terrestrials are my favorite form of fly, especially crickets in the fall. usually my eyes and ears are sufficient "seines" for identifying the best time to use them.
in preparation for a trip to Yorkshire, i had asked the guide what to tie up before i arrived. the usual suspects (and some interesting patterns) were suggested, but my offering of crickets was turned down flat. i just assumed that habit and ignorance were at work, but not so!
in 5 days of fishing the River Wharfe this past September i was astonished to hear not one cricket or grasshopper. rainy days, sunny days, morning, evening--nope, no crickets. my hosts are avid hikers, and as we walked through the fields i kept my ears open--nope, nothing.
perhaps the British disdain of terrestrials is more rooted in fact than one might initially assume. as for where the bugs might be: the place was alive with birds of all kinds...
fly fishing and baseball share a totally deceptive simplicity; that's why they can both be lifelong pursuits.