Stevenson screen temperatures - an investigation

Bernard Burton

doi:10.1002/wea.2166

Studies on Beetles of the Family Ptinidae IX.—A Laboratory Study of the Biology of Ptinus tectus Boield

Bulletin of Entomological Research ◽

10.1017/s000748530002558x ◽

1953 ◽

Vol 44 (3) ◽

pp. 461-516 ◽

Cited By ~ 28

Author(s):

R. W. Howe ◽

H. D. Burges

Keyword(s):

Laboratory Study ◽

Large Range ◽

Developmental Period ◽

Economic Losses ◽

High Grade ◽

The Family ◽

Large Populations ◽

Stevenson Screen ◽

Food Value

Ptinus tectus occurs on a large range of foodstuffs in all types of storage places, in warehouse refuse and in the nests of birds. It is widely distributed in cool and temperate areas but is very rarely found in hot climates. In Britain it can survive the winter when exposed in a Stevenson screen to outdoor shade conditions. P. tectus is seldom found on imported cargoes inspected aboard ship, but many British warehouses carry a population of the species resident in the fabric of the premises.The larva is able to bore through cellophane, card and textiles and can also make impressions on wood. The fully fed larva spins a cocoon on the fabric of containers and buildings. Holing of packages and contamination by silk of high grade produce form the chief economic losses caused by the species, but occasionally large populations are found, sufficient to reduce the food value of produce. Unlike the larvae, adult beetles cannot penetrate sound linen bags, but lay eggs through the meshes.In a series of consecutive experiments, performed identically as far as possible, variations in the length of developmental period and in emergence weight of adult beetles were greater than would be expected by chance. The variations could not be related to any single observed or suspected inconsistency of technique or environment. It is desirable therefore to conduct comparative experiments simultaneously.

DEGREE-DAY RELATIONSHIPS TO THE DEVELOPMENT OF LITHOCOLLETIS BLANCARDELLA (LEPIDOPTERA: GRACILLARIIDAE) AND ITS PARASITE APANTELES ORNIGIS (HYMENOPTERA: BRACONIDAE)

The Canadian Entomologist ◽

10.4039/ent1111177-10 ◽

1979 ◽

Vol 111 (10) ◽

pp. 1177-1184 ◽

Cited By ~ 15

Author(s):

E. F. Johnson ◽

R. Trottier ◽

J. E. Laing

Keyword(s):

Pest Management ◽

Natural Enemy ◽

Field Studies ◽

Management Programme ◽

Seasonal Development ◽

Daily Maximum ◽

Degree Days ◽

Degree Day ◽

Temperature Thresholds ◽

Stevenson Screen

AbstractDegree-day relationships in the development of Lithocolletis blancardella (Fab.) and Apanteles ornigis Weed, its major parasite, were established from laboratory and field studies in Ontario apple orchards during 1973, 1974, and 1975. Under constant laboratory conditions, temperature thresholds for development of overwintering pupae were estimated by three methods, and found to be 6.3°, 6.7°, and 5.7°C for L. blancardella, and 10.4°, 10.4°, and 11.3°C for A. ornigis. Degree-day accumulations in the field were calculated by two methods using daily maximum and minimum temperatures recorded from the pupal habitat and a Stevenson screen. Degree-days in the pupal habitat accumulated from 1 January, above 5.7°C for L. blancardella and 11.3°C for A. ornigis were more accurate than Stevenson screen degree-day accumulations for predicting first emergence; however, after emergence, seasonal development was best related to Stevenson screen degree-days accumulated from 1 April, above 6.7°C for L. blancardella and 10.4°C for A. ornigis. This study shows that degree-day relationships can be used in an apple pest management programme to optimize timing of insecticide applications against L. blancardella and preserve A. ornigis, its major natural enemy.

Mean Daily Temperatures at the Ben Nevis and Fort-William Observatories

Transactions of the Royal Society of Edinburgh ◽

10.1017/s0080456800022675 ◽

1910 ◽

Vol 44 (2) ◽

pp. 693-701 ◽

Cited By ~ 3

Author(s):

R. T. Omond

Keyword(s):

Daily Temperature ◽

Average Daily Temperature ◽

Average Temperature ◽

Stevenson Screen

Tables have been prepared of the average temperature at the Ben Nevis and Fort-William Observatories on each day of the year, using the records of the twenty years 1884 to 1903 inclusive. Table I. gives the average daily temperature at Ben Nevis, Table II. that at Fort-William, and Table III. the differences between them. These tables have been prepared as follows :—Ben Nevis Observatory.—In summer the dry- and wet-bulb thermometers were exposed in an ordinary Stevenson screen 4 feet above ground, and in winter in a smaller-sized double-louvred screen, placed on a ladder-like stand, and moved up or down so as to be always about 4 feet above the surface of the snow. These thermometers were read hourly, and the average of the dry-bulb readings for the 24 hours of each day is taken as the temperature of that day. Table I. is the arithmetical mean of the values so computed on each day of the year.

Abstract of Paper on Silver Thaw at the Ben Nevis Observatory

Earth and Environmental Science Transactions of the Royal Society of Edinburgh ◽

10.1017/s0080456800019736 ◽

1902 ◽

Vol 42 ◽

pp. 525-527

Author(s):

R. C. Mossman

Keyword(s):

Freezing Point ◽

Common Occurrence ◽

Stevenson Screen

The phenomenon of silver thaw,—that is, rain falling when the temperature is below the freezing-point and congealing when it falls,—is of somewhat common occurrence at the Ben Nevis Observatory. A prolonged fall of silver thaw occasions considerable inconvenience to the observers; the rain freezes on their coats, gloves, and even on their faces, while everything outside becomes covered several inches thick with solid ice. But the most serious effect is the choking of the louvres of the Stevenson screen where the thermometers are, necessitating frequent changing of the screens.

The effect of climate on the photosynthesis of Picea mariana at the subarctic tree line. 1. Field measurements

Canadian Journal of Botany ◽

10.1139/b75-076 ◽

1975 ◽

Vol 53 (7) ◽

pp. 604-620 ◽

Cited By ~ 40

Author(s):

T. Vowinckel ◽

W. C. Oechel ◽

W. G. Boll

Keyword(s):

Picea Mariana ◽

Dark Respiration ◽

Environmental Parameters ◽

Field Measurements ◽

Dry Weight ◽

Gas Analysis ◽

Tree Line ◽

Stevenson Screen ◽

Analysis System ◽

June July

Field measurements of the diurnal rates of photosynthesis of Picea mariana, the dominant tree species at the subarctic tree line, were made during the summers of 1972 and 1973 at Schefferville, Quebec (latitude 55° N). All relevant plant physiological and environmental parameters were also monitored. Photosynthesis was measured with an open gas analysis system with temperature-controlled cuvettes. Maximum daily rates were 2.0–3.5 mg CO2 g−1 dry weight h−1. Daily totals were between 15 and 30 mg CO2 g−1 dry weight. Temperature was unimportant in affecting daily photosynthesis totals during the summer months. The photosynthesis vs. needle temperature curve had an optimum of 15C. Dark respiration rates were 0.2–0.4 mg CO2 g−1 dry weight h−1 at 15C. The photosynthesis vs. light intensity curve was saturated at 0.8 ly min−1 (1.0 μE cm−2 s−1 PhAR.). As a result, heavy cloud cover considerably reduced daily photosynthesis. No seasonal variations in photosynthesis over June, July, and August were observed. No differences in maximum rates occurred between the three experimental sites. Needle temperatures within the cuvettes were 2–4C above air temperature under full sunlight (1.2 ly min−1). Needle temperatures under natural conditions were up to 7C above Stevenson screen temperatures and fluctuated rapidly with changes in turbulence.

Wheat spike temperatures in relation to varying environmental conditions

Australian Journal of Agricultural Research ◽

10.1071/ar98142 ◽

1999 ◽

Vol 50 (6) ◽

pp. 997 ◽

Cited By ~ 8

Author(s):

J. F. Panozzo ◽

H. A. Eagles ◽

R. J. Cawood ◽

M. Wootton

Keyword(s):

Soil Moisture ◽

Grain Filling ◽

Ambient Air ◽

Moisture Stress ◽

Effect Of Temperature ◽

Crop Canopy ◽

Ambient Temperatures ◽

Hot Days ◽

Stevenson Screen ◽

Wheat Spike

Most field studies investigating the effect of temperature on growth processes use temperatures recorded within a Stevenson screen. These are likely to deviate from temperatures within the plant. This investigation reports a comparative study of methodologies and applications for measuring temperatures in the field during grain development by comparing Stevenson screen, ambient (air temperatures within the crop canopy), and wheat spike temperatures. Miniature sensors were inserted into wheat spikelets located midway on the spike of a primary tiller at anthesis. Located also within the crop canopy, and at the same height as the spike sensors, were sensors to measure ambient temperatures. Stevenson screen temperatures were also recorded at the site. Temperatures were recorded automatically every 12 min during grain filling from anthesis to maturity. Plants were grown in dryland and irrigated conditions within the same location, with the aim of determining differences in plant temperatures between stressed and non-stressed plants. Stevenson screen temperatures did not relate closely to ambient or spike temperatures. Plants growing in adequate soil moisture conditions had spike temperatures lower than ambient temperatures, but in some dryland trials, where soil moisture was limiting, spike temperatures equalled ambient temperatures, indicating that the plants were under moisture stress. Temperature differences of up to 5˚C were observed between the spikes of irrigated and non-irrigated crops on a hot day. Neither ambient nor screen temperatures gave an accurate measurement of spike temperature on hot days. Spike temperature differences between 2 cultivars, awned and awnless, were investigated. Trends were not consistent over both years; however, in 3 of the 4 environments, the maximum spike temperatures were higher for the awned cultivar (Hartog) than the awnless cultivar (Halberd). On very hot days, when ambient temperatures exceeded 40˚C, spikes of Hartog were cooler than those of Halberd.

7. The Thermal Windrose at the Ben Nevis Observatory

Proceedings of the Royal Society of Edinburgh ◽

10.1017/s0370164600004247 ◽

1888 ◽

Vol 14 ◽

pp. 416-419

Author(s):

A. Rankine

Keyword(s):

The North ◽

North Side ◽

Mean Temperature ◽

Northern Half ◽

Stevenson Screen ◽

The Mean

The Table, showing the Thermal Windrose, accompanying this paper, was computed from the observations made at the Ben Nevis Observatory during the three years ending May 1887. It shows the mean temperatures, on the mean of the three years, of the different winds for each month, for the year, and for the seasons. The direction of the wind is observed to the thirty-two points of the compass, but in this table the temperatures are only shown for eight points, the intermediate points having all been added on to these eight points in the same way as that described by Mr Omond inh is paper on " Winds and Rainfall" in the Journal of the Scottish Meteorological Society, namely, the by winds were added to their adjacent octants, and the points half-way between the octants were on the odd day of each month added to the octant to their right, looking out from the centre of the compass card, i.e., they were veered. two points, and on the even days to that on their left, i.e., they were backed two points. The mean temperature of each direction of wind for each month was found by tabulating the hourly observations of temperature under the direction of wind observed at the same time, or under its octant as above, and then taking the arithmetical mean. When the wind was variable, or its direction doubtful, the temperature was entered in the column for calms and variables. These variable winds belong chiefly to the northern half of the compass, their existence being principally due to the abrupt and precipitous character of the north side of the Ben. The temperatures given in the table are those indicated by thermometers which in summer and autumn are protected in the regulation Stevenson screen, and in winter and spring in a smaller pattern of the same, which can be shifted up or down a ladder-like stand, so as to be always at or near the standard height of 4 feet above the surface of the snow.