Beatitudes means blessed or happy.
The first 8 lines make the poem sound like bad news, and the word "contagious" sets the mood for the poem. The pastoral tradition celebrates the beauty of the natural world and the simple pleasure of living in the countryside. However, the first 8 lines of the poem seem to claim the exact opposite, with words like "contagious" "surge" "cold", and "waste."
I think that there are three phrases which create comic tone:
dangling from his arm
someone who grew desperate
to fold up a bush
Answer is in the attachment