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The Pannonian Basin is a sediment-filled back-arc basin which was formed during the Late Paleogene–Neogene period. Such sedimentary rocks like bauxites or kaolinites, which are important with regard to industry in the region, are the products of former weathering processes. However, our knowledge about the palaeoenvironmental conditions which led to the formation of these mineral resources has not yet been integrated. For this purpose, the former biomes, climatic classes as well as karstification, weathering and paedogenic processes were investigated over the last 34 mys using the southeastern regions of China and the United States as climatically analogous regions. By the second half of the Oligocene, the conditions of intensive chemical weathering ceased to exist in the Pannonian Basin, which enabled the formation of lateritic bauxites during earlier periods. However, up to the mid-Serravallian Stage, intensive karstification as well as the formation of haematite-rich ultisols and alfisols continued when humid subtropical climatic conditions came about. The modelled biomes indicate that aridification during the Early to Middle Miocene led to the formation of less dense vegetation, exacerbating the re-deposition of weathering products. These conditions resulted in the accumulation of haematitic and kaolinitic sedimentary rocks in the fossilized karst depressions. The progressive cooling following the mid-Pliocene decreased the intensity of karstification, moreover, the cessation of humid subtropical conditions brought the sedimentation of haematitic and kaolinitic sedimentary rocks in the Pannonian Basin to an end. [ABSTRACT FROM AUTHOR]

Paedogenesis is a unique reproductive mode shown only by some fungivorous gall midges (Diptera: Cecidomyiidae) and a coleopteran species in insects. Recently, we found various species of paedogenetic gall midges in their natural habitats, such as decayed trunks and branches on the forest floor in Japan. In this study, we established a continuous rearing technique for paedogenetic gall midges in the laboratory using Flammulina velutipes mycelia growing on potato dextrose agar (PDA) media. In addition, the effects of temperature on the paedogenetic larval development were examined for Mycophila sp. A. The generation period of one paedogenetic cycle was 5.9 days at 24°C and a mother larva produced 15–16 young larvae on average. The developmental zero and thermal constant in the paedogenetic development were estimated to be 8.3°C and 92.7 degree-days, respectively, with the traditional linear method. The laboratory rearing method established in this study is useful for studying the developmental traits of paedogenetic gall midges as well as for examining the mechanism of reproduction mode shift from a paedogenetic to holometabolic life cycle. [ABSTRACT FROM AUTHOR]

Some species of mycophagous gall midges（Diptera: Cecidomyiidae）exhibit paedogenesis and are regarded as serious pests of mushroom cultivation. In Japan, Mycophila speyeri and Heteropeza pygmaea were previously found to infest the mycelia of mushrooms in indoor cultivation factories, but the occurrence of paedogenetic species in natural habitats was not previously reported. During field surveys, we first found paedogenetic gall midges in natural habitats, such as decayed trunks and branches on the forest floor in Japan. Based on morphological examinations of larvae as well as adults of some species, we confirmed the occurrence of paedogenetic gall midges belonging to at least five genera as follows: Miastor, Mycophila, Heteropeza, Heteropezula, and Leptosyna. These gall midges were found on white-rot but not on brown-rot fungi in the field. These results indicate that wood-decaying fungi responsible for white rotting trunks and branches harbor diverse paedogenetic gall midges on the forest floor in Japan. [ABSTRACT FROM AUTHOR]

This article discusses theoretical aspects of studies on viviparous organisms and provides new approaches to understanding the evolution of viviparity. Viviparity is considered here not as a "great biological advantage," but as the simplest way of birth, that in terms of biodiversity is in the minority; it is realized only in cases in which, due to various reasons, laying eggs is impossible or poorly compatible with newly acquired morphological and/or physiological characteristics. Aberrations of the reproductive sphere, changes in its ancestral state and changes leading to viviparity, can be divided into three main groups: (1) the appearance of oogamy in the ancient colonial protists and multicellular organisms before the appearance of any mechanisms for extrusion of immobile oogamete (or zigote); (2) evolutionary conversions from external to internal fertilization in organisms that have no specialized oviducts with accessory glands and spermathecae; (3) abnormalities in well-developed female reproductive systems: the loss of insect reproductive organs (in cases of paedogenesis, neoteny, or paedomoprhosis), larval meiosis, change of fertilization area from ectodermal parts of oviducts to intragonadal fertilization. All the above mentioned evolutionary rearrangements are considered from the point of view of an analytical review of viviparity in the largest biological taxa from archaic multicellular organisms to the most advanced groups of invertebrate and vertebrate animals. [ABSTRACT FROM AUTHOR]

This article is a second part of the themed issue "Aberrant cytogenetic and reproductive patterns in the evolution of Paraneoptera insects", prepared by the Russian-Bulgarian research team. Here, analysis of aberrations related to the egg development is provided based on literature data and the author's own investigations. Evolutionary aspects of ovoviviparity/viviparity are also briefly discussed. Material and methods, terminology and nomenclature of taxonomic names are listed in the first paper of the issue (Gavrilov-Zimin et al. 2021). [ABSTRACT FROM AUTHOR]

Paedogenetic fossil midges of the family Lestremiidae are revealed for the first time. Only eight species of eight gall midge genera belonging to five tribes of the subfamily Micromyinae (Lestremiidae) and two species of two genera of Porricondylinae (Cecidomyiidae: Porricondylinae sp., Holoneurini sp.) have previously been described from the Santonian Taimyr amber of Yantardakh. The new tribe Krassiloviolini trib. nov. differs from other tribes of Lestremiidae in the strong reduction of veins and flagellomeres, slightly differing in length first and second tarsomeres of the middle and hind tarsi, 3-segmented apical plates of the ovipositor, and the presence of paedogenesis. A new genus and species, Krassiloviola geniusloci gen. et sp. nov., is described based on a female that is characterized by the first front tarsomere 1.3 times as long as the second, short 2+7-segmented antennae, presence of stem and large narrow sensoria on flagellomeres, wide wings with strongly reduced vein R5, slightly forked Cu, and absence of fragment C behind the fusion with R5. The presence of two very large specific eggs is evidence of the existence of paedogenesis in the Late Cretaceous. Previously, fossil paedogenetic eggs have only been known in Miastor vlaskini (Fedotova et Perkovsky) described from the Late Eocene Rovno amber. [ABSTRACT FROM AUTHOR]

1. Insects with complete metamorphosis (holometaboly) are extremely successful, constituting over 60% of all described animal species. Complete metamorphosis confers significant advantages because it enables organisms to optimise life-history components through temporal partitioning, and thereby to exploit multiple ecological niches. Yet holometaboly can also impose costs, and several lineages have evolved life cycle modifications to avoid complete metamorphosis. 2. In this review, we discuss different strategies that have evolved that result in the loss of complete metamorphosis (type I and type II paedomorphosis). In addition, the ecological pressures and developmental modifications that facilitate this avoidance are considered, as well as the importance of life cycle complexity in life-history evolution. 3. Interestingly, only female holometabolous insects have entirely avoided complete metamorphosis, and it is always the ancestrally juvenile morphology that is retained. These findings point to a strong sex-biased trade-off between investment in reproduction and development. While the loss of complete metamorphosis in females has occurred independently on several occasions across holometabolous insects, only a small number of species possessing this ability have been described. 4. Thus, complete metamorphosis, which originated only once in insects, appears to have been almost fully retained. This indicates that significant modifications to the holometabolan metamorphic ground plan are highly constrained, and suggests that the transition to complete metamorphosis is evolutionarily irreversible. [ABSTRACT FROM AUTHOR]

Abstract: Quantitative trait loci (QTL) for age at smoltification and adult maturation have been mapped in several salmonid species but less is known about precocious male parr maturity. Phenotypic information on length at age, precocious male parr maturation (paedogenesis), early smoltification, and adult sexual maturation was recorded for four double-backcross families of F1 European/North American trans-Atlantic salmon that had been genotyped for 320 (family A) or 121 (families B, C and D) single nucleotide polymorphisms (SNPs). The locations of QTL for early smoltification and for precocious parr and adult maturation in Atlantic salmon (Salmo salar) were identified and then compared with QTL in homologous chromosomal arms of rainbow trout (Oncorhynchus mykiss). Novel QTL for precocious male parr maturation on Ssa05, Ssa07, Ssa09, Ssa10, Ssa12, Ssa16 and Ssa20 were significant at the genome-wide level as were QTL for early smolting detected on chromosomes Ssa05, Ssa08, Ssa13, and Ssa23. As predicted, precocious male parr were significantly less likely to become early smolts. Two QTL for adult sexual maturation on chromosomes Ssa21 and Ssa23 were significant at the chromosome-wide level as were QTL for adult length on Ssa05 and Ssa24. Separate analysis of family A resulted in novel QTL being detected on Ssa01q for early smolting, Ssa17 and Ssa22 for precocious maturation, and on Ssa03 and Ssa20 for length at the early smolt measuring period. The two chromosomes (Ssa21 and Ssa23) that contained QTL for adult maturation were homologous to two chromosomes (Omy22 and Omy4) that contain QTL for adult maturation in rainbow trout. [Copyright &y& Elsevier]

Background: Extreme environmental conditions can give rise to extreme adaptations. We document growth, sexual maturation and fecundity in two species of African annual fish inhabiting temporary savanna pools. Results: Nothobranchius kadleci started to reproduce at the age of 17 days and size of 31 mm and Nothobranchius furzeri at 18 days and 32 mm. All four study populations demonstrated rapid growth rates of up to 2.72 mm/day (23.4% of their total length). Both species may produce diapausing embryos or embryos that are able to hatch in as few as 15 days, resulting in a minimum generation time as short as only one month. Incubation on the surface of damp peat moss results in high embryo survival (73%) and a high proportion of rapidly developing embryos (58%) that skip diapauses and hatch in less than 30 days. We further demonstrated that rapid growth and maturation do not compromise subsequent fecundity. Conclusions: Our data suggest that both species have the most rapid sexual maturation and minimum generation time of any vertebrate species, and that rapid maturity does not involve paedogenesis. [ABSTRACT FROM AUTHOR]

Abstract: This study characterises and compares Cr, Ni, Pb, Cu, Zn and Cd (HMs) contents and the main edaphic parameters in arable soils (AS) from western areas of the Andalusian Autonomous Community (SE Spain) with greenhouse soils (GS) from the province of Almería, one of the most productive agricultural systems in Europe. We explored 199 GS and 142 AS, representing local and regional scales of variation in this important Mediterranean area. The hazardousness of HMs was particularly relevant in GS where agricultural practices, which centre on maximising production, end up with products that finally enter the human food chain directly. Despite their similar edaphic characteristics, the main differences between AS and GS were nutrients and HM contents such as P, K, Cd, Pb and Zn, suggesting the widespread use of agrochemicals in greenhouse farming. Cd concentration in GS tripled that in AS. Here, we conclude that despite anthropogenic HM input, the association patterns of these elements were similar on the two spatial variability scales. Cd, Pb and Zn contents, and partly those of Cu, were related with agricultural practices. On the short spatial scale, grouping these HMs gave very high contents in GS. The associations found with Cr and Ni suggest a lithogenic influence combined with a paedogenic effect on spatial maps; this natural origin input becomes more marked on the long spatial scale represented by AS, where the main Cr and Ni contents were found in the vicinity of Mountain areas not influenced by human activities. [Copyright &y& Elsevier]

Several aspects of the biology of Xylotrechus arvicola (Olivier), an emerging grape pest, were studied under laboratory conditions. Four diets were tested to rear this species in the laboratory. Among them, only one made rearing from larva to adult possible. The highest mortality, in all cases, was recorded during the first days of larval development. Larvae were kept 45 days at 8°C to break diapause in order to reduce the normal field larval developmental time. The species' developmental time was similar between sexes, while pupal developmental time and weight were significantly greater for females than for males. As part of a complementary study, life table parameters of females obtained from the larvae reared on the artificial diet were compared to those of females emerged from field-infested grape root wood. Both laid the majority of eggs in the first two weeks after emergence, and they had a similar pre-laying period. Nevertheless, the females from the diet-reared larvae lived significantly longer, laid eggs over a longer period of time and showed higher fertility than those emerging from infested grape root, suggesting that diet fulfils larval nutritional needs. The species’ laboratory-reared population exhibited a low intrinsic growth rate value (rm=0.01) as a result of its long egg-to-adult developmental time and its high larval mortality. [ABSTRACT FROM PUBLISHER]

The comparative efficacy of 2 anthelmintics (ivermectin and levamisole) against Baylisascaris transfuga migrating and encapsulated larvae was studied in mice. A total of 60 BALB/c mice inoculated each with about 1,000 embryo- nated B. transfuga eggs were equally divided into 6 groups (A-F) randomly. Mice of groups A and B were treated with ivermectin and levamisole, respectively, on day 3 post-infection (PI). Mice of groups A-C were killed on day 13 PI. Similarly, groups D and E were treated with ivermectin and levamisole, respectively, on day 14 PI, and all mice of groups D-F were treated on day 24 PI. The groups C and F were controls. Microexamination was conducted to count the larvae recovering from each mouse. The percentages of reduction in the number of migrating larvae recovered from group A (ivermectin) and B (levamisole) were 88.3% and 81.1 %, respectively. In addition, the reduction in encapsulated larvae counts achieved by ivermectin (group D) and levamisole (group E) was 75.0% and 49.2%, respectively. The results suggested that, to a certain extent, both anthelmintics appeared to be more effective against migrating larvae than encapsulated larvae. However, in the incipient stage of infection, ivermectin may be more competent than levamisole as a larvicidal drug for B. transfuga. [ABSTRACT FROM AUTHOR]

Abstract: Despite nearly three decades of paleomagnetic research on the extensive Chinese loess deposits, a convincing explanation has yet to be developed for how Chinese loess becomes magnetized. To address this problem, we conducted re-deposition experiments using weakly consolidated Holocene Chinese loess that was disaggregated in the laboratory, and compare our results with published paleomagnetic data. We simulated a depositional remanent magnetization (DRM) associated with dry deposition of eolian sediments, and a post-depositional remanent magnetization (PDRM) in which the sediment was water-saturated after deposition. The simulated DRM faithfully records the declination of the applied field, but with systematic inclination flattening. Addition of minor water slightly improves recording of the applied field, but inclination flattening persists. Reliable recording of the applied field occurs for PDRM simulation in water-saturated sediment. Our synthesis of paleomagnetic data from Chinese loess indicates that time-averaged paleomagnetic directions are often indistinguishable from the expected geocentric axial dipole (GAD) field, but in many cases inclinations are shallower than for a GAD field. We conclude that the Chinese loess is magnetized by a combination of DRM and PDRM mechanisms, with water content providing the dominant control on which mechanism aligns the detrital mineral fraction. Where pedogenesis causes neoformation of magnetic minerals, an additional chemical remanent magnetization (CRM) will occur. The magnetization of Chinese loess therefore appears to be controlled by a complex time-varying combination of DRM, PDRM and CRM mechanisms. [Copyright &y& Elsevier]

The mites of Erythraeoidea of Finland were studied. All of the scarce and unconfirmed data on the occurrence of Erythraeoidea mites in Finland were assembled and supplemented with present research data. In Finland, Erythraeoidea are represented by 22 species: 21 species belong to Erythraeidae family, and one species to Smarididae. The presence of 10 species previously indicated in literature was confirmed. Furthermore, the study revealed the occurrence of 10 species new to the fauna of Finland. For four species, active postlarval stages that have not been described in the literature previously, were discovered. [ABSTRACT FROM AUTHOR]

Abstract: Diapausing larvae of Omphisa fuscidentalis contain soluble and membrane-bound trehalase in the midgut. Soluble trehalase activity accounts for three-fourths of the total trehalase activity in midgut homogenates. The exposure of diapausing larvae to juvenile hormone analog (JHA) induced pupation, accompanied by an increase in soluble trehalase activity at the beginning of the prepupal period. Injection of 20-hydroxyecdysone (20E) increased the level of soluble trehalase activity 5 days postinjection in a dose-dependent manner. In contrast, no increase in membrane-bound trehalase activity was observed under the same conditions. We cloned the cDNAs that encode the soluble and membrane-bound forms of trehalase in O. fuscidentalis trehalase-1 (OfTreh-1) and trehalase-2 (OfTreh-2), respectively. Treh-1 encodes a 581-aa protein while Treh-2 encodes a 648-aa protein with one putative transmembrane domain near the C-terminus. The mRNA expression level of Treh-1 was 27-fold higher than that of Treh-2 in diapausing larval midgut. Following the exposure of diapausing larvae to JHA, Treh-1 mRNA expression increased gradually until the prepupal period whereupon it increased dramatically; in contrast, the mRNA expression of Treh-2 remained at its initial level. Similarly, 20E upregulated Treh-1 expression but had no effect on Treh-2 expression. Taken together, these results suggest that an increase in the soluble trehalase activity at pupation is caused by upregulation of Treh-1 gene. Moreover, membrane-bound trehalase does not appear to be involved in the dynamic changes in the hemolymph trehalose concentration that occur during the larval–pupal transformation. [Copyright &y& Elsevier]

Abstract: Introduction : The use of zebrafish (Danio rerio) larvae was investigated to predict adverse visual effects and to establish the potential application of this organism in early drug safety assessment. Methods Following a comparison of the effects of 4 compounds in TL and WIK strains of zebrafish larvae, a blinded validation set of 27 compounds was tested on WIK strain of larval zebrafish in the optomotor response (OMR) assay. Selected compounds were also tested in the optokinetic response (OKR) and locomotor assays. Larvae were exposed from 3–8 days post-fertilisation (d.p.f.) by immersion in embryo culture media (E3) containing the compound in 1% DMSO (v/v). At 8 d.p.f. toxicity was assessed and the OMR or OKR assays were undertaken at non-toxic treatment levels. Compounds were then rated as ‘red’, ‘amber’ or ‘green’ according to their effects on visual function prior to unblinding of the identities of the test compounds. Results Overall, the OMR assay revealed a good concordance between the effects of compounds in WIK strain zebrafish with the data available from other in vivo and in vitro models or the clinic: thirteen out of nineteen positive compounds produced the expected effect while six of the eight negative compounds were correctly predicted. This gave an overall predictivity of 70% with a sensitivity of 68% and a specificity of 75%. The two false positive compounds were further tested in locomotor and optokinetic response assays and it was shown that a motility defect, rather than an effect on vision, had given rise to the positive result in the OMR assays. Therefore, the OMR assay would best be employed with other techniques to identify false positives. Further studies on two of the false negatives at higher concentrations suggested that the initial concentrations tested were too low. Therefore, it should be ensured that the maximum tolerated concentration is tested in the OMR assay. A comparison of four standard compounds in the OMR assay in WIK and TL zebrafish wild type strains revealed no difference in sensitivity between the strains. Discussion Overall, these results suggest that the OMR assay in zebrafish could be useful in predicting the adverse effects of drugs on visual function in man and would support its potential as a screen for ‘frontloading’ safety pharmacology assessment of this endpoint in vivo. [Copyright &y& Elsevier]

Abstract: As for some temperate forage, some tropical tanniniferous plants (TTP) from browsing might represent an alternative to chemical anthelmintic. The anthelmintic effect of four TTP (Acacia pennatula, Lysiloma latisiliquum, Piscidia piscipula, Leucaena leucocephala) on Haemonchus contortus was measured using two in vitro assays. First, the effects of increasing concentrations of lyophilized extracts (150, 300, 600, 1200μg/ml PBS) were tested on H. contortus larvae (L3) using the larval migration inhibition (LMI) test. An inhibitor of tannin, polyvinyl polypyrrolidone (PVPP), was used to verify whether tannins were responsible for the AH effect. Secondly, the effects of extracts on larval exsheathment were examined. Larvae (L3) were in contact with extracts (1200μg/ml) for 3h, and then were exposed to an artificial exsheathment procedure with observations of the process at 10min intervals. A general lineal model (GLM) test was used to determine the dose effect in the LMI test and the difference of the percentage of exsheathed larvae between the control and the treatment groups. A Kruskal Wallis test was used to determine the effect of PVPP on LMI results. The LMI test showed a dose-dependent anthelmintic effect for A. pennatula, L. latisiliquum and L. leucocephala (P <0.01), which disappeared after PVPP addition, confirming the role of tannins. No effect was found for P. piscipula on H. contortus in the LMI test. However, all four plant extracts interfered with the process of L3 exsheathment which might be involved as a mechanism of action of tannins on H. contortus larvae. A. pennatula, L. latisiliquum and L. leucocephala could be used as an anthelmintic for the control of H. contortus after confirmation based on in vivo studies. [Copyright &y& Elsevier]

Abstract: This study tested the hypothesis that milk has a direct effect on the establishment of infection with Teladorsagia circumcincta, and provides information on the effects of suckling on resilience to infection in young lambs. Of 46 six-week-old twin-born lambs, one from each twin was allowed to continue suckling (S−) and its twin-weaned (W−) while both were concurrently infected with an average of either 0 (−0; n =7/group), 250 (−250; n =8/group) or 1000 (−1000; n =8/group) third stage infective larvae (L3) of T. circumcincta per day, providing six treatment groups. All groups grazed minimally contaminated pasture, and after 42 days were slaughtered for necropsy. Low pasture larval contamination was confirmed in W0 and S0 lambs by faecal egg counts (FEC) of less than 30 eggs per gram (EPG) and burdens of less than 140 worms. There was no difference in FEC between weaned and suckled lambs. Within infection regime, total worm burdens were 55–60% greater in the weaned compared with their suckled counterparts (P =0.05), and represented 27 and 17%, respectively, net establishment of larvae. The greater worm burdens of both groups of weaned animals, which compared with their suckled counterparts, and of those infected with 1000 compared with 250 larvae per day, were associated with shorter female adults that had fewer eggs in utero, perhaps indicating intra-worm population regulation, but highlighting the limitation of FEC in assessing nematode burdens of such young lambs. There was no effect of infection on live weight gain of either weaned or suckled groups and the possibility was raised that, in such young lambs, immune unresponsiveness may be responsible. The major benefit of continued milk consumption appears to lie more in providing nutrients for enhanced growth rather than in improving resilience of the lambs to infection. [Copyright &y& Elsevier]

Abstract: PCR with specific primers against Pseudoalteromonas sp. LT-13, and Denaturing Gradient Gel Electrophoresis (DGGE) of PCR-amplified 16SrDNA, was used to monitor the bacterial community in samples of early stages of scallop larvae suffering high mortality. Samples were taken of larvae from different tanks, water in the tanks, eggs/sperm, inlet water and algal cultures. The DGGE profiles revealed one dominating band that was always present in samples of scallop larvae suffering high mortality. The band was sequenced and demonstrated high sequence homology to Pseudoalteromonas sp. LT-13, a bacterium previously isolated from the hatchery. Samples from different locations in the production unit were collected four times in an 11-month period and tested for the presence of LT13 by PCR. Seventy-four percent of the samples collected in April 2003 contained LT-13. In this period the mortality of the scallop larvae was no less than 96.8%. In two of the other samples the mortality was moderate (83.3–78.0%), and LT-13 was detected in 30 and 57% of these samples. High mortality (98.3%) also occurred in the February 2003 sampling period; however, LT-13 was detected in just 39% of the samples. These results indicate that the bacterium is not an obligate pathogen, but rather an opportunistic bacterium that may be used as an early indicator of the conditions in the hatchery. [Copyright &y& Elsevier]

Chigger mites were collected from 1,080 wild birds of 37 species at Certak (Czech Republic), in the western Carpathian Mountains, from 29 July to 24 September 2005. The prevalence of infestation with chigger larvae was 7%. A total of 325 chigger specimens from 10 bird species was identified and three chigger species were found: Neotrombicula autumnalis, N. carpathica, and N. inopinata, the latter two species being reported on new hosts. Neotrombicula carpathica is reported in the Czech Republic for the Wrst time. A total of 509 chigger larvae found on 79 host specimens were examined by polymerase chain reaction (PCR) for the presence of Borrelia burgdorferi s.l. DNA (fragments of the rrf (5S)—rrl (23S) intergenic spacer), and Anaplasma phagocytophilum DNA (epank1 gene). A fragment of specific Borrelia DNA was amplified through PCR in one sample, and the PCR product was further analyzed by reverse line blotting assay, whereby both genospecies of B. garinii and B. valaisiana were proved. This sample pooled five chigger larvae collected from one Sylvia atricapilla on 11 August 2005. No A. phagocytophilum DNA was amplified. We conclude that larvae of the genus Neotrombicula can be infected with Borrelia genospecies originated from their present or former hosts. [ABSTRACT FROM AUTHOR]

The guava weevil, Conotrachelus psidii, is a major pest of guava in Brazil causing severe reduction in fruit quality. We assessed its susceptibility to Heterhorhabditis baujardi LPP7 infective juveniles (IJs) in the greenhouse and under field conditions applying the nematodes in cadavers of seventh instar Galleria mellonella larvae. Field persistence of these nematodes in the soil was evaluated through G. mellonella-baiting. Insect cadaver concentrations of 2, 4 and 6 applied in pots in the greenhouse experiment caused significant mortality compared to the control. Significance differences were observed in the field between control and treatments only when six cadavers per 0.25 m2 were applied. Infective juveniles from the cadavers persisted 6 weeks after application in the field, but decreased greatly thereafter. Our work demonstrates that H. baujardi LPP7 IJs emerging from G. mellonella cadavers can be efficacious against guava weevil fourth instar larvae. Also, we demonstrated the long-term persistence of IJs in the soil. [ABSTRACT FROM AUTHOR]

The origin of marine invertebrate larvae has been an area of controversy in developmental evolution for over a century. Here, we address the question of whether a pelagic “larval” or benthic “adult” morphology originated first in metazoan lineages by testing the hypothesis that particular gene co-option patterns will be associated with the origin of feeding, indirect developing larval forms. Empirical evidence bearing on this hypothesis is derivable from gene expression studies of the sea urchin larval gut of two closely related but differently developing congenerics, Heliocidaris tuberculata (feeding indirect-developing larva) and H. erythrogramma (nonfeeding direct developer), given two subsidiary hypotheses. (1) If larval gut gene expression in H. tuberculata was co-opted from an ancestral adult expression pattern, then the gut expression pattern will remain in adult H. erythrogramma despite its direct development. (2) Genes expressed in the larval gut of H. tuberculata will not have a coordinated expression pattern in H. erythrogramma larvae due to loss of a functional gut. Five structural genes expressed in the invaginating archenteron of H. tuberculata during gastrulation exhibit substantially different expression patterns in H. erythrogramma with only one remaining endoderm specific. Expression of these genes in the adult of H. erythrogramma and larval gut of H. tuberculata, but not in H. erythrogramma larval endoderm, supports the hypothesis that they first played roles in the formation of adult structures and were subsequently recruited into larval ontogeny during the origin and evolution of feeding planktotrophic deuterostome larvae. [ABSTRACT FROM AUTHOR]

The effect of timing of the first feeding (2, 3, 4, 5, 6, 7, and 8 days post-hatch, dph), on survival and on growth of laboratory-reared obscure puffer (Takifugu obscurus) larvae was examined. Larvae began to feed exogenously at 2-3 dph (2.96±k0.05 mm in total length) at 24 °C. Survival of larvae initially fed at 2, 3, 4, and 5 dph was similar (73.2-78.8%), while survival decreased sharply for those larvae whose first feeding was at 6 dph (22. 1%), and no larvae were able to survive when food was not offered until 7 and 8 dph. The feeding incidence of larvae fed for the first time at 2, 3, 4, and 5 dph reached 100% in 24 h, whereas the feeding incidence decreased gradually in the larvae fed for the first time at 6 and 7 dph. and no feeding occurred in the larvae introduced to food at 8 dph. According to the feeding incidence, the point of no return occurred between days 6 and 7 after hatching. After 18 dph, no statistically significant differences in mean total length were detected among the larvae fed for the first time at 2, 3, 4, and 5 dph, while the larvae fed for the first time at 6 dph were significantly smaller. To ensure a successful transition from endogenous to exogenous feeding, timing of first feeding of obscure puffer larvae must be before 5 dph. [ABSTRACT FROM AUTHOR]

Predaceous larvae of the water scavenger beetle Tropisternus setiger (Germar) are common inhabitants of variable environments in which prey availability may vary widely. We conducted laboratory experiments to assess the effect of prey density on developmental times and survivorship of the preimaginal stages of T. setiger. We also examined the effect of the number of consumed prey on the larval size of instar III. Four different prey densities (one, two, four, and eight preys a day) were tested and both developmental time and survivorship differed significantly among them. Larvae fed one or two preys daily showed a longer developmental time and a lower survivorship than larvae fed four or eight preys a day. Moreover the consumption of four preys a day increased larval developmental success, and to consume one prey a day affected survivorship through the larval period. On the other hand, prey density had no effect on the final larval size. [ABSTRACT FROM AUTHOR]

1. Life-history theory predicts that organisms should speed up development in response to time constraints. However, acceleration of development carries energetic costs that have to be compensated, e.g. by an increase in foraging rate. For the wing dimorphic water strider Gerris lacustris (L.), the hypothesis was tested that the adjustment of development to time constraints is limited by the availability of food resources. 2. Six cohorts of larvae hatched increasingly late in the season were reared under two feeding regimes. For each cohort and experimental group the physiological time (in degree-days) of larval development was estimated. 3. In both high- and low-food groups there was a significant reduction of physiological time for development towards the end of the season. Furthermore, within cohorts, physiological development time was always lower in the high-food group than in the low-food group. However, there was no significant interaction effect between food treatment and cohort. 4. The results demonstrate that G. lacustris has the flexibility to adjust development to time constraints. In addition, 20% of the ‘low-food individuals’ developed into the short-winged morph while all of the ‘high-food individuals’ became long-winged. The limitation of food may thus lead to a reduced allocation of energy into the development of the flight apparatus. This may explain the strong increase in short-wingedness at the end of the season in natural populations, which are highly food limited. [ABSTRACT FROM AUTHOR]

The growth of 1 month old juvenile sole, Solea senegalensis, was monitored 6 months in net cages placed at the bottom of earthen ponds in commercial fish farms in the Tagus and Sado estuaries (Portugal). The post-larvae were stocked at a density of 50/m2. Cages of two different sizes (2 and 6 m 2) were used to protect the post-larvae from predators and to facilitate the monitoring of fish growth and survival over time without significant changes in environmental pond conditions. The specific growth rates ranged from 1.30% in 7 month juveniles to 3.18% per day in 2 month old juveniles. The survival rates presented some variability (65%±26%), sometimes as much as 90% or 99%. After 7 months sole juveniles attained an average length of 11.78±2.26 cm and an estimated weight of 13.98 g. Sole of this weight are tolerant to abrupt changes in environmental conditions (temperature and water turbidity) and can escape from predators. The cages used proved to be very effective in preventing natural predation in the ponds and, at the same time, allowed the development of natural prey suitable for sole juveniles. These results show that it is possible to raise 1 month old sole, in cages set in earthen ponds, fed upon natural prey, thus overcoming one of the main constraints of the life cycle of this species: survival of post-larvae. [Copyright &y& Elsevier]

Most ecological studies consider conspecific individuals as ecologically equivalent, assuming that inter-instar variation is weak and has a limited influence on functional processes. To test this assumption, we investigated the life history and trophic basis of production in two predatory stoneflies, Perlodes microcephalus and Isoperla acicularis, in a mountain stream. The variety of prey types increased with predator size. However, larvae started their development with a strictly phytophagous diet (3 months), then ingested both vegetal material and animal prey (2–3 months). Finally, larvae were strictly carnivorous when head width reached 1.1 mm. Young (herbivorous) I. acicularis larvae occurred from June to August. Young P. microcephalus larvae hatched in October, and were herbivorous until December, when I. acicularis larvae were omnivorous. Competition for animal prey was likely to occur in the spring, but P. microcephalus grew faster and emerged earlier. The cohort productions were mostly based on carnivory (78.7–90.7%), because most production occurred in later instars. Ontogenetic diet shifts could play a role in the structuring of species assemblages by adjusting species'' requirements to the temporal dynamics of environmental conditions, including food availability and biotic interactions. However, their incidence on global processes is quantitatively limited, large individuals having the greatest impacts on the way energy flows. [Copyright &y& Elsevier]

The seasonal variation in growth and mortality of Syacium gunteri larvae in the southern Gulf of Mexico was analyzed. Plankton samples, as well as temperature and salinity measurements were obtained during eight cruises in 1992 and 1993. Larval growth was estimated based on daily marks on sagitta otoliths, using the Laird-Gompertz model since it yielded the best hatching size (HS) estimates. Mean daily growth (MDG) and HS showed a cyclical variation pattern. In both years the highest values were recorded in spring (1992, MDG = 0.19 mm d-1 and HS = 1.47 mm; 1993, MDG = 0.23 mm d-1 and HS = 1.58 mm) and the lowest in winter (1992, MDG = 0.14 mm d-1 and HS = 1.08 mm; 1993, MDG = 0.15 mm d-1 and HS = 1.21 mm). The variation pattern of these parameters was directly and closely related to that of temperature. The mortality rate ranged from 0.05 to 0.26, also with a cyclical pattern, but contrary to that of growth and temperature. Cyclical patterns are not well documented for tropical and subtropical areas, such as the southern Gulf of Mexico, where fish spawn throughout the year and spring may be considered the beginning of the cycle, with spring cohorts showing the highest growth rates and those of winter the lowest. The greater change in temperature that occurs from winter to spring may be the factor triggering these events. [ABSTRACT FROM AUTHOR]

The attack, escape and predation rates for larvae of aphidophagous ladybird Propylea dissecta (Mulsant) and Coccinella transversalis Fabricius were quantified as a potential mechanism leading to the differences in the incidence of cannibalism and intraguild predation. These rates were compared at four larval instars within and between the species. The attack rates of larvae of C. transversalis were significantly higher than those of P. dissecta towards conspecific and heterospecific victims. For both species, third instars exhibited maximum tendency to attack. Escape rates in C. transversalis were higher than P. dissecta . In P. dissecta , the second instars made a greater number of escapes than other conspecific instars after being attacked by same stage cannibal or heterospecific predator. In P. dissecta , first instars suffered maximum mortality due to cannibalism and intraguild predation by conspecifics and heterospecifics of the same and older developmental stage. No larvae of C. transversalis were eaten by P. dissecta of the same stage. These results suggest that the larvae of P. dissecta were more often potential cannibals than intraguild predators, while the reverse was the case in C. transversalis. Based on this finding, it could be predicted that in patchy prey habitats, high rates of larval cannibalism in P. dissecta would occur with a high risk of cannibalism of first instars. Larvae of C. transversalis would respond as intraguild predators, while those of P. dissecta as intraguild prey. The greater size and walking activity of C. transversalis could be possible reason for this tendency. [ABSTRACT FROM AUTHOR]

Abstract: When environmental conditions are unsuitable to support nematode reproduction, Caenorhabditis elegans arrests development before the onset of sexual maturity and specialised ‘dauer’ larvae, adapted for dispersal, and extended diapause are formed. Dauer larvae do not feed and their metabolism is dependent on internal food reserves. Adult worms which express defects in the insulin/insulin-like growth factor receptor DAF-2 also display enhanced longevity. Whole genome mRNA expression profiling has demonstrated that C. elegans dauer larvae and daf-2 adults have similar transcription profiles for a cohort of longevity genes. Important components of this enhanced longevity system are the α-crystallin family of small heat shock proteins, anti-ROS defence systems, increased activity of cellular detoxification processes and possibly also increased chromatin stability and decreased protein turnover. Anaerobic fermentation pathways are upregulated in dauer larvae, while long-lived daf-2 adults appear to have normal oxidative metabolism. Anabolic pathways are down regulated in dauer larvae (and possibly in daf-2 adults as well), and energy consumption appears to be diverted to enhanced cellular maintenance and detoxification processes in both systems. [Copyright &y& Elsevier]

Abstract: A new genus and species of Loricifera, Titaniloricus inexpectatovus (Pliciloricidae) represented by a new type of Higgins-larva is described from the deep sea of the Angola Basin. The new larva is characterized by its gigantic size which is unusual for larval Loricifera, by six rows of scalids on the unit of introvert and neck, by an additional transversal row of scales marking the anterior rim of the collar, by a high number of thoracic plates, by more than 160 longitudinal ridges forming plicae on the loricate abdomen, by tubular toes with a broad basal part and undulated cuticle, and by two pairs of long anterior setae. The exuvium of the presumable sixth instar Higgins-larva of T. inexpectatovus gen. et sp. n. functions as a shelter for several instars: a large simplified seventh instar larva which is paedogenetic and contains some rests of smaller Higgins-larvae, and rests of adult specimens. The paedogenetic or seventh instar larva is morphologically not identical with the sixth instar Higgins-larva from which it moults because of the following transformations: all body regions form a sack-like trunk on which only the scalids of introvert and neck persist as small protoscalids. One of the smaller Higgins-larvae inside contains an adult ready to leave it. The large sixth instar Higgins-larva and the simplified seventh instar paedogenetic larva it contains seem to function together as a “mother larva” for a new larval generation, which has the ability to moult directly into a postlarva and then into an adult. These adults have a size not different from that of other adults of Pliciloricidae. It remains unclear whether these instars represent a new life cycle or just an additional phase in a more complex life cycle such as is often found in other taxa of Pliciloricidae especially from the deep sea. An adult specimen from the same locality as the giant larva is briefly described and assigned with caution to the same species T. inexpectatovus sp. n. The larval gigantism of a deep-sea loriciferan probably reflects adaptations to the deep-sea habitats they inhabit. [Copyright &y& Elsevier]

Changes in host acceptance is an important factor in the host specialization of phytophagous insects, and knowledge of the genetic organization of this behaviour is necessary in order to understand how host shifts occur. Here we describe the inheritance of adult host acceptance (oviposition) in three closely related species ofYponomeutaLatreille (Lepidoptera: Yponomeutidae), and their interspecific hybrids.Yponomeuta cagnagellus(Hübner), a specialist onEuonymus europaeusL. (Celastraceae),Y. malinellusZeller, a specialist onMalusspp. (Rosaceae), andY. padellus(L.), oligophagous on a number of Rosaceae, were tested for their acceptance of parental hosts in choice tests. Acceptance ofE. europaeusis semi-dominant in hybrids ofY. cagnagellus× Y. padellus, and in hybrids ofY. cagnagellus× Y. malinellus. The dominance of this acceptance was confirmed in oviposition tests with backcross hybrids: backcross hybrids F1×  Y. cagnagellusoviposited mainly onE. europaeusand F1×  Y. padellusstill deposited more than half of their egg masses onE. europaeus. Reciprocal hybrids did not differ in their host acceptance, indicating that the trait is autosomal. We further studied the effect of larval food on adult host acceptance (‘Hopkins host selection principle’) in split full-sib F1 families. Larval diet influenced oviposition only in one of two hybrid crosses. The F1 hybrid ofY. padellus×  Y. cagnagellus, reared onPrunus spinosaL., deposited a significantly lower percentage of egg masses onE. europaeuscompared to their full-sib sisters fed withE. europaeus. We did not find this in the reciprocal cross. However, still more than half of the egg masses are deposited onE. europaeusby hybrids that have no experience on this host. We conclude that the semi-dominant character of acceptance ofE. europaeusand a tendency of Rosaceae-feedingYponomeutato deposit egg masses on this host may have created the opportunity for the host shift of the predecessor ofY. cagnagellusfrom Rosaceae to the Celastraceae. This shift may have been further facilitated by a weak tendency of adults to oviposit on their larval food source. [ABSTRACT FROM AUTHOR]

Abstract: The potential of the leaf beetle Charidotis auroguttata as a biocontrol agent for cat’s claw creeper Macfadyena unguis-cati (Bignoniaceae), an environmental weed in Australia, and risk to non-target plants was evaluated under quarantine conditions. In no-choice tests, C. auroguttata adults and larvae fed on many plant species across different families, but egg to adult development occurred only on the target weed. However, when neonate larvae from the target weed were transferred onto Myoporum boninense australe (Myoporaceae), a non-target native plant, 11.7% completed development, as compared to 95% of larvae that completed development on the target weed. Larval development on this non-target species also took twice as long as on the target weed. No larvae completed development on other test plants. In choice tests, leaf area consumption by adults and larvae was significantly more on the target weed than on other plants, and oviposition occurred only on the target weed. In the no-choice demography trials, adults laid eggs from the second week after emergence on the target weed, with an average of 0.286eggs/female/day, resulting in an 18-fold increase in the adult population over 16 weeks. On My. boninense australe adult survival remained high, but oviposition commenced only from the 10th week after emergence with an average of 0.023eggs/female/day, and none of the eggs developed into adults. In the choice demography trials, oviposition on the target weed was evident from the fourth week onwards, while on the non-target plant oviposition commenced only from the 14th week. Only 10% of total adults and 11.3% of total eggs were found on the non-target plant, and none of these eggs developed into adults. Although the biocontrol agent can ‘spill-over’ from the target weed to the non-target native plant and cause adult feeding damage, the non-target plant could not sustain a viable insect population on its own. This agent was not approved for field release in Australia due to perceived risk to non-target species. [Copyright &y& Elsevier]

We evaluated the role that demography may play in the formation of local aggregations ofSinularia flexibilis(Quoy&Gaimard, 1833), a soft coral that commonly dominates inshore coral reefs of the Great Barrier Reef (GBR), Australia. Two populations on inshore reefs of the Palm Islands were censused once a year for 3?years, starting 10 mo after the extensive bleaching mortality in early 1998. Larger colonies became more prevalent over time; mean colony size increasing by 35%, from 276 cm2 in 1998 to 373 cm2 in 2000. Growth rates were size dependent, with smaller colonies growing proportionally faster than larger colonies. Change in size relative to initial size indicated an expected mean annual growth of 128 cm2 for a 50-cm2 colony. Zero growth was predicted at 532±21cm2, with colonies larger than this likely to undergo fission or shrink. Forty-three percent of colonies were undergoing fission at any time at both localities. Most new colonies were produced by fission (70%,n=285), with the remainder produced by the recruitment of sexually produced larvae (19%) or by colony translocation (11%). The sexual and asexual recruitment rates were 0.24 and 1.0 recruits m-2 year?1, respectively. Opportunistic recruitment and rapid growth following disturbances are commonly assumed to be the mechanisms leading soft corals to dominate locally. In this study, these mechanisms operated more slowly than expected, with no net change in population size. [ABSTRACT FROM AUTHOR]

After investigation of the type specimens of 11 genera of ceriantharian larvae, it was concluded that the overwhelming majority of planktonic forms should be referred to the family Arachnactidae. Despite the fact that the presence of acontioids is traditionally considered as the only characteristic feature of this family, in most of the species acontioids develop at rather late ontogenetic stages. The importance of another feature, the presence or absence ofp-rhabdoids, was considered. Members of suborder Penicillaria (Arachnactidae) typically havep-rhabdoids in the endoderm of alternate mesenteries and in acontioids. Members of suborder Spirularia (Cerianthidae and Botrucnidiferidae) have nop-rhabdoids and all cnidae in their mesenteries are restricted to the region of the mesenteric filament. In Arachnactidae the number of known larval forms significantly exceeds the number of benthic ones. The planktonic forms with developing and mature gonads were described in this family. The paedogenetic origin of Arachnactidae is discussed. It seems likely that, due to the uniformity and deficiency of definite morphological characteristics of the benthic members of the family Arachnactidae, only cnidom and type of the planktonic larva can be used for reliable taxonomical identification of the polyps. [ABSTRACT FROM AUTHOR]

Complex life cycles (CLCs) contain larval and adult phases that are morphologically and ecologically distinct. Simple life cycles (SLCs) have evolved from CLCs repeatedly in a wide variety of lineages but the processes that may underlie the transition have rarely been identified or investigated experimentally. We examined the influence of larval growth rate on the facultative expression of alternative life cycles (metamorphosis or maturation as gill-bearing adults [= paedomorphosis]) in the salamander Ambystoma talpoideum. We manipulated growth rates by altering the amount of food individuals received throughout larval development. The expression of alternative life cycles in A. talpoideum is influenced by growth via food levels, but the same growth rates at different points in the larval period elicit different responses. Individuals were more likely to metamorphose (i.e. express a CLC) when food levels and growth rates were high later in development and more likely to mature without metamorphosing (SLC) when growth rates were comparatively low during the same point in development. Growth rates at particular points in development, rather than overall larval growth rate, may be an important proximate factor in salamander life-cycle evolution. © 2003 The Linnean Society of London, Biological Journal of the Linnean Society, 2003, 80, 639–646. [ABSTRACT FROM AUTHOR]

Studies of host-parasitoid interactions undertaken at Alexandra Fiord, Ellesmere Island, Canada, during the summers of 1994, 1995, and 1996 revealed only two species of tachinid flies parasitic on arctic Gynaephora species. Exorista thula sp. nov. (described herein by D.M. Wood) is from the North American Arctic and is parasitic on Gynaephora groenlandica. Remarks on the systematics of Exorista subgenus Exorista in North America and an identification key for arctic and subarctic species of the tribe Exoristini are included. Chetogena gelida, parasitic on Gynaephora rossii, and E. thula were found to be extremely host specific. Both species of parasitoids developed predominantly on final-instar larvae of their respective hosts, but E. thula also emerged from the penultimate instar (9% of E. thula adults, 19% of hosts) and occasionally from the pupal stage (4% of E. thula adults, 3% of hosts) of G. groenlandica. [ABSTRACT FROM AUTHOR]

Cannibalistic behavior among Ochlerotatus triseriatus larvae was studied to determine whether cannibals are able to alter their attack behavior based on their relatedness to newly hatched conspecific prey larvae. Fourth instar larvae, reared in one of four different initial densities, were placed with newly emerged first instars and, after 48 h, the number of first instar larvae remaining was recorded. Our data suggest a Type III functional response of non-kin fourth instar larvae to first instar prey density. Several significant effects emerged from our analysis model, namely that the number of first instar prey available, the relationship of the first instar larvae with the cannibals, and the density at which the fourth instar cannibals were reared all affected the number of first instar larvae consumed. [ABSTRACT FROM AUTHOR]

Although most insects reproduce in the adult stage, facultative larval or pupal reproduction (paedogenesis) has evolved at least six times indepently in insects, twice in gall midges of the family Cecidomyiidae (Diptera). Paedogenesis in gall midges involves the precocious growth and differentiation of the ovary in an otherwise larval form. We have previously shown that the timing of expression of the Ecdysone Receptor (EcR) and Ultraspiracle (USP), the two proteins that constitute the functional receptor for the steroid hormone 20-hydroxyecdysone, regulates the timing and progression of ovarian differentiation in Drosophila melanogaster (Diptera: Drosophilidae). Here we test the hypothesis that precocious activation of EcR and USP in the ovaries of paedogenetic gall midges allows for precocious ovarian differentiation. Using monoclonal antibodies directed against insect EcR and USP proteins, we first show that when these gall midges are reared under conditions that promote typical, metamorphic development, up- regulation of EcR and USP occurs in the final larval stage. By contrast, in the paedogenetic life cycle, EcR and USP are up-regulated early in the first larval stage. A similar pattern is seen for two independently-evolved paedogenetic gall midges, Heteropeza pygmaea and Mycophila speyeri. We discuss our results in the context of developmental constraints on the evolution of paedogenesis in dipteran insects. [ABSTRACT FROM AUTHOR]

The mpi gene encodes a maize proteinase inhibitor (MPI) protein whose mRNA accumulates in response to mechanical wounding. In this study, mpi gene expression in response to different types of damage was investigated. In mechanically damaged leaves of maize (Zea mays L.), mpi mRNA accumulation was affected by the degree of damage inflicted on the leaf. Consecutive wounds resulted in higher levels of mpi transcripts. The MPI protein was expressed in Escherichia coli and purified. Polyclonal antibodies were then produced and used to study MPI accumulation in insect-wounded and mechanically wounded maize leaves. When larvae of the lepidopteran insect Spodoptera littoralis were fed on maize leaves, MPI accumulated in tissues adjacent to the wound site. The level of inhibitor accumulation was higher in leaves chewed by larvae than in leaves that had been damaged mechanically. Longer feeding periods also resulted in higher levels of MPI accumulation. Additionally, the inhibitory properties of MPI toward mammalian and insect digestive serine proteinases were determined. Contrary to the majority of the plant proteinase inhibitors described, MPI is an inhibitor of mammalian elastase that only weakly inhibits mammalian chymotrypsin. However, both elastase and chymotrypsin-like activities from the larval midgut of S. littoralis were effectively inhibited by MPI. We discuss these results with regard to the function and evolution of plant proteinase inhibitors. The availability of a plant proteinase inhibitor which is able to inhibit the two types of insect digestive proteinase, elastase and chymotrypsin, might be useful for engineering protection against lepidopteran insect pests in transgenic plants. [ABSTRACT FROM AUTHOR]

Morphology and sexual reproduction in Chlorogonium capillatum Nozaki, Watanabe & Aizawa sp. nov. (Volvocales, Chlorophyta) originating from Miyatoko Mire, Japan, were studied under controlled laboratory conditions. Vegetative cells of this new species were fusiform with blunt anterior and posterior ends, and they had a massive parietal chloroplast and numerous contractile vacuoles distributed throughout the protoplst. Several to many pyrenoids were randomly distributed in the chloroplast, but they disappeared under the light microscope when grown photoheterotrophically. During asexual reproduction, the first division took place transversely without a preceding rotaion of the parental protoplast. In sexual reproduction, the parental protoplast divided successively to form 32 or 64 small, biftagellate isogametes. After gametogenesis, the gametes did not escape from the parental cell (gametangial) wall, within which pairs of the adjoining gametes fused to form quadriflagellate zygotes. Such zygotes were then released from the parental cell wall and developed into hypnozygotes, which at maturity developed numerous thin spines or hairs on the zygote wall. On zygote germination, four biflagellate germ cells were released from the zygote wall separately. This type of gametic union, "paedogamy," has not previously been described in the green algae except for Chlorococcum echinozygotum Starr. Chlorogonium capillatum can be clearly distinguished from other described species of Chlorogonium by its numerous contractile vacuoles and blunt anterior and posterior ends in vegetative cells as well as by its unique sexual reproduction, in which paedogamous conjugation occurs, and numerous thin spenes or thairs that develop on the hypnozygote walls. [ABSTRACT FROM AUTHOR]

Paedogenetically developing eggs of the gall midge Heteropeza pygmaea are not deposited, but develop in the hemocoel of the mother larva. The nurse chamber remains present in the cleaving egg, and the follicular epithelium does not form a chorion but envelops the growing egg during embryonic development. It is possible to obtain 'naked' eggs, i.e. eggs lacking the follicular epithelium, which are able to develop up to the blastoderm stage but remain spherical instead of assuming an elongated shape. Oogenesis of normal and naked eggs has been studied at the ultrastructural level with special reference to the nurse chamber. It is shown that the nurse chamber nuclei develop large nucleoli during oogenesis, indicating that the nurse chamber supplies the oocyte with ribosomal RNA (rRNA). The dense bodies in the nurse chamber may represent an intermediate stage in the transport of the rRNA from the nurse chamber to the oocyte; they are probably not related to the polar granules in the oocyte. It is also shown that the intercellular bridge joining the nurse chamber to the oocyte disappears shortly before cleavage initiation. During egg cleavage the follicular epithelium surrounds the nurse chamber, which degenerates and is gradually absorbed by the growing egg plasmodium. Naked cleaving eggs are never attached to a nurse chamber or to relics of it. Naked oocytenurse chamber complexes frequently aggregate, which may indicate a role of the follicular epithelium in follicle separation during normal development. [ABSTRACT FROM AUTHOR]

1. The sensory canal system of the adult Notopterus chitala and Notopterus notopterus has been described with a view to supplement OMARKHAN'S investigations (1949) on the larval forms of the former species. It has been found to be constructed on the same fundamental plan in both the species. 2. The sensory canals of the head form a completely closed system of spacious channels enclosing large neuromasts capped with cupulae; the roofs of the canals are generally not protected by bones and are thus placed in direct contact with the skin at several places. The neuromasts are elongated in a plane perpendicular to the long axis of the canals, and the lumen of the canals at the location of the neuromasts is considerably reduced. 3. The temporal canal is prolonged anteriorly above the eye up to the posterior nostril and the supraorbital canal remains quite independent from the rest of the canals. The preopercular and infraorbital canals are thrown into saccular dilatations at certain points. 4. The temporal canal dilates into a large sinus at the point where the preopercular canal opens into it. The anatomical relationship of this temporal sinus with the membranous labyrinth has been described. 5. The topography of the lateral-line canal of the body and its relations with the scales have been described. This canal remains completely independent of the cephalic canals in the adults of both the species. 6. On the basis of the available data, evidence has been provided against OMARKHAN'S contention (1949) that the abbreviation of the ontogenetic processes in the development of canals in N. chitala is correlated with the existence of a closed system of canals in the adult. Instead, it has been suggested that it might be possible to correlate it with the life history and ecological conditions of the fish. 7. The topography and the structural peculiarities of the cephalic sensory canals of the adult Notopterus have been analyzed from a functional point of view. It has been concluded that the entire cephalic sensory canal system in this fish has become exceptionally specialized to perform its chief function of perceptions meclianial disturbances in the surrounding water. The significance of the temporal snius-membranous labyrinth connexion has been discussed in relation to the shape ana habit of the fish and it has been inferred that this connexion might be of Assistance to the membranous labyrinth in effecting equilibration of the fish. [ABSTRACT FROM AUTHOR]

Abstract: Myiasis infestations caused by the larvae of flies mostly belonging to Cyclorapha suborders are frequently encountered in Turkey, which is located in the subtropical zone. The skin is a common site for myiasis, and the infestations are likely to develop in infected tissues and poorly attended wounds of the skin. The case, a 30-year-old male patient, was diagnosed with psoriasis 18 years ago. He had psoriatic scales on his right big toe and was receiving corticosteroid and immunosuppressive drugs. A total of 11 fly larvae were removed from the infected right first toe of the patient. Structures of the stigmas seen in the cross-sections taken from the final segments of these larvae were examined and determined as Sarcophaga spp. larvae. Patients with infected tissues should be extremely cautious about their wound hygiene and take required fly control measures especially during summer as flies can find a suitable environment for sustenance. [Copyright &y& Elsevier]

Temperature is one of our most important physical cues, with extremes eliciting painful sensory warnings of tissue damage. Two recent publications present findings in Drosophila that implicate different neural substrates for low- and high-temperature responses, as well as indicating that a transient receptor potential (TRP) channel family member, painless, plays a role in these responses. [Copyright &y& Elsevier]