This traditional nursery rhyme comes from the old times of rural England.

There is a karaoke version at the end.

A swarm of bees in May
Is worth a load of hay.

A swarm of bees in June
Is worth a silver spoon.

A swarm of bees in July
Is not worth a fly.

A SWARM= A large number of insects, especially when in motion.

IS WORTH= If something is worth X, we mean that X is its value.
- This ring is worth 50 pounds
- My family is worth all my time and devotion

A LOAD OF HAY= The amount of hay that you can put in a cart. (see hay, see cart)

A FLY= A very common insect (see picture). If something is not worth a fly, then it has no value.

In old times, people kept bee hives to produce honey, but they usually left them alone in a natural state. To keep the bee colonies plenty and healthy, they used to capture new bees every year and bring them to the bee hives. For some reason, early swarms (captured in May or June) were better than later ones (captured in July or August), probably because the bees were more used to going their own way and were harder to adapt to the new colony. So this rhyme is just stating the fact that early bees were the best for the occasion.