EFFECTS OF VARIOUS FACTORS ON THE LOCAL DISTRIBUTION AND DENSITY OF COCCINELLID ADULTS ON CORN (COLEOPTERA: COCCINELLIDAE)

1971 ◽  
Vol 103 (8) ◽  
pp. 1115-1120 ◽  
Author(s):  
B. C. Smith
Keyword(s):  
Plant Density ◽  
High Elevation ◽  
Maximum Amount ◽  
Coleomegilla Maculata ◽  
Adult Density ◽  
Local Distribution ◽  
Intact Plants ◽  
Corn Field ◽  
Coccinella Transversoguttata

AbstractThe adult densities of Hippodamia tredecimpunctata tibialis (Say), Coccinella novemnotata Hbst., and Coccinella transversoguttata richardsoni Brown, on corn fluctuated in July and August and reached their maxima at pollination, whereas the density of Coleomegilla maculata lengi Timberlake fluctuated much less. C. maculata, H. tredecimpunctata, and C. transversoguttata were more numerous on plants with a liver diet applied to their foliage than on untreated plants. H. tredecimpunctata, C. novemnotata, and C. transversoguttata were less numerous on plants that had their tassels removed and produced no pollen than on intact plants. C. maculata, H. tredecimpunctata, and C. transversoguttata were more numerous on plants exposed to the maximum amount of sunshine than on plants that were shaded for part of each day. H. tredecimpunctata was more numerous on plants situated at low elevation than at high elevation, whereas C. transversoguttata was more numerous at high than at low elevation. C. maculata and H. tredecimpunctata were more numerous on plants near the middle of a corn field than on plants at the perimeter of a field adjacent to buckwheat, whereas C. novemnotata and C. transversoguttata were most numerous on plants near the perimeter. Two-species associations of C. maculata and H. tredecimpunctata, C. novemnotata and H. tredecimpunctata, C. novemnotata and C. transversoguttata, and C. novemnotata and H. tredecimpunctata occurred on individual plants. Plant density and time of planting affected coccinellid density. Adult density was greatest at a plant density of 3.2 plants per square metre and adults were more numerous on early than on late planted corn.

Rapid increases in shrubland and forest intrinsic water-use efficiency during an ongoing megadrought

2021 ◽  
Vol 118 (52) ◽  
pp. e2118052118
Author(s):  
Steven A. Kannenberg ◽  
Avery W. Driscoll ◽  
Paul Szejner ◽  
William R. L. Anderegg ◽  
James R. Ehleringer
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Pinus Ponderosa ◽  
Plant Density ◽  
High Elevation ◽  
American Southwest ◽  
Past Century ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
Negative Impacts

Globally, intrinsic water-use efficiency (iWUE) has risen dramatically over the past century in concert with increases in atmospheric CO2 concentration. This increase could be further accelerated by long-term drought events, such as the ongoing multidecadal “megadrought” in the American Southwest. However, direct measurements of iWUE in this region are rare and largely constrained to trees, which may bias estimates of iWUE trends toward more mesic, high elevation areas and neglect the responses of other key plant functional types such as shrubs that are dominant across much of the region. Here, we found evidence that iWUE is increasing in the Southwest at one of the fastest rates documented due to the recent drying trend. These increases were particularly large across three common shrub species, which had a greater iWUE sensitivity to aridity than Pinus ponderosa, a common tree species in the western United States. The sensitivity of both shrub and tree iWUE to variability in atmospheric aridity exceeded their sensitivity to increasing atmospheric [CO2]. The shift to more water-efficient vegetation would be, all else being equal, a net positive for plant health. However, ongoing trends toward lower plant density, diminished growth, and increasing vegetation mortality across the Southwest indicate that this increase in iWUE is unlikely to offset the negative impacts of aridification.

PREDACEOUS COCCINELLID OVIPOSITION RESPONSES TO JUNIPERUS WOOD

1969 ◽  
Vol 101 (11) ◽  
pp. 1199-1206 ◽  
Author(s):  
M. I. Boldyrev ◽  
W. H. A. Wilde ◽  
B. C. Smith
Keyword(s):  
Laboratory Experiments ◽  
Egg Laying ◽  
Adalia Bipunctata ◽  
Coleomegilla Maculata ◽  
Juniperus Virginiana ◽  
Coccinella Transversoguttata

AbstractIn laboratory experiments at Belleville and Guelph, Ont., four species of coccinellids, Cycloneda munda (Say), Adalia bipunctata (L.), Coccinella transversoguttata richardsoni Brown, and Coleomegilla maculata lengi Timberlake, revealed strong attractances to Juniperus virginiana L. (juniper) for oviposition. This attractancy was due to the specific odour of Juniperus wood. Egg laying rates were not affected by distances up to 70 cm in laboratory cages in a greenhouse where temperatures ranged from 24.0° to 29.5 °C. This phenomenon may be used to aggregate ovipositing coccinellid females in places where aphids are expected to occur in damaging numbers.

SEASONAL OCCURRENCE AND RELATIVE ABUNDANCE OF APHID PREDATORS AND PARASITOIDS ON PUBESCENT POTATO PLANTS

1985 ◽  
Vol 117 (10) ◽  
pp. 1231-1237 ◽  
Author(s):  
John J. Obrycki ◽  
Maurice J. Tauber
Keyword(s):  
Solanum Tuberosum ◽  
Relative Abundance ◽  
Coleomegilla Maculata ◽  
Seasonal Occurrence ◽  
Hippodamia Convergens ◽  
Aphid Parasitoid ◽  
Potato Plants ◽  
Aphid Predators ◽  
Coccinella Transversoguttata

AbstractDuring 2 field seasons, Coccinellidae (primarily Coccinella transversoguttata richardsoni, Coleomegilla maculata, Hippodamia convergens, H. tridecimpunctata, and H. glacialis) were the most abundant predators on potato hybrids (Solanum tuberosum × S. berthaultii, F3) with various densities of glandular pubescence. Highly pubescent clones had the highest percentage of predator eggs, while clones with the lowest trichome densities had the highest percentages of immature and adult predators. By comparison, high numbers of aphid parasitoid mummies (primarily Aphidius and Praon spp.) occurred on clones with moderate to high densities of glandular pubescence. During both years, predators and parasitoids were most abundant in late July and August.

AEC Mountaineer broadglumed wheatgrass

2001 ◽  
Vol 81 (4) ◽  
pp. 745-747 ◽  
Author(s):  
B. A. Darroch ◽  
S. N. Acharya ◽  
J. Woosaree
Keyword(s):  
Key Words ◽  
Plant Density ◽  
High Stress ◽  
High Elevation ◽  
Mature Seed ◽  
Elymus Trachycaulus ◽  
Cultivar Description ◽  
Primary Advantage ◽  
Slender Wheatgrass ◽  
High Elevations

AEC Mountaineer broadglumed wheatgrass, Elymus trachycaulus subsp. violaceus (Horneman) A. & D. Love, is a cultivar developed for reclaiming and revegetating disturbed sites at high elevations. It is the first cultivar of broadglumed wheatgrass available in Canada. Its primary advantage over other subspecies of slender wheatgrass is its ability to grow rapidly and produce mature seed at elevations as high as 2300 m. Production of mature seed enables plants to propagate, thus increasing plant density and stand longevity in high stress, high elevation environments. Key words: Broadglumed wheatgrass, slender wheatgrass, Elymus trachycaulus, reclamation, cultivar description

Statistical analysis of classification

1966 ◽  
Vol 24 ◽  
pp. 188-189
Author(s):  
T. J. Deeming
Keyword(s):  
Multivariate Analysis ◽  
Statistical Analysis ◽  
Classification Scheme ◽  
Analytical Procedure ◽  
Narrow Band ◽  
Scientific Research ◽  
Maximum Amount ◽  
Amount Of Information

If we make a set of measurements, such as narrow-band or multicolour photo-electric measurements, which are designed to improve a scheme of classification, and in particular if they are designed to extend the number of dimensions of classification, i.e. the number of classification parameters, then some important problems of analytical procedure arise. First, it is important not to reproduce the errors of the classification scheme which we are trying to improve. Second, when trying to extend the number of dimensions of classification we have little or nothing with which to test the validity of the new parameters.Problems similar to these have occurred in other areas of scientific research (notably psychology and education) and the branch of Statistics called Multivariate Analysis has been developed to deal with them. The techniques of this subject are largely unknown to astronomers, but, if carefully applied, they should at the very least ensure that the astronomer gets the maximum amount of information out of his data and does not waste his time looking for information which is not there. More optimistically, these techniques are potentially capable of indicating the number of classification parameters necessary and giving specific formulas for computing them, as well as pinpointing those particular measurements which are most crucial for determining the classification parameters.

Freeze-Fracture Studies of Membranes in Developing Sieve Elements in a Plant Tissue Culture

1980 ◽  
Vol 38 ◽  
pp. 636-637
Author(s):  
R. D. Sjolund ◽  
C. Y. Shih
Keyword(s):  
Plant Tissue ◽  
Cultured Cells ◽  
Freeze Fracture ◽  
Tissue Cultures ◽  
Sieve Elements ◽  
Intact Plants ◽  
Plant Tissue Cultures ◽  
Whole Plants ◽  
Energy Dependent ◽  
Similar Elements

The differentiation of phloem in plant tissue cultures offers a unique opportunity to study the development and structure of sieve elements in a manner that avoids the injury responses associated with the processing of similar elements in intact plants. Short segments of sieve elements formed in tissue cultures can be fixed intact while the longer strands occuring in whole plants must be cut into shorter lengths before processing. While iyuch controversy surrounds the question of phloem function in tissue cultures , sieve elements formed in these cultured cells are structurally similar to those of Intact plants. We are particullarly Interested In the structure of the plasma membrane and the peripheral ER in these cells because of their possible role in the energy-dependent active transport of sucrose into the sieve elements.

The effect of 8 days of microgravity on regeneration of intact plants from protoplasts

1994 ◽  
Vol 92 (3) ◽  
pp. 404-411 ◽  
Author(s):  
Ole Rasmussen ◽  
Carolyn A. Baggerud ◽  
Hilde C. Larssen ◽  
Kjell Evjen ◽  
Tor-Henning Iversen
Keyword(s):  
Intact Plants

COMPUTER MODELING OF CHEMICAL EQUILIBRIUMS IN WO3–H2O SYSTEM

2017 ◽  
pp. 35-48 ◽  
Author(s):  
V.P. Bondarenko ◽  
O.O. Matviichuk
Keyword(s):  
Transition Temperature ◽  
Gas Phase ◽  
Single Phase ◽  
Reference Data ◽  
Maximum Amount ◽  
Reaction Products ◽  
Influence Of Temperature ◽  
Equilibrium Chemical ◽  
Program Data ◽  
Good Agreement

Detail investigation of equilibrium chemical reactions in WO3–H2O system using computer program FacktSage with the aim to establish influence of temperature and quantity of water on formation of compounds of H2WO4 and WO2(OH)2 as well as concomitant them compounds, evaporation products, decomposition and dissociation, that are contained in the program data base were carried out. Calculations in the temperature range from 100 to 3000 °С were carried out. The amount moles of water added to 1 mole of WO3 was varied from 0 to 27. It is found that the obtained data by the melting and evaporation temperatures of single-phase WO3 are in good agreement with the reference data and provide additionally detailed information on the composition of the gas phase. It was shown that under heating of 1 mole single-phase WO3 up to 3000 °С the predominant oxide that exist in gaseous phase is (WO3)2. Reactions of it formation from other oxides ((WO3)3 and (WO3)4) were proposed. It was established that compound H2WO4 is stable and it is decomposed on WO3 and H2O under 121 °C. Tungsten Oxide Hydrate WO2(OH)2 first appears under 400 °С and exists up to 3000 °С. Increasing quantity of Н2О in system leads to decreasing transition temperature of WO3 into both liquid and gaseous phases. It was established that adding to 1 mole WO3 26 mole H2O maximum amount (0,9044–0,9171 mole) WO2(OH)2 under temperatures 1400–1600 °С can be obtained, wherein the melting stage of WO3 is omitted. Obtained data also allowed to state that that from 121 till 400 °С WO3–Н2O the section in the О–W–H ternary system is partially quasi-binary because under these temperatures in the system only WO3 and Н2O are present. Under higher temperatures WO3–Н2O section becomes not quasi-binary since in the reaction products WO3 with Н2O except WO3 and Н2O, there are significant amounts of WO2(OH)2, (WO3)2, (WO3)3, (WO3)4 and a small amount of atoms and other compounds. Bibl. 12, Fig. 6, Tab. 5.

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