The fine structure of the egg shells of the cabbage maggot, Delia radicum L. (Diptera: Anthomyiidae), and its relation with developmental conditions and oviposition site

1997 ◽  
Vol 75 (4) ◽  
pp. 535-541 ◽  
Author(s):  
N. Neveu ◽  
M. R. Allo ◽  
J. P. Nénon ◽  
X. Langlet ◽  
E. Brunel ◽  
...  
Keyword(s):  
Fine Structure ◽  
Relative Humidity ◽  
Climatic Conditions ◽  
Delia Radicum ◽  
Vitelline Membrane ◽  
Hatching Rate ◽  
Longitudinal Strip ◽  
Egg Shells ◽  
Cabbage Maggot ◽  
Developmental Conditions

The fine structure and evolution of the egg shells of the cabbage maggot, Delia radicum, were studied in a French strain. The chorion did not undergo any modification at oviposition and consisted of three layers, except for the longitudinal strip, where the outer layer was lacking. The vitelline membrane of the oocyte was transformed by densification after oviposition. Differences in the longitudinal strip of the chorion were found between three strains of D. radicum. The strip was 650 μm long in the French strain and a Canadian strain, but only 250 μm long in a Moroccan strain. We also studied the effect of relative humidity on the hatching rate of eggs of the French strain and found that low relative humidity decreased the hatching rate. Finally, the function of the longitudinal strip was discussed in relation to climatic conditions.

scholarly journals The effect of cooling irrigation on the blooming dynamic of plum

2010 ◽  
Vol 16 (4) ◽  
Author(s):  
L. Lakatos ◽  
I. Gonda ◽  
M. Soltész ◽  
Z. Szabó ◽  
J. Nyéki
Keyword(s):  
Relative Humidity ◽  
Frost Damage ◽  
Relative Effect ◽  
Climatic Conditions ◽  
Water Requirement ◽  
Control Plot ◽  
Logistic Curve ◽  
Treated Plot

The objective of the present study is to explore the effect of cooling irrigation (aspersion) on the beginning of bloom and on the micro-climate of the plantation. The results show that the water sprayed in the orchard by micro-jet influenced decisively the temperature of the plantation. At higher temperatures (around 20 °C), the drop of temperature may attain 5–7 °C. A low relative humidity of the air may increase the relative effect, The frequent repetition (20 minute intervals) may keep the temperature low also in the buds. The beginning of bloom may delayed for more than ten days. The dynamics of blooming was characterised by a logistic curve in the treated as well as in the control plot. In the treated plot, the curve was steeper than in the control in spite of equal temperatures measured in the plots. Under our (Hungarian) climatic conditions, the method is successfully used to delay blooming dates. The main result is the diminution of the frost damage in the spring and the security of yield. The costs and water requirement should be calculated later.

scholarly journals The effect of some seasonal conditions on oestrus occurrence in cows

2009 ◽  
Vol 52 (5) ◽  
pp. 459-465
Author(s):  
B. Bülbül ◽  
M. B. Ataman
Keyword(s):  
Seasonal Variation ◽  
Relative Humidity ◽  
Environmental Temperature ◽  
Suppressive Effect ◽  
Climatic Conditions ◽  
Holstein Cows ◽  
Ovarian Activity ◽  
Environment Temperature ◽  
Humidity Index ◽  
Annual Distribution

Abstract. In this study, the effect of climatic conditions on oestrus occurrence was investigated by using 9 972 oestrus records of cows recorded between 1995 and 2003. A distinct seasonal variation in the oestrus occurrence was determined. Oestrus occurrence observed in January, March, November and December was less than that in June and September (P<0.05). Annual distribution of the oestrus occurrence was positively correlated with environment temperature and insulation duration, but it was negatively correlated with rainfall (P<0.01). However, there was no relationship between oestrus occurrence and relative humidity. In addition to these, there was a slight decrease in the oestrus response when the temperature-humidity index (THI) was above 72; nevertheless, this decrease was not significant (P >0.05). The data presented in this study demonstrated that the increase in the environmental temperature up to 23 °C did not cause a suppressive effect on the ovarian activity. In conclusion, annual distribution of the oestrus occurrence is positively correlated with environment temperature and insulation duration whereas it is negatively correlated with rainfall in Holstein cows, in this study.

THE CROSS-VENTILATED TUNNEL SMOKEHOUSE

1946 ◽  
Vol 24f (1) ◽  
pp. 81-90
Author(s):  
E. P. Linton ◽  
A. L. Wood
Keyword(s):  
Relative Humidity ◽  
Climatic Conditions ◽  
Steam Consumption ◽  
The Cross ◽  
One Year ◽  
Short Time

A tunnel smokehouse with an output of 3000 lb. of smoked fillets per nine hour day has been in operation about one year. The temperature, relative humidity, and smoke velocity are controlled at optimum values independent of climatic conditions. Hence the colour and shrinkage of the product may be standardized and losses from cooking and dropping of the fish avoided. The relatively short time of smoking of two to three hours reduces spoilage of the fish to a minimum with resulting improvement in quality. Power and steam consumption have been kept as low as feasible.

scholarly journals Thermophysiological Comfort of Surgeons and Patient in an Operating Room Based on PMV-PPD and PHS Indexes

2020 ◽  
Vol 10 (5) ◽  
pp. 1801 ◽  
Author(s):  
Radostina A. Angelova ◽  
Rositsa Velichkova
Keyword(s):  
At Risk ◽  
Relative Humidity ◽  
Operating Room ◽  
Air Temperature ◽  
Indoor Environment ◽  
Thermal Environment ◽  
Climatic Conditions ◽  
Clothing Insulation ◽  
Indoor Thermal Environment ◽  
Predicted Heat Strain

There are different actors in an operating room (OR), who have controversial requirements for the indoor thermal environment. While the patient is at risk of perioperative hypothermia, the surgeons are in a state of thermophysiological discomfort. The study presents an analysis of the thermophysiological comfort of both patient and surgeons in an OR. Surgical clothing ensembles with three values of clothing insulation are simulated. Different indoor environment conditions (air temperature and relative humidity) are tested. The analysis is based on the calculation of predicted mean vote and predicted percentage of dissatisfied (PMV-PPD) indexes and assessment of the climatic conditions categories. Discussion of the predicted heat strain is also presented. The simulated results and their analysis show considerable discrepancies between the thermophysiological comfort of the patient and the surgeons, even when dressed in a light protective ensemble, in the same indoor environment.

Neoseiulus baraki (Acari: Phytoseiidae) survival and walking in response to environmental stress

2019 ◽  
Vol 24 (3) ◽  
pp. 487 ◽  
Author(s):  
Vaneska Barbosa Monteiro ◽  
Girleide Vieira França ◽  
Manoel Guedes Correa Gondim Jr ◽  
Debora Barbosa Lima ◽  
Jose Wagner Silva Melo
Keyword(s):  
Relative Humidity ◽  
Environmental Stress ◽  
Survival Time ◽  
Environmental Conditions ◽  
Walking Speed ◽  
Tracking System ◽  
Climatic Conditions ◽  
Stress Factors ◽  
Neoseiulus Baraki ◽  
Increasing Temperature

Living organism is exposed to the influence of various environmental conditions. These environmental conditions can trigger stress and compromise the fitness of the organism. As living organisms, phytoseiid mites are frequently exposed to a range of environmental stressors. In the present study, we attempted to explore the responses of the Neoseiulus baraki to environmental stress factors (temperature and humidity). Initially, the effect of different temperature (18–33 °C) and relative humidity (10–95%) levels on the survivorship of unfed N. baraki females was evaluated. Next, we estimated the walking parameters (distance traveled and average walking speed) with a computerized tracking system and we tested how N. baraki is constrained in their effective displacement by their ability to walk and survive in absence of food. The proportion of surviving N. baraki as well as mean survival time decreased significantly with increasing temperature. The opposite trend was observed to relative humidity. The distance covered by N. baraki reduced with increasing temperature (when only taking the temperature dependence of the survival time but not of walking speed and neither the tortuosity of the walking path) ranged from 550 m at 18 ºC to 100 m at 33 ºC. Under climatic conditions representative for the Tropics (27 ºC and 75 % RH) N. baraki was able to survive up to 1.5 days (36 h) without feeding and covered 0.9 m in 10 min as displacement estimated by walking.

scholarly journals Microbial Control of Cabbage Maggot-Preliminary Screenings of Fungal Isolates, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 413-413 ◽  
Author(s):  
Richard Meadow ◽  
John D. Vandenberg ◽  
Anthony M. Shelton ◽  
D. Wesley Watson
Keyword(s):  
New York ◽  
New York State ◽  
Microbial Control ◽  
Delia Radicum ◽  
Cornell University ◽  
Southern Corn Rootworm ◽  
Centrifuge Tube ◽  
Lepidoptera Pyralidae ◽  
Agricultural Experiment ◽  
Cabbage Maggot

Abstract Adult CM were exposed to dry conidia of isolates of Beauvaria bassiana (Bb), Metarhizium anisopilae (Ma) or Paeciomyces fumosoroseus (Pf). Two B. bassiana isolates were from Cornell University (P89, L90) isolated from Musca domestica (Diptera: Muscidae), one was from Mycoteh Corp., Butte, MT (Myc 726) originally isolated from southern corn rootworm, Diabrotica undecimpuntata (Coleoptera: Chrysomelidae), re-isolated from a grasshopper, Melanoplus sp. (Orthoptera:Acrididae), and then re-isolated from silverleaf whitefly, Bemesia argentiflora (Homoptera: Aleyrodidae). The other isolates were from the USDA-ARS Collection of Entomophagous Fungal Cultures. One B. bassiana isolate, 4012, was isolated from Delia radicum (Diptera: Anthomyiidae). The P. fumosoroseus isolates were number 1626 from M. autumnalis (Diptera: Muscidae), 1644, 1645, 1867 and 1868 from M. domestica, 1646 from Calliphora spp. (Diptera: Calliphoridae), and 887 from unidentified Diptera. The M. anisopilae isolates were 2521 from Deois spp. (Homoptera: Cercopidae), 3540 from Gelleria mellonella (Lepidoptera: Pyralidae) and 4862 and 4865 from soil. Flies from rearings at the New York State Agricultural Experiment Station, Geneva, NY, were exposed to the fungi by placing 5 flies in a centrifuge tube containing conidia scraped directly from culture plates. The flies were then released into small screened plastic cages, which were placed in chambers with constant temperature of 21° C and L:D 15: 9. There were 3 replicates. Mortality was assessed after 48, 120 and 160h. Dead flies were placed in petri dishes with moistened filter paper to assess infection.

A new method of measuring skin humidity

1976 ◽  
Vol 41 (2) ◽  
pp. 256-258 ◽  
Author(s):  
H. Reinhart ◽  
G. Brenneisen
Keyword(s):  
Relative Humidity ◽  
Switching Time ◽  
Time Measurement ◽  
Climatic Conditions ◽  
Logic Circuit ◽  
Simple Circuit ◽  
Measuring Chamber ◽  
Resistance Bridge ◽  
Temperature Recording ◽  
Long Time

A device suitable for the long-time measurement of relative skin humidity is described. This is a simple circuit with a resistance bridge for lithium chloride sensors connected to a digitally steered logic circuit, which causes dried air to stream intermittently through a measuring chamber placed on the skin in such a way that the relative humidity over the skin is maintained at a constant level. The number of switching time periods is proportional to the relative humidity (secretion performance) of the skin and can be counted, recorded, or directly fed into a digital calculator. The apparatus, including a two-channel version with skin temperature recording, has proved useful in sleep investigations under extreme climatic conditions.

The Effect of a Difference in Temperature and Humidity on certain Reactions of Female Aëdes aegypti (L.)

1952 ◽  
Vol 43 (1) ◽  
pp. 221-229 ◽  
Author(s):  
Alec H. Parker
Keyword(s):  
Relative Humidity ◽  
Aedes Aegypti ◽  
Room Temperature ◽  
Climatic Conditions ◽  
Effect Of Temperature ◽  
Full Description ◽  
Temperature And Humidity ◽  
Conditioning Effect ◽  
The Difference ◽  
C 50

Sir Rickard Christophers (1947) working at 25°C. and a relative humidity of 80–90 per cent. found female Aëdes aegypti to be attracted by a warm dry surface at 40°C., and to be unaffected by a moist surface at room temperature. The writer (1948), working at 28°C. and 50–70 per cent. R.H. (usually near 50 per cent.) found the opposite: a warm dry surface at temperatures from 36°C. to 40°C. had no effect, while a moist surface at room temperature exerted a quite definite attraction. The purpose of the present experiments was to test the hypothesis that the difference between the results obtained in these two investigations was due to the difference in the ambient temperature and humidity.Repetition of the relevant experiments at 25°C, 85–90 per cent. R.H., and 28°C, 50–55 per cent. R.H., gave results indicating that temperature and humidity difference operating at the time of the experiment could account for part but not all of the discrepancy. There are indications that the remainder may have been a result of the conditioning effect of temperature and humidity differences operating on the insect prior to the experiment.The results emphasise the need for a full description of the climatic conditions under which behaviour work of the type discussed is performed.

The tylenchid (Nematoda) egg shell: structure, composition and permeability

Parasitology ◽  
1976 ◽  
Vol 72 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Alan F. Bird ◽  
M. A. McClure
Keyword(s):  
Basic Structure ◽  
Vitelline Membrane ◽  
Chemical Components ◽  
Rotylenchulus Reniformis ◽  
Lipid Layer ◽  
Tylenchulus Semipenetrans ◽  
Different Temperatures ◽  
Egg Shells ◽  
Egg Shell ◽  
Lipid Layers

SummaryThe fine structure of egg shells of four different genera belonging to the order Tylenchida has been examined. The species examined were Meloidogyne javanica, Rotylenchulus reniformis, Tylenchulus semipenetrans and Pratylenchus minyus. They are all similar in their basic structure, being composed of vitelline membrane, chitin and lipid layers, but there is considerable variability in the thickness of these layers.We have retained the conventional nomenclature because of its convenience, but it is clear that these layers have a variety of chemical components. However, they do appear to contain the compounds from which they take their name. Thus chitin occurs in the chitin layer, and lipid in the lipid layer. The latter is removed by the technique used in isolating the shell from the egg. Chemical analysis of the hydrolysis products of these shells has revealed a high (35 %) proline content which appears to be a characteristic of those nematode egg shells which have been examined so far. These analyses and treatment with enzymes indicate that the chitin layer is a chitin–protein complex.Experiments on the permeability of eggs of M. javanica at different temperatures indicate that changes in permeability are not due to the melting of a single lipid with a distinct melting point as had been thought in the past. We have found that Arrhenius activation energies calculated from the two slopes of an Arrhenius plot were 17·8 kcal/mol and 43·0 kcal/mol respectively, the transition from one to the other taking place at 62°C. We think that these changes are due to changes in the properties of lipoprotein membranes in the lipid layer. These membranes appear to be of paramount importance in controlling the permeability of the nematode egg shell.

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