New species of Plectrocnemia and Nyctiophylax (Trichoptera, Polycentropodidae) from China

Four new species of genus Plectrocnemia and 4 new species of genus Nyctiophylax are described, namely: Plectrocnemia verticalissp. n.; Plectrocnemia acuminatasp. n.; Plectrocnemia cryptoparameresp. n.; Plectrocnemia qianshanensissp. n.; Nyctiophylax (Nyctiophylax) senticosussp. n.; Nyctiophylax (Paranyctiophylax) gracilissp. n.; Nyctiophylax (Paranyctiophylax) pungenssp. n.; and Nyctiophylax (Paranyctiophylax) auriculatussp. n.     

Two New Species of the Genus Plectrocnemia Stephens (Trichoptera: Polycentropodidae) from the Russian Far East

Two new species of the genus Plectrocnemia Stephens, Plectrocnemia levanidovae, sp. n., from Sakhalin Island and the southern Kuril Islands, and Plectrocnemia martynovae, sp. n., from southern Primorye, are described and illustrated. The new species belong to the P. tortosa Group and are the sister species of P. tortosa Banks, from China, and P. appensata Mey, from Vietnam.     

A New Species of Plectrocnemia from Sicily (Trichoptera,Polycentropodidae)

Plectrocnemia alicatai sp.n. from Sicily (Nebrodi Mountains) is described and figured from the adult male.     

Location of copper in larvae of Plectrocnemia conspersa (Curtis) (Trichoptera) exposed to elevated metal concentrations in a mine drainage stream

Using histological techniques together with transmission electron microscopy and X-ray microanalysis, copper-containing granules (which also contain significant amounts of sulphur) have been observed in the cells of the malpighian tubules and in the subcuticular region of larvae of Plectrocnemia conspersa. It is suggested that the granules in both these regions are primarily pigment granules, which provide a mechanism for taking potentially toxic concentrations of copper (and possibly other metals) out of circulation. This mechanism of metal tolerance may in part account for the reported occurrence of larvae of P. conspersa in waters with elevated concentrations of trace metals.     

Microsatellites for the net‐spinning caddisfly Plectrocnemia conspersa (Polycentropodidae)

Six polymorphic microsatellites were developed for the caddisfly Plectrocnemia conspersa from two enriched partial genomic libraries. These represent the first microsatellites published for the order Trichoptera. We show that, whilst it is possible to develop a highly enriched library, isolation of polymorphic microsatellites is difficult for this species, as has been found in some other of invertebrate groups. The genotypes of 160 individuals were determined using these new loci. Observed heterozygosities ranged from 0.013 to 0.788. Despite their problematic isolation, polymorphic microsatellite loci show greater levels of variation than previously studied allozyme markers.     

Genetic population structure and neighbourhood population size estimates of the caddisfly Plectrocnemia conspersa

1. We used both genetic and ecological methods to evaluate the role of history and the scale of colonisation in structuring populations of the caddisfly Plectrocnemia conspersa. There was no genetic differentiation between sites up to 20 km apart, despite population sizes suggesting that genetic drift could create substantial variation at this scale. 2. Genetic differentiation between populations separated by more than 20 km was greater than expected given the contrasting short‐range trend, and implied a neighbourhood population size that is implausibly small. Therefore, the evolutionary processes that affect the short‐range trend do not explain differentiation over greater distances. 3. At small scales (<20 km), relatively short flights by winged adults spread over a number of generations could account for the spread of genes. For instance, dispersing individuals could found small (often temporary) populations, which may then grow and exchange genes with larger and more permanent local populations, amplifying the effects of the initial gene flow. 4. Over larger scales (20–500 km), substantial gaps between regions containing suitable habitat patches could reduce the number of colonisation events. Genetic patterns at this scale may date from the time they were last colonised. Previous ecological studies have rarely examined the dynamics of aquatic insect populations over these larger geographical scales, yet these processes may be central to their persistence and spread.     

The genus Pringsheimiella (Chlorophyta), including P. sanctae-luciae sp. nov.

In re-assessing the genus Pringsheimiella , seven species are referred to this taxon. These are: P. scutata (Reinke) Marchewianka, the type species of the genus; P. gratulans (Weber-van Bosse) Nielsen & McLachlan comb. nov, renamed from Ochlo-chaete gratulans Weber-van Bosse; P. udoteae (Børgesen) Schmidt & Petrak; P. con-chyliophila Feldmann; P. crenulata (Lami) Nielsen & McLachlan comb. nov., renamed from Ulvella crenulata Lami; P. mauritiana Børgesen, which may be synonymous with P. crenulata but requires further study; and P. sanctae-luciae sp. nov.     

The genus Plectrocnemia Stephens of Japan (Trichoptera; Polycentropodidae)

The Japanese species of the genus Plectrocnemia Stephens (Trichoptera; Polycentropodidae) are revised based on examination of male material. Five new species are described: P. divisa, P. suzukii, P. corna, P. scoparia, and P. odamiyamensis. P. levanidovae Vshivkova et al. is recorded from Japan for the first time and redescribed. P. wui (Ulmer), P. tochimotoi Schmid, P. tsukuiensis (Kobayashi), and P. okiensis Kobayashi are redescribed. Arctopsyche hirayamai Matsumura is transferred to Plectrocnemia and redescribed. P. asuana Kobayashi, P. kadowakii Kobayashi, and P. makiensis Kobayashi are transferred to the genus Nyctiophylax Brauer.     

Recruitment, kin and the spatial genetic structure of a caddisfly Plectrocnemia conspersa in a southern English stream

1. Our objectives were to examine small‐scale patterns in oviposition and genetic relatedness in a population of the stream‐dwelling caddis Plectrocnemia conspersa and, in particular, to look for any evidence of the spatial proximity of close kin and, therefore, ‘patchy recruitment’. 2. In order to examine the distribution of related larvae at the beginning of the aquatic phase, we searched the stream for egg masses. Spatially and temporally structured samples of larvae were then collected from the stream over four sample dates within one generation. The genetic relatedness of these field‐collected larvae, estimated using six polymorphic microsatellite loci, was subsequently compared with that of larvae reared from individual egg masses in the laboratory. 3. Egg masses were laid in clusters or ‘hot spots’ along the stream. The mean relatedness coefficient within reared egg masses ranged from 0.327 to 0.525, and differed significantly from that estimated for the population as a whole (0.070), indicating that the markers were sufficiently powerful to identify groups of siblings. Each egg mass was likely to be the progeny of one father, although the possibility of a small contribution from a second male could not be excluded for a few masses. 4. Mean relatedness within the spatially structured groups of larvae in the stream, even those in close proximity to each other, did not differ from the background population level estimate, suggesting that siblings disperse away from each other very quickly and that kin structure does not persist over time. 5. Changes in spatial genetic structure late in the larval life indicated that neighbouring larvae were less closely related than the population overall, possibly suggesting some direct or indirect means of avoiding kin when approaching the onset of pupation. 6. Our counts of egg masses suggested that survival through the egg stage and early larval life was apparently very high (>50%) for a non‐social insect, and may be a consequence of the colonial net that is briefly occupied by first instar larvae. 7. The number of egg masses laid in the stream (approximately 400 in the sample year), the lack of a spatial genetic structure showing evidence of families even early in larval life, and the high survival of eggs and early instar larvae, all refute the ‘patchy recruitment hypothesis’ for this species.     

Various characteristics of lipid metabolism of Bacillus brevis var. G.-B

Some characteristic features of the lipid metabolism of Bacillus brevis var. G.-B. natural variants and Bacillus brevis mutant 101 were studied. The authors found that upon submerged cultivation gramicidine S-producing P+-variant and B. brevis mutant 101 synthesized higher amounts of tocopherols as compared to other colonial-morphological variants. The highest tocopherol content was observed in P+-variant, whose cells contained the highest amount of total lipids as compared to other gramicidine S-producers.     

New records of polycentropodid caddisflies from Korea (Insecta: Trichoptera)

Four species of the family Polycentropodidae –Plectrocnemia baculifera, P. kusnezovi, Paranyctiophylax hjangsanchonus and Polyplectropus nocturnus– are recorded from Korea. Polyplectropus nocturnus is newly recorded from the Korean peninsula. The other three species are recorded from the Republic of Korea for the first time.     

Biological properties of a Bacillus brevis 101 mutant

Some features of the Bacillus brevis 101 mutant producing the antibiotic gramicidin S are described. The mutant is very close to the initial P+-variant of Bacillus brevis var. G-B by cultural, physiological and biochemical characteristics. The most typical features of Bacillus brevis 101 are high antibiotic activity (up to 2 g/l) and the specific phenotype of the colonies. The phenotypical features of Bacillus brevis 101 are dependent on the conditions of its cultivation. On minimal media rich in organics a change of the culture correlated with a lower antibiotic activity.     

Seven new species of caddisflies (Insecta: Trichoptera) from the Rovno amber (Eocene of Ukraine)

Seven new caddisfly species of the families Polycentropodidae, Psychomyiidae, and Lepidostomatidae are described from the Late Eocene Rovno amber: Holocentropus kobodok sp. nov., H. zhiltsovae sp. nov., Plectrocnemia nastigermania sp. nov., P. ucrainica sp. nov., Nyctiophylax terreusbos sp. nov., Lype essentia sp. nov., and Lepidostoma quasitypica sp. nov.     

Respiratory behaviour of larvae of four species of the Family Polycentropodidae (Trichoptera)

Larvae of Plectrocnemia conspersa and Polycentropus flavomaculatus from flowing water and Cyrnus flavidus and Holocentropus picicornis from still water were selected for study. In the above sequence, these larvae are associated with increasing ranges of temperature in their natural habitats. Experimental determination of lethal temperatures and investigations on ventilation frequency indicated that the larvae were increasingly tolerant of temperature in the same sequence of species. C. flavidus and H. picicornis showed infrequent ventilation which was little affected over wide ranges of temperature and dissolved oxygen but was stimulated erratically by water flow. P. conspersa and P. flavomaculatus showed more active ventilation which was more sensitive to changes in temperature and dissolved oxygen and was decreased by water flow. Consideration of ventilation in relation to oxygen uptake in P. conspersa and P. flavomaculatus suggests that ventilation activity may account for some 60–70% of active oxygen uptake. Differences in ventilation behaviour may thus be important in limiting larval distribution in stream systems.     

BIOLOG系统鉴定黄瓜根围促生菌的初步研究

对筛选出的８株具有明显促生防病作用的黄瓜根围促生菌ＣＮ１１,ＣＮ３１,ＣＮ４５,ＣＮ１ １６,ＣＮ１２９,ＸＢ１２０,ＸＢ５,ＸＢ４１通过ＢＩＯＬＯＧ法进行了分类鉴定,分别为：铜绿假单胞菌（Ｐｓｅｎｄｏｍｏｎａｓ ａｅｒｕｇｉｎｏｓａ）,波纹假单胞菌（Ｐ． Ｃｏｒｒｕｇａｔａ）,短芽孢杆菌（Ｂａｃｉｌｌｕｓ ｂｒｅｖｉｓ）,荧光假单胞菌Ｂ型（Ｐ． Ｆｌｕｏｒｅｓｃｅｎｓ ｔｙｐｅ Ｂ）,铜绿假单胞菌（Ｐ． Ａｅｒｕｇｉｎｏｓａ）,荧光假     

Ten new species of caddisflies (Insecta: Trichoptera) from the Baltic amber

Ten new species of caddisflies of the families Polycentropodidae (nine) and Molannidae (one) are described from the Eocene Baltic amber: Holocentropus peregrinator sp. nov., H. proximorepertus sp. nov., H. dugoi sp. nov., H. fundamentalis sp. nov., H. telergon sp. nov., Plectrocnemia varigoria sp. nov., P. synthesia sp. nov., P. novokshonovi sp. nov., Nyctiophylax valideturbidus sp. nov., and Molanna okraina sp. nov.     

Sperm structure of Trichoptera. III. Hydropsychidae,polycentropodidae and philopotamidae (Annulipalpia)

Spermatozoa from 9 species belonging to 3 families of trichopteran suborder Annulipalpia (Philopotamidae : Philopotamus ludificatus, P. montanus, Wormaldia occipitalis, W. copiosa; Polycentropodidae: Plectrocnemia geniculata, Polycentropus mortoni, P. irroratus, Cyrnus trimaculatus; Hydropsychidae: Hydropsyche pellucidula) were studied by light, scanning, and transmission electron microscopy. The absence of axonemal dynein arms and a consequent sperm immotility are characteristic of the species studied. The presence of 7, rather than 2, central microtubules is shared by Polycentropodidae and some Philopotamidae. A greater variability in the sperm axoneme was found within Philopotamidae than in the other families. The species of the genus Wormaldia have an axial vesicle rather than microtubules and their axonemes have a 9 + 9 + 0 or 13 + 13 + 0 pattern. Hydropsychidae have spermatozoa provided with numerous finger-like appendages containing microtubular doublets. The progressive loss of sperm flagellum and motility within the group is discussed.     

Structural study of the basal bodies of the flagella of Bacillus brevis var. G.-B. P+

The structural organisation of the flagellum basal body was studied in Bacillus brevis var. G.-B. P+ by electron microscopy. It was compared with that of Escherichia coli MS 1350. The basal body of a B. brevis flagellum contains, in addition to two pairs of rings on a rod, another ring-like structure (d = 13.6 nm, h = 4.3 nm) which we referred to as a "collar". The collar makes the basal body of B. brevis different from that of B. subtilis, another Gram-positive bacterium. The collar seems to fasten the flagellum of B. brevis to the cell wall. We have concluded that the basal body can differ not merely among bacterial systematic groups, but also among bacteria belonging to one and the same genus. The role of individual elements in the structure of the basal body of bacterial flagella is discussed.     

Foraging in a patchy environment by a predatory net-spinning caddis larva: A test of optimal foraging theory

Summary The predatory larvae of the caddis Plectrocnemia conspersa (Curtis) cause significant prey depletion in a habitat in which prey are patchily distributed. Optimal foraging theory predicts that under these circumstances a predator should stay in any given patch until the prey capture rate there drops to a value equal to the average for the habitat as a whole. This was tested using a combination of field and laboratory data and the results were in broad agreement with the prediction. A second prediction is that the marginal capture rate should be higher in a habitat richer in prey and this was not supported. It is argued that by using a simple rule-of-thumb (constant giving-up-time) P. conspersa is able to approach the optimal solution for much of the time.