Level 1

Survival Instinct: This should be your default choice, to give your pushes extra survivability.
Regenerative Microbes: Get this instead if your team has no healer and you have a lot of squishy people.

Level 4

Adrenal Overload: Get this and focus on hatting the basic attackers during teamfights.
Sustained Carapace: If for some reason you don't have basic attackers (or they suck), take this instead and focus on hatting any squishy assassins or supports your team might have during teamfights.

Level 7

Networked Carapace: This one's the only real choice here, to give your pushes extra survivability.

Level 10

Evolve Monstrosity: If you're on a 3-lane map or the enemy team is agressively pushing teamfights.
Ultimate Evolution: If your team is in dire need of help in teamfights or you're on a smaller map.

Level 13

Bombard Strain: This should be your default choice, for extra damage while pushing.
Soma Transference: Get this if you don't have a healer on your team and can't do without the extra healing.
Assault Strain: If you didn't get Survival Instincts on level 1, you're gonna want to take this instead.

Level 16

Locust Brood: This is the only real choice here. (Don't forget to keep up with the timer!)

Level 20

Locust Nest: Get this if you can safely get into the enemy's half of the map (especially during objectives)
Hivemind: You should get this talent if your team needs help in teamfights but you didn't get Ultimate Evolution.
Evolutionary Link: Very situational, only get this if there's a hypercarry on your team that needs additional protection during teamfights.
Evolution Complete: You should never get this talent, ever. (seriously, if I see you take this talent I will slap you with a trout)