Cicada summer - final edit

[Brownlie]

This is another I've worked on for so long I can't see it any more - any help would be appreciated.



Underground
for seventeen years
they grew and waited; -- Well, I like the way it works in the poem, but your syntax would read a little awkwardly in prose without a comma after years, or by saying it like this: They grew and waited for seventeen years underground. Maybe even, They grew and waited, underground, for seventeen years.
this dawn they escape.
As light strengthens
they climb high, cling
to tree trunks, branches, twigs;
reeds bend under their weight.
Their creamy skins darken, -- I suppose creamy and dark are more ambiguous ways of representing shades that are like white and black. The poem may benefit from some fancy more exact colors.
split, reveal black gargoyles with
glassy red pinhead eyes. Crawling,
they leave their husks behind. Crinkled
thumb-sized wings pump up,
stretch and set. Then -- Maybe a comma here, but the line break already gives you a pause.
the din begins: first painful light, -- I really like this colon here
struggle to climb, torment of split skin, -- I suppose you might want to replace the adjective with a detail that suggests "torment."
birth shock, the urge to mate, do it again, - I like do it again: it gives the whole poem a sort of cyclical feeling
all given voice until the air shakes
and shrieks like an unoiled machine. Within
that alien orchestration you can hear
the faint mechanical chant of a choir
the one in St. Augustine’s cathedral
that so terrified you as a child.

These things are creepy. The unoiled machine is not a bad way to describe them. I don't know how much you know about cicadas, but you may benefit from putting in more exact details about them. I sort of think about that Short story "Consider the Lobster," by David Foster Wallace. Here's some supposed information on Cicadas I've pilfered from Wikipedia that may be helpful.

"The male cicada has loud noisemakers called "tymbals" on the sides of the abdominal base. Its "singing" is not the stridulation (where one structure is rubbed against another) that characterizes many other familiar sound-producing insects, such as crickets. Rather, the tymbals are regions of the exoskeleton that form a complex membrane with thin, membranous portions and thickened ribs; contracting the internal tymbal muscles produces a clicking sound as the tymbals buckle inwards, and the relaxing of the muscles causes the tymbals to return to their original position, producing another click. The interior of the male abdomen is mostly hollow, which amplifies the sound. A cicada rapidly vibrates these membranes, and enlarged chambers derived from the tracheae make its body serve as a resonance chamber, further amplifying the sound. The cicada modulates the sound by positioning its abdomen toward or away from the substrate. Additionally, each species has its own distinctive song.[1]

Average temperature of the natural habitat for the South American species Fidicina rana is approximately 29 °C (84 °F). During sound production, the temperature of the tymbal muscles was found to be significantly higher.[16] Cicadas sing most actively in hot weather and do their most spirited singing during the hotter hours of a summer day, in a roughly 24 hour cycle.

Although only males produce the cicadas' distinctive sound, both sexes have tympana, which are membranous structures used to detect sounds. They are thus the cicadas' equivalent of ears. Males can disable their own tympana while calling.[17]

Some cicadas produce sounds up to 120 dB (SPL),[17] among the loudest of all insect-produced sounds.[18] This is notable because the song is loud enough to cause permanent hearing loss in humans should the cicada sing just outside the listener's ear. Conversely, some small species have songs so high in pitch that the noise is inaudible to humans.[6] Species have different mating songs, ensuring that the appropriate mate is attracted. It can be difficult to determine from which direction(s) a cicada song is coming because the low pitch carries well.

In addition to the mating song, many species also have a distinct distress call, usually a broken and erratic sound that the insect emits when seized. A number of species also have a courtship song, which is often a quieter call and is produced after a female has been drawn by the calling song."

Well, I've tried to help you anyhow. Thanks for posting.