What is the Chinese live beetle hobby up to?

So, recently I was bored and mentally ill again (I say that as if I had ever stopped being bored and mentally ill) and chewed through 10 years (and counting) of Baidu forum posts in the span of an afternoon or two*. This did not make me any less bored let alone less mentally ill, but I can't deny it was kind of productive.

*I couldn't be bothered to create an account so I used various gimmicks to get at the loginwalled posts, for example opening links in new tabs, and force-switching the website between desktop and mobile formats on the same device

But without further ado here's some things I've observed:

- Cetoniinae familiar to the European hobby (e.g. Mecynorrhina, Eudicella, and, unsurprisingly, Goliathus) are apparently common in the Chinese live trade

- The above observation may not seem very noteworthy, but on the other hand there is a striking lack of interest in rearing both China-native and exotic Rutelinae; while Chinese hobbyists certainly can and do import American insects (I have long been aware that Dynastes grantii sometimes makes it there alive), I did not encounter any posts about live Chrysina and seriously doubt any of the popular North American species have been reared there (tho I know US-unavailable Chrysina have been reared in Japan)

- Addendum I: the colorful, relatively small "junebug" type hornless native rutelines (Anomala and similar-shaped genera [as opposed to native Popillia] seem to be most frequently mentioned) are posted about primarily by beginners who mistake them for cetoniines and/or haven't "graduated" to the conventional hobby scarabs yet; advanced hobbyists tend to call them "trash" or "dregs" (sometimes affectionately but in most cases just derogatorily, à la "rough fish" in sportfishing) despite their diversity, colors, and considerable size (many of the "dregs" species, though relatively small, are only relatively small; they're quite large by US beetle standards)

- Addendum II: reportedly "they're" quite cannibalistic as larvae, to the point of attacking each other on contact even moments after being put together in empty containers, and are also weirdly vagile as far as scarab grubs go (unclear what "they're" refers to, but probably Anomala and/or similar types since properly kept US Chrysina do not seem particularly so); this does not seem to be the primary reason people hate them. I think they're just spoiled for choice and really stuck up about it, they're often quick to call anything "trash" if it's too common, even the more easily encounterable Large Impressive Native Stags, but especially non-giant insects of any sort (I mean Charismatic Megafauna bias is of course present in the US as well, but one doesn't see the same sort of socioculturally-normalized blatant scorn among enthusiasts there as much)

- Addendum III: however, the "boar/pig* scarabs" (猪金龟; Dicaulocephalus and several other genera) seem to have a bit of a cult following despite the smallness of their horns and dull coloration (and weirdly enough some of their fans are the same people who hate colorful Anomala-types); from what I can gather, they last about a month as adults [shorter than a number of more-popular shortlived hobby scarabs], obligately require a cold period of around 15 Celsius once mature in order to pupate, get deformed during the adult molt easily if the larva lacks access to sufficiently compactable substrate while building its pupal cell, and can eat regular fruit/jelly as adults despite, you know, being rutelines

*猪 does not have either an actually derogatory or affectionately derogatory connotation here; the adults are simply very pig-shaped

- Prionotheca coronata is raised occasionally, but darklings of any sort are not popular (seemingly even less popular than in the Western world, where Bugs in Cyberspace and similar insectfluencers are undoubtedly contributing to the mainstreamization of feigners and headstanders; did you know A. verrucosus is now so well loved that it's actually being imported alive to Europe?) With that being said, I did encounter a few other African tenebrionid spp. being kept

- There have been some consistent, repeatable successes in breeding several spp. of Carabus and other carabids and raising larvae to adulthood; the gist of what was said was that Carabus eggs are weirdly fragile even by egg standards and should not be touched directly (found this out the hard way some yrs ago after close relative Calosoma laid an egg on my hand - it was like tofu, even gentle handling that wouldn't kill an aphid popped the egg immediately, and I have in fact picked up live aphids for the record), too much humidity is bad (aim for no condensation and no glistening of substrate, but not dry enough that the dirt changes color), larvae of some species may be harmed and eventually killed by unnatural foods like saturniid pupae and red meat (my long-held personal suspicion is that this is because many insect spp. used as feeders have an unhealthily high fat content for carabids, the adults being strong enough to tolerate it anyway. Calosoma has been reported in an English-speaking research paper somewhere to refuse beef after being fed too much of it). You can read more here cause I'm too tired to keep talking, though the author says elsewhere that the snail diet isn't a one size fits all, i.e. doesn't work for rearing entomophagous spp.

Collection update

50-ish Cryptocephalus spurcus larvae (F1)
7-ish Eleodes littoralis adults (F1, I may release these, we'll see)
Disabled Eleodes acuticauda female sent to Arthroverts, he says it is apparently now hiding normally again when it sleeps

Baccharis salicifolia (several)
Salvia leucophylla (1 specimen)
Salvia mellifera (1 specimen)
Cuscuta subinclusa (a lot)
Calasterella died a few months back =(
Croton californicus (2 specimens)
Monardella viminea "Russian River" (1 specimen)
Clinopodium chandleri (1 specimen)
Trifolium fragiferum (several)
Eriogonum elongatum? (cutting, hope it roots)
Iva hayesiana (several)
Grindelia stricta (several)
Encelia californica (several)
Salix (native one I assume, only 1 specimen)
Artemisia californica (several)
2 leafy Marchantiophyta spp., non-gemmiferous permanent fern gametophytes, & that one unidentified Chinese moss (several colonies)
Strobilanthes dyeriana or whatever its true name is (1 specimen and the branch I broke off of it)
Scorzonera? (1 specimen) I actually had this one for a while but never mentioned it, also differently shaped leaves from the same plant key to different species [it's really phenotypically plastic] so clearly someone needs to revise the genus

All of the native shrubs/trees are juveniles or medium adults (except for 1 Croton around full size, but full size adult Croton is the size of a medium juvenile sagebrush anyway).

Apparently some C. spurcus individuals are unsuited to captivity too

The latest one I caught seems pretty afraid of me (it tends to duck to the opposite side of the plant whenever it sees me, whereas some other individuals don't react to suspicious visual stimuli, only vibrations) and keeps trying to fly away and flee its hostplant to the point that it's not eating properly even when I don't come near it, I guess the whole "insects have personalities" thing is true yet again?

I released it because insect personalities are (disturbingly) somewhat heritable apparently habitat fragmentation can make some butterflies evolve to be less explorative and I don't want to raise a batch of specimens that's constantly terrified of me (not to mention the hassle of having to put them back on their plant).

I no longer love my new dirt molecule!

Some of the Exema were running up and down their plant frantically and then flew away (they did eat the sagebrush I provided though). I think I shall return all of them to their habitat, they clearly are stressed somehow.

Elater lecontei have also been released a few days ago, as will the 2 remaining Tiaja (neither of which has apparently laid eggs) and Xerophloea (which seems unfertilized) soon.

Cryptocephalus spurcus larvae are doing well tho, they doubled in size in like only a day or two. Also noticed they will eat lettuce like C. sanguinicollis.

Plans to rehome the disabled Eleodes acuticauda (which is miraculously still alive after all this time, having already seen 2 years, and in that time has lost only a palp even though old tenebs are supposed to be losing legs left and right) are also in the works, since I'm depressed and feeding it drains my mental health (plus it is doing that thing again where it won't hide under its provided shelters because they apparently emit some sort of bad odor only it can smell, and since it is so hard to find unmoldy bark here I'm not sure I can provide it a suitable replacement). Might get rid of the 6 or 7 surviving E. littoralis that I raised from the wild females' larvae too, depending on how stressed they are and I am (though currently they are apparently mostly inactive/buried and not throwing any fits unlike the acuticauda as far as I can tell).

The small millipedes are still doing somewhat ok though since they hide their eggs in the substrate where I can't euthanize them they are inevitably overpopulating as per law of nature and I always feel bad about it. That's why I like cryptocephalines and external-laying Auchenorrhyncha, if they're not laid underground or embedded in plant tissue you can just squish the eggs guilt free, it's not like eggs have feelings.

Caved and took home 5 Exema (albeit from Artemisia)

I love my new dirt molecule!

Cryptocephalus spurcus hatched

Sudden rainstorm today, which raised the indoor humidity so high I was struggling to breathe, and it apparently kicked some of the eggs out of dormancy. They're already feeding on the rotten Baccharis salicifolia leaves I've made for them.

Apparently one trick to making rotten leaves without mold is to force them underwater and keep them there for about a week, molds in my area do not appear to survive on plant litter when too wet (but can grow in the very small air bubbles that form underwater on said leaves).


Also: my suspicion that there was some similarly late-summer-active cryptocephaline in the hard chaparral was confirmed, I found some Exema on brickellbushes on the road leading to Chantry Flat. I did not keep them though because I have something coming up next month and can't risk it since brickellbushes are so hard to come by in the trade (and I have none).

Exema eats live foliage as larvae but I wonder if there are any detritivorous late summer equivalents within reach of me.

New macro lens!

Unrelatedly all Cryptocephalus have been released since I now have enough eggs.

one more spurcus female caught

Darker morph than usual, though the Santa Fe Dam population seems to vary only weakly. Going to try and see how heritable the morphs are, so separating the different females' eggs.

I don't know if C. spurcus is found at higher elevation pinebush habitats (e.g. Deukmejian) but at Santa Fe it is definitely in danger of local extinction, as pinebushes (and by extension the beetle, which is not found on every pinebush) occupy only a small portion of the total habitat, and scalebrooms/mulefats seem to occur mostly in areas unsuitable for larval development (e.g. lack of detritus, no shelter from sun, mysterious other factors, etc.)

Also went to Monrovia Canyon to search for hard chaparral, riparian, and sclerophyll forest cryptocephalines but found none. The habitat restoration there is horrible as is par 4 course here, they put Salvia apiana a few inches from the river among other things. That's like like the most blatantly xeromorphic sage ever how could they ughhhhhhhhhhhhhhh.

Xerophloea is now in culture again

solomon hendrix refused to take it past genus tho (citing unrevised taxonomy).

Why are dodders ectoparasitic?

Old pic of my C. subinclusa

Anyone with a passing familiarity with heterotrophic parasitic plants knows that they are mostly invisible. Monotropa, Rafflesia, Orobanche, Pholisma: all undetectable lumps and/or strings buried in their hosts or in the ground, shortlived flowers notwithstanding.






So why the hell doesn't Cuscuta do that?






The dodder literature is silent on the matter, but we can make a few deductions. First off: Cuscuta is in the bindweed family. This seems a bit too on the nose, if you ask me, like it's from some sort of video game with a questionable understanding of biology that went "oh they don't look similar but they're related because they're both twine vines!" What's next, dodders with wings?
I mean, monotropes don't superficially look like free-living members of Ericaceae either but it doesn't feel as weird to me that they're related.

But obviously this is real life so Cuscuta really is in the Convolvulaceae apparently [shrug]. According to a low-effort glance at the taxonomy literature the genus's position in the family is unclear, but I do think that the twining ability shared by dodders and morning glories is a synapomorphy of the clade (I have no proof but I do feel that this isn't one of the cases where climbing behavior convergently evolves multiple times within a family).

If we assume this to be true then the evolution of Cuscuta's particular growth habit is not particularly surprising. One is tempted to conclude that evolutionary constraints have so far prevented dodders from becoming full endoparasites, and that this is a highly imperfect solution because evolution is imperfect, and/or that perhaps given more time to evolve the distant descendants of dodders may circumvent said constraints and become fully internal parasites.




Is that really the story, though? I mean, don't get me wrong, evolution is imperfect but I find that it is not as imperfect as people tend to think sometimes. A lot of traits that get handwaved away as "oh just arbitrary stuff caused by phylogenetic history, not everything the blind watchmaker does has to have a function" actually turn out to be pretty important adaptive features.

I suspect external climbing is an important part of the dodder life history strategy. The dodders I've worked with (and seemingly other dodders, from what I've seen online) appear to be tender-shoot specialists, and apparently die of malnutrition on sufficiently mature stems even when they manage to penetrate them. Which is a bit weird, since mature stems carry nutrients to the more nutritious juvenile tissues at their tips and if you've encircled the former it seems like you could intercept the nutrients going to the latter right? But leafhoppers and aphids able to feed on mature stems also tend to preferentially move to and feed directly on tender shoots when they can afford it, so I suppose whatever logic governs nutrient extraction efficiency applies to both the herbivorous insects and herbivorous plant in question. Also, dodders seem to feed only or mainly on plant parts they are wrapped around and not the rest of the plant; I have repeatedly seen strawberry petioles and nightshade stems that have been wrapped rapidly wither and die while all adjacent uninfested ones on the plant remain healthy. Though I have seen both C. subinclusa and C. californica form green islands on dying host tissue in certain circumstances (though not others), so some limited level of nutrient redirection seems likely.

Suppose you are a dodder and wish to maximize your intake from tender shoots while minimizing the volume of tissue you grow, given realistic environmental constraints. To get from one tender shoot to another on an adjacent branch, an obligate stem endoparasite would have to grow all the way down the branch and all the way up the other branch. Why do that when you can just bridge the gap by growing across? It's much less of a distance, and air is presumably a less resistant medium to grow through than rigid plant tissue. Plus being ectoparasitic allows dodders to span multiple hosts at once; this seems not that common in wild adult subinclusa and californica, but is apparently a major means of spread for temperate dodders, and juvenile subinclusa (in order to get at the part of the tree that's nonwoody enough to actually penetrate mechanically, since regardless of how nutritious it is or isn't the main trunk is just too thick to drill through) often start out feeding on small herbaceous plants and gradually climb taller and taller plants until they reach the edible portions of the tree.

You may have seen me occasionally complaining about my dodders mindlessly climbing upwards the same way ladybugs and a lot of other foliage-inhabiting insects do; while it's definitely pretty annoying in captivity (since when the old host is exhausted and you put a new host that's shorter next to it the dodder often struggles to find it), the adaptive benefits of this in nature are pretty clear.

Today's non-adventure

Checked the "loose sands Notibius zone" part of Santa Fe Dam Recreation Area though since the pictures were taken in the future of this post and it had rained by then the sand in them is temporarily not loose to see if it had any cool summer endemics the more stable sand elsewhere lacks.

Kind of disappointed the Cryptocephalus there were still spurcus, also found a whole bunch of 5mm-ish microweevils on scalebroom flowers I didn't keep because they looked like they might be gall inquilines (weevil larvae as a general rule are endophages on seeds and other high-calorie plant parts and these were too fat to fit into any of the seeds nearby. Even if they were stem borers or root eaters though I'm not willing to take any chances because I only have one scalebroom myself and it's still in its whiteleaved "larval" stage, assuming that's even the oviposition host, and I don't happen to have either mature individuals or any individuals of any of the other plants in that microhabitat).

No big deal though, I was expecting pretty much exactly all this to happen (and I did take home both the spurcus I caught anyways, for genetic diversity, so I'm not exactly complaining). I wonder if the unmarked and/or sunshine yellow morph lives in my area? Well, probably not the latter, that's probably a high-desert special, but unmarked beige ones seem likelier. The stripes undoubtedly help them camouflage as marcescent flowers/seedheads of pinebush so I've been looking on scalebrooms for stripeless ones, albeit to no avail (scalebrooms seem to provide poorer habitat somehow [probably due to their vestigial adult leaves translating to poorer microclimate protection and poorer edible leaflitter], this year I only saw one on that plant and it was striped and it got away).

The previous spurcus are both gone [one released after it laid enough eggs, the other escaped and died and I still feel extremely bad about its death] so my current cryptocephaline population remains at two, not counting the 32 eggs.