Re: East Coast Cicada Hatch
The last Cicada hatch I remember occurred around 2002, so according to Wikipedia, it was Brood VIII (genus Magicicada). I recall an unbelievable amount of the Cicadas (quite sizeable) in PA and NJ. Although I am simply guessing, I would believe that trout would be bloating full after a few of these.
No doubt they would grow very fast during the few weeks of this hatch, yet it seems it may be difficult to catch many trout on cicada-imitations simply due to the fact that each trout may only have say for example, less than 10 cicadas a day (resulting in 10 hits). In comparison, most other hatches typically consist of much smaller size bugs, which converts to more hits, for example, it may take 50 or 100 BWO's or smaller Mayflies to equal the weight of one or two Cicadas. If 50 BWO's equals the weight of 1 Cicada (which is a guess) this would equate to 500 hits a day for a BWO hatch versus 10 hits for a Cicada Hatch. You would have a better chance of getting a hit during a BWO hatch simply because of the larger number of (smaller weight) bugs the trout needs to fill up.
At a certain point, the trout will have Cicadas bursting from their mouths and will stop feeding. Good luck getting your own imitation into their mouth before this happens, a rare hit, but I would imagine catching a trout during one of these hatches would be really cool, I would expect the trout to be really really really fat and I would honestly expect you to be able to see the Cicadas inside their mouths.
Of course, I've never fished during one of these Cicada hatches, and it's entirely possible that trout simply don't appreciate the fine acquired taste of Magicicadas.