Quametopia gen. n. is established on the basis of recent phylogenetic analysis of taxa formerly assembled under the genus Mumetopia Melander, 1913 to include M. terminalis (Loew, 1863) and two new closely related Nearctic species of Anthomyzidae. The new genus is diagnosed and its phylogenetic relationships discussed. Quametopia terminalis (Loew, 1863) comb. n. is transferred from Mumetopia and redescribed based on revision of the type material (lectotypes of Anthophilina terminalis Loew, 1863 and its synonym Mumetopia nitens Melander, 1913 are designated) and other extensive material. Quametopia clintonia sp. n. and Q. amplistylus sp. n. (both from Canada, USA) are described and relationships of all three Quametopia species discussed. Immature stages of Q. terminalis and Q. clintonia sp. n. obtained by means of adult-to-adult rearing are described (1st- and 2nd-instar larvae for the first time in the family Anthomyzidae) and illustrated. Keys to adults, eggs, larvae and puparia of Quametopia species are presented. Biology (habitat and host-plant associations, life history) of Q. terminalis and Q. clintonia sp. n. are studied in detail and their ecological separation demonstrated. Distribution of all Quametopia species is reviewed. and Jindřich Roháček, Kevin N. Barber.
Pyridoxal kinase (PLK; EC 2.7.1.35) is a key enzyme in the metabolism of vitamin B6 (VB6) in Bombyx mori. A fusion expressional vector pET-22b-BPLK-His was constructed using a sub-cloning technique, the recombinant B. mori PLK was then expressed in Escherichia coli, purified and characterized. Bioinformatics were used to deduce the protein structure and genomic organization of this enzyme. Using Ni Sepharose affinity column chromatography, the recombinant protein was purified to very high degree (approximately 90%). The recombinant PLK exhibits a high specific enzymatic activity (1800 nmol/min/mg of protein). The maximum catalytic activity of this enzyme was recorded over a narrow pH range (5.5-6.0) and Zn2+ is the most effective cation for catalysis under saturating substrate concentrations. When only triethanolamine is present as the cation, K+ is an activator of PLK. A double reciprocal plot of initial velocity suggests that the enzyme catalyses the reaction by means of a sequential catalytic mechanism. Under optimal conditions, the Km value for the substrates of ATP and pyridoxal are 57.9 ± 5.1 and 44.1 ± 3.9 µM. B. mori's genome contains a single copy of the PLK gene, which is 7.73 kb long and contains five exons and four introns, and is located on the eighth chromosome. The PLK may be a dimer with two identical subunits under native conditions, and it is hypothesized that each monomer contains eight α-helices (α1-8), nine β-strands (β1-9) and two segments of 310 helices. and Shuo-Hao HUANG, Wang MA, Ping-Ping ZHANG, Jian-Yun ZHANG, Yan-Feng XIE, Long-Quan HUANG.
1_Macrosiphum euphorbiae. Three tomato cultivars (Scintilla, Beefmaster and Rio Grande) were used in the experiments. The results for three watering regimes were compared with those of a control, which was well watered every three days: stressed plants received one third of the water supplied to the control over each three-day interval (experiment 1); stressed plants received a gradually decreasing amount of water (100% at the first watering and then 80%, 60%, 50%, 40% and 20%) every three days (experiment 2); stressed plants received the same amount of water as the control but at longer intervals, that is when evident signs of wilting appeared (experiment 3). The results showed that water stress either enhanced, had an adverse effect or had no effect on aphid population growth, depending on the cultivar and watering regime. No difference was recorded in the population dynamics of M. euphorbiae feeding on Beefmaster tomato plants subjected to different levels of water stress. In the case of the cultivar Scintilla, live aphids were less abundant on stressed plants than on well watered ones in experiment 1 and 3 but not in experiment 2., 2_The highest variability in aphid population dynamics on the plants grown under the different water stress protocols was recorded on the cultivar Rio Grande. In experiment 1, the initial peak in aphid numbers was higher on the water stressed plants than on the control and then decreased to lower numbers than on the control. In experiment 2, there were no differences in the numbers of aphids infesting stressed and control plants. In experiment 3, there were fewer aphids on stressed than on control plants after six days, as in experiment 1, but there was no initial peak in aphid numbers., Anna R. Rivelli ... [et al.]., and Obsahuje seznam literatury
Warmer temperatures in the past 30 years have significantly influenced the seasonal development of insects throughout Europe. As a result of the outbreaks of black flies that have occurred in southeastern Lithuania since the 1970s it is hypothesized that this increase in black fly activity is due to the change in climate. To test this hypothesis the development of Simulium maculatum Meigen under different conditions was determined. This revealed that the time of hatching of S. maculatum eggs in Lithuania was influenced by winter air temperatures, especially those in March. Pupation in S. maculatum is associated with the increase in air and water temperatures that occur at the end of April and in May. The emergence of S. maculatum black flies occurs most often in May. At a water temperature of 13.2°C (1999), S. maculatum took 42 days to develop and half this time (21 days) when the water temperature was 18.8°C (2005). The number of black flies that emerged each year was determined by air temperature but unaffected by rainfall in June (either per month or per ten-day period). and Rasa Bernotienė, Galina Bartkevičienė.
n this study we addressed a question of whether experimental manipulations that increase life span also reduce physical activity and molecular oxidative damage. We used three phenotypes of male and female Pyrrhocoris apterus that survive for different lengths of time, diapausing insects, reproductive insects and insects from which the corpus allatum, the source of juvenile hormone, was surgically removed. Protein carbonyl content of the thoracic muscles was used as an index of molecular oxidative modification. Diapause or ablation of the corpus allatum (allatectomy) was associated with an extended life span of both sexes, but only those individuals that were in diapause were less active. The carbonyl content, both relative (per protein unit) and absolute (per thorax) increased with age in reproductive insects of both sexes. However, the associations between the carbonyl content and diapause and allatectomy differed in males and females. In males, the carbonyl content was not associated with either diapause or allatectomy. There was no age-related increase in the relative and absolute carbonyl levels in diapausing females, while only the increase in the relative carbonyl level was absent in allectomized females. Overall, the results indicate that both allatectomy and diapause prolonged life span, but had different and sex-specific effects on locomotor activity and carbonyl content. Only the extension of the life span of diapausing females was correlated with both reduced locomotor activity and reduced carbonyl content., Marcela Buricova, Magdalena Hodkova., and Obsahuje seznam literatury
Paysandisia archon (Burmeister, 1980) (Lepidoptera: Castniidae) is an accidentally introduced pest that damages palm trees in the northern Mediterranean area. To our knowledge, there are no experimental studies on its mating behaviour, and little is known about its biology and ecology. In the present study, we used outdoor experiments to investigate several characteristics of the reproductive behaviour of P. archon: sexual maturity, diel periodicity of mating, occurrence of polyandry and delay between mating and laying eggs. The results indicate that 73% of the individuals studied were sexually mature three hours after adult emergence. Mating peaked between 14:00 h and 15:00 h and 87% of the females were fertilized and started laying eggs 1.25 (± 1.14) days after mating. Females were generally monandrous, but nevertheless remained attractive after mating. The results of this study provide the necessary background knowledge for studying several aspects of P. archon reproductive biology, in particular oviposition, sex pheromones and their role in mediating mating behaviour in this pest. These results are the first step in developing tools for monitoring populations of this pest., Roxane Delle-Vedove ... [et al.]., and Obsahuje seznam literatury
1_The respiratory metabolism of different polyphenic forms of the pea aphid, including wingless and winged asexual females (virginoparae), sexual females (oviparae) and winged or wingless adult males, was investigated using a micro-respirographic method. The records revealed sub-nanoliter amounts per min of O2 consumption or CO2 output. Respiratory metabolism of individuals was monitored for 3 to7 h after removal of the aphid from the food plant. Most of the recordings were for relatively large (3.5 mg), wingless asexual females (virginoparae). These aphids exhibited a continuous and very regular respiratory gas exchange (example: specimen of 3.5 mg body mass consumed 180 nl of O2 per min; released simultaneously 300 nl CO2 per min; = standard metabolic rate of 3085 µl O2 / g / h; R.Q. = 1.66). This continuous pattern of respiration occurred only when the aphids were kept at relatively high humidity. By contrast, aphids of various seasonal forms exhibited discontinuous respiratory gas exchange when kept in relatively dry air (atmospheric, room conditions). These patterns can be briefly described as follows: (a) Short and rather small micro-cycles of CO2 emission, manifested usually by the sudden expiration of 60–120 nl of CO2 once every 5 min; (b) Larger bursts of 240–480 nl of CO2 with a periodicity of one hour; (c) Enormously large, discontinuous bursts of 10–14 µl CO2, duration 10–30 min, repeated with a periodicity of several hours. There was no constant pattern of diffusive CO2 emission (DGC). The aphids exhibited a pattern of CO2 release that was appropriate for the external conditions, such as temperature and humidity, and internal physiological conditions such as metabolic activity, availability of reserve substances (carbohydrate, lipid) and water. Certain stages (wingless virginoparae) exhaled volumes of CO2 greatly in excess of their O2 consumption (R.Q. over 1.5)., 2_Sudden exhalations of CO2 from the body were a consequence of a bulk production and outflow of CO2 and not due to the diffusion of CO2 previously accumulated within the tracheal system. Due to their generally high metabolic activity (1142 to 6780 µl O2 / g / h), aphid tissue and organs produced relatively large amounts of metabolically formed carbonic acid. The resulting respiratory acidaemia was moderated by outbursts of gaseous CO2, liberated from liquid carbonate buffers by a regulatory mechanism based on enzymatic hydration and neutralization of carbonic acid by discontinuous formation of gaseous CO2., Karel Sláma, Pavel Jedlička., and Obsahuje seznam literatury
The effects of tannic acid on mean values and genetic variation in fitness-related traits (mass, relative growth rate) and specific activities of digestive enzymes (total proteases, a-glucosidase and lipase), and genetic variation in their plasticity, were investigated in fifth instar larvae of Lymantria dispar L. (Lepidoptera: Lymantriidae) originating from two populations with different host use histories (oak and locust-tree). The two populations did not differentiate with respect to fitness-related traits, i.e. adverse effects of tannic acid were similar in both populations. However, Robinia larvae, which originated from the locust-tree forest, were characterized by higher total protease and lipase activity and lower a-glucosidase activity than Quercus larvae, which originated from the oak forest. Higher plasticity of lipase and lower plasticity of a-glucosidase in response to tannic acid were also recorded. Quantitative genetic analysis revealed mostly significant expression of genetic variation in the examined traits and trait plasticity, suggesting the potential for evolution of adaptive plastic responses to new environmental conditions and presence of a stressor. The genetic correlations observed between the environments significantly differed from “one”, which indicates there are no constraints on the evolution of trait plasticity., Marija Mrdakovic ... [et al.]., and Obsahuje seznam literatury
Various disturbances in forests often result in the formation of open habitats with characteristics that are distinctly different from those of the original forest (microclimate, illumination, stand age and composition). These disturbances affect the habitat heterogeneity in time and space and seem to drive forest succession and changes in biodiversity in forests. Little is known about how the colonization of deforested habitats by Orthoptera is influenced by environmental factors. We studied the association between the structure of orthopteran assemblages and the age of clear-cuts, vegetation structure and other environmental parameters (size, elevation, altitude). This involved 33 clear-cuts of three age categories in broadleaved forests dominated by European beech. The Orthoptera were sampled using sweep netting and by counting individuals recorded along transects that ran parallel to those used for recording the structure of the vegetation. We recorded significant differences in the number and abundance of species in the three age categories of clear-cuts. Grasshopper species were more abundant than bush-crickets in first year clear-cuts. Species capable of flight occured in all three age categories of clear-cuts (>62% of the 27 species recorded). All the species of Orthoptera identified were present in two year-old clear-cuts. The species composition and abundance of Ensifera and Caelifera differed in their association with the six vegetation parameters studied. While the Caelifera occurred in habitats with bare ground the Ensifera mainly occurred in those with a higher proportion of shrubs and trees. There was also a positive correlation between number of species of Orthoptera and area of the clear-cut regardless of its age as well between the number of species of Orthoptera and elevation., Anna Sliacka, Anton Krištín, Ladislav Naďo., and Obsahuje seznam literatury
The planthopper genus Pseudoparicana Melichar, 1914 is revised. Three previously known species, P. curvifera (Distant, 1907), P. sanguinifrons Muir, 1931 and P. tepida Melichar, 1914 are re-described and P. analoga Wang & Malenovský sp. n. is described as new. Lectotypes are designated for P. curvifera and P. tepida. An identification key and illustrations of diagnostic characters, including male and female genitalia, are provided for all taxa and the systematic position of this genus and the asymmetry of the genitalia of the species are briefly discussed. As far as known, the distribution of Pseudoparicana is restricted to New Guinea and the Aru Islands., Rong-Rong Wang ... [et al.]., and Obsahuje seznam literatury