Large & Small Bulb Flies
Sat, 19 Jun 2004 08:44:44 PDT
In a message dated 19-Jun-04 12:06:18 AM Pacific Daylight Time, writes:

> Does anyone know of a control, other than hot water, for Narcissus flies? I 
> have never seen as many as this year. I have lost count of how many I have 
> swatted over the last few months. All my friends have them.

Hi Mark ~

Welcome to the real world!  It's probably worse this year for you because of 
the heat and dryness and lack of previous control.  Cool wet/rainy weather 
tends to keep the flies grounded more and with less chance to mate, there are 
fewer eggs laid.

Both types of fly are endemic here in Oregon, as they are anywhere daffodils 
are grown, alas.  If there was any reason for near microscopically examining 
any new purchases before planting them, it is this.  When I lived in MN, there 
were no daffodil flies that I was aware of and before I planted anything, I 
made absolutely certain there were no parasites of any kind on or in the bulbs.  
Unfortunately, bulb mites are difficult to eradicate by just cleaning the 
bulbs, although some miticides that were on the market back then could be mixed 
up and poured into a little hole surrounding the bulb to create a mud coating 
for the bulb that concentrated the miticide around the bulb killing the mites.  
Effective for a few bulbs, but impossible for large plantings.

Here, in Oregon, I use Dursban (chlorpyrifos) having bought a supply before 
it was banned from use.  Interestingly, the product carries the lowest toxicity 
rating and is completely safe when used outdoors and according to the label.  
It seems that people don't read, can't read or are unwilling to read (it's 
one of the above!!) and used the chemical indoors to combat indoor insects and 
managed to kill off members of their family.  Thus, the government, in its 
effort to protect us from our stupidity has banned the compound, even though it 
was very effective on the listed insects and crops.  It has now been banned from 
use in Oregon even though under careful control by a trained applicator, as I 
said, perfectly safe to use.  

I am a licensed pesticide applicator and have to be to buy and use most of 
this stuff.  I have been using Dursban (in liquid form) at the rate of 2 ml 
(22.4% Active Ingredient)/gallon of water applied in a drenching spray around the 
base of the leaves/per 100' of row.  I think it has been able to control the 
fly, although this will be the first year since beginning to use this stuff 
that I will be digging sprayed bulbs.  Another compound that is approved for use 
on Narcissus here in the USA is Dylox (I don't know what the active ingredient 
is for this one; any chemical supply house will have the technical documents 
on hand and can tell you.)

Unfortunately, if you're just getting started with a spray program this 
season, you won't be catching many of next season's insects since they're probably 
already in the bulbs.  One needs to begin spraying (on daffodils, at any rate) 
shortly after bloom fades and every seven to ten days thereafter.  Usually, 
three to, possibly, four applications seem to suffice here, or so I've been 
told.  I don't have long enough experience to be able to state for certain.  I 
will be moving my collection to a new lease over the next two or three years and 
everything will be hot water treated to keep any parasites off the new 
ground.  Unfortunately, that will only be good for one year with the daffodil fly 
since feral daffodils grow everywhere here along almost every fence row on every 
farm and I'll simply be setting out a new and well fertilized smorgasbord for 
them -- unless I begin a spray regimen the following Spring to keep them at 

All best,

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