Skip to main content

Ralph Holzenthal caddisfly (Rhyacophila lignumvallis) from Corsica in Rhyacophila tristis (Schmid 1970) group

Dlium Ralph Holzenthal caddisfly (Rhyacophila lignumvallis) from Corsica in Rhyacophila tristis (Schmid 1970) group

NEWS - Ralph Holzenthal caddisfly (Rhyacophila lignumvallis Graf & Rázuri-Gonzales, sp. nov.) from the island of Corsica (France) was established as a new species in the Rhyacophila tristis (Schmid 1970) group based on morphological analysis and the mitochondrial cytochrome c oxidase subunit I (mtCOI), including sequences from 16 of the 28 species in the group.

Rhyacophila Pictet 1834 with 814 living and 30 fossil species is the largest genus of caddisflies in the world, distributed mainly in the northern hemisphere, but also in temperate and tropical India and Southeast Asia. One of the groups is the R. tristis group in the branch Rhyacophila invaria.

R. lignumvallis is most similar to Rhyacophila pubescens Pictet 1834, Rhyacophila tsurakiana Malicky 1984, Rhyacophila ligurica Oláh & Vinçon 2021, Rhyacophila harmasa Oláh & Vinçon 2021 and Rhyacophila abruzzica Oláh & Vinçon 2021. However, R. lignumvallis differs in the shape of the X tergum, the dorsal arm of the phallic apparatus in lateral and ventral views, the shape of the aedeagus and parameres, and the second segment of the inferior appendage.

The dorsal surface of the X segment is convex in all these species but narrower and taller in R. lignumvallis, R. tsurakiana, and R. harmasa. However, in dorsal view, R. lignumvallis has a slightly membranous, mesal-notched, and bulging X segment, whereas the X segment in R. tsurakiana appears flatter. In addition, the dorsal branch of the X tergum is rounded and wider in R. lignumvallis, whereas it is narrower in R. tsurakiana and R. harmasa.

The dorsal appendage of the phallic apparatus in R. lignumvallis is longer than the aedeagus and its parameres. This is also the case in R. harmasa, R. ligurica, R. pubescens, and R. tsurakiana but not in R. abruzzica. However, the shape of the dorsal appendage in lateral view in the new species is digitate and slightly curved dorsad, whereas R. harmasa has a slightly wider apical half, R. ligurica has a low protuberance on the mesal part of its dorsal surface, and R. tsurakiana has a straight and flat dorsal appendage.

In R. abruzzica, the dorsal appendix is broad and widens medially in lateral view. Compared with R. lignumvallis, R. tsurakiana, and R. abruzzica, the dorsal appendage of the phallic apparatus is much longer and clearly exceeds segment X in dorsal view in R. harmasa, R. pubescens, and R. ligurica. In ventral view, the dorsal appendage is straight and rounded apically in R. lignumvallis, slightly inflated apically and rounded apically in R. harmasa, nearly straight and truncated apically in R. ligurica, tapering basally and truncated apically in R. tsurakiana, and rectangular in R. abruzzica.

The aedeagus and parameres of R. lignumvallis are most similar to those of R. pubescens. However, in lateral view, the tip of the aedeagus in the new species is more slender and slightly more curved apically than that of R. pubescens. In lateral view, the parameres of the new species are broader than those of R. pubescens. In ventral view, the parameres of the new species are club-shaped and curved, whereas in R. pubescens, the parameres are digitate and directed posterad. The second segment of the inferior appendix in the new species is triangular, with a straight dorsal margin, whereas all other species have a concave dorsal margin.

DESCRIPTION

Adult male. Specimen in ethanol, mostly denuded; dorsally brown, ventrally light brown. Legs light brown with slightly darker tibial spurs. Head with frontal setal wart triangular; antennal setal wart subtriangular and smaller than frontal setal wart; posterior setal warts oval and connected to ocellar setal warts via a raised cuticular “bridge”. Forewing length (8.8 mm, N = 1) mostly denuded, with sparse, very short light brown setae and golden brown microtrichia. Hind wings also mostly denuded, with slightly longer light brown setae. Forewing with crossveins connecting costal (C) and subcostal (Sc) veins; subcostal (Sc) and first radial (R1) veins, first (R1) and second radial (R2) veins (r), fifth radial (R5) and first medial (M) veins (r-m), first medial (M) and first cubital (Cu1) veins (m-cu), and first cubital (Cu1) and second cubital (Cu2) veins. Hind wing with crossveins connecting subcostal (Sc) and first radial (R1) veins, fifth radial (R5) and first medial (M) veins (r-m), and M3+4 and first cubital (Cu1) present.

Male genitalia. Segment IX longitudinally short in lateral view, anterior and posterior margins slightly concave, dorsal half slightly longer than ventral. Dorsal surface of segment X membranous, slightly inflated, shallowly notched mesally in dorsal view. Dorsal branch of segment X short and rounded in lateral view. Anal sclerites partially fused to each other basally and to segment X, in lateral view, directed ventrad. First article of inferior appendages rectangular in lateral view, slightly broader basally than apically; in ventral view, slightly broader apically than basally, with a small setose bump basally on mesal surface. Second article of inferior appendages quadrangular in lateral view, dorsal and ventral margins slightly diverging, posterodorsal margin straight, at a 130° angle to dorsal margin; in ventral view, mitton-shaped, mesal margin with very short, peg-like setae basally and longer setae apically. Phallic apparatus with dorsal appendix straight in lateral view, slightly curved dorsad, rounded apically, longer than parameres and aedeagus; in ventral view, straight, lateral margins slightly sinuous, rounded apically. Parameres in lateral view broader than aedeagus, slightly curved posterodorsad, ventral margin straight, dorsal margin slightly sinuous, rounded apically; in ventral view, club-shaped, directed mesad. Aedeagus in lateral view slender, slightly sinuous, tapering towards its apex; in ventral view, slender and straight.

Original research

Rázuri-Gonzales E, Graf W, Heckenhauer J, Schneider JV, Pauls SU (2024). A new species of Rhyacophila Pictet, 1834 (Trichoptera, Rhyacophilidae) from Corsica with the genomic characterization of the holotype. ZooKeys 1218: 295-314, DOI:10.3897/zookeys.1218.132275

Dlium theDlium
Labels:

Popular posts from this blog

Humpback whales (Megaptera novaeangliae) manufacture bubble-nets as tools to increase prey intake

NEWS - Humpback whales ( Megaptera novaeangliae ) create bubble net tools while foraging, consisting of internal tangential rings, and actively control the number of rings, their size, depth and horizontal spacing between the surrounding bubbles. These structural elements of the net increase prey intake sevenfold. Researchers have known that humpback whales create “bubble nets” for hunting, but the new report shows that the animals also manipulate them in a variety of ways to maximize catches. The behavior places humpbacks among the rare animals that make and use their own tools. “Many animals use tools to help them find food, but very few actually make or modify these tools themselves,” said Lars Bejder, director of the Marine Mammal Research Program (MMRP), University of Hawaii at Manoa. “Humpback whales in southeast Alaska create elaborate bubble nets to catch krill. They skillfully blow bubbles in patterns that form a web with internal rings. They actively control details such ...
Read more

Lolot (Piper sarmentosum)

Lolot pepper ( Piper sarmentosum ) is a species of plant in Piperaceae, perennial herb, erect or lodging, creeping rhizome, up to 120 cm long, branched, enlarged branches, cylindrical stems, brown or green, often grooved, growing on the forest floor and shade. P. sarmentosum has leaf stalks up to 15 cm long, up to 13 cm wide, green, alternately arranged, heart-shaped, pointed tips and flat margins. The leaves have 5 main veins from the base of the blade, linear and slightly curved to the tip, glands on the upper surface and many fine pinnate veins. The upper side is shiny green, the lower side is pale green. The flowers are white. The fruit grows in the upper armpit of the leaf, is slightly oval and green. The leaves are used as a medicine for asthma, malaria, stomach ache, tinea versicolor, toothache, difficulty urinating, aches and pains, maintaining stamina, antibacterial, antimicrobial, antioxidant, and so on. TAXON Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiosperma...
Read more

Cogon grass (Imperata cylindrica)

Cogon grass ( Imperata cylindrica ) is a species of plant in the Poaceae, an annual grass, sharp leaves, long and scaly shoots, creeping underground, white or purplish flowers, very adaptive and grows in all climates. I. cylindrica has sharply pointed shoot tips that emerge from the ground, up to 3 meters high, short stems, rising above the ground surface. Leaves are long ribbon-shaped, pointed tip, narrow base, up to 100 cm long, very rough and sharply serrated edges, long hairs at the base and wide veins. Inflorescences in panicles, up to 28 cm long, spikes long-haired and white to 1 cm. The seeds spread quickly with the wind or via rhizomes that quickly penetrate the soil. This species grows in tropical to subtropical areas, elevation up to 2000 meters, temperature 20-40C, rainfall 500-3500 mm/year, pH 4-7.5, lots of sunlight to a bit of shade. This plant dominates open land, former forests, dry rice fields, roadsides and so on. This plant contains mannitol, glucose, sacharose...
Read more