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Photo#47471
Leptura emarginata - Stenelytrana emarginata

Leptura emarginata - Stenelytrana emarginata
7 km east of Paw Paw, Morgan County, West Virginia, USA
July 6, 1991
Size: 32 mm
Collected on trunk of rotten oak tree (hard say for sure, but was probably either Quercus alba or Q. montana). 39.5224, -78.3641

Fermenting Baits
Hey, I recognize this is almost 17 years later, but...
I am perusing a PhD in a red oak dominated forest with a focus on Nitidulidae beetles. Fermenting baits are well documented for these beetles (e.g. pineapple, melon, banana, molasses, whole wheat bread dough). I have been using bread dough with bakers yeast with success, but what I find on red oak tree wounds are not always the same species that I find in the bait traps.

I was actually curious about the comment about the reports of John D. Glaser's checklist form the New Maryland Entomologist Vol 3 No 1 regarding oak forests and the frequency of occurrences of these beetles that are attracted to fermenting baits.

Here's my question:
Would somebody be able to help me by referring literature suggesting that oak-dominated forests may be good areas to study insects that are attracted to fermenting baits (and more importantly, why that might be)?

I am studying the ecology of oak tree wounds and fungi in attracting Nitidulidae species as part of a larger project in New Brunswick.

Cheers,
Michael

 
Fermenting baits in oak forests
The WV Quercus forests mentioned here were probably about 2/3 "white" (alba, montana) and 1/3 "red" (coccinea, rubra, velutina), so very different from where you are. I am guessing that NB is nearly 100% Q.rubra, with maybe some rare Q.alba and Q.macrocarpa here and there? Maybe a good place to start if looking for more information would be latest posting (May 22, 2023) on Ted MacRae's website/blog.

 
Fermenting baits in oak forests
Thanks for the information!
For others looking at similar questions here's the link to Ted MacRae's blog:
https://beetlesinthebush.com/

m

First Time Leptura emarginata
Found and photographed my first Leptura emarginata. Found it on a ferminting peach I left on my oriole feeded. Had never seen one before and so I captured him to take some photos of. Tooks some quick shots for ID and will try to take some better photos before releasing.
Del Rio, Val Verde County, TX

Collecting through the use of a molasses bucket...
Why not install netting or screen wire in the bucket that will allow the insects to approach, but not enter, the sticky bait. The odor obviously is the attractant here--use that and avoid the loss of specimens. A mere trace applied to the netting/screen should suffice to keep the attention of the insects.

 
Try it.
See if it works.

Fermenting Molasses
This great beetle is just one of many reasons to try using fermenting molasses as a specialized collecting technique which I think ranks only behind the use of blacklights and pitfall traps baited with dung or carrion in terms of the number and diversity of beetles that you may see. As with these other techniques, fermenting molasses will attract some beetles that are almost impossible to collect any other way. Take Leptura emarginata for example. They are not uncommon but are extremely fast flyers that rarely come down below tree-top level. See Eric Eaton's comments under photo #6858 to see what I mean (By the way, congratulations to Stephen Cresswell for actually getting a live one on film which is almost impossible). Fermenting molasses can attract huge numbers of carabids, staphs, silphids, clicks, scarabs, and nitidulids among other things. Plus, there is the occasional spectacular cerambycid such as L. emarginata or Pupuricenus axillaris and humeralis. In an addenda to Charles Staines's excellent Checklist of Maryland Cerambycidae (Original Article: Maryland Entomologist, Volume 3, Number 1, April 1987; Addenda: Volume 3, Number 4, March 1992), John Glaser reports seeing HUNDREDS of these latter three species in Western Maryland coming to "fermenting sweet baits hung out in oak-dominated forests." Can you just imagine that! Well, I don't know what his secret recipe is and I'm sure mine is nowhere near as good but it still works pretty well. Mix one pint of molasses, one pint of water, and one packet of activated bread yeast. Let stand in the sun for a day or two and then sit back and watch what comes in. (Beware of leaving the bait pail unattended for long periods as you may end up unintentionally killing many moths and sometimes even nymphalid butterflies because they get all gummed up in the sticky sugar and you can't really wash them off.)

 
shower or bubble bath?
Frank, can you please share how you separate the beetles from the molasses? (I assume the bait is in the bottom of the pail vice suspended above another collection media) And do you hang the pail very high above ground, or just out of critter reach?

Thanks for the inspiration!
Tim

 
More on fermenting molasses
No, I just pour some in a bucket and let it sit. You need to check it every few hours and fish the bugs out because not only will they drown but they start to decay very quickly. I put the bucket on the ground although it is not a bad idea to suspend it in some way as it is very common to find the pail knocked over with all the contents gone - probably from raccoons or opossums looking for candy-coated insect treats - yum!

 
Thank you for this technique, Frank.
I've tried other recipies with underwhelming results: yeast, water and maple syrup; and yeast, water and malt. I guess I'll invest in some molasses. I have filled my liquid baits with wadded paper towels to minimize the La Brea Tar Pits effect.

 
beetle bait recipe
I just photographed something two days ago which was identified (verbally - I haven't uploaded the photos yet) as Leptura gigas. Will post it to the Guide soon. Anyway, it came to my butterfly bait, which is a blend of yeast, brown sugar, dark beer (Shiner Bock), and overripe/moldy fruit. The fruit is mostly bananas but also includes bits of grapes, strawberries, watermelon, oranges, apples, bell peppers, whatever my daughter decides not to eat. I mash the fruit, sprinkle one thin layer each of yeast and sugar, pour on a bottle of beer (minus a swallow or two), mix, and store in the fridge with the cap loose (if the cap is tight the gas pressure can build up and explode the bottle, or at least splatter bait everywhere when you open it! make sure the container is no more than 3/4 full, too). I spread the bait on flat wooden surfaces, mostly logs, tree stumps, branches, or chunks of bark. I regularly see Gymnetis caseyi at my bait, Placosternus difficilis almost as often. And I've only been doing it since November, no idea what else I might get this summer... I have heard of other people using molasses with good results, have not tried it myself yet.

Cheers,

Josh


Joshua S. Rose, Ph.D.
World Birding Center
Bentsen-Rio Grande Valley State Park
joshua.rose_NO_SPAM@tpwd.state.tx.us
956-584-9156 x 236

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