So, I have 3 species of eusocial animals in this world, however for now I'll just be talking about this one considering the other two have fairly obvious answers for how they would murder large Dragons (size, being stupidly resistant, and just sheer numbers, with their larva eating meat and one of them being extremely territorial).
They are Eusocial Wyverns that live in groups of normally a thousand or so individuals that do not morph aside from size when fitting a certain Caste (similar to Naked Mole-Rats and some Bee species), strong bite, sharp teeth, and an stinger at the end of their tail with a breath weapon as a possibility. They are about the size of rats.
For these reasons, I doubt humans would pose much of a problem (who wants to deal with wasps the size of rats?), not to mention they pollinate crops and hunt down pests such as mice, rats, and other similarly sized animals.
The dragons they would have to deal with every once in a while are about the size of elephants when they're adults and are assumed to have a breath weapon. Their main goal would be to eat the equivalent of their larva and possibly a honey-like substance they produce to feed them during the winter.
The eusocial wyvern's goal is to chase off the dragon at the very least regardless of their breath weapon, how would they do so?