Chimarra cf. marginata Linnaeus 1767

Bemmoussat-Dekkak, Soumya, Abdellaoui-Hassaine, Karima, Sartori, Michel & Zamora-Muñoz, Carmen, 2021, Contribution to knowledge of the Trichoptera of northwestern Algeria: New species records for the Algerian fauna and taxonomic remarks for the Maghreb fauna, Zootaxa 5068 (2), pp. 186-210 : 191-193

Chimarra cf. marginata Linnaeus 1767

Material examined. Chouly wadi ( CH 0): 15 L, 25.V.2015; 1 ♂ P, 13.v.2017.

Distribution. Chimarra marginata is the only widely distributed species of Chimarra in Europe and the Maghreb ( Neu et al. 2018). Our specimens were collected at 1065 m a.s.l.

Taxonomical Note. The collected larva has all of the diagnostic characters that distinguish genus Chimarra (as C. marginata ) from other genera of philopotamids in European keys ( Edington & Hildrew 1995; Rinne & Wiberg-Larsen 2017; Waringer & Graf 2011): Black ovoid spot posterolaterally on each side of pronotum separate from black posterior margin ( Fig. 3A ); forecoxae each with long process ending in black bristle ( Fig. 3B : a1), and frontoclypeus with deep U-shaped notch asymmetrically on anterior edge ( Fig. 3D : a2). However, when comparing our material with Spanish specimens and of C. margi nata, the Algerian larva has darker brown color on the head and pronotum ( Figs 3A, 3B, 3D ) and a small tooth in the center of the notch ( Fig. 3D : a2) like the la rva of marginata ( Fig. 3E ) illustrated by Rinne & Wiberg-Larsen (2017). The notch on the head of the larva illustrated by Rinne & Wiberg-Larsen (2017) is situated slightly to the left of the midline and in the middle as shown by Edington & Hildrew 1995), however in the Algerian and Spanish specimens, this notch is situated slightly to the right of the midline as shown by Waringer & Graf (2011).

The genitalia of the mature male pupa (or pharate male) are similar to those of European marginata , and only two small variations can be highlighted: (1) the lateral lobes of tergum X are curved inwards ( Fig. 4A : a4) rather than outwards ( Tobias & Tobias 1983) and (2) the posterior margin of each inferior appendage is rounded ( Fig. 4B : b4) instead of angular and with a small tooth ( Tobias & Tobias 1983). The aedeagus has many small spines on the posterior part that can be seen in lateral ( Fig. 4C ), ventral ( Fig. 4D ), and dorsal views ( Fig. 4E ).

Chimarra marginata is a widespread species and, although small variations in the different populations along its distributional range might be expected, it would be interesting to collect more specimens to verify that it is one Chimarra species.

Figures

FIGURE 3. Chimarra marginata (Linnaeus 1767) from Spain and variant from northwestern Algeria. 3A, Habitus of the larva of Chimarra cf. marginata, left lateral. 3B, left forecoxa, trochanter, and femur of Chimarra cf. marginata from northwestern Algeria (a1 = long process ending in black bristle); 3C: forecoxa, trochanter, and femur of Chimarra marginata larva from Spain (a1 = long process ending in a black bristle). 3D, head and pronotum of Chimarra cf. marginata from northwestern Algeria, dorsal (a1 = membranous labrum, a2 = tooth in excision of anterior margin of frontoclypeus); 3E, head and pronotum of Chimarra marginata from Spain, dorsal. Scale bars = 1 mm.

FIGURE 4. Chimarra cf. marginata (Linnaeus 1767) from northwestern Algeria, male genitalia. 4A, tergum X, ventral (a4 = lateral lobes). 4B, inferior appendages, ventral (b4 = posterior margin of inferior appendages). 4C–4E, distal end of aedeagus: 4C, left lateral; 4D, ventral; 4E, dorsal. Scale bars = 0.25 mm.