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This group of Casuarina glauca gall types has me puzzled. I can't find any information about them. They are undescribed species perhaps. There appears to be some sort of relationship between them, which I will explain below.

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First off we have the galls that are easily mistaken for Cylindrococcus which I wrote about here: https://www.inaturalist.org/projects/casuarina-glauca-galls/journal/73965-the-deceptively-named-casuarina-gall-cylindrococcus-spiniferus. The experts on Inat think they are probably a wasp or maybe a fly.

I'll refer to this first type as cone galls:

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They can occur with or without what I'll call fluffy ball galls:

These fluffy ball galls are also thought to be wasps by Inat experts, or at least not scale insects.

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The fluffy ball galls can occur alone without cone galls:

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The fluffy ball galls sometimes occur with what I'll call club galls:

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I recently saw an example of club galls without the fluffy ball galls:

Perhaps the club galls become cone galls? Seems doubtful, here's an observation which includes what looks like small immature cone galls: https://inaturalist.ala.org.au/observations/133555616

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Then, there are hard woody galls that appear as though they grew from the fluffy ball galls:

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This fluffy ball gall sort of looks like it might be turning into a hard woody gall:

If the fluffy ball galls do 'grow up' to become hard woody galls, which i doubt, not many of them seem to make it to maturity.

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What is the relationship between all these gall types? Where does one species end and another begin?
The occurrence of different gall types together seems too frequent to be coincidental.

Perhaps the fluffy ball galls provide an advantageous spot for other species to build their galls? Are there parasitic or symbiotic relationships involved? Could sexual dimorphism between galls explain some of the variation? Or does one gall type metamorphose into another type? Seems doubtful.

So many questions. Please share any theories you may have, no matter how crackpot.

There are a couple of other mysterious gall types that I think are unrelated to this particular confusion of galls, I will leave those for another post.

For now I will keep on observing and looking for clues.

Deceptive because it doesn't grow on species in the Casuarina genus. Rather Cylindrococcus spiniferus is limited to Allocasuarina species. To add to the confusion galls on Casuarina Glauca can resemble Cylindrococcus galls. These are Cylindrococcus galls https://www.inaturalist.org/taxa/503065-Cylindrococcus-spiniferus/browse_photos?place_id=6744.
Here is an example of a Casuarina glauca gall that looks kind of similar https://www.inaturalist.org/observations/145104003.

It would be reasonable to assume the C. glauca gall was formed by a creature that was at least related to Cylindrococcus, however it seems that they aren't even in the same order. Cylindrococcus is a Felt Scale insect in the family Eriococcidae, in the order Hemiptera.

According to the experts here on Inat the Casuarina glauca galls like the one above are likely to be wasps and in the order Hymenoptera. Or maybe even flies, order Diptera.
See https://www.inaturalist.org/observations/60815964 and https://www.inaturalist.org/observations/55606554

My own misidentification of one of these C. Glauca galls as Cylindrococcus really got me interested: thanks to @penelopeuq for correcting my ID. It is both baffling and intriguing that these seemingly common galls can't be identified, but apparently that's not at all unusual with galls. Perhaps there is more information out there that i can't access as I'm not a scientist. For now I will patiently remain baffled and intrigued.

I wrote a little about this project here:
https://www.inaturalist.org/journal/vavilovian_mimic/73956-casuarina-glauca-galls-project