Bees usually swarm when a group of them leave their old hive and seek to establish a new one. This usually happens in the late Spring - early Summer after they've increased their population by a significant amount. Beekeepers can take advantage of this time to establish new hives in their bee-houses. In general, the best time to do this is in May or June. It's usually not worthwhile for a beekeeper to establish a new hive in July. Hence the rhyme below...
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.
Photos & Illustrations


Comments
This rhyme and illustration can be found in The Real Mother Goose (1916), illustrated by Blanche Fisher Wright.
The 2nd illustration can be found in The Big Book of Nursery Rhymes (circa 1920) edited by Walter Jerrold (1865 - 1929) and illustrated by Charles Robinson (with some graphical editing of the 2nd image by Lisa Yannucci).









