It is important to note that no matter what type of reaction a Beagle has had in the past, a stronger reaction to any sort of sting can happen at any time.
For example, a Beagle may have been stung 10 times by a swarm of bees and was fine, but later may be stung by 1 wasp and have a bad allergic reaction. For this reason, whether 1 insect or a swarm of them is on your Beagle, your actions should be the same.
1) Do not attempt to hose down the insects, swat them off your Beagle with a towel or flail your arms. Any of these actions can cause the insects to attack more ferociously.
2) Take immediate action to remove your Beagle from the area of attack.
Most insects attack dogs due to believing that they are defending their territory.
Therefore, the goal will be to quickly leave the area. If you can, it is best to pick up your Beagle and run to shelter.
Most flying insects including African Killer Bees can be outrun and to this end, it is best to run in a straight line. If you are in an open area, you will want to get at least 50 yards away.