought "Oh, my, that's a strong smell" -- get some seeds or seedlings, and go wild. And, as many of these things are either perennials, or reseed as easily as any plants imaginable (the secret to growing them year round is chicken poop plus neglect), the amount of maintenance involved in a mosquito-repellent garden is as minimal as you care to make it. 
The big key, of course, is that the smells must be layered, and they must be random. An herb garden laid out in neat rows, plainly labelled and arranged to suit a cook... that may get you in Better Homes and Gardens, but it won't stop the mosquitoes. No, far better to plant willy-nilly, and mix it up. That keeps the mosquitoes from acclimating to the pungency of your microenvironment; they take a whiff or two of your garden, and keep right on trucking, and if your neighbors were not savvy enough to follow your haphazard example, well, they can just stay inside and hope all their windows and doors are properly sealed, while you sit on your porch, sipping your lemonade in mosquito-free comfort.  
As with our recent discussion of cockroaches, the simple reality is that there is no hope of ever eradicating mosquitoes, and therefore we will continue to hear of new epidemics like the Zika fever outbreak of 2015-16; viruses evolve more rapidly than any other living things, and they are borne by mosquitoes, so news like this is inevitable, and will continue for as long as there are people to report it.  
The best we can hope for is to learn and adapt ourselves, so that we may mitigate the harm that comes from our interactions with the rest of the natural world. We only run into real trouble as a species when we forget that Homo sapiens are part of a much larger system than our own immediate surroundings. 
Since it is just about time to be putting new plants out for Spring, and since we are entering the final stages of the latest El Niño event, it's a good time to think about implementing these strategies into our yards/gardens/patios/porches, not just to stave off Zika, but to keep ourselves healthy and protected from whatever the next Zika turns out to be. 
Happy farming!   


Home is where your creepy-crawlies are

You cannot begin to preserve any species of animal unless you preserve the habitat in which it dwells. Disturb or destroy that habitat and you will exterminate the species as surely as if you had shot it. –  Gerald Durrell
The Asthma and Allergy Foundation of America reports that 78 to 98 percent of urban homes have cockroaches. The Centers for Disease Control (CDC) note that there are 55 species of cockroaches in the United States, and while in general, they are tropical in origin and therefore prefer warm, moist environments, the reality is that most roaches have tolerances to heat, cold, moisture, and drought which far outstrip not only their mammalian neighbors (including, obviously, humans), but also a large percentage of their fellow arthropods.
Practically every home has roaches.  Houses are built for them
as much as for humans.  Maybe moreso.
The overwhelming majority of those homes with a roach infestation make use of some form of industrially produced chemical poison as a management strategy.
The most common poisons are pyrethrins, notably deltamethrin, a pyrethroid ester insecticide which has been popular with pest control experts for thousands of years – its original form, of course, was much more dilute, as it is derived from a compound found in crushed Chrysanthemum plants which Chinese herbalists have used since before written records began. The modern deltamethrin products such as Raid brand ant and roach sprays are typically classified as non-toxic to humans, given that the amount usually used per application does no more than insult (the medical term for irritate) on contact. 
It is worth noting, however, that measurable amounts of deltamethrin cross from a mother's bloodstream into the milk of nursing infants; it is also worth noting that deltamethrin toxicity has been observed in sometimes fatal amounts in cattle, making our unwillingness as consumers to at least pause and think about our basic approach to battling bugs somewhat problematic. 
Small wonder, then, that they love human habitations, areas designed to protect us against the vagaries of the elements, but which also provide them with not just shelter, but also food and water.  It's enough to give one the heebie-jeebies, thinking about the fact that their perfect home is right behind that wall, no matter which wall you happen to be looking at at any given time. 
Apart from simply making most people feel “icky” of course, roaches pose a significant health problem for humans.  Ironically, it is their very proximity to humans which makes them common carriers of pathogenic microbes -- in nature (that is, when not living in a human dwelling but rather in their more native habitat of leaf litter and rotting material), cockroaches (as with all members of the insect class Blattodea carry only a minimal bacterial load, most of which poses little to no immunological problem for humans.
In proximity to Homo sapiens, however, that bacterial and viral load increases dramatically, making roaches a significant vector of human diseases, ironically doing the most damage in this regard in hospitals and other health facilities. There is no better way to get sick than to hang out in a hospital or doctor's office.

Most insecticides are variations on
poisons discovered thousands of
years ago.  The "science" of insect
control is pretty much guesswork.
Even without the threat of spreading bacterial and viral diseases, roaches represent a significant threat in terms of the spread of allergens and endangering asthmatic patients, as well.
 particularly foul musk associated with cleaning out attic or basement spaces, which is so often attributed to mold or mildew? It is usually neither; it is more likely the smell of roach droppings and roach carcasses.

All of which explains our compulsion to 
eradicate the nasty little critters. It also explains our extraordinary frustration at being utterly incapable of doing so.

At this point in a Myrtle post, you are probably expecting us to talk about the virtues of roaches, or the evils of chemical control, or some such.
We suppose you'd be partially right
 – we advocate a completely different approach from the norm when dealing with roaches, reducing the emphasis on killing them, and definitely reducing our reliance on chemical additives to our shared environment, but make no mistake, we hate the little buggers every bit as much as you do. We simply recognize that when one thing is not working, we should probably try something else. 
So, what are the most effective strategies for controlling pestilential cockroaches? The Centers for Disease Control (CDC) recommend a four-part integrated management strategy, focusing on:
Prevention – eliminating the food and refuse which nourish and hide roaches, as well as sealing off possible entry points from the outside environment
Sanitation – not only removing their food and shelter, but also sanitizing any areas they might cross (both to prevent them from picking up germs in the first place, and to prevent them from leaving any germs behind)
Trapping – making use of non-chemical trap devices ("Roach Motel" type traps), which have the dual advantage of being long lasting, and (owing to the communal nature of roaches) affecting multiple generations
Chemical Control – the aforementioned pesticidal solutions
The CDC, as far as a broad outline goes, has pretty much got it spot on. Where we would quibble with them is in some of the particulars of how these four points get implemented.  We'll take each item in turn:
It is definitely true that a clean kitchen/bathroom/closet/garage, etc. will have fewer roaches than will a dirty one, but that is not quite enough. 
The very design of modern (particularly modern American) homes and other buildings is seemingly custom made for the spread of cockroaches.  Remember, they don't ask for much when it comes to a satisfactory little Blattodean existence. A dry place to lay their eggs – such as might be found underneath any built-in cabinets, or behind any walls; a little organic matter to munch on – of any kind at all, be it a breadcrumb, a Tootsie Roll wrapper that fell behind the couch, or a smidgen of toothpaste on the bathroom sink... and they are set up for luxury roach living. 
We recently tore out our kitchen countertops, owing to a niggling voice in the back of our heads that something was not quite right. We told ourselves that it was because a family of four, living in a 900 square foot house, needed to maximize space... but we knew that this was only part of the reason. 
Note the spaces in a typical built-in cabinet that
are invisible to the human eye.  Roaches can
(and almost definitely do) live there.
It wasn't until we found that our pristine, well-washed and often-mopped kitchen was home to a nest of roaches who found the impregnable seal around the baseboards of our built-in bar and countertops to be not-so-impregnable that we realized the simple truth:  built-ins are a bad idea.We have not yet completed our kitchen remodel, but we know for sure it will have a couple of tremendous advantages over those of practically everyone whose advice we have chosen to ignore:1) It will be much cheaper; rather than buying new counters and cabinets, we will be relying on smaller, mobile tables and rolling islands, which can always be counted on to not hide anything (or anyone), while still fulfilling all the functions of their more expensive built-in counterparts.2) It will be much easier to install and maintain, while maximizing the interior space of our home reserved for human use only. 
When we came to this epiphany, we naturally sought examples online of counterless kitchens. To date, we haven't found other examples of folk doing it this way, but that isn't about to stop us. If a kitchen as impeccably clean as that kept by the somewhat OCD Mrs. Myrtle Maintenance was home to hidden roaches, we can promise you that there are creepy-crawlies under your sink, too.  (Don't feel bad -- no matter how much she tells herself otherwise, Martha Stewart has roaches in her kitchen. Bet good money on it.) 
More than likely, what the CDC had in mind dovetails nicely with what Myrtle thinks about the question of sanitation. Not only should food items be stored where roaches and other pests cannot get at them, but all cooking and cleaning surfaces should be regularly cleaned and sterilized.  Naturally, we recommend alcohol, vinegar or similar less-toxic varieties of disinfecting cleansers, foregoing bleach as much as possible, though we certainly do not begrudge medical facilities going all-out in their war against microbes. 
The main thing to remember is, when sanitizing, the focus is not merely on cleaning up after bugs, but also on cleaning up after humans, because bugs only spread disease if they have come into contact with disease, and the place where they are likely to have encountered pathogenic microbes is any unsanitized surface we have used. 
Much as "Kleenex" brand tissues have dominated the market so long that "kleenex" is now the generic term for all tissues, Black Flag brand "Roach Motels" have dominated the market for roach traps so strongly that everyone remembers "Roaches check in, but they don't check out."  The concept behind the trap is simple: pheromones attract roaches into a trap from which they cannot exit. 
No pesticide is necessary; after the roaches have been immobilized, they are typically cannibalized by other roaches, who are then, themselves immobilized, the roaches have been immobilized, they are typically cannibalized by other roaches, who are then, themselves immobilized, and so on, until the pheromone eventually wears out. 
The advantages to this form of control are innumerable, not least of which is that the traps are quite literally non-toxic to anyone (not even the roaches), relying as they do on roach behavior to isolate and control their population.
The least toxic of the commercial control products.
The disadvantages involve the need for changing out the traps every few months... along with the fact that they can begin to smell somewhat unpleasant if they are working well. On the bright side, that's only a problem if they are actually doing their job. 
Chemical Control: 
Here (as you might have predicted), CDC and Myrtle take divergent paths. The most common roach control method in America is to spray the snot out of our houses with a cocktail of chemicals in hopes that our foolhardy creation of their perfect breeding grounds can be overcome by our foolhardy addiction to pumping chemicals into the environment at ever increasing levels.

The aforementioned pyrethroid pesticides may not cause immediate death, and their carcinogenicity is marginal, but the idea that in combination with other environmental stressors the addition to our homes of irritants which decrease the effectiveness of our immune systems even temporarily is anything other than a bad idea is preposterous.  
Furthermore, pyrethroids are extremely toxic to fish and amphibians. If you're naïve enough to believe that spraying under your counters isn't going to affect what goes into the graywater coming out of your house, and then into the creeks and rivers in the countryside, all I can say is, you need to turn off the TV and start reading some science journals. 
There are several other categories of chemical control which present their own problems, though even the "best" chemical solutions unquestionably ought to form a last line of defense, coming in solidly behind the first three concepts discussed above. Some of the alternatives include:
  • Boric acid - use in low quantities only, and in very specific applications to areas such as behind new baseboard installations, or other places where there is little chance of direct ingestion by humans or pets. Fatal to insects in small doses, it is also carcinogenic to mammals in large doses, so treat it accordingly.
  • Poisoned bait containing hydramethylnon or fipronil - use these at all, and Myrtle will personally hunt you down and peck you into next Tuesday. These substances, much like pyrethroids, are extremely toxic to aquatic life; in addition, however, they are also extremely toxic to bees, butterflies, birds, small mammals, and children. Fipronil, in particular, has come into more widespread use as the Texas Agriculture Commission has foolishly suggested it as an "emergency measure" to control the Raspberry Crazy Ant. The "solution" is more crazy than the ant, we assure you.
  • Herbal repellents - here, you are back in familiar Myrtle territory. Several plant-based odors are repugnant to roaches, including bay leaves, catnip, mint, cucumber, and garlic. In Singapore and Malaysia, taxi drivers use pandan leaves (Pandanus amaryllifolius) to keep roaches out of their cabs. Since pandan is a common ingredient in Indian and Bangladeshi cooking, finding it ought not to be too difficult for most Myrtle readers.
It is a truth so universally acknowledged that virtually all of us can remember discussing it as children: long after humans have ceased to walk the Earth, cockroaches will remain. It seems to us at Myrtle's place that the best way to cope with this fact is to stop trying to win, and start finding some way to effect a tactical retreat.  
Rather than attempting to win an unwinnable war, perhaps we ought instead to seek a separate peace -- the roaches can own the forest floor. As for the floors of our houses? Well, at Myrtle's place, at least, we're going to make sure those floors are all visible and sweepable. Most houses are (if we are being honest with ourselves) perfect habitats for roaches as much as for people. 
We aim to change that equation. If the roaches want to hide, let 'em hide in the chicken coop. 
Happy farming!