A key to larvae and pupae of Sericostoma personatum (Spence) and Notidobia ciliaris (Linné) (Sericostomatidae : Trichoptera) in Britain

SUMMARY. Certain larvae and pupae have been identified as Notidobia ciliaris (Linné) by rearing field-collected larvae to the adult stage and by rearing larvae from eggs laid by a female in captivity. The larvae differ in many important respects from larvae of this species described by earlier workers. Characters are provided to distinguish these larvae and their associated pupae from those of Sericostoma personatum (Spence). The habitat and distribution of both species in Britain is outlined.     

A revised key to larvae of the genus Plectrocnemia (Polycentropodidae: Trichoptera) in Britain, with notes on Plectrocnemia brevis McLachlan

SUMMARY. The key distinguishes the previously unknown larva of Plectrocnemia brevis McLachlan from larvae of the other two British Plectrocnemia species, P. conspersa (Curtis) and P. geniculata McLachlan. Notes are given on the larval habitat, life cycle and identification of the adult of P. brevis.     

A new species of Amphoropsyche (Trichoptera, Leptoceridae) from Ecuador, with a key to the species in the genus

A new species of Amphoropsyche Holzenthal is described from Ecuador. It is similar to a group of species with dorsomesal processes on the preanal appendages (i.e., Amphoropsyche woodruffi Flint & Sykora, Amphoropsyche refugia Holzenthal, and Amphoropsyche aragua Holzenthal), but can be distinguished from these and other members of the genus by the short, digitate dorsomesal processes on the preanal appendages and the broad lateral processes of tergum X of the male genitalia. A key to males of the 14 species now known in the genus is presented based on characters of the genitalia.     

Wing-scales of Pseudoleptocerus chirindensis Kimmins (Trichoptera: Leptoceridae)

The African species Pseudoleptocerus chirindensis belongs to a small group of Trichoptera most unusual in having scaly wings. Electron microscope studies reveal 13 structurally distinct kinds of cuticular process on the wings, including several types of squamiform and hair-like macrotrichia. These are described in detail and their possible functions inferred. The optical properties of the scales forming the colour pattern of the forewings are related to ultrastructural elements including diffraction and thin film interference systems. Trirhopteran scale structure is compared with that of the Lepidoptera, the sister-group in the Amphiesmenoptera. Differences are found and it is tentatively concluded that wing-scales have evolved independently in the two orders.     

A new lotic species of the genus Leptocerus Leach (Trichoptera, Leptoceridae) from Japan

A new lotic species of leptocerid caddisfly, Leptocerus fluminalis sp. nov., is described based on adult and immature stages from Japan. The habitat and gut contents of this species are noted.     

A new classification of the long-horned caddisflies (Trichoptera: Leptoceridae) based on molecular data

Background  

Leptoceridae are among the three largest families of Trichoptera (caddisflies). The current classification is founded on a phylogenetic work from the 1980's, based on morphological characters from adult males, i.e. wing venation, tibial spur formula and genital morphology. In order to get a new opinion about the relationships within the family, we undertook a molecular study of the family based on sequences from five genes, mitochondrial COI and the four nuclear genes CAD, EF-1α, IDH and POL.     

Sexual dimorphism in relation to swarming and pair formation patterns in leptocerid caddisflies (Trichoptera: Leptoceridae)

North European Leptoceridae (Trichoptera) perform three types of swarming flight patterns: (1) swarming males of Athripsodesand Ceracleafly in horizontal zigzag patterns over the water surface, (2) the Mystacidesspp. perform vertical zigzag movements, and (3) the flight of males of Triaenodes unanimisMcLach. is a mixture of the horizontal and vertical zigzagging. Also three groups of pair formation behavior can be distinguished. In the first group, of Athripsodesand Ceraclea,the females fly into the male swarms, where they are grasped and carried to the riparian vegetation by the flying males with the females hanging upside-down in genitalia coupling. In the second group, a Mystacidesfemale is caught by a male, when approaching a swarm and both use their wings to fly in tandem to the shore where they copulate. In the third group, of Triaenodes bicolor(Curt.) and Oecetis lacustris(Curt.), the males fly searching for females sitting on aquatic plants and when a female is found the male lands and they copulate immediately while clinging to the plant. The different swarming and mating behaviors might have favored selection for three types of sexual dimorphism: (1) longer forewings in males than females in species which fly in copula, (2) larger eyes in males of the vertically zigzagging species, and (3) much smaller males in the group where males search for females sitting on aquatic plants. In the second group approaching females are detected by males before reaching the swarm and in the third group the female almost always mates with the male which is the first to find her. In conclusion, we suggest that females of Athripsodesand Ceracleahave a greater choice among swarming males than do females of Mystacides, T. bicolor,and O. Lacustris.     

The larva of Oecetis tripunctata (Fabricius, 1793) (Trichoptera,Leptoceridae)

Oecetistripunctata is a widely distributed leptocerid in Europe, ranging from the Iberian and Apennine peninsulas and the Central and Western European highlands to the plains of Eastern Europe. The long, single-bladed mandibles are indicative for a predacious lifestyle. This paper describes the previously unknown larva of Oecetistripunctata. Information on the morphology of the 5th larval instar is given, and the most important diagnostic features are illustrated. A synoptic key for the European species of Oecetis is also provided. In the context of existing identification keys the larva of Oecetistripunctata keys together with Oecetisintima and Oecetisnotata. Oecetistripunctata is separated from the other two species by the fact that a double row of long setal fringes is lacking at the hind tibiae and that several long setae are present on the protrochantinus.     

Male Age,Copulation Duration and Insemination Success in Mystacides azurea (Leptoceridae,Trichoptera)

Time in copula in the swarming caddis fly Mystacides azurea L. (Trichoptera: Leptoceridae) ranged from 0.33 to 44.5 min. It increased with male age (wing wear) and male dry weight, but was independent of male and female size (forewing length), female wing wear and number of eggs in the females. Older males failed to transfer sperm during copulation more frequently than did younger ones. It is suggested that females benefit by interrupting prolonged copulations if sperm is not transferred rapidly, since being in copula might increase the risk of predation. Alternatively, young and old males follow different mating tactics; old males have a lower chance to acquire new mates and they do better by monopolizing a female, once they get one, by prolonging the copulation.