Richard J. Anthony Brimfield, OH 44240 RJA4CPA@aol.com

Richard J. Anthony
Brimfield, OH 44240
RJA4CPA@aol.com
The rose Midge; Dasineura rhodophaga Cocquillett is commonly classified as an uncommon pest
by most non-rosarians. Midge damage was first identified in 1886 in New Jersey. Since that time
it has been found in most northeastern states and on both coasts. If you ask the serious exhibitor
you will find that the Midge is actually much more common than most rose growers are aware
of. This is primarily due to the fact that often Midge is either undetected or misdiagnosed. This is
often the case among non exhibitor rose growers.
Non exhibitor’s rosarians typically do not grow as many roses as exhibitors do and they usually
do not spend the amount of time in the garden that most exhibitors spend. For those of you who
have experienced the devastation that Midge can cause in a garden, you know exactly why I refer
to the Midge as the exhibitor’s worst enemy. When damage is evident and not diagnosed
correctly and taken care of immediately, Midge will wipe out all or most blooms in short order.
What happens is the adult Midge will lay its eggs inside the sepal of an emerging flower. The
tiny maggot (about 1/20 of an inch in length) that hatches will feed in this area and cause the tip
of the flower to shrivel and darken or become distorted often with the bud turning to a forty five
degree angle. If the problem is detected, diagnosed correctly and treated appropriately, it is
normally brought under control rather quickly.
Conversely, if undetected, misdiagnosed and left untreated the resultant devastation is not
something you will want to experience. The life cycle of the Midge is quite short; about nine
days from the time eggs hatch until a new set of eggs hatch new Midge. This is where the
problem really presents itself as once the Midge gains a foothold it is very difficult to bring the
problem under control as eggs continue to hatch and a new set of Midge is reproduced on
average of about every nine days. It doesn’t take an accountant to see the exponential impact if
left untreated; complete eradication of blooms in the rose garden is the result.
Now that I have sufficiently alarmed you please understand that all is not lost; an outbreak of
Midge can be treated with success. I had a major Midge problem four years previous and
unfortunately it cost me the entire fall rose show season due to it going undetected initially. To
make matters worse I did not treat it properly in the beginning. What I did to successfully combat
Midge I will relate to you. I am not a chemist but rather a bean-counter who definitely
understands the concepts of consistency and overkill.
This is exactly what I did to combat the problem. The one thing I took away from this experience
is a very important lesson; consistency is the primary element in treating Midge as it is with most
other rose related concerns. Once Midge was diagnosed and after doing extensive research, I was
able to find a few bags of Diazinon which I quickly exhausted on 500+ rose bushes. This contact
killer of insects was but the first step in my treatment program. My research suggested that any
product that contained an ingredient identified as IMIDACLOPRID would work in reducing
and/or eliminating the Midge. Several Bayer products contain the ingredient as does Merit which
in my opinion just might be the better choice as it has a higher concentration of the ingredient.

In my less than humble opinion, the key to success is consistency as well as over kill. I used the
Bayer granular product around the drip line to the tune of one cup per large flowered bush and
one half cup for minifloras and miniature roses. I also used Merit as both a drench every week
initially and as a spray every three days until I had buds setting without noticeable Midge
damage; on average it takes one complete bloom cycle to bring the problem under control. I
alternated the Merit spray with other systemic and contact insecticides. I did this from mid
August until October every three days for the spray and every other week for the drench after the
first two applications. What worked? I have no idea to be quite honest but I was getting blooms
in October after the initial treatment and the following spring I was able to resume exhibiting.
As I indicated, I am a firm believer in consistency and over kill. While it might be nice to know
which or what actually product or treatment actually worked best my primary concern was to
eliminate the problem and this was accomplished to my satisfaction. Another thing I have come
to accept is that Midge is almost always present and cannot be completely eliminated. It can be
brought under control and if you are willing to accept an occasional shriveled up flower bud or a
distorted or turned bud, I suggest you treat your roses at minimum two or three times a year.
Doing so and Midge should not be a major cause of concern in the rose garden. I use the Bayer
granules around the drip line in early May and again in mid August of each year along with
spraying with Merit monthly. This has resulted in very few shriveled or turned buds in over 600
roses this year and that is something I can live with.
One thing about Midge that I have learned the hard way is to treat each new potted rose you
receive whether it is a small rooted cutting or a mature potted plant with caution. Midge spend
part of their life cycle in the ground and if you bring Midge into your garden via a new potted
rose the potential exists to contaminate your entire garden if you do not treat the potted rose as if
it is Midge contaminated.
As I mentioned earlier in this article, I am a firm believer in overkill and this is but another
example over overkill that works. To my way of thinking Midge is an exhibitors worst enemy
and I am not about to relive what I experienced four years prior. Treat Midge with consistency
and you should never have a concern about your roses.