Common name Genus / species Nymph type Emergence Prefferd nymph habitat Nymph Size Tails Nymph Tied Nymph Most active  Recommended Nymph Patterns Emerger Pattern Dun Pattern Spinner Pattern Streams identified in                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
         
         
Blue Winged Olive - Dark Blue Quill Baetis  (vagans) Swimmer March - May Under water vegetation 6m - 9mm #16-22 2 or 3 Streamlined Warmest part of the day Blue winged olive - Pheasant tail -  Baetis deerhair emerger #14-16-18 parachute Blue winged olive - Adams - Compara dun Dark Blue Quill #14-16-18 Compara spinner wbcr inlet March 20 / Amawalk Wood Street  March 30 / East Branch Croton Falls April 2 2:30 -West Branch Croton Falls Spillway East Branch April 13 ** Cemetery Pool
Blue Winged Olive - Dark Blue Quill Pseudocloeon  (carolina) & Dubium Swimmer May -August Gravel runs and riffles 4mm -5mm 2 Streamlined Dusk Blue winged olive - Pheasant tail -  Blue winged olive - Pheasant tail -  Blue-winged Olive #20-22 Compara spinner West Branch & Amawalk May 13 / East Branch Cemetery Pool June 7 - East Branch Cemetery Pool Aug 20
Blue Winged Olive - Dark Blue Quill Baetidae  (cloeon)- Simplex & Insignificans Swimmer Summer Gravel runs and riffles 4mm - 5mm 3 Streamlined Dusk Blue winged olive - Pheasant tail -  Blue winged olive - Pheasant tail -  Blue-winged Olive #22-28 Compara spinner East Branch Cemetery Pool June 7
Leadwing Coachman -Slate Drake - Dun Variant - Mahogany Dun Siphlonuridae Isonychia (bicolor) Swimmer May - July    (in quieter water or behnd obstructions) Gravel runs and riffles 12mm -16mm 3 Streamlined Afternoon or Evening Compara Nymph - Zug Bug- Iso Nymph Floated in Film Lead Wing Coachman Wet- Grayish Quill Body Klinkhammer Dun Variant # 10 - #8 White-Gloved Howdy
Leadwing Coachman -Slate Drake - Dun Variant - Mahogany Dun Siphlonuridae Isonychia  - (sadleri) June - September June - July    (in quieter water or behnd obstructions) Gravel runs and riffles 13mm - 16mm 3 Streamlined Afternoon or Evening Compara Nymph - Zug Bug- Iso Nymph floated in film. Lead Wing Coachman Wet- Grayish Quill Body Klinkhammer Dun Variant #10 White-Gloved Howdy
             
 Hendrickson - Female

Male -  Red Quill

 Ephemerella (subvaria) Crawlers End of April Very early May- Water temp. 50-55 Fish generally will only take Duns off surface if night time temps are mostly above 50 Deg. Stream bottoms with riffles, smooth runs slow silty stretches and thick vegetation 10mm - 12mm 3 Robust Afternoon Hares ear - pheasant tail - Dark Hendrickson Dark Cahill wet - Floating nymph Thorax Hendrickson, Hendrickson, Red Quill  Light Cahill  Compara dun x12-14 Trico poly wing - Compara spinner Amawalk Wood Street April 26 watertemp 50   3:00pm (Duns) East Branch Croton Falls West Branch Croton Falls Spillway April 24 April 28 / East Branch cemetery pool April 12-13 ** / West Branch CF inlet April 23                                                        Note: **  this year was unusually early.
Sulphur - Pale Evening Dun Ephemerella invaria Crawlers May - June Medium-to-Fast currents 7.5mm - 9.5mm 3 Robust Late Morning to early evening Hares ear - pheasant tail - Dark Hendrickson, Little Marryatte Little Maryatt Wet Deerhair emerger Sulphur, Pale Evening Dun Compara spinner, Sulphur spinner Amawalk Wood Street  April 28 May 22 ** - Titicus - West Branch Croton Falls Spillway May 18 - East Branch Cemetery pool May 1 - Titicus June 10
Sulphur - Pale Evening Dun Ephemerella dorothea Crawlers Late May - Early July Pools And slow water 5mm 7mm 3 Robust Late Morning to early evening Hares ear - pheasant tail - Dark Hendrickson Little Maryatt Wet Deerhair emerger Sulphur, Pale Evening Dun Compara spinner, Sulphur spinner Amawalk Wood Street - Titicus - West Branch Croton Falls Spillway (Nymphs) - Titicus June 21
Blue-winged olive Ephemerella  cornuta subgeneus Drunella Crawlers May - July Runs, Riffles and Eddies of pocket-water 9mm - 10mm 3 Wide & Flat Morning to mid-day Especially on Cloudy days Blue-winged olive, Hares ear, Small pheasant tails.  Whyatt Deerhair Emerger, Blue-winged olive wet Blue-winged olive #14 #16 Blue-winged olive East Branch Cemetery Pool June 7
Blue-winged olive -  Tiny Dun Variant Ephemerella subgenus (attenella) Crawlers June - July Slow pools and Back waters 6mm - 8mm 3 Wide & Flat Morning to mid-day Blue-winged olive, Hares ear, Whyatt Deerhair Emerger, Blue-winged olive wet Blue-winged olive Blue-winged olive
Blue Quill,Dark Blue Quill, Blue Dun, Iron Blue Dun, Slate -winged Mahogany Dun Paraleptophlebia (adoptiva) Crawlers April - water temp. 50's Pools, side currents and moderate Gravelly runs 6mm - 8mm 3 Slender and Streamlined Mid-morning to early afternoon Hares ear - Pheasant tail Blue Quill,Dark Blue Quill, Blue Dun, Iron Blue Dun, Slate -winged Mahogany Dun  #18 #16 Amawalk April 14 / East Branch Cemetery Pool May 22 / West Branch Spillway May 22
Trico's - Caenie Hatch - Tiny White-winged Black - Black Caenis Tricorythodes Crawlers Late July thru October waters temps. 52-56 Sand and gravel bottoms - Mar-rich silt - Subaquatic weed beds 3 - 5mm 3 long thin Morrning pheasant tial size 20 - 26 wet size 28-26 dark body light wing #24 #26 Rusty spinner - trico cdc spinner West Branch Croton Falls Spillway July 1
             
Light Cahil - Gray Fox - Ginger Quill Stenonema (fuscum & rubrum)- Re-Classified -

Stenonema Group

 Clingers  June - July in slower eddies and side currents Rapids & riffles 12 - 16mm 3 long tied at right angles Wide flat 7 streamlined Afternoon Quill Gordon - March Brown - Hares Ear Hares ear wet - Pheasant tail soft hackle - Quill Gordon wet Compara dun - Quill Gordon - March brown #8 #10 Compara spinner   East Branch Cemetery Pool May 24
March Brown - Gray Fox - Ginger Quill Heptageniidae (stenonema vicarium)- Re-Classified - Stenonema Group Clingers May - July Rapids & riffles 14mm - 16mm 3 Wide flat Throughout the day Quill Gordon - March Brown - Hares Ear Hares ear wet - Pheasant tail soft hackle - Quill Gordon wet Compara dun - Quill Gordon - March brown #8-10-12 Compara spinner Beverkill May 10
Light Cahill - Ginger Quill - Cahill Stenonema ithaca & Stenacron interpunctatum canadense - Re-Classified - Stenonema Group Clingers  June - July in slower eddies and side currents Riffles and Runs !0mm-16mm 3 long tied at right angles Wide flat 7 streamlined Afternoon Cahill - Hares-ear Hares-ear wet - Cahill wet #10-12-14 Cahill - compara dun   East Branch Cemetery Pool May 24
Quill Gordon - Iron Dun Epeorus pleuralis Clingers April - June Rapids - Riffles - Swift  Gravelly Runs 6 -10mm 2 Wide flat Behind Obstructions - Water temp 50's Hares ear  - Quill Gordon  Hares Ear Wet - Quill Gordon Wet Quill Gordon - Iron Dun #16-18 East Branch -Amawalk April 12 - West Branch Croton Falls inlet April 24
             
Green Dake Hexagenia now Litobrancha recurvata Burrowers May - July Stream bottoms with soft muddy sandy/gravel bottom 17mm  22mm 3 Streamline Dusk Green Drake Hares ear Green Dake #6-8
Green Drake - Coffin Fly - Shad fly - Shaddie - May Fly - Green Fly Ephemera guttulata Burrowers May - June Stream bottoms with soft muddy sandy/gravel bottom 18 - 30mm 3 Streamline Dusk #6-8
Yellow Drake - Yellow Dun - Cream Variant - White Dun Ephemera varia Burrowers June - August Stream bottoms with soft muddy sandy/gravel bottom 13 16mm 3 Streamline Mid-Day #6-8
             
Golden Drake - Cream Dun - Evening Dun - Cream Variant - Yellow Drake Potamanthus distinctus Crawling - Swimmer June - August Stream bottoms with soft muddy sandy/gravel bottom 13-16mm 3 Streamline Dusk #8-10
             
Brown Stonefly Stonefly (March 5 Amawalk rt. 6 / hb) cr March 10 /  March 20th wbcf inlet size 12 & 20 Large Gravel and rubble 4mm - 12mm 2 Typical 9:00am - 12:00 noon Little brown Stone - Early Black Stone wbcf inlet March 20th size 14 & 20
Black Stonefly Stonefly (March 5 Amawalk RT. 6 / Hollowbrook) March 10 cr size 14-16-20 Large Gravel and rubble 4mm - 12mm 2 Typical 9:00am - 12:00 noon Little brown Stone - Early Black Stone (March 5 Amawalk RT. 6 / Hollowbrook) March 10 Cross river size 14-16-20 / Beverdam March 22 1:00
             
How to use this chart  
start with the month your fishing  
look at the time of day your fishing  
what type of water are you fishing  
look at temerature of the water