6
Adult Key: families
1. In the fore wings the posterior median is forked not far from the origin and the branch M3+4 diverges from M1+2 with a large angle, nearly right, forming a quite ample veinless space and forcing the first cubital to analogue divergence . . . 8
M1+2 M3+4
- In the fore wings the posterior median doesn’t fork in that way . . . . . . .
. 2
2. In the fore wings the main longitudinal veins are reduced and joined in couples, whose tips end fused together; only seven veins, including the costa, get to the wing’s margin, while the crossveins have almost disappeared . . Oligoneuriidae
- In the fore wings the main longitudinal and intercalary veins are normally developed, and at least twenty of them get to the margin . . . . . . . . 3 3. Fore wings held lenghtwise when at rest, ciliate margin, hind wings absent, small size; the body rarely measures more than 4 mm excluding tails, gills are simple . . . Caenidae
Ma 1 Ma 2
Mp 1 Mp 2 Cu 2
- Hind margin of the wings is not cove red with hairs. Hind wings are present, sometimes absent. Segmented claspers. Different sizes . . 4
Cu 1 A1 7
8
4. In the fore wings the two branches of the anterior median (MA) are not forked: proximately MA2 appears clearly separated from MA1. Hind leg tarsi consist of four joints (Baetidae besides may be recognized by having only two tails, hind wings remarkably reduced, less than 1/5 of the fore wings, or absent) . . . Baetidae This important family is immediately recognizable by its two tails, highly reduced or absent hind wings, intercalary veins (one or two) at the wing margin and turbinate eyes in the males.
- In the fore wings the two branches of the anterior median are normally forked. Hind legs’ tarsi consist of 4 or 5 joints . . 5 5. In the fore wings, between the cubital veins, there aren’t important intercalary veins, but from Cu1 arise some arched s- shaped veins (sometimes forked) that end on the hind margin of the wing . . . . . . . Siphlonuridae
Cu 1 The family Siphlonuridae presents only two tails and inhabits still or slowflowing waters and wet zones, also at high altitudes; they prefer environments with rich underwater vegetation.
Cu1
- In the fore wings, between the two cubital veins, there are from 3 to 5 intercalary veins . . . . . 6 6. In the fore wings, between the two cubital veins, there are 4 intercalary veins which form two couples of different lenght; the longer is the proximal one . . . Heptageniidae
l ta le e bi up pl al cu co ou bit st al l c cu fir st ima nd i d ox co pr se
The family Heptgenidae presents moreover only two tails and four wings rich in veins (the hind wings are about a third of the fore wings). Among its five genera, Epeorus, the most specialized, inhabits mountain rapid waters; Ecdyonurus and Rhythrogena mountain but also hill waters, only with pebbly bottom and moderately running water. Heptagenia, live both in torrents at moderate altitudes, and in plain slow- flowing rivers.
9
10
- In the fore wings, between the two cubital veins, there are from 2 to 5 intercalary veins, hind legs claws of four joints . . 7 7. In the fore wings the proximal margin of second cubital (Cu2) is much nearer to the first cubital(Cu1) than to the first anal (A1). Between M3+4 and Cu1 there are some short intercalary veins . . . . . . . Ephemerellidae
Ephemerellidae S. ignita
Leptophlebiidae P. submarginata Both the families present three tails.
- In the fore wings the proximal margin of the second cubital (Cu2) is nearer to the first anal (A1) than to the first cubital (Cu1) or, at least, in the middle between them. Between M3+4 and Cu1 there aren’t intercalary veins. Hind claws of four or five segments (gen. Choroterpes) . . . . . . Leptophlebiidae 8. Subtransparent, almost opaque, waxen, whitish and translucid wings. Weak, membranous and involute legs, except for the fore legs of the male, the imago of the male presents two long tails and the middle tail shorter than claspers, whereas the female has three tails . . . . . . Polymitarcyidae
Above: in evidence tails, middle tail and claspers of E. virgo male imago. The involute and weak hind legs are quite visible. The short tail of the male, normally developed in the female, is the most clear character to determine exactly this monospecific family. Here on the right: the three female tails are visible in more than one insect in this picture taken during a hatch on the Verzère (France, August 2005). 11
12
- Transparent, colourless or spotted wings, sometimes with yellowish colour. Normally developed legs . . . . 9 9. Three articled claspers
.
.
.
Potamanthidae
Potamanthus luteus: three articled claspers (foto tratta da “Moscas para la Pesca� publ. Everest S. A. 1987; for has been impossible to get in touch with the editor, we will pay eventual copyrights on request). In the section about genera you will find the photographs of both male and female subimago.
- Claspers of four segments
.
.
Ephemeridae
Key to preimaginal stages: families 1. Remarkable prominent mandibular processes, anteriorly projecting over the head, beyond the front margin of the fore labium. Tracheal branches consisting of two long and thin plates, fringed along the margins. . . . . . . 8 - Not prominent mandibles, as above, tracheal branches not as above. . . . . . . . 2 2. Head remarkably flattened with parietal and frontal areas expanded in frontal and lateral plates covering the buccal organs. Eyes in clear dorsal position. . . . 3 - Head slightly flattened or not at all, without lateral laminar structures. Eyes in lateral or latero-dorsal position. . 4 3. Head is mostly longitudinal extended. Maxillae are provided with abundant tracheobranchial filaments. . . . . . . . Oligoneuriidae
.
13
14
- Maxillae lack tracheal branches. Head: broader than long . . . . . . Heptageniidae
.
4. Fringed tails, but only on the internal side
.
.
5
- Fringed or hairy tails on both sides
.
.
6
5. The posterior angles of ninth dorsal tergum are extended in spinous lateral processes, caudally turned (see also the key to the genera) . . . . . . Siphlonuridae
Spinous processes turned backwards.
Only one italian species: Siphlonurus lacustris. Tracheal branches consisting of well developed gills (the first 2 are double, the others simple). Tails shorter than body, fringed on the internal side, middle tail fringed on both sides.
- Ninth dorsal tergum not extended in processes at hind angles . . . . . . Baetidae
.
6. Seven pairs of abdominal gills. . . . .
.
. . . Leptophlebiidae
15
16
- Five or six pairs of abdominal gills.
.
.
.
7
7. Segments 1- 6 bearing six pairs of tracheal gills: the first pair is rudimentary, the second one is extended in two rectangular plates covering the succeeding gills. . . . . . . . Caenidae
- Segments 3- 7 bearing five pairs of gills(four are visible dorsally over the abdomen) joined latero-dorsally on the hind margin, consisting of a plate which protects two series of respiratory lamellae. . . . . . Ephemerellidae