Baetiella trispinata
General appearance
Body size medium-small up to about 5mm long (excluding antennae & cerci)
Body color yellow
brown; thoracic nota with some brown markings and tubercules
Body shape dorso-ventral flattened
Head
The details for mouthparts
illustrated in the following pictures
Thorax
Pro- and mesonotum with numerous small tubercules
dorsally; metanotum with a single large tubercule medially
Mesonotum with two longitudinal narrow pale stripes next to midline (shown in mature larvae only)
Hindwing pads reduced
Femora with long dense bristles dorsally;
a single row of setae on hind femora and tibiae dorsally (cf. two rows in Labiobaetis vera)
The details for each leg illustrated in the following pictures
Abdomen
Gills I - VII single without serrate margins and untracheated
Posterior margins of terga I - III with single median dorsal tubercle, but paired dorsal tubercules on
terga IV - IX
Central filament is greatly reduced to give a two-tailed impression; cerci length longer than body length by 1.3 times.
Legs |
The mouthparts of labrum, mandibles, maxillae and labium are illustrated as follow (hypopharynx is excluded).
Labrum |
Mandibles |
Maxillae |
Labium |
Distribution:
Widespread in Hong Kong, specimens are recorded from Tai Po Kau Forest Stream, Lam Tsuen River, Ng Tung Chai, Shing Mun, Pui O and Shek Mun Lap (Lantau Island).
Reference:
Tong, X. & Dudgeon, D. (2000) Baetiella (Ephemeroptera, Baetidae) in Hong Kong, with descriptions of a new species. Entomological News 111: 143-148.