Dryoceocelus australis lives solely on an island group in Australia. They were thought to be extinct after 1930 until two dozen were spotted again in 2001. The IUCN lists them as critically endangered currently.
Read more here about the conservation efforts by zoos in Australia to ensure the species survival.
Pair bonding between the male and females has been reported, but is not definitive. Anecdotal evidence suggests the Lord Howe stick insects are gregarious and thus finding a male and female together may just be the expression of this trait. Research from Patrick Honan in 2008, examined 9 pairs from the Melbourne Zoo found that the behavior was consistent for each pair daily, but varied depending on the pair. Some pairs were always found together, but in some cases the female would be found in the nesting box and the male outside the nesting box.
Finally, here is an amazing video of hatching Lord Howe island stick insects from Zoos Victoria if you haven’t seen it already.