The best way to tell is to go outside at night with a flashlight and catch the culprits in the act. Control requires knowing what is causing the damage.

The notches at the edges indicate root weevils. The adults feed at night and, when startled/jostled, drop from the plant.

The edges of the cuts appear to be brown. In other words, the critters have eaten what they want & are long gone.

Earwigs seem to appear after all the rains we had ~ tho not so bad in the early part of Spring due to an early start of the sunny/hot days of early May & that gave my clems time to flash their first blooms beautifully!
Oh but as soon as the series & intermittent rains & storms returned, earwigs started showing up & started their nighttime activities ~ devouring the beautiful blooms as well & loved to hide during the day in the centerfolds of very young leaves of many of my Hydrangeas leaving them holey as well!

They hide in dark humid places & quickly drop themselves when discovered!

I was out early this AM contemplating on when to prune down Snow Queen that is at the tail end of her most productive bloom-time, when all her last efforts-newly opened blooms were turned into cut-out snow-white laces!!! No signs of the culprits in sight & not even in the curled & folded leaves nor were they dropping out like familiar earwigs or weevils!

Well it gave me the push to go ahead w/ the advice to prune hard now ~ I hummed *Angel of the Night from Phantom of the Opera* as I took on the daunting task of pruning a huge tangled mess! Whew mission accomplished!

The easy way to prune a huge tangled mess is to chop it off below the mess and dump the whole thing in the yard debris bin. No need to sort through trying to save this vine or that. Just whack it all off.

Thanks for the reassurance as that was exactly what I did altho not so easy as I have never really pruned since planting several years ago (believe it or not I suffered the dried look but not as long as the Buddleias) consequently all the twines went in a tortuous route thru the old tomato cage & the tent trellis I created over (LOL)!

I got scared about hard prune so I chopped only to 18" ~ should I go closer to ground by how much more?

Thanks for all the help ~ I feel that I'm the only veteran-Clem-owner that knew nothing about Clem care!!!

I cut mine closer to the ground. It is not unusual for all the stems left to die back but twice as many to sprout up from the ground. So, I don't like to see 18" of dried stems...