Hesperentomidae, Price, 1960

Galli, Loris, Capurro, Matteo, Colasanto, Elisa, Molyneux, Tony, Murray, Andy, Torti, Carlo & Zinni, Matteo, 2019, A synopsis of the ecology of Protura (Arthropoda: Hexapoda), Revue suisse de Zoologie 126 (2), pp. 155-164 : 156

Key to Acerentomata families

1A Only abdominal appendages I two segmented .........................................................................................................2

1B Abdominal appendages I and II two-segmented ......................................................................................................3

2A Sternite VIII with two anterior and four posterior setae: formula 2/4................................ Hesperentomidae (part)

2B Sternite VIII never with 2/4 setae, normally with four anterior and none or two posterior setae: formula 4/0 or 4/2 ..................................................................................................................................................... Acerentomidae

3A All three pairs of abdominal appendages two-segmented with a terminal vesicle and four setae ..........................4

3B Abdominal appendages I and II two-segmented with a terminal vesicle and three to four setae, appendages III unisegmented without terminal vesicle and with two to three setae .............................................................................5

4A Labial palps with tuft of setae, three distinct setae and basal sensillum; pseudoculi with a large triangular prolongation in the proximal part .......................................................................................... Protentomidae (part)

4B Labial palps with tuft of setae and three distinct setae, but without basal sensillum; pseudoculi pear-like, strongly elevated and with a median S-shaped cleft......................................................................... Hesperentomidae (part)

5A Abdominal sternites II-VI all with an even number of posterior setae (seta Pc always absent) ............................... ............................................................................................................................................ Hesperentomidae (part)

5B An odd number of setae in the posterior row (seta Pc present) of at least one of the abdominal sternites II-VI ....... ................................................................................................................................................ Protentomidae (part)