I suppose I should give a more in depth insight just in case someone who knows Tarantula more appears.
I don't know a lot about Tarantula, but he should have a skill advantage here, once again, it seems like most people in the big two comics have a ridiculous skill scaling and the BW lads don't have a lot of statements for skill, only visual feats. Still, Blackarachnia is not a bad figher per say, and can likely match up slightly with Tarantula.
The AP and LS advantage is hers, but the AP advantage is barely there and the LS probably won't come into play since she doesn't throw enemies, and it would only factor if Tarantula uses those as his main thing. Blackarachnia's stun beam is an easy win condition but she would need to hit him first, which might prove hard since his acrobatics should give him enough room to dodge it, as Cheetor did the same (Although he also is faster then Blackarachnia).
Tarantula's poison likely wouldn't work. Cybertronians are usually portrayed closer to living beings then robots (They have their own diseases, poisons and can get drunk, although only radiation poison was mentioned in the 2021 BW series), they still, however, have wildly different anatomies so a poison that affects organic beings would likely not affect a Cybertronian.
One thing that might not be good for Tarantula is Blackarachnia's web. She can only it in her alt mode, but she has done it at least twice, both of those mid battle and one of them was when she was in a 8v20 battle (Her being part of the 8 fighters), those webs can restrain people that are stronger then Nyx (Which is where Blackarachnia gets her LS at 18 Tons) so that is also a win condition for her.
Overall, while I do think Tarantula might have the acrobatics not get immediately destroyed by the Stun Beam while also likely being more skilled to take her in combat, Blackarachnia does need one hit of her Stun Beam, which he can not disarm and, if that takes a while, her energon webs are too strong for Tarantula to tear apart so I'm voting her for now