A simple guide to cranefly larvae (family - level ... - FreshwaterLife

A simple guide to cranefly larvae (family - level determination)
(Richard Chadd, Sept 2006).
1: First-stage separation.
The easy bit -
1 - Spiracular disc (the flat bit with two dark 'holes' in it at the posterior end) with six
lobes around it (Fig. 1)………………………….……..Tipulidae ('True' Craneflies)
- spiracular disc with five or fewer lobes……………………………………………2
2 - Entire body with prominent processes (Fig. 2).…………..Cylindrotomidae
Usually found in stagnant, dystrophic bogs (always in association with aquatic or
semi-aquatic mosses)
- no prominent processes…...Limoniidae & Pediciidae (Short-palped Craneflies)
Fig. 1: Tipulidae (posterior end): numbers refer to spiracular lobes
Fig. 2: Cylindrotomidae (habitus)
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1/2
3/4
5/6

2: Second-stage separation.
The slightly trickier bit -
There are five genera of Pediciidae in Northern Europe: Dicranota, Pedicia,
Tricyphona, Ula and Nasiternella. The latter is not a British species and Ula lives in
fungi. The remaining three have two cylindrical lobes on the anal segment. The
only other genus with this feature is Antocha (formerly Taphrophila), which is a
limoniid, but does not possess any spiracles (two dark 'holes') on the anal
segment (and lives in a silk tube).
So, having used the key above to separate Tipulidae, Cylindrotomidae and
Limoniidae/Pediciidae, separate the latter pair as follows:
1 - two obvious, cylindrical & hairless posterior lobes present (Figs. 3 & 4)……….2
- one posterior lobe (Fig. 5), or apparently 2 flattened lobes, with a thick tuft of
hair (see note* below) or 4 to 5 obvious lobes present (Fig.
6)……………………………………….Limoniidae (except Antocha vitripennis)
2 - spiracles present……………………………Pediciidae (G: Dicranota, Pedicia
and Tricyphona)
- spiracles absent (Fig. 7)………………………Limoniidae (Antocha vitripennis
only). Lives in a silken tube, attached to stones in flowing water
*N.B. Genus: Pilaria (F: Limoniidae) is variable, dependent on the speciesgroup:
P. filata gp. possesses only a single, thick lobe, as in Fig. 5.; P. discicollis gp., on
first sight, seems to have two lobes. On close examination, however, it actually
has 2, well-separated & obvious lobes, plus two additional lobes which are closely
opposed to the bases of the other two & fairly small. The whole lot is swathed in
thick hair, which sticks out as a single tuft in P. filata gp., and as two tufts in
P.discicollis gp. (P. nemoralis gp. is very obviously 4-lobed, with a rudimentary
5 th dorsal lobe).
So, only follow the first part of this couplet (to couplet 2) if you have two obvious,
hairless & cylindrical lobes, as in Figs. 3, 4 and 7. If you have a lot of hair
growing from the lobes, look carefully, and what you think is two lobes is
actually 4, and is therefore a limoniid. The lobes tend to be slightly flattened in
this case.
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Fig. 3: Dicranota sp. (Pediciidae) - 2 lobes, plus 2 spiracles
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Fig. 4: Dicranota sp. (habitus) - 2 lobes plus
2 spiracles

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Fig. 5: Pilaria sp.
(Limoniidae) - Single lobe,
with single hair-tuft. May
also appear to have 2
lobes, but has two smaller
additional lobes. Always
very hairy.
Fig. 6: Eloeophila sp./Hexatoma
sp. (Limoniidae) - 4 lobes, (note 2
spiracles, same position as in
Dicranota & Pedicia)

Fig. 7: Antocha vitripennis - 2 lobes and no spiracles
3: Final thought.
If you obtain specimens of limoniids or pediciids, at least 90% of the time, the genera
you will find will be Dicranota (Pediciidae), Eloeophila (Limoniidae) and Pilaria
(Limoniidae), all of which are illustrated above. If all else fails, just look at the
pictures!
Occasionally, you will get others, such as Pedicia and Hexatoma, but the key above
will allow for these. If you feel like a bit of stimulation (and have an inclination
towards actually producing data for some 'biodiversity' purpose) try using Nilsson or
Brindle to take your specimens to genus level (in some cases, such as Antocha, this
allows a species determinations to be made. Several are Red Data).
Version 3: Sept. 2006