PA Hatches

Dates are approximate. Cooler or warmer temperatures can alter the times of emergence.

Common Name Scientific Name Date of Emergence Time Size
Little Blue Wing Olive Baetis tricaudatus April 1 Late Morning 16 – 20
Blue Quill P. adoptiva April 18 Late Morning 18
Dark Quill Gordon Ameletus ludens April 18 Afternoon 14
Quill Gordon Epeorus pleuralis April 20 Early Afternoon 14
Hendrickson E. subvaria April 21 Early Afternoon 14
Black Quill Leptophlebia cupida April 25 Early Afternoon 14
Great Speckled Olive Dun Siphloplecton basale April 20 Early Afternoon 14
Little Blue Dun Acentrella carolina May 1 Afternoon/Evening 20
Sulphur Dun E. rotunda May 12 Evening 16
Gray Fox Stenonema fuscum May 15 Afternoon 12-14
Pale Evening Dun E. septenttrionalis May 15 Evening 14-16
Pale Evening Dun Heptagenia aphrodite May 18 Evening 16
March Brown Stenonema vicarium May 18 Morning/Afternoon 12-14
Light Cahill Stenacron interpunctatum May 23 Evening 14
Chocolate Dun E. bicolor May 25 Morning/Afternoon 16
Green Drake E. guttulata May 25 Evening 8-12
Brown Drake E. simulans May 25 Evening 10-12
Light Cahill Stenonema ithaca May 25 Evening 14
Dark Green Drake Litobrancha recurvata May 25 Afternoon/Evening 6-10
Slate Drake Isonychia sadleri May 25 Evening 12
Cream Cahill Stenonema modestum May 25 Evening 14-16
Blue Wing Olive Dun E. drunella comuta May 25 Late Morning 14
Blue Wing Olive Dun E. drunella longicomus May 25 Early Morning 16
Pink Cahill Epeorus vitreus May 25 Evening 14-16
Sulphur Dun E. invana June 1 Evening 16-18
Dark Blue Quill E. seratella deficiens June 1 Evening 16-20
Blue Quill P. mollis June 3 Morning/Afternoon 18
Iron Blue Dun L. johnsoni June 5 Late Morning 16
Little Blue Wing Olive Dun Baetis levitans June 5 Afternoon/Evening 20
Little Blue Wing Olive Dun E. drunella simplex June15 Morning/Afternoon 18-20
Little Blue Wing Olive Dun E. drunella lata June 15 Morning/Afternoon 16
Light Cahill Leucrocuta marginalis June 15 Evening 14
Cream Cahill Stenonema pulchellum June 15 Evening 14-16
Sulphur Dun Ephemerella dorothea June 15 Evening 18
Yellow Drake Ephemera varia June 20 Evening 12
Blue Quill P. guttata June 25 Morning 18
Golden Drake A. distinctus June 25 Evening 12-14
Pale Evening Dun Heptagenia species June 25 Evening 16
Pale Morning Dun Centoptilium July 15 Morning 22
Little White Mayfly Caenis species July 15 Evening 28
Trico Tricorythodes species July 15 Morning 24
Slate Drake Isonychia harpei July 23 Evening 12-14
White Mayfly Ephoron leukon August 15 Evening 14-16
Big Slate Drake Hexagenia atrocaudata August 18 Evening 8
Slate Drake Isonychia bicolor August 25 Afternoon/Evening 14
Little Blue Wing Olive Baetis tricaudatus September 1 Afternoon 16-20
Little Blue Dun Acentrella carolina September 15 Afternoon 20

Caddis and Stoneflies

Little Olive Caddis Hydropsyche bronta April 10 Morning/Afternoon 16
Little Black Caddis Chimarra atterima April 15 Late Morning 18
Grannom Brachycentrus numerosus April 20 Morning/Afternoon 12
Cream Caddis Psilotreta species April 25 Morning/Afternoon 14
Green Caddis Rhyacophila species May 1 Morning/Afternoon 14
Dark Brown Caddis Deplectrona species May 15 Morning/Afternoon 12
Little Black Stonefly Capnia vemalis March 1 Morning/Afternoon 16
Early Brown Stonefly Strophopteryx fasciata April 29 Noon 14
Great Brown Stonefly Phasganophora capitata April 20 Morning/Afternoon 12
Light Stonefly Isoperla signata May 8 Afternoon 14
Spotted Sedge Symphitopsyche slossanae May 23 Afternoon 14
Dark Blue Sedge Psilotreta frontalis June 5 Evening 12
Yellow Sally Isoperla bilineata June 5 Afternoon 14
Little Green Stonefly Alloperla imbecilla June 5 Afternoon 16
Great Stonefly Phasganophora capitata June 5 Afternoon/Evening 10
Great Brown Stonefly Acroneuria lycorius June 15 Morning/Afternoon 12
Green Caddis Rhyacophila species July 10 Morning/Afternoon 14