If soloing in CN, the bees/crawlers should get you to around 50. The real benefit in not leaving the zone, however, is you can head toward the Simurgh spawn and take out lizards and exorays into the 60s since you'll have the rewards bonus built up. Having a means of stealth is handy to get past the bees and minimize lizard links, but isn't required if you're careful and with trusts.
The tree is similar in that you can roll through crabs or spiders into the 70s, then jump up toward the Aery path to hit 99 out of it.