( Note: Hoxia 39 is actually a Moon, it is sometimes referred to as a planetary / celestial or astronomical mass for simplicity's sake )

The Ideal environment to grow supermassive insects

Creating giant arthropods requires a very specific environment, and in order to create the optimal conditions for the propagation giant arthropods whilst still retaining ecological biodiversity mostly consists of replicating the Carboniferous period’s environment, but to a much greater extent. Luckily, the unknown terraforming civilization that revamped Hoxia's star system appeared to have designed such conditions themselves.

Section 1: Hoxia 39's Astrophysics

( Work in Progress )

This planet will also be smaller in mass, with a gravity only 55% of that of Earth, similar to most other seed world evos to encourage gigantism, This allows for individual organisms to grow larger without having to worry about supporting weight.

With a mass around ~17.5 % of earth’s mass and around 55% of the gravity.  Despite its lesser mass,  it would still possess a disproportionate 55-56% the diameter of Earth’s because of differing internal density/ It will also be close to 50% of Earth’s total surface area, around 250 million sq kilometers / 96 million square miles. This means that it would only possess around 25 million square km / 9.6 million sq miles of dry land. ( Compared to earth’s 149 million square kilometers / 57 million square miles of dry land ) 

Erosion is slower, and meteor impacts are more common.

Hoxia is not tidally locked, and experiences a day night cycle.

There are periods where the exomoon is completely shrouded in darkness by a lunar eclipse.

Sparse nitrogen rich meteorites impacts aids in building much of its atmosphere.

Section 2: Generalized Exomoon Environment / Atmosphere

The exomoon will has a large majority of its traits be completely borrowed from Earth, including all conditions suitable for life as well as a tilt and rotation to recreate weathers and day / night cycles.

it orbits an exoplanet known as Vulkos, albeit at a much farther distance allowing it to have tides, as well as a nighttime light source as most insects rely on the moon to migrate ( which is why they are attracted to light ). 

Plate tectonics are not very active, it will be much more reduced in order to lower Volcanic Outgassing carbon emissions, as well as decreasing the expansion of ocean size ( Volcanism for the most part is what creates ocean size ). Most of the planet’s carbon emissions will come from its arthropod life forms and a series of supervolcanoes along its Southern Island Chains. The volcanoes will be active in certain times, going off in sequentially around a period encompassing 10,000 years. It goes dormant for up to several million years afterwards. In its dormant state, volcanoes will eventually be capped with snow and ice, being indistinguishable from its surrounding mountain ranges. These mountains and volcanoes will usually be positioned much farther from the tropical belt to decrease land travel difficulties for such smaller major lifeforms, to encourage more active ecological interactions. This planet however, will start off with significant variations in mountain size and elevation in a large portion of its surface in combination with less tectonic activity, creating an uneven planetary crust on dry land. The underwater terrain will be artificially modified / terraformed to be relatively shallow, basically meaning that oceans aren't as deep. These oceans usually range from an extremely tiny 200-400 feet / 60 - 120 meters deep, with some maximum depth areas reaching up to 2000 feet / 600 meters.

The planet will also be slightly warmer than Earth, to promote a tropical and frequent raining across the surface of the planet. This aids in putting out forest fires from such high quantities of oxygen in its atmosphere, which is required for insect size. This will also supplant the large quantity of swamp lands.

The Planet’s continental areas will mostly be in “island” like, similar to the Canadian Arctic Archipelago. This is so that isolated competition and speciation occurs with much more proximity ( since insects are smaller compared to vertebrates ), with many bodies of shallow water as well as land submerged in floodwater. This also means that the oceans will cover a larger amount of surface area, compared to Earth, with roughly 90% of its surface covered in water.

Section 3: The Artificially Seeded Biosphere

• NO VERTEBRATES. Unlike most other seed worlds that have a handful of invertebrates and then their desired vertebrate animal, this world will have only invertebrates as the substantial fauna. Reason: backbones. Animals with an endoskeleton will eventually become stronger than invertebrates via a musculoskeletal system, obviously, and then become competitors. The reason why the Carboniferous had such large insects was because their ecological niche was not yet occupied by larger vertebrates.  Any vertebrate at all would eventually overcome the arthropods in due time. Because of this, although it's usually desirable to keep at least one vertebrate tetrapod on a seed world, for this world, no vertebrates will exist.

-TLDR: NO VERTEBRATES will be added, nor will they ever exist to ensure competition only occurs between invertebrates

. #arthropod supremacy

-Much of the planet is blanketed in oceans, which means the most prominent life on Hoxia will be an enormous quantity of phytoplankton ( microscopic algae,  photoysynethtic cyanobacterium and and other macroalgae seaweeds like kelp ). These photo synthesizers will constantly output an enormous amount of oxygen. 

-This planet will primarily host several species of genetically modified trees. These trees are extremely hardy, fireproof, with much more enhanced versions of giant fireproof trees similar to Redwoods and Sequoias. This is so that they can resist the highly combustible nature of Hoxia because of such high oxygen levels. They will also have incredibly durable bark to also resist physical degradation.

-These trees are also extremely resistant to rot and bacteria, similar to a much more powerful version of Black Locust / Brazilian Walnut  trees on Earth, which use taxofolin and flavonoids to prevent rot and decay. This is to stave off the evolution of wood rotting bacteria and fungus, which could lower the oxygen levels by prematurely releasing carbon stored in trees. ( This is what also caused the oxygen decline towards the end of the Carboniferous period on Earth )

-Hoxia's oxygen percentage reaches around 39%, which is what its named for.

-These trees will release a modified biocide that keeps them clean from bacterial infections, similar to modern day plants that use antimicrobial compounds Phytoalexins and Phytoanticipins. Their other purpose however, is also to kill off foreign lifeforms that attempt to live off of them.

-Various trees and plants bear fruit, however most of them will have a much tougher / armored outerlayer ( aka exocarp / exicarp )

-All other plantlife present will also have similar modifications 

Similar to Carboniferous era trees, the deceased logs will quickly be covered up and buried or carried downstream as much of them reside in swampy tropical eras that experience flooding frequently.

-No Basidiomycota, fungi will be seeded / introduced

-No Actinobacteria or other wood eating bacteria will ever be initially seeded/ introduced.