Ptychoptera delmastroi sp. n. (Diptera: Ptychopteridae) from Italy

Ptychoptera (Paraptychoptera) delmastroi sp. n. is described from North Italy and compared with other species of the subgenus, including structural details of the auxiliary male sexual organ.     

Feeding ecology of the freshwater detritivore Ptychoptera paludosa (Diptera, Nematocera)

1. We examined selected aspects of the nutritional ecology of larval Ptychoptera paludosa and their role in nutrient cycling in the Breitenbach, a first-order stream in Hesse, Germany.
2. Food preference experiments demonstrated significant preference for sediments with a high organic matter content and live bacteria.
3. pH was circumneutral in all sections of the gut.
4. Enzymatic activity (β-glucosidase and amino-peptidase) in different parts of the gut was measured using 4-methylumbelliferyl-β- D -glucopyranoside (MUF-Glc) and leucine-4-methylcoumarinyl-7-amide (Leu-MCA). β-glucosidase activity was highest in the hindgut.
5. The mean larval gut passage time was between 7 and 8 h.
6. The egestion rate of last instar larvae was about 0.35 mg dry weight (DW) faeces per larva h^–1 and about 1.25 mg ash-free dry weight (AFDW) faeces per mg larval AFDW day^–1.
7. Larval faeces contained at least 4–18 times more organic matter than the average in the sediments in which they were feeding, that is, larvae fed selectively, extracting organic matter from sediments.
8. P. paludosa larvae are important in the dynamics of detritus in slow-flowing reaches of the Breitenbach. They gather organic material from the sediment to a depth of 3 cm, and release it as faeces onto the sediment surface. A total of 770 g DW faeces m^–2 yr^–1, comprising about 16% organic matter, was produced by the Ptychoptera population.     

Resource utilization by the freshwater deposit feeder Ptychoptera townesi (Diptera: Ptychopteridae)

SUMMARY 1. False crane fly larvae, Ptychoptera townesi (Diptera), occurred in high densities in a flow-controlled section of stream where fine particulate organic matter (FPOM; 0.45 μm to 1 mm in diameter) had accumulated, but were quite rare both upstream and downstream from the section.
2. In laboratory studies, P. townesi grew only on FPOM less than 250 μm. Larvae consistently grew fastest when fed small particles (0.45–53 μm in diameter).
3. Ptychoptera townesi consumed relatively small amounts (0.002 mg per mg animal dry mass day⁻¹) of FPOM (0.45–53 μm). They had long gut content passage times (greater than 19 h) and relatively high efficiencies of conversion of ingested food to body substance (20.7%). Gut content passage times were variable, and depended partially on the nature of the substrate.
4. False crane fly larvae compacted FPOM into faecal pellets considerably larger in size than particles ingested. They lost mass when allowed to feed on their own faecal material, as well as on faeces greater than 250 μm in diameter produced by shredders. However, they survived and grew on shredder faeces (53–500 μm in diameter) that contained a mixture of smaller particles and particles too large for ingestion.
5. The overall pattern of resource utilization by P. townes involved slow handling of relatively small volumes of food, which probably passed once only through a complex alimentary tract.     

The Light and Electron Microscopic Cytology of Janacekia adipophila N. Sp. (Microspora, Tuzetiidae), a Microsporidian Parasite of Ptychoptera paludosa (Diptera, Ptychopteridae)

ABSTRACT. The microsporidium Janacekia adipophila n. sp., a parasite of Ptychoptera paludosa larvae in Sweden, is described based on light microscopic and ultrastructural characteristics. Merogonial stages and sporonts are diplokaryotic. Merozoites are formed by rosette-like division. Sporonts develop into sporogonial plasmodia with isolated nuclei. These plasmodia give rise to 8–16 sporoblasts by rosette-like budding. A sporophorous vesicle is initiated by the sporogonial plasmodium. Sporoblasts and spores are enclosed in individual sporophorous vesicles. Granular inclusions of the vesicles, visible using light microscopy, discriminate sporogonial stages from stages of the merogony. The monokaryotic, fresh spores are oval with blunt ends, measuring 4.2-6.3 × 9.1-11.2 μm. Macrospores are formed in small numbers. The spore wall has three subdivisions and the exospore is electron-dense. The polaroplast has two parts: closely arranged lamellae anteriorly, wider sac-like compartments posteriorly. The isofilar polar filament, 191–264 nm wide, has 12-13 coils, which are arranged in one layer in the posterior half of the spore. The electron-dense inclusions of the sporophorous vesicle are modified during sporogony, and vesicles with mature spores are traversed by 21–27 nm wide tubules, which connect the exospore with the envelope of the vesicle. The walls of the tubules, the envelope of the vesicles, and the surface layer of the exospore are all identical double-layered structures. The microsporidium is compared to microsporidia of Ptychopteridae and Tipulidae and to related microsporidia of the family Tuzetiidae.     

Laboratory investigation on community composition, emergence patterns and biomass of wood-inhabiting Chironomidae (Diptera) from a sandy lowland stream in Central Europe (Germany)

Wood-inhabiting chironomid communities were investigated from June 1998 to July 1999 by laboratory rearing of randomly collected submerged branches from a headwater and mid-reach site of a sandy lowland stream, separated by an impoundment used for fishery purposes. Total annual emergence (males and females) from headwater samples was higher (2551 ind m^–2 y^–1) compared to the mid-reach (1576 ind m^–2 y^–1), which could be due to disturbances caused by frequent impoundment openings resulting in high discharge events. Chironomid community from branches comprised three subfamilies, with Orthocladiinae (18 species, 2189 ind m^–2 y^–1) clearly predominating at the headwater (total of 36 species). Mid-reach samples (total of 48 species) showed similar emergent numbers of Orthocladiinae (19 species, 786 ind m^–2 y^–1) and Chironominae (26 species, 764 ind m^–2 y^–1). Tanypodinae were caught very rarely in the laboratory emergence (12 ind m^–2 y^–1 at both sites). Shannon-Wiener diversity index for the mid-reach chironomid community was higher (2.52) than for the headwater community (1.68). Chironomid species composition on woody debris was similar between stream sites, with a Sørensen index of 0.75, but showed different dominance structures indicated by a Wainstein index of 0.26. Total adult biomass (in the manner of dry mass) during the study period was higher for wood-dwelling chironomids from the headwater (158.2 mg m^–2 y^–1) compared to the mid-reach (123.8 mg m^–2 y^–1), but individual biomass was higher for mid-reach chironomids (0.079 mg ind^–1 vs. 0.062 mg ind^–1 at the headwater), indicating the predominance of larger species. Total biomass of wood-inhabiting chironomids in the investigated lowland stream was low compared to other field emergence studies, which could be attributed to the laboratory approach for investigating the emergence from a single substrate type (submerged wood) instead of the integrative field surveys where chironomids from all habitats were caught. Main reason for the lack of chironomid species closely associated to wood in this sandy lowland stream could be infrequent but episodic disurbances caused by the anthropogenic induced highly fluctuating discharge regime of the downstream study site.     

Life Cycle of Polytomella caeca (Phytomonadida, Polyblepharidae)

SYNOPSIS. Polytomella caeca (Phytomonadida, Polyblepharidae) reproduce by binary fission and sexual reproduction. The sexual process increases in frequency as the population becomes denser. Normally 2 monoecious isogametes engage their anterior flagella prior to fusion, which occurs by merging of the cells from their anterior to their posterior ends. This is followed by a period of zygotic enlargement before cleavage of the zygote into 4 daughter cells. Encystment occurs throughout the flagellates' bloom until they represent 80% of the individuals at the end of the bloom. Cysts are a resistant, not reproductive stage. The observations were made over long periods of time by following individual flagellates in microcultures and by viewing living cells taken at various stages from larger cultures.     

Life History of Bittacomorpha clavipes (Fabricius) (Diptera: Ptychopteridae) in an Ozark Spring,U.S.A.

A population of Bittacomorpha clavipes was studied in an Ozark spring from July 1987- August 1988. Measurement of larval head capsules (N=4,544) showed B. clavipes has four distinct larval instars. Seasonal distribution of immature and adult life stages suggests that this population has an asynchronous, non-seasonal, multivoltine life history with at least three cohorts. First instar larvae and pupae were collected during all months except December through March and December through February, respectively. Adults and larval instars II-IV were collected throughout the year. Larval recruitment generally paralleled adult flight periods, and the presence of adults during all months sampled indicates a correlation with ovipositional periods. The life history documented here for B. clavipes suggests that limiting factors for growth and reproduction are not seasonally dependent for this population.     

A New Species of Dysmorphococcus (Phacotaceae,Volvocales) and Its Life Cycle

This paper deals with the morphology and life cycle of a new species of Dysmorphococcus oblatus Yu et Wei (Phacotaceae, Volvocales) from Africa. The alga seems to be morphologically rather distinct from the other members (lorica, protoplast and number of pyrenoid). Moreover, a comparison is made of overall morphological and reproductive characteristics of the present taxon with the other 8 known species of this genus. The cultural experiment of the life cycle of this alga reveals certain attributes unrecorded for early described species of this genus. The alga is homothallic, and heterogametic and sexual reproduc-tion produces 32-64 male gametes and 2 female gametes.     

Six New Species of Dobsonflies from Venezuela (Megaloptera: Corydalidae: Corydalinae)

Six new species of dobsonflies (Megaloptera: Corydalidae: Corydalinae) from Venezuela are described and illustrated, two in the Neotropical genus Chloronia and four within the New World genus Corydalus. Chloronia contains 15 previously described species. The new species Chloronia gaianii and C. marthae, each from the southern tepui and Andean regions, appear to be most closely related to C. hieroglyphica (Rambur) and C. mirifica Navás, respectively. Corydalus contains 30 previously described species. The new species Corydalus clavijoi, of Andean affinity, appears most closely related to C. tesselatus Stitz; C. crossi, from Auyán-tepuí, might be closely related to C. nubilus Erichson; and both C. hayashii and C. mayri, from westernmost Guayana Shield area and Aracamuni tepuis, respectively, clearly belong in the distinct and monophyletic C. arpi Navás species group. Keys for identification of the Venezuelan species of both genera are provided.     

Ptychopteridae (Insecta: Diptera): History of its study and limits of the family

Paleontological Journal - The history of the study of extant and extinct ptychopterids is reviewed. The morphology of the ptychopterid imago and preimaginal stages is discussed. Synonymy of...     

Checklist of the familes Chaoboridae,Dixidae, Thaumaleidae,Psychodidae and Ptychopteridae (Diptera) of Finland

A checklist of the families Chaoboridae, Dixidae, Thaumaleidae, Psychodidae and Ptychopteridae (Diptera) recorded from Finland is given. Four species, Dixella dyari Garret, 1924 (Dixidae), Threticus tridactilis (Kincaid, 1899), Panimerus albifacies (Tonnoir, 1919) and Panimerus przhiboroi Wagner, 2005 (Psychodidae) are reported for the first time from Finland.     

Contributions to the Life Cycle of Peneroplis planatus (Fichtel and Moll) Montfort

Direct observations of schizonts and agamonts releasing megalospheres clarified the asexual phase of the life cycle of Peneroplis planatus and made it most probable that this species has a paratrimorphic life cycle. Specimens with maximum lengths between 837 and 3,503 μm released about 500 to 1,500 megalospheric juveniles, which possessed two chambers (proloculi and flexostyles) prior to emergence from the parental shell. The presence of gamonts was not shown and was only implied by the occurrence of the agamonts. Since agamonts and schizonts have been found from December to May and since asexual reproduction occurs in spring in Elat, sexual reproduction probably occurs at another time of year (June to December). More detailed studies of this species need to be conducted throughout the year to improve our knowledge of the life cycle of this species.     

Life history strategy and taxonomic position of gall midges (Diptera: Cecidomyiidae) inducing leaf galls on Styrax japonicus (Styracaceae)

Four gall midge species (Diptera: Cecidomyiidae) that induce leaf galls on Styrax japonicus (Styracaceae) were identified to generic level based on larval morphology. Three of these gall midges, which induce whitish hemiglobular galls, flattened subglobular galls, and purple globular galls, respectively, were identified as three genetically distinct species of Contarinia, and the remaining species, which induces globular galls with dense whitish hairs, was identified as a species of Dasineura. Field surveys in Fukuoka, Japan, revealed that adults of these gall midges emerged and oviposited in late March to mid‐April at Mount Tachibana (approximately 200 m a.s.l.) and in late April to early May at Mount Sefuri (about 1050 m a.s.l.), coinciding with the leaf‐opening season of S. japonicus. Larvae of these gall midges mostly developed into third instars by June and then left their galls and dropped to the ground. These species therefore have a life history strategy that differs from that of another S. japonicus‐associated gall midge, Oxycephalomyia styraci, which overwinters as the first instar in ovate swellings, matures rapidly in spring, and emerges directly from the galls.     

Aspects of the Life History of the Salema, Sarpa salpa (Pisces, Sparidae), off the Canarian Archipelago (Central-East Atlantic)

Life history of the salema, Sarpa salpa, off the Canarian archipelago was studied from samples collected between January 1998 and December 1999. Fish ranged from 119 to 452 mm in total length and from 24.9 to 1491.7 g in weight. The species was characterized by a protandric hermaphroditism. The overall sex ratio was unbalanced in favour of males (1 : 0.41). The reproductive season extends from September to March, with a peak in spawning activity in December–January. Males reached maturity at a smaller length (226 mm, 2 years old) than females (294 mm, 3 years old). Males, females and all fish showed an isometric growth. The morphometric relationship between length and mass for the whole population was described by the parameters: a = 0.0000134 and b = 3.01. A concentric pattern of opaque and translucent zones was readily distinguishable on the otoliths. Two rings, one opaque and one translucent, were laid down each year on the otoliths; the opaque zone was formed during the summer months, and the translucent zone during the winter months. Individuals aged 0 to 11 years were found. The parameters of the von Bertalanffy growth equation for all individuals were: L = 479 mm, k = 0.212 year^–1, and t₀ = –1.08 year.     

Life Cycle,Feeding and Production of Isoptena serricornis(Pictet, 1841) (Plecoptera,Chloroperlidae)

Some aspects of the biology and ecology (life cycle, feeding and production) of a population of Isoptena serricornis in the Rudava River (Slovakia) are studied, reported and discussed. The life cycle is annual, with slow growth in autumn‐winter and fast growth in late summer and spring. The growth decreased two weeks before the Fall Equinox and increased two weeks after the Spring Equinox. The flight period spans from the end of May to the beginning of July. The presence of large sand particles in the gut of all studied nymphs is of note, and indicates that I. serricornis acts as a deposit‐collector species. Nymphal food is principally composed of detritus, unicellular organisms and, in nymphs of intermediate or large size, Chironomidae larvae. Adult food is composed fundamentally of different types of pollen grains. Males usually have lower food content than females. Annual production of this species (∼694–750 mg · m⁻²) is very high in relation to other previously studied Chloroperlidae. This is probably largely responsible for I. serricornis being one of the most abundant components of the macroinvertebrate community in its habitat in the Rudava River. A negative correlation between production and temperature was observed.     

酪蝇的羽化节律和交配行为

【目的】为了明确酪蝇Piophila casei的羽化节律和交配行为,为深入研究酪蝇的性信息素打下基础。【方法】在室内条件[温度(27±1)℃,光周期L︰D=14︰10]下观察了酪蝇的羽化节律和交配行为。【结果】结果表明,化蛹后第8天成虫羽化最多,羽化高峰期出现在由暗期进入光期的前后,雄虫略早于雌虫羽化。观察结果表明,当雄虫接近蛹壳时会表现出"触摸"、"经过"、"扑"、"抱握"等动作,而雌虫仅有"触摸"、"抱握"的动作。当遇到同性成虫或者已交配雌虫时,雄虫会"追逐"对方,当接触到对方时雄虫会表现出"抱握"、"触摸"动作以进行识别,被识别雄虫会"翘起腹部末端"使对方离开,已交配雌虫则猛烈"摆动身体"使对方离开。当遇到处女雌虫时,雄虫跳跃到雌虫背上迅速进行交配。雌虫羽化后1 min即可交配,雄虫羽化后30 min可交配,交配平均持续时间10 min。雄虫间会有交配竞争行为发生,后来者会跳跃到先来者背上,向下弯曲腹部试图越过先来者与雌虫交配。【结论】酪蝇的羽化高峰出现在进入光期前后。成虫对蛹壳有显著趋性,雄虫主动追逐识别异性,较雌虫表现出更强烈的交配欲望。     

The life histories of two species of Sialidae (Megaloptera) from Japan

The life histories of two species of Sialidae (Megaloptera) from Japan were investigated, focusing on their larval climbing and emergence conditions and then adult emergence behaviours. At the Rokuman pond, a fence trap and pitfall traps were constructed beside the pond to collect final-instar larvae of Sialis yamatoensis and Sialis japonica as they climbed for pupation in the night. In the two species, 48–49% of climbings occurred under wet ground conditions, due to rainfall during or before the climbing night. Approximately 50% of larval climbings occur under dry ground conditions, during continuous sunny or cloudy weather. This is thought to be due to pupation occurring close the edge of the pond. Male and female adult emergences were nearly simultaneous in both species. Pupal periods varied, later final-instar larvae climbings resulted in shorter pupal periods. Ground temperature is thought to have an effect on pupal periods.     

Life Cycle Assessment of Water Production Technologies - Part 1: Life Cycle Assessment of Different Commercial Desalination Technologies (MSF,MED, RO) (9 pp)

- Preamble. This series of two papers analyses and compares the environmental loads of different water production technologies in order to establish, in a global, rigorous and objective way, the less aggressive technology for the environment with the present state of the art of the technology. Further, it is also presented an estimation of the potential environmental loads that the considered technologies could provoke in future, taking into account the most suitable evolution of the technology. - Part 1 presents the assessment of most commercial desalination technologies which are spread worldwide: Reverse Osmosis, Multi Effect Desalination and Multi Stage Flash. Part 2 presents the comparative LCA analysis of a big hydraulic infrastructure, as is to be found in the Ebro River Water Transfer project, with respect to desalination. - DOI: http://dx.doi.org/10.1065/lca2004.09.179.1 - Intention, Goal and Background. In this paper, some relevant results of a research work are presented, the main aim of which consists of performing the environmental assessment of different water production technologies in order to establish, in a global, rigorous and objective way, the less aggressive technology for the environment of potable water supply to the end users. That is, the scope of this paper is mostly oriented to the comparative Life Cycle Assessment of different water production technologies instead of presenting new advancements in the LCA methodology. In Part 1, the environmental loads associated with the most widespread and important commercial desalination technologies all over the world - Reverse Osmosis (RO), Multi Effect Desalination (MED) and Multi Stage Flash (MSF) – are compared. The assessment technique is the Life Cycle Analysis (LCA), which includes the entire life cycle of each technology, encompassing: extraction and processing raw materials, manufacturing, transportation and distribution, operation and final waste disposal.- Methods and Main Features. The software SimaPro 5.0, developed by Dutch PRé Consultants, has been used as the analysis tool, because it is a well known, internationally accepted and validated tool. Different evaluation methods have been applied in the LCA evaluation: CML 2 baseline 2000, Eco-Points 97 and Eco-Indicator 99. Data used in the inventory analysis of this Part 1 come from: a) existing plants in operation; b) data bases implemented in the SimaPro 5.0 software -BUWAL 250, ETH-ESU 96, IDEMAT 2001. Different scenarios have been analyzed in both parts in order to estimate, not only the potential of reduction of the provoked environmental loads with the present state of the art of technology, but also the most likely future trend of technological evolution. In Part 1, different energy production models and the integration of desalination with other productive processes are studied, while the effect of the most likely technological evolution in the midterm, and the estimation of the environmental loads to the water transfer during drought periods are considered in Part 2. Results and Discussion The main contribution to the global environmental impact of desalination technologies comes from the operation, while the other phases, construction and disposal, are almost negligible when compared to it. Energy is very important in desalination, for this reason the environmental loads change a lot depending on the technology used for providing the energy used in the desalination process. Among the different analyzed technologies, RO is the least aggressive desalination technology (one order of magnitude lower than the thermal processes, MSF and MED) for the environment. When integrating thermal desalination with other productive processes taking advantage of the residual heat, the environmental loads of thermal desalination technologies is highly reduced, obtaining similar loads to that of RO. The environmental loads of desalination technologies are significantly reduced when an energy model based on renewable energies is used. Taking into account the technological evolution, which is experiencing the RO, a reduction of its environmental load by about 40% is to be expected in the mid-term. Conclusion The main conclusion of Part 1 is that, with the present state of the art of the technology, RO is clearly the desalination technology with a reduced environmental load (one order of magnitude lower than the thermal processes, MSF and MED). In the case of thermal desalination technologies, their environmental load can be highly reduced (about 1,000 times less) when integrated with other industrial processes. In the case of RO, the scores and the airborne emissions obtained from an electricity production model based on renewable energies are about 65-70 times lower than those obtained when the electricity production model is mainly based on fossil fuels. Recommendations and Outlook Although desalination technologies are energy intensive and provoke an important environmental load, they present a high potential in being reduced since: a) in the mid-term, it is to be expected that the different technologies could improve their efficiency significantly, b) the environmental loads would be highly reduced if the energy production models were not mainly based on fossil fuels and c) the energy consumption, particularly in the case of thermal desalination, can be drastically reduced when integrating desalination with other productive processes. The results presented in this paper indicate that a very interesting and promising field of research is available in order to reduce the environmental load of these vigorous and increasing desalination technologies.     

Development time and pupation behavior in theDrosophila melanogaster subgroup (Diptera: Drosophilidae)

This study is an in-depth analysis of intersexual, intraspecific, and interspecific variability in larvopupal developmental time, pupation site preference, and larval and pupal survival of a number of isofemale lines of the speciesDrosophila mauritiana, D. melanogaster, D. sechellia, D. simulans, D. teissieri, andD. yakuba. There was no significant sex differences in pupation height, but females eclosed significantly earlier than males in all species. In addition, the suggestion of a strong negative correlation between larval developmental time and pupation height could not be confirmed in this study. The hypothesis that differences in pupation height provide a basis for niche partitioning between closely related species with overlapping distributions was tested by three planned orthogonal contrast analyses of variance. First, the two speciesD. teissieri andD. yakuba, with largely overlapping distribution, were significantly different in pupation height. Second, the two allopatric, nonoverlapping island speciesD. mauritiana andD. sechellia did not significantly differ in pupation height. However, the absence of a significant difference in the final contrast between the two cosmopolitan speciesD. melanogaster andD. simulans, which are often found together, makes us cautious to accept the hypothesis.