Keeping Phasmids, Courting Danger?

[Arthroverts]

Hello all, I go through stages of interest in invertebrates oftentimes. Right now the current stages are millipedes, assassin bugs, Orthopterans, and Phasmatodea. I blame my recently reacquired fervor for the last on recent conversations with some friends.

Anyway, such recent conversations turned to the subject of Peruphasma schultei as a method of biological control for the invasive Asian privet in the USA where I am located. Now, this is probably a bad idea as P. schultei will also eat bramble (Rubus sp.) which is native to the USA, and then there would be just another invasive species. This got me thinking however, setting aside legal concerns, about the subject of keeping phasmids responsibly.
Now, you may be thinking that phasmids are already kept responsibly, even the ones with a high potential for establishing themselves in the wild if they escape, and that is (mostly) true. To my knowledge only Carausius morosus and Exatasoma tiaratum have become established here in the US, and only the latter can be reasonably assumed to have been solely introduced by hobbyists as it is less common in classrooms and entomological displays than C. morosus is, amongst the dozen-odd species kept with some frequency by American enthusiasts.
However, as we have seen time and again not everyone is as responsible or careful as they should be, and it is easy to make mistakes when it comes to disposing or transferring extra eggs. So, I was wondering if there were any phasmids that could be kept with a reasonable assurance that even if they did escape, would be unable to find food and thus unable to establish themselves. My search turned up several possible species, some of which feed strictly on (as far as it is seen) Epipremnum sp. (ex: E. aureum, or pothos), like Metriophasma diocles. Another plant genus that does not have any native representatives in my state, Euonymus, is fed upon by such species as Trachythorax sp. "Kon Chu Rang."

Anyway, this has been making me reconsider how phasmids could be kept in the USA responsibly. By only keeping very specific species, it should be possible to prevent infestations entirely even in the event of an escape (unless someone lives by a Euonymus greenhouse). I am curious to hear other thoughts relating to this.

Thanks,

Arthroverts

 

[ColeopteraC]

Hello all, I go through stages of interest in invertebrates oftentimes. Right now the current stages are millipedes, assassin bugs, Orthopterans, and Phasmatodea. I blame my recently reacquired fervor for the last on recent conversations with some friends.

Anyway, such recent conversations turned to the subject of Peruphasma schultei as a method of biological control for the invasive Asian privet in the USA where I am located. Now, this is probably a bad idea as P. schultei will also eat bramble (Rubus sp.) which is native to the USA, and then there would be just another invasive species. This got me thinking however, setting aside legal concerns, about the subject of keeping phasmids responsibly.
Now, you may be thinking that phasmids are already kept responsibly, even the ones with a high potential for establishing themselves in the wild if they escape, and that is (mostly) true. To my knowledge only Carausius morosus and Exatasoma tiaratum have become established here in the US, and only the latter can be reasonably assumed to have been solely introduced by hobbyists as it is less common in classrooms and entomological displays than C. morosus is, amongst the dozen-odd species kept with some frequency by American enthusiasts.
However, as we have seen time and again not everyone is as responsible or careful as they should be, and it is easy to make mistakes when it comes to disposing or transferring extra eggs. So, I was wondering if there were any phasmids that could be kept with a reasonable assurance that even if they did escape, would be unable to find food and thus unable to establish themselves. My search turned up several possible species, some of which feed strictly on (as far as it is seen) Epipremnum sp. (ex: E. aureum, or pothos), like Metriophasma diocles. Another plant genus that does not have any native representatives in my state, Euonymus, is fed upon by such species as Trachythorax sp. "Kon Chu Rang."

Anyway, this has been making me reconsider how phasmids could be kept in the USA responsibly. By only keeping very specific species, it should be possible to prevent infestations entirely even in the event of an escape (unless someone lives by a Euonymus greenhouse). I am curious to hear other thoughts relating to this.

Thanks,

Arthroverts

Would sp. that exclusively feed on invasive or non-native sp. apply.

If so you could add some of the eucalyptus exclusive Aussie sp. such as tropidoderus sp. to that list (unles the eucalyptus is deemed as worth protecting)

There are also quite a few species that can feed on bramble and other natives but cannot sustain a full life cycle or more than one generation on it. E.g. Pseudodiacantha Macklottii, which can only thrive well
on Rhododendron. Developing a natural preference to it.

You can raise phyllium on guava as well.


The primary difficulty with rearing Phasmids with no native foodplant is that your food supply would be patchy and expensive.

Some people raise a few sp. on plants like salal and guava as the phasmids fair better on them. They often find that such plants are seasonally or occasionally unavailable. One would need to consider this.

 

[goliathusdavid]

It's interesting that you mention Peruphasma schultei as a possible biological control agent. I agree that it is probably a bad idea (I'd even go so far as to say a terrible one) but I have been thinking a lot recently about beneficial insect introduction as I am actually quite near the major USDA facility investigating use of exotic inverts as biocontrol agents, the Beneficial Insects Introduction Research Unit in Newark, DE. Almost went to UDelaware due to their connection with it. Ended up choosing a place doing some equally cool research on welfare in zoos. Anyway, I highly recommend checking out their work, it is totally fascinating stuff.

As for species that can be kept with low risk, I can't think of any right off the bat. Even the species you listed, with their extremely limited diets, might theoretically take to some plant species here in the US- the truth is we just don't know for sure. Personally, I don't think it's worth the risk. I've had the chance to work with four different Phasmid species at two institutions now, and I don't think there's anyway of getting around extreme containment. And, as you said, many individuals keeping them are not nearly as careful as they should be.

Keeping Phasmids for me is like keeping big cats- best left to institutions. I mean unlike big cats they won't kill you, but they might cause a serious agricultural crisis

 

[Arthroverts]

Would sp. that exclusively feed on invasive or non-native sp. apply.

If so you could add some of the eucalyptus exclusive Aussie sp. such as tropidoderus sp. to that list (unles the eucalyptus is deemed as worth protecting)

There are also quite a few species that can feed on bramble and other natives but cannot sustain a full life cycle or more than one generation on it. E.g. Pseudodiacantha Macklottii, which can only thrive well
on Rhododendron. Developing a natural preference to it.

You can raise phyllium on guava as well.

The primary difficulty with rearing Phasmids with no native foodplant is that your food supply would be patchy and expensive.

Some people raise a few sp. on plants like salal and guava as the phasmids fair better on them. They often find that such plants are seasonally or occasionally unavailable. One would need to consider this.

Oh of course; my list was not supposed to be exhaustive. But since there are no US-native Eucalyptus plenty of the Australian species would work great.

Ah, I was not aware, that is great to know.
A lot of Phyllium can switch to other food plants though, which can be problematic.

Not necessarily. There are a lot of ornamental plants, such as the Euonymus, Eucalyptus, and Epipremnum (of which I have quite a lot of) mentioned afore, that can be acquired easily from yards, nurseries (so long as they are properly cleansed first), and even your own household (or family-members households). Privet (Lingustrum sp.) is also quite common as a hedge, though a lot of the species that eat it also eat other, native species.
Salal is native where I am at (as far as I am aware).

It's interesting that you mention Peruphasma schultei as a possible biological control agent. I agree that it is probably a bad idea (I'd even go so far as to say a terrible one) but I have been thinking a lot recently about beneficial insect introduction as I am actually quite near the major USDA facility investigating use of exotic inverts as biocontrol agents, the Beneficial Insects Introduction Research Unit in Newark, DE. Almost went to UDelaware due to their connection with it. Ended up choosing a place doing some equally cool research on welfare in zoos. Anyway, I highly recommend checking out their work, it is totally fascinating stuff.

As for species that can be kept with low risk, I can't think of any right off the bat. Even the species you listed, with their extremely limited diets, might theoretically take to some plant species here in the US- the truth is we just don't know for sure. Personally, I don't think it's worth the risk. I've had the chance to work with four different Phasmid species at two institutions now, and I don't think there's anyway of getting around extreme containment. And, as you said, many individuals keeping them are not nearly as careful as they should be.

Keeping Phasmids for me is like keeping big cats- best left to institutions. I mean unlike big cats they won't kill you, but they might cause a serious agricultural crisis

Ah, how interesting! I will definitely look into their research.

Theoretically, but it must be noted that a lot of cultures fail in captivity while switching to another food plant that the stock isn't used to (this is from what little I know and have seen). A lot of European enthusiasts have done a lot of experimentation and found phasmids to have, in the relative sense, rather narrow dietary preferences across the board.

Thanks,

Arthroverts

 

[Joey Spijkers]

Theoretically, but it must be noted that a lot of cultures fail in captivity while switching to another food plant that the stock isn't used to (this is from what little I know and have seen). A lot of European enthusiasts have done a lot of experimentation and found phasmids to have, in the relative sense, rather narrow dietary preferences across the board.

This is really species specific though. I have kept different Phasmid species in the past, and as I’m in Northern Europe, there is no risk, so I mainly kept species that accepted a wide variety of food plants. Species like Eurycantha calcarata or sungaya inexpectata, but also many others, would eat plants they had never been offered before, without any hesitation or issues. If they escaped in the US in a state with an acceptible climate for them, they would eat anything they can find pretty much.

But yes, many species have a much narrower food preference, some of which wouln’t eat any natives.
Australian Eucalyptus eaters were the first ones that crossed my mind. Some of them will also accept bramble though, although generally not very successfully long term.