Drywood termites in window blinds - Ask Extension
I am interested in determining the status of a drywood termite nest. I installed wooden window blinds in my home near Boston, Massachusetts, in Janu...
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Drywood termites in window blinds #382988
Asked January 24, 2017, 2:22 PM EST
I am interested in determining the status of a drywood termite nest. I installed wooden window blinds in my home near Boston, Massachusetts, in January, 2014. A 1/4 tsp of frass appeared on the windowsill in Fall of 2015 but I did not know what it was. A second 1/2 tsp pile appeared in the same place in November, 2016. This time it was identified and the source was made clear from kick holes in the end of the blind rail (see picture). The kick holes are the only defects in the otherwise painted rail. I have seen no evidence of swarming. I am trying to figure out if I can determine with confidence that the infestation was confined to the rail so that I can avoid an expensive fumigation. (All blinds have been removed from the house.)
My questions are: 1) Could the nest mount a swarm through the kick holes or would there be a larger exit hole? (i.e. if there are only the tiny kick holes can I assume the nest has not swarmed.) 2) Short of a swarm would immature forms leave the nest through kick holes and establish new nests? 3) Can I treat the blinds (e.g. by freezing- how low for how long?) to insure that all organisms perish? 4) Once the organisms are dead I would like to open the nest and inspect it. What should I look for to help determine whether the infestation is confined to the rail?
Thank you,
Greg
My questions are: 1) Could the nest mount a swarm through the kick holes or would there be a larger exit hole? (i.e. if there are only the tiny kick holes can I assume the nest has not swarmed.) 2) Short of a swarm would immature forms leave the nest through kick holes and establish new nests? 3) Can I treat the blinds (e.g. by freezing- how low for how long?) to insure that all organisms perish? 4) Once the organisms are dead I would like to open the nest and inspect it. What should I look for to help determine whether the infestation is confined to the rail?
Thank you,
Greg
Suffolk County Massachusetts
Expert Response
Based on the size of the exit holes in your photos and your description of the frass I think it is most likely that your blinds are infested with one of the Powderpost Beetles. Powderpost Beetles were already in the wood that was used to construct the binds. This happens occasionally because the wood was not properly cured and dried before use in construction of the blinds.
You have several treatment options:
You have several treatment options:
- Do nothing. There is a very good chance that you have seen the last of the adult beetles exiting the wood. You can keep an eye on the situation and make a decision if and when another exit occurs.
- Heating the entire blind in an oven at 120 to 140 degrees F for six hours will kill all life stages of Powderpost Beetles.
- Place the entire blind in a freezer at 0 degrees F for 72 hours; however, more time may be needed if the wood is more than 2 inches thick. Caution: wrap the item tightly with plastic and keep as airtight as possible prior to freezing. When removing the item, it should be allowed to thaw to room temperature when still wrapped in plastic to prevent damage to the surface finish because of condensation. Also, objects with glue joints should be handled carefully while frozen as the joints can become brittle.
- Insecticide treatments include partial or whole structure fumigation, wood injection, or surface application of a liquid residual. I recommend hiring a pest management professional for all insecticide treatment options. Surface applications can also be used to prevent or delay re-infestation. Although I think you are at very low risk for re-infestation.
Dear Clyde- Thank you for your prompt and helpful response. After reviewing web info on powderpost beetles I'm still concerned that these may be drywood termites. I've attached a photo of the frass. It is not powdery or sawdust-like at all. Instead it is hard, granular, and faceted, matching the descriptions I've read of termite frass. The blinds came from California and I do think that the pests were already in them when they were installed.
1) Would the procedures you describe for killing powderpost beetles also kill drywood termites?
2) What can I look for when I open the nest that would distinguish between the two?
Thanks again,
Greg
1) Would the procedures you describe for killing powderpost beetles also kill drywood termites?
2) What can I look for when I open the nest that would distinguish between the two?
Thanks again,
Greg
I wish I had seen the frass picture before answering your questions. These are clearly drywood termite fecal pellets. Sorry for the misdirection! Drywood termites do sometimes transport in existing furniture and other wooden items. This is obviously what happened here! Thank you for your persistence!
Drywood termites can withstand high temperatures. An example is in attics where temperatures can exceed 130 degrees F. You may be able to do an oven treatment, but the temperature would need to be higher than I suggested earlier. I would shoot for around 150-160. Caution: this temperature could damage the wood and/or other parts of the blinds.
My personal preference would be to use the freezing treatment discussed earlier because drywood termites don't survive in cold conditions very well. I would extend the exposure time by 48 hours to make sure all termites are dead.
If you open the wood to examine the nest area, the gallery walls will appear smooth (as if sanded) and pellets should be present. The gallery will both cross and stay within the wood grain. This is because drywood termites eat both the spring and summer wood.
I hope this information helps!
Drywood termites can withstand high temperatures. An example is in attics where temperatures can exceed 130 degrees F. You may be able to do an oven treatment, but the temperature would need to be higher than I suggested earlier. I would shoot for around 150-160. Caution: this temperature could damage the wood and/or other parts of the blinds.
My personal preference would be to use the freezing treatment discussed earlier because drywood termites don't survive in cold conditions very well. I would extend the exposure time by 48 hours to make sure all termites are dead.
If you open the wood to examine the nest area, the gallery walls will appear smooth (as if sanded) and pellets should be present. The gallery will both cross and stay within the wood grain. This is because drywood termites eat both the spring and summer wood.
I hope this information helps!
Dear Clyde-
Sorry I didn't include the frass photo in the first request. I was trying to keep it focused. Thanks for the update. I plan to freeze the blinds when I get a chance (I need to access my in-law's freezer) and then I'll open the nest. Can I contact you later to discuss the results?
Best,
Greg
Sorry I didn't include the frass photo in the first request. I was trying to keep it focused. Thanks for the update. I plan to freeze the blinds when I get a chance (I need to access my in-law's freezer) and then I'll open the nest. Can I contact you later to discuss the results?
Best,
Greg
Greg,
No problem on not sending frass photos, I'm just glad we were able to get it figured out! Yes! Please do contact me later if needed.
Dear Clyde-
Here at long last is a bit of followup on my termite problem. Lacking a freezer large enough to contain the blinds we left them outdoors all winter 2016-17. In April I opened the nest in the blind rail and found two reproductives, three soldiers, and 67 immatures. (Photos attached.) All of the termites were dead and there was no evidence that any had left the nest. We remounted the blinds and have seen no further evidence of termite activity. The issue appears to be settled though we will remain vigilant.
Thank you again for your prompt and knowledgeable help. You helped us avoid an expensive and distasteful fumigation and we are very grateful.
Happy New Year!
Greg Clark (and Meredith Fields)
Here at long last is a bit of followup on my termite problem. Lacking a freezer large enough to contain the blinds we left them outdoors all winter 2016-17. In April I opened the nest in the blind rail and found two reproductives, three soldiers, and 67 immatures. (Photos attached.) All of the termites were dead and there was no evidence that any had left the nest. We remounted the blinds and have seen no further evidence of termite activity. The issue appears to be settled though we will remain vigilant.
Thank you again for your prompt and knowledgeable help. You helped us avoid an expensive and distasteful fumigation and we are very grateful.
Happy New Year!
Greg Clark (and Meredith Fields)
I'm happy that this difficult situation turned out positive for you! Great solution!
