This is a well-known English folk proverb about beekeeping, and it can be understood by tracking the value of a bee swarm across the summer months.
Early in the season, in May, a captured swarm has almost the entire summer ahead of it to build comb and gather nectar, so it is described as being worth a full load of hay. By June the swarm still has a fair stretch of the season left, so its worth is compared to something valuable but smaller, a silver spoon. By July, however, so little of the productive season remains that the swarm cannot build up enough stores to be worthwhile, so it is called not worthy at all.
Reading the three lines together in order therefore gives the complete traditional saying.
the correct answer is 'A swarm in May is worth a load of hay; a swarm in June is worth a silver spoon; but a swarm in July is not worthy.'