NOTES ON THE BIOLOGY OF THE LEAFHOPPER APHRODES BICINCTA (HOMOPTERA: CICADELLIDAE) IN THE OTTAWA AREA

1970 ◽  
Vol 102 (6) ◽  
pp. 750-758 ◽  
Author(s):  
L. N. Chiykowski
Keyword(s):  
Room Temperature ◽  
Trifolium Pratense ◽  
Cold Treatment ◽  
Peat Moss ◽  
Adult Males ◽  
Female Adult ◽  
Nymphal Stage ◽  
Long Period ◽  
Female Survival ◽  
Early Instar

AbstractNymphs of the leafhopper Aphrodes bicincta (Schrank) first appeared in the field at the end of May or early June. Emergence of nymphs was protracted over a long period with second and third instar nymphs still being found when adult males were already present. Early instar nymphs were found on strawberry, Trifolium pratense L., T. hybridum L., Plantago major L., Taraxacum officinale Weber, Capsella bursa-pastoris (L.) Medic., Erigeron canadensis L., and a species of Brassica. There was only one generation per year, the winter being spent in the egg stage. Eggs deposited in plants in the field hatched when brought into the greenhouse during the winter months.In greenhouse studies, eggs were most often found oviposited on the surface of the soil or completely embedded in the petioles of leaves and in clumps of peat moss. Although eggs held at room temperature (70°–75°F) occasionally hatched, cold treatment (45°–50°F) of several weeks resulted in eggs hatching in as short a time as 14 days following their return to room temperature. There were five instars in the nymphal stage. The first four were relatively uniform in length but the fifth was at least 3 days longer than any other instar. Male insects completed the nymphal stage in 38.4 days and female insects in 41.3 days. Descriptions and measurements of the five nymphal instars and male and female adult insects are given. Adult male insects survived well for about 4 weeks and then declined rapidly. Female survival remained relatively high for at least 8 weeks. Some females have lived for up to 20 weeks. Fecundity varied with one female producing 51 offspring and others producing 1.

scholarly journals Effects of Substitution of Y with Yb and Ce on the Microstructures and Mechanical Properties of Mg88.5Zn5Y6.5

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Long Period ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.

Some Effects of Host Age on Parasitism by Nasonia vitripennis (Walk.) (Hymenoptera: Pteromalidae)

1963 ◽  
Vol 95 (8) ◽  
pp. 881-886 ◽  
Author(s):  
H. G. Wylie
Keyword(s):  
House Fly ◽  
Host Age ◽  
Adult Males ◽  
Nasonia Vitripennis ◽  
Female Adult ◽  
Different Ages

AbstractMortality of immature Nasonia vitripennis (Walk.) was least on young house fly pupae (less than 48 hours old, at 24.5 ± 0.5 °C.) and increased with increasing host age. Increased mortality on old hosts was manifested principally as a decrease in female adult progeny, numbers of adult males and of mature diapause larvae remaining approximately constant. Reduction in the percentage of females in the adult progeny reared on old hosts probably resulted from superparasitism. This kills more female than male larvae and occurred more commonly on old hosts, each of which provides a smaller quantity of suitable food for the immature parasites. Adults reared on old hosts were smaller and relatively fewer of them were able to emerge. The proportion of the total mature parasite progeny that remained in diapause was greater on old hosts, probably because of qualitative differences in the food provided by hosts of different ages.

Development of formulations of biological agents for management of root rot of lettuce and cucumber

2000 ◽  
Vol 46 (9) ◽  
pp. 809-816 ◽  
Author(s):  
G A Amer ◽  
R S Utkhede
Keyword(s):  
Bacillus Subtilis ◽  
Pseudomonas Putida ◽  
Fusarium Oxysporum ◽  
Wheat Bran ◽  
Root Rot ◽  
Room Temperature ◽  
Pythium Aphanidermatum ◽  
Growth And Yield ◽  
Peat Moss ◽  
Subtilis Strain

The effect of various carrier formulations of Bacillus subtilis and Pseudomonas putida were tested on germination, growth, and yield of lettuce and cucumber crops in the presence of Pythium aphanidermatum and Fusarium oxysporum f.sp. cucurbitacearum, respectively. Survival of B. subtilis and P. putida in various carriers under refrigeration (about 0°C) and at room temperature (about 22°C) was also studied. In all carrier formulations, B. subtilis strain BACT-0 survived up to 45 days. After 45 days of storage at room temperature (about 22°C), populations B. subtilis strain BACT-0 were significantly higher in vermiculite, kaolin, and bacterial broth carriers compared with other carriers. Populations of P. putida were significantly higher in vermiculite, peat moss, wheat bran, and bacterial broth than in other carriers when stored either under refrigeration (about 0°C) or at room temperature (about 22°C) for 15 or 45 days. Germination of lettuce seed was not affected in vermiculite, talc, kaolin, and peat moss carriers, but germination was significantly reduced in alginate and bacterial broth carriers of B. subtilis compared to the non-treated control. Germination of cucumber seed was not affected by any of the carriers. Significantly higher fresh lettuce and root weights were observed in vermiculite and kaolin carriers of B. subtilis compared with P. aphanidermatum-inoculated control plants. Lettuce treated with vermiculite, and kaolin carriers of B. subtilis, or non-inoculated control lettuce plants had significantly lower root rot ratings than talc, peat moss, bacterial broth, and P. aphanidermatum-inoculated control plants. Growth and yield of cucumber plants were significantly higher in vermiculite-based carrier of P. putida than the other carriers and Fusarium oxysporum f.sp. cucurbitacearum-inoculated plants.Key words: Bacillus subtilis, Pseudomonas putida, Fusarium oxysporum f.sp. cucurbitacearum, Pythium aphanidermatum, talc, vermiculite, alginate, kaolin, peat moss, wheat bran, oat bran.

Biological estimation of oestrogenic activity in red clover (Trifolium pratense): relative potencies of parts of plant and changes with storage

1963 ◽  
Vol 30 (2) ◽  
pp. 243-249 ◽  
Author(s):  
D. S. Flux ◽  
R. E. Munford ◽  
G. F. Wilson
Keyword(s):  
Room Temperature ◽  
Trifolium Pratense ◽  
Red Clover ◽  
Biochanin A ◽  
Reduced Pressure ◽  
Ovariectomized Mice ◽  
Fresh Material ◽  
Freeze Dried ◽  
Relative Potencies ◽  
Different Parts

SummaryImmature ovariectomized mice were used to compare the oestrogenic activities of different parts of the same clover plants; to estimate the relative potencies of biochanin A, genistein and diethylstilboestrol; and to compare the effects of different methods of storage on the oestrogenic potency of red clover leaf and petiole. Test materials were incorporated in the diet fed to the mice and the uterine weight response was used to measure oestrogenic activity.With material harvested at four different times, the leaf or leaf and petiole had the highest activity; small and large stem fractions of the plant were both relatively less active, and blossom and seed head were inactive.Comparison of successive estimates of the relative potency of isoflavones and diethylstilboestrol indicated that the relative responsiveness to the two types of oestrogen did not remain constant. Thus comparisons of estimates of oestrogenic activity of plant material, obtained in terms of diethylstilboestrol in different experiments, could be invalid.The potencies of alcohol, acetone and freeze-dried preparations were compared after storage for 18, 115, 212 and 230 days. Of the procedures tested, the most satisfactory was that in which fresh material was placed in 95% alcohol and the liquor and residue dried and stored at room temperature over concentrated sulphuric acid at reduced pressure.

Post-release breeding of translocated sharp-tailed grouse and an absence of artificial insemination effects

2019 ◽  
Vol 46 (1) ◽  
pp. 12
Author(s):  
Steven R. Mathews ◽  
Peter S. Coates ◽  
Jennifer A. Fike ◽  
Helena Schneider ◽  
Dominik Fischer ◽  
...  
Keyword(s):  
Artificial Insemination ◽  
Male Reproduction ◽  
Conservation Strategies ◽  
Adult Males ◽  
Female Reproduction ◽  
Nesting Habitat ◽  
Restoration Site ◽  
Female Survival ◽  
Population Restoration ◽  
Nest Initiation

Context Translocation has become a widely used method to restore wildlife populations following extirpation. For some species, such as lekking grouse, which breed at traditional mating grounds, reproduction is linked to culturally established geographic locations. Cultural centres are lost upon extirpation, making restoration into otherwise rehabilitated habitats especially challenging. The process by which species with culturally dependent reproduction sometimes become re-established is poorly understood and merits investigation to improve conservation strategies. Historically, population restoration of North American lekking grouse (Tympanuchus spp. and Centrocercus spp.) via translocation has yielded poor results, in part because translocation sites lack leks, culturally determined breeding locations for which breeding adults form a high degree of philopatry. Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus; CSTG) occurs in <10% of its historic range, but the existence of rehabilitated historic habitat provides for the potential of population restoration via translocation. Aims We reintroduced CSTG to vacant habitat in north-central Nevada, USA, from 2013 to 2017, with concordant goals of promoting females to nest and males to lek. We tested the utility of performing artificial insemination (AI) on females before translocation and we conducted paternity analyses to understand male reproduction. Methods We monitored females for the effects of AI on nest initiation, nest survival and egg fertility. We used post-hatch extra-embryonic membranes and other tissues to evaluate paternity of chicks produced at the restoration site. Key results Artificial insemination had no effect on female survival or nest initiation, and did not fertilise any eggs within nine sampled clutches (n=102 eggs). Most paternity was attributable to male residents that had survived for ≥1 year at the restoration site before the arrival of translocated females. Conclusions Artificial insemination neither aided nor harmed female reproduction. A small number of translocated, resident adult males sired reproduction following female release. Implications The presence of resident males at restoration sites may be more likely to result in post-translocation reproduction than is pre-translocation AI. Restoring CSTG to vacant habitat should focus on translocating females into suitable nesting habitat while simultaneously ensuring that reproductively capable males are available within or adjacent to the nesting habitat.

A RHEED study of Cu3Au (110) surface

1992 ◽  
Vol 50 (2) ◽  
pp. 1460-1461
Author(s):  
Yi Huang ◽  
John M. Cowley
Keyword(s):  
Electron Diffraction ◽  
Auger Electron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Room Temperature ◽  
High Energy ◽  
High Energy Electron ◽  
Ion Scattering ◽  
Long Period ◽  
The Ideal

In recent years the Cu3Au (110) surface has been studied by many authors to reveal its ordering structure and order-disorder transition phenomena. A 2×1 structure which corresponds to an ideal truncation of the ordered bulk crystal and a 4×1 reconstructed structure have been observed. Using ion scattering methods, McRae et al have determined the Au fractions in the first and the second layer at room temperature, which deviate from the ideal bulk value and indicate the segregation of Au to the surface. But the question how the atoms are rearranged in the 4×1 structure and why some of the Au stays in the second layer have not been answered. Another important question about Cu3Au (110) surface is whether the long period ordering structure (LPS) exists on the surface. In present work the Cu3Au (precise composition Cu71.7Au28.3) (110) surface is studied with Auger electron Spectroscopy (AES) and Reflection High Energy Electron Diffraction (RHEED) which have not been used to study the Cu3Au surface before.

Preparation of Mg-TM-Y (TM=Transition Metal) Alloys with Long Period Stacking Ordered Phase and their Superior Mechanical Properties

2016 ◽  
Vol 879 ◽  
pp. 815-819
Author(s):  
Takaomi Itoi
Keyword(s):  
Room Temperature ◽  
Rolling Direction ◽  
Alloy Sheet ◽  
Rolled Sheet ◽  
Composition Ratio ◽  
Lpso Phase ◽  
Transition Metal Alloys ◽  
Long Period ◽  
Superior Mechanical Properties ◽  
Plane Sheet

Mg-Ni-Y alloy with composition ratio of 1 : 2 (Ni : Y) consisted of Mg, and 18R-type long period stacking ordered (LPSO) phases, whereas composition ratio of 1 : 1 (Ni : Y) consisted of Mg,14H-type LPSO and Mg2Ni phases, respectively. After hot-rolling at 693K, strong basal texture parallel to the plane sheet was formed in the LPSO, and Mg phases. Tensile test was performed along rolling direction (R.D) from room temperature (R.T) to 573K. The Mg98Ni1Y1, Mg96Ni2Y2, Mg94Ni3Y3, Mg97Ni1Y2 and Mg94Ni2Y4 rolled sheets exhibited 0.2% proof stress (σ0.2) of 232MPa, 255MPa, 358MPa, 337MPa and 393MPa, and elongation (δ) of 6%, 5%, 7%, 15% and 7% at R.T, respectively. The σ0.2 of the Mg-Ni-Y rolled sheet tend to increase with increasing of area fraction of the LPSO phase. After annealing at 773K for 0.6ks, the δ of Mg-Ni-Y rolled sheet tend to increase, while the σ0.2 decreased due to randomization of the Mg phase by re-crystallization. The Mg-Ni-Y rolled sheets exhibited high σ0.2 above 200MPa at 473K. Additionally, it was noted that σ0.2 of the Mg94Ni2Y4 rolled sheet exhibited 329MPa at 473K and 211MPa at 573K. Thus, the LPSO phase have high thermal stability and is attribute to strengthening of the Mg-Ni-Y alloy sheet at high temperature.

Mass rearing of the common field cricket, Gryllus pennsylvanicus burmeister (Orthoptera, Gryllidae), for use as a test insect in toxicological studies

1964 ◽  
Vol 54 (4) ◽  
pp. 805-809 ◽  
Author(s):  
C. R. Harris ◽  
H. J. Svec
Keyword(s):  
Milk Powder ◽  
Fine Sand ◽  
Mass Rearing ◽  
Field Cricket ◽  
Adult Males ◽  
Nymphal Stage ◽  
Gryllus Pennsylvanicus ◽  
Large Numbers ◽  
Toxicological Studies ◽  
The Common

A method of rearing Gryllus pennsylvanicus Burm. is described, designed to yield large numbers of first-instar nymphs of uniform age for toxicological investigations Nymphs are reared to the fourth instar in glass vessels containing a little soil, which prevents cannibalism, and then transferred to glass-topped stock cages having sides and floors of aluminium screening and each accommodating 250 individuals. A mixture of dog-food pellets, oatmeal and milk powder, with fresh oats or clover, is provided throughout as food, and petri dishes of moist fine sand for oviposition. After separation from the sand by sieving, the eggs are incubated in moist soil at 24°C. for one month, subjected to 4°C. for three months to eliminate the obligate diapause, and then returned to 24°C., when 70 per cent, hatch after 15–18 days. The diapause enables eggs to be stored at 4°C. until required. At 24°C., the nymphal stage lasted about 81 days, the adult males and females, which are produced in equal numbers, survived about 62 and 56 days, respectively, oviposition extended over 11 weeks and the average number of eggs laid per female was 970·6.

scholarly journals III. DECREASE OF LABELED DNA IN CELLS OF THE ADRENAL MEDULLA AFTER INTERMITTENT EXPOSURE TO COLD

1969 ◽  
Vol 42 (2) ◽  
pp. 460-468 ◽  
Author(s):  
S. R. Pelc ◽  
Maria Pia Viola-Magni
Keyword(s):  
Dna Synthesis ◽  
Mitotic Index ◽  
Adrenal Medulla ◽  
Room Temperature ◽  
Statistical Evaluation ◽  
Cold Treatment ◽  
Labeling Index ◽  
Initial Value ◽  
Exposure To Cold ◽  
Intermittent Exposure

Italico rats were injected with thymidine-3H 6 hr after the end of 300 hr of intermittent cold treatment. This plan of experiment ensured replacement in the adrenal medulla of lost DNA which is specifically sensitive to cold treatment and has a labeling index sufficiently high for statistical evaluation. The labeling index in the adrenal medulla decreases to one-half of the initial value within 10 days in animals subjected to further intermittent cold treatment and within 32 days in animals kept at room temperature. The very low mitotic index and the absence of doubling of the labeling index show that the observed labeling cannot be ascribed to pre-mitotic DNA synthesis. The concept of metabolic DNA adequately explains the findings.

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