Well I've been noodling around how to use Tervigon in a competitive list, and this is my notes that I have jotted down so far...
HQ: Winged Dakka'rant, Electro 240
HQ: Winged Dakka'rant, Electro 240
HQ: Tervigon, Thorax Hive: Electro 205
Troops: Hormagaunt Brood, x15 75
Troops: Hormagaunt Brood, x15 75
Troops: Warrior Brood, x3 (Strangle Cannon) 100
Elite: Venothrope
Elite: Veno
Elite: Zoey Brood, x2 100
Heavy: Dakkafex 150
Heavy: Tyranofex,Thorax Hive: Electro, Adrenal (or a second Dakkfex, save 50 points)
Heavy: Mawloc
Toss on Fighter Ace, and Old adversary for your Warlord...Add a Tyrannocyte for a
MC Deepstrike, and that is 1740 I believe.

(I plan on
DS for the Tervigon)
I'm not totally married to this list as of yet. I tend to run a pair of "Bugstars" on foot, and try to toss as many backfield threats down range as I can. I am pretty happy with the results.
This list would be a lot stronger with two Malanthropes to replace the 3 Elites, but I don't have any.

I always have tremendous results from Tyrano, but I am considering turning her into a second Dakkafex for harmony.I normally run a Tyrano, and two Mawlocs for my Heavies, but I'd like to "upgrade" to a Dakkafex (or two)
One thing that has been suggested is Crushing Claws for the Tervigon, I have most of the points available, and I can drop a Hormie for the last 5...

But I don't have it modelled that way...