Do Dynastes Larvae eat Live Tree Roots?

The Mantis Menagerie

The Mantis Menagerie

Fresh Imago
I was talking to a USDA entomologist, and I was told that the reason native Dynastes are regulated is because the larvae will eat live tree roots. I have never read anything saying this was true, but I was hoping there was someone who was more knowledgeable on this topic. I tried finding some scientific papers that either proved or disproved this, but I couldn't access most of the ones that sounded promising. Dynastes larvae eating live tree root seems strange to me because it sounds like they avoid any wood that is not thoroughly decayed in captivity. If they ate live wood, then why go through the process of fermentation?

 
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My understanding is that the reason that ALL scarabaeidae are regulated is because SOME eat live plant roots. Most of our blanket ban on herbivorous insects comes from the damage caused by the japanese beetle when it was first brought here, IIRC.

EDIT: there's actually some progress being made to get certain species out from under these bans (such as the recent release of three Goliathus spp), but that's very unlikely in the case of herbivorous species.

 
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I am currently in the process of trying to obtain Goliathus larvae.

I want to sell D. tityus and granti, but they cannot cross state lines. If they cross state lines (inevitable if I want D. granti), then I can only sell to other people with permits. 

 
I'm curious... is that actually enforced though? Pretty sure almost everyone here has gotten D. tityus or granti without permits... at least, I haven't heard of anyone with the cops banging on their door after ordering from Peter. Has anyone ordered and actually had their grubs taken and/or fined...?

As for the tree roots thing, I could believe it... maybe. I wish I could test it. When it flooded here last year, I found massive larva that HAD to be D. tityus... nothing else that large lives where I am located. They came up from the ground after several days of intense rain and drowned. What's curious is that I live in a pine forest, so I'm not sure what such massive larva were doing here since there's not much else to feed on. My only guess is that they feed on grass roots or the tree roots. Or something else, since our soil is very sandy.

 
For me, it does not matter whether it is enforced. I am trying to obtain the permits for the tropical species, so I have to follow every USDA regulation (despite how ridiculous I think some are). The permits will allow me to sell insects to other permit-holders (mostly insectariums) and to take large, tropical insects to events such as Bugfest at the North Carolina Museum of Natural Sciences. 

I am sure there is some scientific evidence out there either proving or disproving this "Dynastes eat Roots" idea. Enough evidence was shown to the USDA to make those three Goliathus deregulated, so if someone can find enough scientific evidence showing this tree root thing is indeed a myth, then maybe the USDA could be persuaded to reevaluate the regulations on Dynastes. @Beetle-Experience, I remember you mentioned you were working on deregulation in the Goliath Beetle thread. Does it look like the native Dynastes species will be deregulated? 

 
I think there are a couple root eating dynastes, but Tityus and Granti definitely aren’t part of that small portion (I believe carrot beetles count as dynastidae, so that could be where the myth started). 

GelGelada there are accounts of D. Tityus eating well decayed pine wood, although I definitely don’t recommend it as the beetles will probably turn out small and sickly and/or take an extremely long time to emerge.

also, for the most part you don’t have to worry about cross state transactions unless you’re A: trading a well known highly destructive pest species (African land snails for example, as well as ants of just about any kind) and/or B: shipping to a highly regulated state (Hawaii, Tennessee, particularly Florida, etc. I believe a man got arrested for keeping dubias in Florida, they take their importation laws very seriously there, and for good reason.

 
In subfamily Dynastinae, I know there are several phytophagous species, such as the major coconut palm pest: the coconut rhinoceros beetle (Oryctes rhinoceros), but I am wanting to know if the genus Dynastes eats any living plant material. If it is a myth, then this needs to be proven to the USDA. Anyone have links to any scientific papers on this topic?

As I said, I am trying to work with exotic species of insects, so I have to follow every regulation, regardless of whether it is actually enforced. I am not asking whether they are technically regulated. I know for a fact that they are regulated for interstate transport, but I was curious if it the reasoning behind regulating them was valid. Based on this thread, I am thinking that the USDA may not actually have a valid reason to regulate them. 

 
The Mantis Menagerie said:
For me, it does not matter whether it is enforced. I am trying to obtain the permits for the tropical species, so I have to follow every USDA regulation (despite how ridiculous I think some are). The permits will allow me to sell insects to other permit-holders (mostly insectariums) and to take large, tropical insects to events such as Bugfest at the North Carolina Museum of Natural Sciences. 

I am sure there is some scientific evidence out there either proving or disproving this "Dynastes eat Roots" idea. Enough evidence was shown to the USDA to make those three Goliathus deregulated, so if someone can find enough scientific evidence showing this tree root thing is indeed a myth, then maybe the USDA could be persuaded to reevaluate the regulations on Dynastes. @Beetle-Experience, I remember you mentioned you were working on deregulation in the Goliath Beetle thread. Does it look like the native Dynastes species will be deregulated? 
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No, I think we got lucky with the 3 species of Goliathus.

I am able to legally import them but I'm pretty sure no one would want to pay what it would take for me to get them here for them.

 
Beetle-Experience said:
I am able to legally import them but I'm pretty sure no one would want to pay what it would take for me to get them here for them.
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Are you referring to Goliathus or Dynastes? 

Beetle-Experience said:
No, I think we got lucky with the 3 species of Goliathus.
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We shouldn’t be “getting lucky.” It is the USDA’s job to evaluate whether or not a species should be regulated. If a species is proven to not directly nor indirectly harm plants, then how can the Plant Protection Act be applied to it? 

 
The Dynastes tityus or grantii are currently NOT KNOWN to feed on live tree roots. Ask that USDA entomologist whether he even has an entomology degree, and ask if his specialty lies on taxonomy or IPM. In my opinion, saying such a bullshit, he, at least, has never studied or worked with scarabs.

Sure, there are some Dynastine scarab beetles species actually known to feed on tree roots, but that is the case for entirely other group of dynastine tribes. The tribe Oryctini (such as Strategus and Xyloryctes in the US) are known to have a lot of species feeding on live tree roots, but in the U.S., there is only a limited number of studies finding those in tree roots. Strategus species is/are found to damage tree roots in somewhere in the U.S., probably Florida? (palm tree damage).

In case of other plant (not called tree) root damages, well, there are whole lot more like Cyclocephala, Euetheola, etc. etc.. ....

Anyway, Dynastes species in US do not harm live tree roots.

 
The USDA entomologists do not control the laws (as far as I know). The entomologist I spoke to has a PhD in entomology, but he likely focuses on pest species since he works in PPQ. I think the problem is the people making the regulations do not know what they are regulating. 

 
The Mantis Menagerie said:
Are you referring to Goliathus or Dynastes? 

We shouldn’t be “getting lucky.” It is the USDA’s job to evaluate whether or not a species should be regulated. If a species is proven to not directly nor indirectly harm plants, then how can the Plant Protection Act be applied to it? 
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Yes, the "getting lucky" part meaning, don't get your hopes up! Goliathus is in a gray area and we were "lucky" that they decided in favor of allowing them - they were on the fence for about a year and had even decided against it for a while..

 
At this point, I don’t think they even care. 

The reason I’ve heard about more for species not being allowed to cross borders (national and international) is often more about diseases, which is a pretty easy excuse to hide behind, anyone can claim that shipping an insect from one state to another “might” introduce a new disease, parasite, etc. to that area (sadly the evidence is much in their favor, it’s essentially the same thing as Europeans spreading smallpox to Native American tribes, and it takes a lot more work to prove that one individual specimen doesn’t have some hidden disease/parasite than to simply stop the specimens themselves from spreading (ironically humans are probably the most widespread, most destructive pests to ever exist)

 
First, it is the USDA’s job to care. Second, isn’t it just as likely that the unregulated arachnids and vertebrates are vectors? You can import an orb-weaver that would love nothing more than to catch pollinators, but a mantis requires a permit. If their excuse for beetles is concern over vectors, then why deregulate Goliathus? I am sure that there has not been enough research (if it is even possible) to prove Goliathus is not a vector. 

 
The Mantis Menagerie said:
First, it is the USDA’s job to care. Second, isn’t it just as likely that the unregulated arachnids and vertebrates are vectors? You can import an orb-weaver that would love nothing more than to catch pollinators, but a mantis requires a permit. If their excuse for beetles is concern over vectors, then why deregulate Goliathus? I am sure that there has not been enough research (if it is even possible) to prove Goliathus is not a vector. 
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Completely agree. Also, many species of mantids don’t tatrget plllinators, species that resemble dead leaves would most likely barely come in contact with say, perhaps a honeybee. Bark and ground mantids would hunt roaches or beetles. Or, if they are really scared about them reproducing and spreading ban flower-mimic species and allow other species to stay. I hardly beleive that tarantulas, scorpions, etc are allowed while they are not. Both mantids and Ts are predatory. 

 
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