Do they still have the Australian Giant Mantis? What species are currently exhibited in Hero HQ?
I don't think so. There haven't been any mantids on display for quite a long time (the tank has been sitting empty with an "animals back soon" type sign) - I suspect they died out and the South African Mantis were eventually got in as replacements (they are common over a lot of the North Island so are an easy replacement, although they look extremely similar to the native NZ Mantis).
I'll list the current species below with photos of each side of the building to show how the signage looks (i.e. confusing for visitors - these photos are from 2013 but the artwork has changed little despite changes in species on display). You can click on a photo to go to it in the gallery for the full version.
Side one:
*Goliath Stick Insect
*Migratory Locusts (in the tank where the chameleons were previously housed - originally Jackson's Chameleons and then Veiled Chameleons)
Side two:
*Madagascar Day Gecko
*South African Mantis
*African Giant Millipede (originally both right-hand tanks were for Giant Mantis as in the photo below, although just labelled as "mantis")
Side three:
*Scheltopusik
Side four:
*Bolivian Blue-legged Tarantula (in a tank originally holding Leopard Gecko, which is what the artwork still shows. I have literally never seen this spider as she is always inside her burrow)
*Emperor Scorpion
*Emperor Scorpion (these tanks originally held Australian Rainforest Scorpions from memory, despite the desert setting of the artwork)
Side five:
*Pink-toed Tarantula (this one is always in her burrow as well, so I have never seen more than a leg-tip or two)
*Goliath Bird-eating Spider
*Brazilian Black Tarantula (a King Baboon Spider had been in here originally)
*Red-kneed Tarantula
Some of the tanks have no backings (just glass), allowing viewing inside the building where there are loads more tarantula tanks - although the labels are too small to see what is what for most of them - as well as several Scheltopusik tanks. I've seen a tank for Blind Cave Fish in there on a few occasions, and I used to be able to see the Lace Monitors but they aren't in there any more (no idea if they are still kept elsewhere, or if they are gone).
Separate to the Hero HQ building - off to one side, facing the side where the mantis and millipedes are - is the enclosure for the Wellington Green Geckos:
