It's not a bad start.
Some of your point costs aren't quite right. Best check you're using the latest updates.
The warriors and tyrannofex are a bit cheaper than what you've listed.
I wouldn't bother with the adrenal glands and toxin sacs on the tyranid prime, unless you've got absolutely nothing else to spend those points on.
If you drop those upgrades, then combined with the cheaper warriors + tyrannofex you have about 30 spare points. Enough to throw in another venomthrope, or a warrior, or a couple more genestealers.
Jormungandr isn't a bad choice. Although it would be a better one if you had some raveners in the list, that you could use to tunnel in the warriors.
If sticking with Jormungandr, I'd probably drop the venomthropes in favour of raveners. The -1 to hit doesn't really help much these days against the full re-rolls you see in space marine armies. It's still great against stuff like tau and imperial guard. So you'll have to think about what you're likely to run into in your local group.
One decent alternative is Kronos, which would help your tyrannofex and warriors hit more often, along with provide access to a psychic power to make their 6+ to hit with shooting produce 2 hits. It doesn't do much for your assault elements though, aside from use them as a source for an anti-psyker stratagem.
Another decent alternative is Kraken, which is the opposite. Helping your assault elements, while not doing very much for your shooting. Your genestealers would love it, and it would help your warriors get into combat too.