How
to Raise Tadpoles
Caring for a few tadpoles
and watching them turn into frogs (metamorphose) is a fascinating and
rewarding activity for young and old alike. It is also becoming more useful
for scientific reasons, too. There are still many things we don't know
about frogs and many species worldwide are disappearing before our eyes.
Some of the information about a frog's life cycle are far easier to obtain
from frogs and tadpoles in captivity.
It is also much easier
to discover if any diseases are active as sick or dead tadpoles are hardly
ever found in the wild. With the severity of the recent Australian drought,
the rescue of tadpoles from dwindling puddles or overcrowded frog ponds
is that much more important. Do remember, though, that if you are in an
area where mosquito-borne diseases like Dengue and Ross River Fever occur,
you MUST ensure that your tadpole enclosures do not breed any mosquitos.
If you live in Queensland, please refer to the bottom of this page for
specific legal information important to your tadpole keeping.
Tadpoles are generally
easy to keep IF you have them set up CORRECTLY, but there are some simple
guidelines to follow so that your tadpoles will be healthy and change
into frogs successfully. They are:
- tadpoles need a
certain amount of time (for multiple daily feedings, for example) and
their food costs money so don't collect more tadpoles than you have
time, money and sufficient rainwater to care for them
- clean water from
an unpolluted source - preferably rainwater not collected from the roof
- sufficient oxygen
- a suitable container
(or three ...)
- food which doesn't
foul the water
- a watchful eye
during metamorphosis
Where
Are Tadpoles Found?
There are many places
to find tadpoles such as a nearby stream, a swamp, a drainage canal, a
dam, pond, lake or billabong. (Remember to think about your own safety
in approaching bodies of water - there might be a risk from weeds which
your legs can get tangled in, steep slopes, slippery bottoms, etc. In
the tropics, there might also be risks from Leptospirosis in the water,
dengue mozzies, etc. - bring an adult to help collect the tadpoles.) Sometimes
frogs lay eggs in places we would rather they didn't like a swimming pool,
a flooded curbside or an ornamental container in our garden that filled
with water during a heavy rain. If you want to collect tadpoles to raise
in tanks or you have a new frog pond that you would like to stock, we
strongly recommend that you read our page on Tadpole
Movements. There are serious disease problems around most of Australia
and you would not want to find yourself with a tank or pond with contagious
animals in it (disinfecting a contaminated pond can be a labourious, dreaded
task).
After you have read
the Tadpole Distribution page, then you are ready to rescue some tadpoles
from a rapidly dwindling puddle or receive extras from a frog pond owner
in your neighbourhood. One of the most common questions about collecting
tadpoles is how to avoid collecting the tadpoles of cane toads (referred
to as TOADpoles for clarity). To tell the difference, visit the Toadpoles
vs Tadpoles page.
Some people believe
that collecting any animal from the wild is wrong and some states have
regulations to control this. In Queensland, it IS legal to collect and
keep tadpoles until they have turned into frogs and you do not need a
licence or permit to KEEP tadpoles but you will need a permit to MOVE/rescue
tadpoles (see the Keeping section - QLD regulations
page for more details). However, (according to the current regulations)
they must be released back to where they were collected from or close
to it within seven days of metamorphosis. This regulation, unfortunately,
is completely inadequate when it comes to knowing if the tadpoles picked
up any diseases when they were in the wild. If you wanted to be sure they
did not have chytrid fungus, for example, you would need to keep the juveniles
for at least one month before release.
Most of the known
frog diseases affect the little metamorphs very strongly and cause them
to die within the first three weeks after they leave the water. If you
release all the metamorphs in seven days (as regulated in QLD), you won't
know if they were exposed to disease or not. If you live in QLD, it is
up to you whether you abide by the Queensland regulation. But IFyou are
able to find enough tiny food to keep your metamorphs well fed for four
weeks, then you will be able to release frogs which you can be more confident
don't have a disease. Feeding metamorphs can be a difficult task in drought
affected areas because of the dwindling food supply so if you CAN'T find
enough food, then it would be better to release the metamorphs quickly
and leave it to their instincts and talents to find their own food.
There are genuine
conservation benefits to collecting tadpoles from the wild which include:
- Tadpoles normally
don't survive in the wild as well as they do in captivity (with the
right care) because they are food for other animals and sensitive to
changing conditions and weather patterns. By raising tadpoles in captivity,
more of them can reach metamorphosis to begin their lives as frogs.
- The learning experience
children and adults get from caring for tadpoles and watching them change
into frogs helps keep nature and the environment 'in the picture'. The
more urbanised our towns and cities become, the less connection with
nature we have. After awhile, it becomes 'out of sight - out of mind'
and we lose sight of its importance and the needs of the species that
need a healthy environment to live. Raising tadpoles and thinking about
their needs reminds us that nature is still there and needs to be looked
after.
- Many professional
scientists, veterinarians, biology teachers and wildlife managers started
out as a keeper of native animals when they were young. By being allowed
to care for and learn more about native animals, their interest was
nurtured and kept growing until it became their chosen work. Such career
choices are far less likely if the occupant has not had a long term
interest and interaction with nature and wildlife.
The
Container
The
very first step in setting up your tadpoles is asking what are you going
to put them in. The best containers are shorter and wider as opposed to
taller and narrower. This has to do with the oxygen availability. Any
container made of metal is out of the question, including those coated
with enamel or porcelain. Glass is good but consider the weight of it
when the container has to be moved or cleaned. Broccoli boxes (foam boxes;
styrofoam for our American friends!) are also a good choice. They are
lightweight, insulated by nature and are wide. The plastic molded kiddie
pools are also good if you want to have a large number of tadpoles and
you have the necessary water available.
Plastic
is good but don't use a bucket that has already been used to hold any
cleaning products or other chemicals. The plastic 'small critter
tanks' sold in pet shops are a very good choice:
- they have snap-on
lids to keep the tadpoles in and other things out;
- you can sit and
watch the tadpoles easily;
- you can position
the tank where it will get limited sunlight sometime during the day;and
- the snap-on lid
will be useful when the tadpoles metamorph (important if you have rescued
tadpoles from outside your neighbourhood - the metamorphs will have
to be returned to where you found them)
Sand on the bottom
of your chosen container is very useful for tadpoles. They seem to like
to forage around in it looking for microbials. Where you get the sand
is important. Beach sand is great but you must make sure that every trace
of salt is removed from it before it can be used. (There may be local
restrictions about collecting beach sand so you might want to check that
out first.) To leach beach sand, you need to wash it throughly until the
water comes out clear. Then divide up the sand into several containers
such as plastic ice cream containers. Fill with sand halfway and then
fill with water to the top, stir, then leave sitting for a day. Drain
and rinse and refil. Repeat this procedure until you have done about 6
or 7 water changes. By then, all the salt should have reverse-osmosed
out of the sand.
To save the hassle
of leaching salt, use river sand instead from a section of river that
is not tidal. Quarry sand can also be used but the it should be soaked
the same way as the beach sand for one or two water changes. Aquarium
gravel is only recommended if it is the tiny, very round pebbles. Avoid
the glass gravels or larger pebbles.
Arrange the sand along
the bottom til it is about half an inch/15mm deep. Then carefully add
the rain water (see Water below). Let the tank sit for a few minutes so
that the sand settles and the water clears. Then you can add plants (see
Oxygen below) and tadpoles. (If you are caring for a batch of tadpoles
which has turned out to be diseased, don't bother with the sand as it
will make the frequent water changes more difficult.)
How many containers
will you need? It depends on how many tadpoles you plan to accommodate.
The 'best practice' rule of thumb is that you should have a litre of water
for each tadpole by the time it gets to adult size. When they are small,
you can fit more than that but you will need to divide them up as they
get bigger. A container that holds 20 litres of water (about 4 gallons)
should only have 20 or 30 full grown tadpoles in it. Be aware that overcrowding
tadpoles causes a whole array of problems and increases the amount of
work you will need to do dramatically.
Many people ask about
snails in the tadpole tank. If you are in the USA, snails should be removed
and a full water change done immediately after because snails can carry
larval trematode worms (flatworm parasites) which attack the tadpoles
and cause deformities. (The deformed frogs problem infamous in the US
midwest is caused by these larval parasites.)
The
Water
Tadpoles have gills
so they need really clean water just like your aquarium fish. If you plan
to get some tadpoles, you'll need to get your water ready before
you bring the tadpoles home. The best practice is to use rain water but
if you are in a drought area, you might not have any access to this. (If
you are in or near an industrialised area in the northern hemisphere,
the local rain water might be too polluted to risk with tadples so distilled
water from the shops is recommended.) Stream water can be used but the
risk of disease means that it would be better to boil the stream water
and let it cool completely. Then store it in closed containers so it stays
clean. (Folks often ask about spring water but some "spring"
water has been checked by the USDA and found to be tap water so you might
need to try to find out the exact source of your favourite brand before
using.)
If neither of these
options is available, then tap water can be used but not straight from
your tap! At least not right away. There are two ways you can prepare
tap water for your tadpoles:
- add a water conditioner
from your aquarium shop which instantly ages water, stir well and then
let the water sit for at least an hour; or
- let the tap water
sit in an uncovered, non-metalic container for at least 4 days before
using it.
Tap water contains
chemicals which will kill your tadpoles. Letting it sit for a few days
allows these chemicals to evaporate out of the water. If you plan to keep
tadpoles, it is a good idea to store extra aged water in several very
clean plastic milk containers (put the cap back on the bottle after the
water has aged to keep it clean). Keep a steady supply of aged water on
hand for water changes.
Many houses have
old copper pipes and no amount of aging will remove the copper from the
water. If this is the situation in your home, it is far better to collect
rain water for your tadpoles. It's easier and cleaner and it falls free
out of the sky (if your local council charges for water, then this last
point will ring home to you)! When collecting rain water, it would be
better to avoid water coming off the roof if your roof is metal. Arrange
a series of plastic containers on the lawn instead to collect the rain
and then bottle it. Alternatively, water that has been filtered can be
used but only if you can verify that the filter removes all traces of
chlorine, chloramine, ammonia and metals.
Once you have your
tadpoles happily setup in your tank, foam box or other chosen container,
you'll need to watch for fouling of the water. Tadpoles + food + droppings
= ammonia. When ammonia builds up in the water, the tadpoles will start
looking sluggish. If left in the same water, the tadpoles will start to
die. Once the water starts to look like weak tea or is cloudy or has small
bubbles forming on the surface of the water, it's time to change the water.
You can also buy an ammonia test kit at your aquarium shop with will tell
you exactly when the water needs to be changed. You will not need to change
the water very often at all unless you are putting too much food in or
you have put too many tadpoles in.
If the water is just
beginning to look a bit "off", then a partial water change is
needed. Carefully scoop out about 1/3 of the water - putting a net over
the mouth of the cup will help keep the tadpoles from getting sucked in.
Slowly add fresh rain water so that all the sand is not churned up. If
the tank has been left too long and the water is so bad that tadpoles
are looking poorly, then a complete water change is needed. Put aside
a bowl with fresh rain water in it and gently scoop up the tadpoles using
a soft net. Be careful not to bump or scratch the tadpoles. They have
soft skin and damage during handling can result in deformities when the
tadpoles turn into frogs. Clean the tank, rinse very well and wash the
sand; then set up again like you did in the beginning.
Oxygen
and Hiding
According to the calls
we get, lack of oxygen seems to be one of the most common mistakes in
raising tadpoles. If you are raising tadpoles collected from a stream,
it is best to have an aerator running gently; if they are from stagnant
water, aeration might be disruptive and stressful so underwater aquatic
plants will be essential for providing oxygen. These plants also provide
some shelter and hiding areas for the tadpoles.
Many people choose
decorative plants such as water lilies, reeds or floating ferns but these
do not provide enough oxygen for the tadpoles and the amount of the water's
surface they interfere with may actually reduce the amount of oxygen available.
Leafy plants suspended in the water are the best type of plants to use.
A small amount of floating fern can be used but this should not be allowed
to cover over more than 25% of the surface. Even pest weeds such as combomba
are okay so long as they are removed from the wild and NOT dumped back
to the wild when you're finished with the tadpoles. If the leaves have
some algae growing on them, the tadpoles will eat the algae.
The more tadpoles
being kept in the container, the more underwater plants you'll need but
don't choke up the tank with plants. If you need to fill the tank with
plants, then you probably have too many tadpoles in it. In order for the
plants to survive, they will need some sun each day. The tadpoles also
need sunlight to obtain vitamin D which in turn helps them process calcium.
Position the tadpole containers on a covered veranda or other spot where
they can get an hour or two a day of sun but no more than that. Too much
sun will heat the water too much!.
The
Food
Tadpoles have a long,
coiled intestine which is designed for eating plant matter but they love
protein when they can get it. Plant material can be any variety of lettuce
or spinach which must be boiled or frozen before giving to the tadpoles.
(Freezing uses less energy because your refrigerator is always on anyway.)
Organically grown lettuce is better so you can be sure it hasn't been
sprayed with harmful chemicals before you buy it. Old leaves with algae
on them from creeks can also be used as a supplement but these leaves
could be a source of disease so avoid urban drains. Do not use
celery leaves!
Whatever plants you
decide to try, make sure that they are not toxic and always wash the leaves
thoroughly, then boil or freeze them. There's a saying: "if in doubt,
leave it out". Even
better than risking chemicals on commercially grown crops is to use a
compressed algae fish product called Algae Disks which might be sold by
your local aquarium or pet shop. A combination of food types is good.
Plant protein can
be given to the tads once or twice a week and increased to several times
a week after back legs have formed. Protein is very easy to provide because
tadpoles will eat bottom feeder algae fish food tablets. Many types are
available at your pet shop but a good one is Tetra Pleco-Min 5 Star formula
which contains a high protein algae called Spirulina. Some people use
other forms of protein such as cooked egg yolk or a chicken bone tied
on a string and dangled in the water but these will foul the water immediately,
are the wrong kind of protein and should be avoided.
Feeding tadpoles requires
small amounts of food frequently. You should only throw in a small amount
of food which will be gone in about 8 hours. It is better to throw in
food a couple times a day rather than once a day or every other day. Don't
put a couple days worth of food in to save time - this will instantly
foul the water and you'll have to spend a lot more time doing a partial
or full water change. A tadpole's whole life is to eat constantly so keep
an eye on the tank and add more food as soon as the last lot is gone.
The
Critical Time: Metamorphosis
When you see front
legs (arms) on your tadpoles, they are fast approaching the delicate stage
of turning into a frog. This is an amazing stage in a frog's life where
the sort of special effects that you see in some movies actually take
place in real life. At this time:
- the mouthparts
completely change
- gills stop functioning
and lungs start to work
- the intestinal
track changes from the long intestine of a plant eater to the short
intestine of a protein eater (insects are almost entirely protein)
- the skin changes
from the smooth, slimy skin of an underwater dweller to porous skin
which allows air and water through
- limbs containing
bones grow out of a body which had no limbs or bones
- the tail muscle
and fin deteriorates and is reabsorbed by the body
When your new frogs
leave the water, they might still have a full tail but they can jump.
The tail will shrink and be gone in one or two days. (Each species is
different so some will leave the water with full tails and others will
leave the water with the tail almost gone.) Although most of the tadpoles
I've kept simply shimmy or climb up the side of the tank when they leave
the water, not all tadpoles will do this. You should put something in
the container which the metamorphs can climb onto. It should start under
the water and stick out of the top and it should be fixed so it doesn't
move. This could be a fat stick or a rock - whatever you can find, so
long as it is not made of metal. Water hyacinth is excellent for this
but it is a pest (in Australia) so don't dump it back into the wild when
you're finished with it! Floating ferns are also good.
Experience is the
best teacher when it comes to metamorphs. But the most important thing
when a metamorph emerges from the water is that is should be removed from
the tadpole tank immediately. (If you are raising tadpoles which came
from your yard or neighbourhood originally, then they can be allowed to
simply take off on their own. If you are rescuing tadpoles from another
location, you need to catch each metamorph and place it in a tank so it
can be returned to its place of origin.) Once the new frog has started
using its lungs to breathe, it is often unable to use the gills anymore
(this depends on the species). If the new frog falls back into the water,
it could drown.
Some species are unable
to climb out of the water at all, even with a rock. The Ornate Burrowing
frog lays its eggs in flooded grassy areas and has a fast developing tadpole.
Ideally, the tadpoles are ready to leave the water by the time the puddle
they're in dries up. They simply wait for the water to drain away. This
doesn't happen in a tank or pond so the metamorph floats on the surface
for a day and then drowns. If you are keeping a ground species, you need
to fetch the metamorphs out of the water as soon as their tail is about
half its original length. The tail will start to crinkle up and this is
a sign that it's time to go!
If you plan to keep
your new frogs for a short time or if you have rescued tadpoles which
will need to be returned, you should have a small plastic pet tank ready
to place the little frogs in. Put some leaf litter and a small piece of
curved bark inside for the frogs to hide in. Some small branches from
a bush will also provide hiding and perching space for tree frogs. If
you have rescued a ground dwelling species, use some of the same sand
you prepared for the tadpole tanks in the bottom of the frog tank but
make it a bit deeper.
Spray the inside walls
of the frog tank with aged tap or rain water daily so that the humidity
stays high. A shallow jar cap filled with rain water can be placed on
the bottom of the tank in case any of the frogs want more water but make
sure that the water is no deeper than the the frogs' shoulders when it
sits so that the frog won't drown.
The new frogs will
not start to eat until the tail has been completely reabsorbed. Once the
tail is gone, trap some tiny flies (such as vinegar or fruit flies) and
put them in the tank. To keep them in the tank, a sheet of thin fabric
can be stretched over the top of the tank but under the lid. Housefly
larvae (maggots) are also enjoyed by metamorphs. Some species of ground
dwelling frogs like those tiny dark ants so try some in the tank. If the
frogs eat them, you will have another food to use besides vinegar flies.
If the frogs ignore them or spit them out, don't use the ants anymore.
Do not try to feed green ants to your new frogs -- the ants will kill
them. If the tank is on a patio or near an open window, you can also put
small pieces of banana or orange in the bottom corners (without the fabric
under the lid). The tiny flies will smell the fruit and enter the tank
through the lid holes.
Ready
to Rejoin the Bush
When it is time to
release your frogs, the best place to do this is usually at the place
you collected the tadpoles from -- although sometimes, this is not the
best thing to do. If you rescued the tadpoles from a swimming pool or
flooded curb or from a stream that has since been polluted or developed
over, then you need to find someplace else nearby to release the frogs.
Choosing the best release site depends on the species of frog you have.
Refer to a frog guide and see what is described for the habitat of your
species. Then look for a site that matches that description.
The best time to release
tadpoles is on cloudy/rainy days or late afternoons so that the sun is
not too strong, the temps are starting to cool but there is still enough
light for the tadpoles to move around and choose hiding spots.
The
tadpoles are dying -- what's wrong?
If you find that
large numbers of tadpoles are dying in your containers, then something
is wrong. Use this checklist to see if something needs to be fixed:
- Is the water clear
or is it starting to go 'off'? Have you done an ammonia test?
- Has anyone put
their hands in the water in the last 24 hours?
- Have any cane
toads gotten into the container?
- Have any chemicals
splashed into the water?
- Has anyone sprayed
any room fresheners, carpet cleaners, bug sprays or other aerosols nearby?
- What sort of water
did you use?
- Did you use an
old container of fish food (which might have gone mouldy)?
- Did you wash the
lettuce leaves thoroughly before freezing/boiling?
- Is there enough
oxygen in the water? Do the tadpoles spend any time hanging vertically
from the water's surface? If yes, this means there's not enough oxygen.
- Are the tadpoles
growing at very erratic rates - some are getting big while many others
are still the same size they were when they were a week old? This shows
they are too overcrowded in the container.
- Is the container
getting too much sun? Adding an aquarium thermometer will help you monitor
the temperature - above 32 degrees celsius it too high! 27 degrees C
is a good temperature.
- Are the tadpole
deaths occuring at different times during their growth or are all the
deaths occuring at very specific stages such as when rear legs are just
starting or the tadpoles are ready to metamorph? Are any air bubbles,
crimped tails, colour shifts to very pale or very dark, shrinking bodies,
twisted legs, swimming in circles or rolling upside down present? Are
only a few tadpoles dying or are most of them dying?
- Are the tadpoles
okay while all the deaths are occuring only after they metamorph?
- Are the metamorphs
getting enough food?
- Did you disinfect
the tank since you used it for the previous batch of tadpoles? Was the
frog tank rinsed very well before the metamorphs were set up in it?
- Was the bucket
you used to refill their tank used for any cleaning products?
If you are in Australia
and you are having problems with your tadpoles that can't be fixed by
the checklist above, then please contact us to discuss it. If you live
in NQ/FNQ, we will ask you to give us freshly dead tadpoles and metamorphs
so that we can get them tested. We might also ask for some of the live
tadpoles so that we can raise them ourselves to try to determine what
the problem might be. If you are overseas, you need to find someone local
to help you. Phone your nearest Fish and Wildlife office to ask what labs
are nearby to do disease testing.
There are many
details to cover when setting up tadpoles in containers, but if these
are done properly, raising tadpoles will be very easy and not take up
very much of your time. It's only when the setup is wrong that a lot of
labour comes into it. Good luck with your tadpoles and enjoy the experience!
Tadpole
keeping in Queensland
Rescuing tadpoles
is very important to frog conservation but there are laws which can be
used to prevent you from keeping tadpoles if you do not take the right
steps to ensure mozzies can't reproduce. There are two government agencies
which are involved in visiting properties to inspect for mozzie breeding
sites. They can issue you with a warning and you can be prosecuted if
you do not comply with the warning.
The first one is the
Tropical Public Health Unit in Cairns (phone 4050-3600). They only inspect
properties when a case of Dengue has been reported in the immediate vicinity
such as a near neighbour. They are only concerned with the breeding of
mozzies which are known to carry a disease and they can provide information
and advice to you so that you know what needs to be done around your property
to stop disease-carrying mozzies from breeding. They can identify mozzie
species and they are also experimenting with various types of mozzie-specific
baits which will trap mozzies without interfering with the environment
otherwise.
The second department
which can show up on any property is your local council (e.g., Cairns
Regional Council) and their inspectors will be looking for breeding sites
for ANY mosquito species - not just the disease causing ones. If you are
found to have any mozzie breeding sites on your property, council can
issue you with a notice under the QLD Health Act.
We have received some
complaints from Cairns residents who have expressed concern about what
is happening on their properties when they are not home and who have been
ordered to get rid of their tadpoles. Residents have come home to find
bird baths tipped upside down, or been alone at the back of the property
only to turn around and have council staff standing behind them! In one
case, we were informed that council staff dumped out a tank full of rescued
frog tadpoles while the homeowner was at work. We contacted Cairns Council
to enquire about normal procedures for mozzie inspections. We were told
the following:
- Cairns City Council
inspectors do NOT have the authority to wander around your property
if you are not home. They are allowed to walk up to the front door and
knock - if no-one is home, they are supposed to leave a notice in your
letterbox for you to contact them.
- Council inspectors
are NOT supposed to interfere with items on your property. If a breach
is found, they are supposed to issue you with a warning to comply.
- Council inspectors
will have clearly visible photographic ID badges and will be wearing
tan jumpsuits with the CCC logo embroidered on them.
- Council inspectors
are supposed to be knowledgable about how to keep tadpoles without breeding
mozzies and should be prepared to discuss your tanks and ponds with
you if they feel you are not taking sufficient action to avoid mozzie
breeding.
Both TPH Unit and
council inspectors can order you to get rid of your tadpoles but they
CANNOT dump out a tank or pond of tadpoles themselves (frogs are protected
so this would be a violation of the Nature Conservation Act). If this
should happen on your property, you should lodge a complaint immediately
with proof of who disposed of the tadpoles (you'll probably get a warning
notice). The complaint would go to Mr. Russell Best, QPWS, 5B Sheridan
Street, Cairns, 4870. If you are home when the inspection takes place
and if there are any dispute issues, you should get the names of the inspectors
and phone the relevant agency to discuss the items of dispute.
If you are taking
the correct steps to prevent mozzie breeding in your tadpole enclosures,
then there are no grounds for either agency to force you to get rid of
your rescued tadpoles. The steps you can take to keep your tadpoles and
comply with the QLD Health Act are:
- The most effective
and least labourious method is to have small fish in the enclosure;
natives are better but guppies will do. Pacific Blue-eyes are a lovely
native fish from FNQ but be aware that they are sensitive to change
and must be introduced to the tadpole enclosure according to proper
aquarium procedures (keep fish in bag and hang over side; once an hour,
take out a cup of water and add a cup of water from the enclosure, etc.
- ask the aquarium shop staff to show you how). Mozzies produce a lot
of eggs so if you are using guppies, add one guppy for every five to
seven litres of water in the enclosure; try half that number of Blue-eyes
and increase if they can't keep up with the mozzie numbers. If you add
too many fish, they might start eating the tadpoles so only use the
minimum number of fish to eliminate the mozzies.
- You can also use
tight fitting covers on tanks to prevent mozzie access but they must
be fitted tightly to the lids. Sunlight is needed during the day so
we surround the tanks with some mozzie coils and clear the zone first;
then we take the covers off and replace them before the coils run out.
We use chiffon fabric which is sheer and fine and lets lots of air and
light through. We keep the fabric stretched taught over the tops of
the tanks by cutting lengths of elastic (from the fabric shop) and tying
knots in them so they stretch tightly around the rim of the tank. There
is also a fine flyscreen netting available at Geo Pickers which has
been recommended but we haven't tried it yet ourselves.
- Other garden items
can be sources of mozzie breeding as well such as glogged gutters, bromeliads
(there is a debate on this but be aware), and plant cuttings you are
trying to strike. Many brom growers believe that the plants excrete
a chemical which prevents mozzies using the water in the centre stem
but the researchers dispute this and point to published papers on the
testing that has been done on broms. A small drop of vegetable oil in
the centre of each plant will create a film that prevents reproduction
but we don't know what this might do to a frog's porous skin. Flushing
the centres with the hose still seems to be the slightly more desirable
option if you have small frogs in your yard. If you use the oil option,
it needs to be a very light oil so that it spreads over the water's
surface. A heavy oil will form a ball and sink. Methoprene is also available
to do basically the same thing but this is a chemical in the "endocrine
disruptor" group so we are reluctant to promote its use if frogs
are present on the property.
- Gutters need to
be kept cleared and plant cuttings can be placed in bottles with narrow
necks such as soft drink bottles. Use cotton wool or aquarium wool stuffed
into the neck to prevent mozzies accessing the inside of the bottle.
- There is a red
wriggler which also finds its way into tanks, especially if you have
sand in the bottom, and these are nothing to worry about as far as the
legislation is concerned. They are midges (sand flies), they are not
a mozzie and they do not carry any diseases. The fish should love them.
- Dengue mozzies
in particular will breed throughout the dry season and they have a preference
for the colour black - start changing over your potted plants to other
brighter colours or terra cotta and avoid the cheap black plastic pots
and dishes.
If you have been inspected
and ordered to remove your tadpole enclosures, please contact us immediately.
We can advise you where to release the tads or we might take them ourselves
to complete their rescue and development.
Last updated: Dec. 24th, 2008

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