Origin of the transition from aquatic to terrestrial habits in Nothopsyche caddisflies (Trichoptera: Limnephilidae) based on molecular phylogeny

The larvae and pupae of most caddisflies (Trichoptera) are aquatic, whereas the adults are terrestrial. However, the trichopteran genus Nothopsyche includes species with terrestrial pre-pupal and pupal stages and with an entirely terrestrial life cycle. The phylogenetic relationships within this genus, inferred from sequences of mitochondrial 16S and nuclear 18S ribosomal RNA genes, suggest that Nothopsyche species were originally aquatic and that a single lineage acquired tolerance to terrestrial habitats at the pre-pupal and pupal stages. In this lineage, N. montivaga became completely terrestrial. In addition, the larval case materials changed from plant matter to sand at one point in the phylogeny of this genus.     

Chaetopterygopsis siveci sp.n. from Greece (Trichoptera,Limnephilidae)

Chaetopterygopsis siveci from near the Katara pass, Greece, is described and illustrated.     

Chaetopteryx marinkovicae sp.n. (Trichoptera,Limnephilidae) from Istria,Yugoslavia

Chaetopteryx marinkovicae of the rugulosa‐group from Yugoslavia (Istria) is described and illustrated.     

Structures on the antennal flagellum of a caddisfly,frenesia missa (Trichoptera,Limnephilidae)

Non-innervated macrotrichia and microtrichia, thick-walled chemoreceptors and three kinds of thin-walled chemoreceptors are present on the antennal flagellum of Frenesia missa. One of the thin-walled receptors, the plate organ, is of a type not previously recorded for any insect. About four times as many plate organs are present on the flagellum of the male as on that of the female. They occur also on the maxillary and labial palps.     

The first European Apataniana (Trichoptera,Limnephilidae): Apataniana hellenica sp.n,from Greece

Apatanian hellenica sp.u., the first European representative of this genus, is described from Greece.     

A molecular phylogeny of Planorboidea (Gastropoda, Pulmonata): insights from enhanced taxon sampling

Planorbid gastropods are the most diverse group of limnic pulmonates, with both discoidal and highspired taxa. Phylogenetic relationships among these genera are confused and controversial. In particular, the monophyly of the limpet‐like taxa (traditionally Ancylidae) is disputed. Even recent molecular studies have concluded that substantially more work is necessary to solve the remaining issues concerning intergeneric phylogenetic relationships and higher taxa systematics. Planorbid snails are of great significance for humans as several members of this group are intermediate hosts of blood flukes (schistosomes) causing a chronic disease, schistosomiasis. We used the two independent molecular markers COI and 18S (concatenated dataset of 2837 nucleotide bp) to infer phylogenetic relationships of 26 genera (27 species) of Planorboidea, represented mostly by type species from mainly topotypical populations. With the majority of the taxa discussed not having been studied previously, this study attempted to test several hypotheses on planorbid phylogenetic relationships using Bayesian inference techniques. The monophyly of Planorboidea (= ‘Ancyloplanorbidae’) is strongly suggested on the basis of our extensive molecular analysis. Besides a distinct Burnupia clade, two major clades were recovered that correspond to family level taxa (traditional Bulinidae and Planorbidae). Considerable rearrangements of suprageneric taxa are evident from the phylogeny inferred. Therefore, the only clades recognized by current classifications and supported by our analysis are Planorbini and Segmentinini. The present study found that Ancylidae as traditionally understood, i.e. covering most freshwater limpet gastropods, is paraphyletic, as the genera of Burnupia and Protancylus have been shown to lie phylogenetically outside the Ancylini. Chromosome numbers and levels of polyploidy are discussed in the light of the new phylogeny. An earlier theory of shell shape evolution, i.e. that of patelliform taxa being most advanced, was not supported by this study; a limpet‐shaped taxon is most basal within Planorboidea. Although many taxa still remain to be studied, our results will hopefully contribute towards a better understanding of this very important group of freshwater organisms. Some taxonomic implications are discussed.     

Isolation and characterization of microsatellite markers in the caddisfly Drusus discolor (Trichoptera: Limnephilidae)

We describe the development of and amplification conditions for microsatellite primers isolated from the caddisfly Drusus discolor. Eight polymorphic microsatellite loci were developed and screened for variability using 37 individuals from two populations from central Europe. The primers yielded an average of 8.6 alleles per loci. No linkage disequilibrium between loci was detected, while three loci showed deviations from Hardy–Weinberg equilibrium in one of the two tested populations.     

Description of a new species of Wormaldia from Sardinia and a new Drusus species from the Western Balkans (Trichoptera,Philopotamidae, Limnephilidae)

New species are described in the genera Wormaldia (Trichoptera, Philopotamidae) and Drusus (Trichoptera, Limnephilidae, Drusinae). Additionally, the larva of the new species Drusus crenophylax sp. n. is described, and a key provided to larval Drusus species of the bosnicus-group, in which the new species belongs. Observations on the threats to regional freshwater biodiversity and caddisfly endemism are discussed.The new species Wormaldia sarda sp. n. is an endemic of the Tyrrhenian island of Sardinia and differs most conspicuously from its congeners in the shape of segment X, which is trilobate in lateral view. The new species Drusus crenophylax sp. n. is a micro-endemic of the Western Balkans, and increases the endemism rate of Balkan Drusinae to 79% of 39 species. Compared to other Western Balkan Drusus, males of the new species are morphologically most similar to Drusus discophorus Radovanovic and Drusus vernonensis Malicky, but differ in the shape of superior and intermediate appendages. The females of Drusus crenophylax sp. n. are most similar to those of Drusus vernonensis, but differ distinctly in the outline of segment X. Larvae of Drusus crenophylax sp. n. exhibit toothless mandibles, indicating a scraping grazing-feeding ecology.     

Revision and synopsis of the caddisfly genus Dicosmoecus (Trichoptera: Limnephilidae; Dicosmoecinae)

Six species of Dicosmoecus are recognized: the palatus species group of Siberia and Japan [palatus (McL.), obscuripennis Banks, and jozankeanus Mats.)]; and the atripes species group of western montane North America [atripes (Hagen), gilvipes (Hagen), and pallicornis Banks]. D. obscuripennis is re‐established as a valid species distinct from palalus and recorded from the Yukon Territory and Alaska, and also Siberia. Keys are provided for identification of males, females, and larvae. Hypotheses of phylogeny and biogeography are proposed, stating that the palatus and atripes species groups evolved independently in Asia and North America respectively; and that obscuripennis of the palatus group extended its range to North America during the Pleistocene Beringian land connection between the two continents.

Data on food, life cycle, habitat, and distribution are given for the North American species. Most Dicosmoecus appear to be generalized predator‐shredders with robust, toothed mandibles; but fifth instar larvae of D. gilvipes feed mainly by scraping rocks for diatoms, a behaviour which is evidently responsible for eroding the slender blade and weakly formed teeth of the mandible, unique to this species, to a uniform scraping edge. D. gilvipes is further distinctive in usually having a 1‐year life cycle, whereas atripes and the other North American species usually have a life cycle of 2 years.     

The response of Melampophylax mucoreus (Hagen) (Trichoptera: Limnephilidae) to rapid sedimentation

The larvae of Melampophylax mucoreus were buried with either 5 mm or 10 mm of four sediment size classes and their response recorded. The majority of individuals (63.8%) were able to extract themselves from the sediment within the 900 second (15 minute) experimental period. Body length was significantly greater in those larvae which excavated themselves compared to those that did not. Sedimentation/burial with finer sediment size classes to a greater depth significantly increased the escape time of larvae. The results are discussed in relation to the impact of sedimentation on larval trichopterans and other benthic organisms.     

Ten polymorphic microsatellite loci isolated from the alpine caddisfly Allogamus uncatus Brauer (Trichoptera: Limnephilidae)

Here we report the development of 10 microsatellite loci for the alpine caddisfly, Allogamus uncatus. Polymorphism as detected in 24 individuals ranged from three to 17 alleles per locus, and observed heterozygosity ranged from 0.087 to 0.864. These primers will enable research on the genetic population structure of this species, the extent of gene flow among alpine permanent and temporary streams, and the genetic consequences of extinction/recolonization events.     

The life cycle and larval growth of Drusus annulatus Stephens (Trichoptera: Limnephilidae) in a mountain stream

The life cycle of Drusus annulatus in a stream in the Brecon Beacons is described, and compared with its life cycle in watercress beds, with particular reference to larval growth.     

The role of phylogeny and ecology in experimental host specificity: insights from a eugregarine-host system

The degree to which parasites use hosts is fundamental to host-parasite coevolution studies, yet difficult to assess and interpret in an evolutionary manner. Previous assessments of parasitism in eugregarine-host systems suggest high degrees of host specificity to particular host stages and host species; however, rarely have the evolutionary constraints on host specificity been studied experimentally. A series of experimental infections were conducted to determine the extent of host stadium specificity (larval vs. adult stage) and host specificity among 6 tenebrionid host species and 5 eugregarine parasite species. Eugregarines from all host species infected both the larva and adult stages of the host, and each parasite taxa colonized several host species (Tribolium spp. and Palorus subdepressus). Parasite infection patterns were not congruent with host phylogeny, suggesting that host phylogeny is not a significant predictor of host-parasite interactions in this system. However, the 2 host stages produced significantly different numbers of parasite propagules, indicating that ecological factors may be important determinants of host specificity in this host-parasite system. While field infections reflect extant natural infection patterns of parasites, experimental infections can demonstrate potential host-parasite interactions, which aids in identifying factors that may be significant in shaping future host-parasite interactions.     

The identification of British limnephilid larvae (Trichoptera: Limnephilidae) which have single-filament gills

SUMMARY. Keys are provided to identify those British limnephilid larvae which are characterized by having gill sites occupied solely by single filaments at the final instar. Most species can be identified at the final instar but many species can also be identified at the earlier instars. A key is also supplied to distinguish the early instar larvae as a group from other limnephilid larvae. Brief notes on distribution and habitat are given. The species identified at least at the final instar are:- Apatania wallengreni, A. auricula, A. muliebris, Drusus annulatus, Ecclisopteryx guttulata, Potamophylax latipennis, P. cingulatus, P. rotundipennis, Melampophylax mucoreus, Allogamus auricollis, Hydatophylax infumatus, Chaetopteryx villosa . It was not possible to segregate Halesus radiatus from H. digitatus, Stenophylax permistus from S. vibex , or S. lateralis from S. sequax .     

Questions of molecular evolution of pheromone communication in caddisflies and lower moths (Insecta: Trichoptera,Lepidoptera)

Recent GS-MS and GC-EAD studies of pheromone production and perception in caddisflies and lower moths have shown that these insects use a rather limited selection of volatiles as attractants. Most of them are alcohols and ketones, although the diversity of chemicals produced by sternal glands of abdominal segment V is much wider, especially in the lower Trichoptera. Sternal pheromone glands produce only short-chain polymers in all Amphiesmenoptera. These glands are part of the ground-plan for the related orders, Trichoptera and Lepidoptera, occurring in both sexes and producing similar but not identical sets of components in males and females. The presence of pheromone volatiles is shown to be restricted to the gland segments (Fig. 1), although some other shortchain polymers do occur in the head of females of Molanna angustata (Molannidae). The pheromone blends of lower Trichoptera (Glossosomatidae, Rhyacophilidae, and Philopotamidae) are multi-component and resemble plant volatiles in composition. A hypothesis of the origin of pheromone communication is proposed postulating basic resemblance of early pheromones and plant volatiles in variety and chemical composition. These pheromones were detected by non-specialized receptors of the amphiesmenopteran ancestor and served as guides for insect aggregation on plants as well as on shores of reservoirs, marking the places suitable for a wide variety of species. The primary aggregation function of pheromones was changed in more advanced communication systems to the species-specific signaling with sex-related asymmetry of signals, although the aggregation significance persisted in some species. Pheromone communication has disappeared in some most advanced lineages (e.g., Leptoceridae) with parallel reduction of glands, secretion, and antennal receptors. The pheromone composition does not show gradual divergent evolution in related species; instead, abrupt transformation of pheromone blends with persistence of major components in remote families seems to be the typical case.     

The life history of Glyphopsyche irrorata (Trichoptera, Limnephilidae): A caddisfly that overwinters as an adult

Glyphopsyche irrorata has adapted to live in ponds with fluctuating water levels and ponds exhibiting winter drought by passing the winter as an adult in the terrestrial environment.
Larvae, which hatch in May and pupate in late August, are detritivorous shredders. Males and females emerge in September, with a sex ratio of one and commence mating in the autumn. The entire population has mated by May at which time females oviposit in the water. Adult males and females are present in equal numbers in the spring and have similar longevities approaching a maximum of 8 to 9 months.     

Morphological vs. molecular evolution: ecology and phylogeny both shape the mandible of rodents

What actually is the expected pattern relating to molecular and morphological divergence? A phylogenetic correlation is expected; however, natural selection may force morphological evolution away from this expected correlation. To assess this relationship and the way it is modulated by selection, we investigated the radiation of the murine rodents, also called as Old World rats and mice. Regarding their diet, they are diversified as they include many omnivorous as well as specialist taxa. The size and shape of the mandible, a morphological character involved in the feeding process, was quantified and compared with an estimate of molecular divergence based on interphotoreceptor retinoid binding protein (IRBP) sequences. Size and shape of the mandible appeared to be related by an allometric relationship whatever the ecology of the taxa. Small size characterizes most murines, causing a dominance of low size distances; still, the frequency of important size differentiation increases with molecular distances. Regarding shape changes, the pattern is much contrasted between omnivores and specialists. A pattern of phenotypic drift characterizes the mandible evolution of taxa sharing an omnivorous diet. Little saturation occurs over more than 10 million years with regard to the shape of the mandible that appears as a valuable marker of phylogenetic history in this context. In contrast, important morphological distances can occur when specialist taxa are involved, even when the molecular divergence is small. Ecological specialization thus triggers an uncoupling of molecular and phenotypic evolution, and the departure from a phenotypic drift pattern.