Although I have never (in 15 years of growing) seen
an aphid on a lily growing in the ground here, I certainly
have seen them occasionally on potted lilies. I do not
consider them much of a threat at our location, but
I realize there are many people who do consider them
one of the worst pests of lilies. Myself, I only feel
threatened when they get into my roses - and that too
is rare on those planted in the ground. I suspect Mother
Nature has a good handle on controlling them under normal
growing conditions as lady bugs are in abundance here,
and the best natural control available. I also suspect
the reason potted lilies are susceptible to attack is
their proximity to the greenhouses and other potted
plants.
Understanding Aphids To battle aphids, you should first have a little
knowledge on how they work, and most importantly, what
to watch for. There are a number of different types
of aphids, the most common is the green aphid, shown
on this page. The most dreaded of all aphids is the
black aphid, for it is persistent and resistant to many
chemicals and sprays. Black aphids reproduce very quickly,
as do all aphids, and if you spot a few you must take
care of them quickly or you will soon have an epidemic
on your hands, and you will have the same problem the
next year! Aphids usually appear by the end of May,
especially after a period of cloudy, cool weather. Aphids
like those conditions, and that is when they reproduce
the most it seems. If you had just a few before the
cloudy weather, give them a week of optimum conditions
and they will infest your plants to the point where
you will be ready to throw them out! At this time of
year aphids cannot fly and concentrate on reproducing
themselves. Later in the year, usually mid August around
here, the aphids go into another cycle where they can
fly, and this is definitely the time to kill them before
they spread even further and settle for winter to repeat
the cycle again for next year.
Aphids are feared by many lily growers as they are
concerned about the transfer of virus from plant to
plant, which can occur with aphids. Aphids are a sucking
insect, inserting their piercing little mouths into
the plant, then moving onto the next one. Example:
Lily #1 has a virus, even though you cannot see any
symptoms. Aphids settle on this infected lily for a
few days, enjoying their steady meal and coating their
mouths and piercing parts with plant juices that contain
the transmittable virus. One day they decide it's time
to move onto lily #2, which is perfectly healthy. First
thing they do is sink their teeth into it, which immediately
transfers the virus as the plant juices already on their
mouths are absorbed by the new lily.
This
picture illustrates clearly just how well they blend
into the stems and leaves of plants, making them hard
to spot - see the green of their body is exactly the
same shade!
Aphids congregating on a succulent rose bud - new growth
is their favorite!
The first telltale sign of aphids is the little white
'fuzz'' that appears, usually at the tips of new growth
and flower buds. The fuzz is actually the aphid midge
(what it is in the first cycle of its life). If you
can spot this stage early, you should be able to control
them before they get totally out of hand.
The first telltale sign of a problem starting - the
aphid midges! These midges have settled on Million Bells,
an annual which seems to be a favorite of theirs.
It is often difficult to spot the midges when they
first appear here, as they appear about the same time
the poplar fuzz starts to fly outside, and it sticks
to everything until we get a nice rain to wash it off.
Close inspection is necessary, and observing the plant
in question up close for a few minutes will show whether
the fuzz moves or not - if it does, it is the midge
rather than fuzz. If you can see the fuzz clearly as
in this picture, you can be sure you have an established
colony on your hands already.
Aphids prefer to be cool, and this is why you will
find so many of them hiding under the leaves of your
plants instead of on the surface.
Controlling Aphids Effective control of green aphids and a small amount
of black aphids can be gained by using a relatively
new product called END ALL, produced by the Safer's
company.
You could also use a bio-control method, such as ordering
lady bugs from the BUG LADY and let them loose in your
garden. They will make a quick lunch of those nasty
aphids for you! Years ago I worked at a daycare, and
I would give the children jars and pay them a penny
for every ladybug they caught and brought to me. I would
take them home and let them loose in the greenhouse.
What a fun way to spend play time for them, and a cheap
and effective control of aphids for me! Lady bugs are
voracious eaters and very hungry when they wake up in
spring.
If you find black aphids, cover your head and moan,
then run for the department store to find a chemical
pesticide called SEVIN. Staff at the Alberta
Agricultural Research Station in Brooks, AB tell
us it is the only pesticide available to the consumer
which will be effective in controlling black aphids.
