Baetis illiesi

General appearance
Body size medium up to about 6mm long (excluding antennae & cerci)
Body spindle-shaped, head without a 'rigid' between antennae (found in Labiobaetis & Alainites)

Head
The details for mouthparts illustrated in the following pictures

Thorax
Hindwing pads present
Villiopore present
All of legs similar, with a large dark brown marks on femora medially; dark marks on tibiae & tarsi distally

Abdomen
Gills I - VII, single, tracheated but poorly seen branched tracheae in young stage
* Terga with spines, but not in triangular shape on posterior margin; Terga II-VIII with submedial pair of brown dashes
Cerci length about less than half of body length

Legs

 

Its mouthparts of labrum, mandibles, maxillae and labium are illustrated as follow (hypopharynx is excluded).

Labrum

Maxillae

Mandibles

Labium

 

Distribution:
In Hong Kong, specimens are recorded from Hatton Road (nr. University of Hong Kong), Shing Mun, Ng Tung Chai, Lam Tsuen River and Tai Po Kau Forest Stream.