daylily pest

Discussion in 'Garden Pest Management and Identification' started by trishhoff, Jul 9, 2003.

  1. trishhoff

    trishhoff Member

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    Location:
    Mayne Island
    I have a large number of daylilies. All of my plants have developed one or more distorted flower buds. Instead of the normal long shape, the buds are rounded, the petals are thick and puckered and the bud usually dries up without opening. If it does open the petals are distorted and lack their normal colour.

    When I open the bud the pistil area is mushy and full of tiny white wormlike insects - 2-3mm long. When I lift them out on my finger nail the rear up and spring off into the air. They jump quite a distance.

    What are they? I am picking off and burning the distorted buds. How should I be managing this problem to prevent it from becoming worse next year. I seem to recall seeing only a few of these buds last year and I did not pay much attention to them. This year I have lost about one third of all my flower buds.
     
  2. Daniel Mosquin

    Daniel Mosquin Paragon of Plants UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

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    Hello and welcome,

    The problem is daylily gall midge, (Contarinia quinquenotata). This is a recent pest introduction to British Columbia (2001). It also seems to be spreading, as the BC Pest Management page below mentions only the Lower Mainland and Bowen Island - not Mayne Island.

    Some links:
    The Pest Management pages of the BC Ministry of Agriculture, Food and Fisheries (link includes photographs)

    American Hemerocallis Society

    A report from Hemerocallis Europa details that the best method to deal with them is to break off and destroy the swollen buds before the adults develop - the suggestion is to dispose of them in a sealed plastic bag and into the garbage. Burning them as you do also works. The author of this article also wisely suggests using early-blooming varieties as trap plants, allowing control of the initial infestation to a select few plants.
     
  3. DaylilyLady

    DaylilyLady Member

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    Langley, B.C.
    Hemerocallis Gall Midge

    In response to questions about Hemerocallis Gall Midge, this is a relatively new pest to B.C., imported from Europe four years ago. I own and operate a large daylily nursery and have been working with the Ministry of Agriculture in identifying and controlling this pest. The initial information and results are available at www.daylilygrowers.com - then click on News for the article on the gall midge.

    Initially, there was deep concern about this pest. Since then, however, the realization that there is only one generation per year and have been quite easy to control has eased the minds of many growers. While Europeans have recommended early yellow varieties be used as traps for this pest, results here have found that our weather conditions are such that that is not quite the case. This year, the adult midge was flying from early May to early June, with the heaviest concentration of insects around May 15th. Sticky traps were also very beneficial in trapping the insects in heavier affected areas. The adult fly lays her eggs and the larvae seem to gravitate to the largest one or two buds on each flowering scape - quite easy to detect as the bud gets abnormally round and misshapen, losing its green color and becoming quite pale. Disposal by burning or sealing in plastic containers has worked well - just be sure NOT to compost these buds. Thankfully, with only one generation per year, once you have taken off the affected buds, the problem is solved for another year. As I repeatedly tell clients, awareness is the key to control - look for the deformed buds beginning late May and dispose of as soon as you see damage. This year, we have seen a 90% decrease in the occurence of the midge due to diligence and careful inspection.

    Pam Erikson, Erikson's Daylily Gardens, Langley, B.C.
     
  4. Daniel Mosquin

    Daniel Mosquin Paragon of Plants UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

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    There is no better source of information than the expert on daylilies in the province. Thanks for the input, Pam.
     
  5. jimmyq

    jimmyq Well-Known Member 10 Years

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    Thanks for the heads up Pam.
     
  6. DaylilyLady

    DaylilyLady Member

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    Gall Midge Update

    Happy to help Daniel, and Paul. I am in the process of updating my website right now with up-to-date info - the problem is hopefully over for this season but something I encourage everyone to keep an eye out for.

    Thanks again.

    Pam Erikson
     
  7. trishhoff

    trishhoff Member

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    Thank you everyone for the information. Pam, do you know at what winter temperature the over wintering pupa will be destroyed. Is this going to be confined to the West Coast or will it possibly become a problem for growers in the colder areas of the country?

    Trish
     
  8. DaylilyLady

    DaylilyLady Member

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    Gall Midge

    Trish - the information so far is that the overwintering pupae are not killed by severe weather. I have spoken with two people in Ohio in zone 5 conditions who have also had gall midge for the past two years. As this pest travels, we will determine what zones it seems more prevalent in. Since so many growers across North America import materials from Europe, it is quite likely that this pest will occur in other areas. I am in close contact with major growers and distributors all around the world and we have discussed gall midge at length through an international email daylily round robin that we all belong to. They all know what to look for and an alert has been issued through the American Hemerocallis Society Journal - so the awareness is out there. As I said before, awareness IS the key to control and I am pleased to hear from people who have less problems with midge this year after having carefully removed suspect buds last year.

    Good luck - I am always happy to answer any questions in hopes of stamping out this pest.

    Pam Erikson
     
  9. RBGINVAN

    RBGINVAN Member

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    As last posting on this was in 2003, is there any updated information on incidence and control of the daylily gall midge? I picked off infested buds last year but it is still a problem - today found 13 infested buds on 7 plants bringing total since end May to about 30. Did not keep records last year so don't know if it's getting better or worse. Now I'm recording incidence by plant and date to see if I can learn anything from the data.

    Any information on how far midges can spread from an infested plant? A walk through the neighbourhood (Vancouver west side) usually reveals a few infested plants. I got a brief mention of the problem in residents' association newsletter and posted on their website (with links to appropriate websites for more info).

    Bob Gordon
     
  10. trishhoff

    trishhoff Member

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    I have been removing the infected buds for three years. I number of infected buds appears to be about the same as last year - one to two infected buds on each scape. The problem has spread to other areas of the island (Mayne Island). I have written an article in the community paper and people are calling to let me know that they are finding infected buds on their plants.

    Trish Hoff
     
  11. RBGINVAN

    RBGINVAN Member

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    Following suggestions in this thread and from other informed sources, I have set out some sticky traps near daylilies, hoping to trap some of the gall midges in the flying stage of their life cycle.

    Can anybody tell me what they look like? I have caught several insects, but don't know what I am looking for and haven't found anything online that helps.

    Bob Gordon
    Vancouver
     
  12. DaylilyLady

    DaylilyLady Member

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    I happened to be browsing and discovered more messages about the gall midge, so I will do my best to answer your questions. My apologies for the delay, but between the nursery, travelling to buy new plants and lecturing, I have a very busy schedule. If you have serious concerns about your daylilies, you are welcome to call my business line at 604-856-5758, leave a message and I will call you back as soon as I can.

    In the meantime, here is an update. The Hemerocallis Gall Midge is still very much a presence in B.C., but since people are now more aware of the problem it gets easier to deal with. Every year, swollen and deformed buds show up around this time (late May to late June) - and walks around the garden should be done with a ziploc bag in hand! People have been concerned that they would have no bloom if they get this pest, however it is important to note that the beauty of daylilies is the fact that the buds all mature at a different rate, allowing for continual bloom for weeks. The gall midge affects only the first, largest buds - so once the initial debudding has been done, the rest of the season should be worry free!

    In response to an identification of the adult fly, the fly is so very small that it is extremely difficult to see with the naked eye. The very tiny fly has an almost translucent pink to its wings, but a microscope would be required for accurate identification. We have weekly traps set at our gardens and the Ministry of Agriculture come by once a week to check the traps and analize the number of flies present. This gives us a way of tracking exactly when the flies are active and how long we should be looking for damage. At present, June 16th, there were 8 flies present in this weeks traps, signifying that the cycle is coming to an end.

    If you see a neighbor or commercial landscape who are apparently unaware of this problem - tell them! Awareness is the only way to get this under control. Personally, I stop and check the medians and parks whereever I can! Daylilies are such a wonderful perennial that they are being used more and more in municipal plantings - but someone is still going to have to check them to make sure they don't enhance the problem!

    Again, if anyone has concerns or questions, call me - I am always happy to help where I can.

    Pam Erikson
    Erikson's Daylily Gardens
     
  13. WesternWilson

    WesternWilson Active Member 10 Years

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    Location:
    Tsawwassen, BC, Canada
    I discovered my beloved "Happy Returns", full of blasted buds today.

    This is the first time I have ever had this problem in my garden.

    I have two questions:

    1. Is there now a recommendation for a soil drench to kill pupae in the soil?

    2. How and where do I get sticky traps to reduce fly-by infestations next spring?

    Thanks all!

    Janet
     

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