Research Article |
Corresponding author: Johann Waringer ( johann.waringer@univie.ac.at ) Academic editor: Ralph Holzenthal
© 2016 Johann Waringer, Hans Malicky.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Waringer J, Malicky H (2016) The larvae of the European species of genus Apataniana Mosely, 1936 (Trichoptera, Apataniidae): descriptions, key and ecology. ZooKeys 586: 121-134. https://doi.org/10.3897/zookeys.586.7758
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This paper describes the previously unknown or insufficiently known larvae of Apataniana hellenica, Apataniana stropones and Apataniana vardusia. Species association was enabled by the fact that the three micro-endemic Apataniana larvae are restricted to Greece and the only Apataniidae species recorded in European ecoregion 6 (Hellenic Western Balkan;
Description, distribution, larvae, identification, ecology
In Europe, the genus Apataniana was unknown until 1987 when Malicky discovered a large number of unknown Apataniidae larvae in a small stream at 1200 m a.s.l. in the Ossa mountains at the southern side of the Olymp massif; at the same location, a number of adults were caught in light traps and described as A. hellenica. The second new species was A. vardusia from a small stream above the tree line at 1750 m above sea level in the Vardusia mountains in Central Greece (
The larval material was sampled by Hans Malicky at the following locations and dates: Apataniana hellenica Malicky, 1987: Ossa mountains, ‘Apataniana stream’ (22°42'E, 39°50'N, 1200 m a.s.l.) on 28 July1991; Apataniana stropones Malicky, 1993: Euböa, Dirfis mountains near Stropones (23°53'E, 38°36'N, 700–900 m a.s.l.) on 24 May1974 and 5 August 1993; Apataniana vardusia Malicky, 1992: Vardusia mountains above tree line, Central Greece (22°08'E, 38°42'N, 1750 m a.s.l.) on 22 October 1991.
A hand net was used to collect larvae, and light trapping obtained the adult material of the three Apataniana species which also included the holo- and paratypes for the species descriptions (details on the latter are given by
Species association was enabled by the fact that the three European Apataniana larvae are the only Apataniidae species recorded in European ecoregion 6 (Hellenic Western Balkan;
Diagnosis. Setae at anterior edge of pronotum long, tapering and with flexuous tips; setal transversal band at 1st abdominal dorsum continuous; 2nd tarsal claw shorter than half tarsal length; central submentum sides converging.
Biometry. Body length of 5th instar larvae ranging from 4.9 to 5.0 mm, head width from 0.73 to 0.74 mm (n= 3).
Head. Head capsule with dense cover of microspinules, roundish in shape and hypognathous (Figs
Apataniana stropones
12–14 Apataniana stropones
Thorax. Pronotum medium brown, surface densely granulated, posterior margins thickened and darkly striped (Figs
Abdomen. 1st abdominal segment with 1 dorsal and 2 lateral fleshy protuberances densely covered by microspinules. Setal transversal band at 1st abdominal dorsum continuous at center, consisting of 45–60 setae (Fig.
8th abdominal dorsum with 14–18 posterodorsal setae; several posterolateral setae on each half of 9th abdominal dorsum. All gills single filaments. Dorsal gills present at most from 2nd segment (postsegmental position) to 4th segment (postsegmental position). Ventral gills ranging from 2nd (postsegmental) to 6th segment (postsegmental). Lateral gills lacking. Lateral fringe extending from start of 2nd to mid 8th abdominal segment. Dorsal of lateral fringe a small number of forked lamellae is present per segment (as in Figs
19–21 Apataniana hellenica
Light brown sclerite on 9th abdominal segment semicircular, with light muscle attachment spots; with 26–33 setae, 6 long and the remainder short to medium in length (Fig.
Case. Fifth instar larval case 5.4–5.5 mm long (n= 3), curved, tapering posteriorly (width at anterior opening 1.8–2.0 mm and at posterior opening 0.9–1.1 mm), consisting of mineral particles of varying size, sometimes mixed with larger particles attached mostly laterally, thereby creating wing-like structures (Fig.
(all morphological characters identical to those of A. stropones except as noted below). Diagnosis. Setal transversal band at 1st abdominal dorsum interrupted at center; central submentum parallel-sided.
Biometry. Body length of 5th instar larvae ranging from 6.4 to 6.9 mm, head width from 0.76 to 0.83 mm (n= 3).
Head. Head reddish brown with paler, wedge-shaped areas from eyes to mandible bases and around anterior border of head capsule (Fig.
Thorax. Pronotum dark brown. Pentangular prosternite with medium brown transverse band; lateral sclerites indistinct. Mesonotum medium brown, posterolateral corners black (Fig.
Abdomen. Setal transversal band at 1st abdominal dorsum interrupted at center, consisting of 30–40 setae (Fig.
Dorsal gills present at 3rd segment (postsegmental position), ventral gills ranging from 2nd (postsegmental) to 6th segment (postsegmental). Lateral gills lacking.
Case. Fifth instar larval case 8.3_8.7 mm long (n= 3), curved, tapering posteriorly (width at anterior opening 2.5–4.9 mm and at posterior opening 1.5–1.8 mm).
(all morphological characters identical to those of A. stropones except as noted below). Diagnosis. Setal transversal band at 1st abdominal dorsum interrupted at center; 2nd tarsal claw longer than half tarsal length; central submentum parallel-sided.
Biometry. Body length of 5th instar larvae ranging from 4.4 to 5.3 mm, head width from 0.70 to 0.73 mm (n= 3).
Head. Head medium brown (Fig.
Thorax. Pronotal surface medium brown, with pale, small, roundish muscle attachment spots. In addition to dense cover of pale, translucent, tapering setae with flexuous tips 20–30 longer setae present on each pronotal half. Pentangular prosternite pale, with medium brown posterior transverse band; lateral sclerites indistinct. Mesonotum medium brown, posterolateral corners black; near anteromedian corner of this black spot with ear-like porus (Fig.
Abdomen. Setal transversal band at 1st abdominal dorsum interrupted at center, consisting of 30–40 setae (Fig.
Case. Fifth instar larval case 6.3–6.4 mm long (n= 3), curved, tapering posteriorly (width at anterior opening 2.4–2.5 mm and at posterior opening 1.3–1.4 mm).
Larval Apataniidae share the following set of morphological characters (
In the framework of the larval key to European Apataniidae of
Within the trio of Apataniana species, the setal transversal band at 1st abdominal dorsum is interrupted at center in Apataniana vardusia and A. hellenica (Figs
Synopsis of characters separating the currently known European Apataniana larvae (5th instars; Trichoptera: Apataniidae) (
Species/ character | Setal transversal band at 1st abdominal dorsum interrupted at center (Fig. |
2nd tarsal claw shorter than half tarsal length (Fig. |
Submentum almost parallel-sided at mid section (Fig. |
Head width (mm) | Distribution |
---|---|---|---|---|---|
Apataniana vardusia | yes | no | yes | 0.70–0.73 | endemic of Vardusia mountains, Central Greece |
Apataniana hellenica | yes | yes | yes | 0.76–0.83 | endemic of Ossa mountains, Eastern Thessalia, Greece |
Apataniana stropones | no | yes | no | 0.73–0.74 | endemic of Dirfis moutains, Euböa, Greece |
With respect to distribution, Apatania hellenica is an endemic species of the Ossa mountains in Eastern Thessalia, A. stropones is endemic to the Dirfis moutains on the island of Euböa and A. vardusia is an endemic species of the Vardusia mountains in Central Greece. The larvae of the three Apataniana species inhabit small brooklets with low water temperatures (
As in the other known larvae of Apataniidae, the mandibles in the three Greek Apataniana species take the shape of scraper blades and lack terminal teeth along their cutting edges; larvae graze autotrophic biofilm and epilithic algae.
Adults of A. hellenica were found in June and July, but not in May and October; ultimate and penultimate larval instars were collected in May, June, July and October, mature pupae at the end of July. Therefore, the adults are on the wing between June and September, with one generation per year, but the presence of many ultimate instar larvae in October may be an indication that some individuals may need more than one year for their development. The phenology of A. stropones is similar. Only one male was collected at the end of June, but at the onset of August not only high numbers of adults but also mature and immature pupae and many ultimate and penultimate instar larvae were observed. In October no adults were present. In A. vardusia, on the other hand, the adult stage is entered later in the year. At the end of May, many larvae but no adults were found. At the end of October, adults, many fresh egg clutches, many empty cases and some ultimate and penultimate larvae were observed.
The three Greek Apataniana species are confined to extremely small areas. A. vardusia was only found in one spring brook some metres long. A. hellenica and A. stroponesare restricted to a couple of brooklets in distances of several hundred metres. These tiny distribution ranges and the extremely low water temperatures of their habitats earmark the trio of Greek Apataniana species as glacial relics. It would be no surprise to detect some more closely related species in other mountain massifs in Greece.
The three species described above belong to the Apatania bulbosa group (
This paper is part of the outcomes of the project “The Drusinae (Insecta: Trichoptera) in a world of global change“ (project number P23687-B17, PI: J.Waringer) funded by the Austrian Science Fund (FWF).