RELATIONSHIP BETWEEN TEMPERATURE AND DEVELOPMENT OF THE CARROT WEEVIL, LISTRONOTUS OREGONENSIS (LeCONTE) (COLEOPTERA: CURCULIONIDAE), IN THE LABORATORY

1986 ◽  
Vol 118 (12) ◽  
pp. 1287-1290 ◽  
Author(s):  
A.B. Stevenson

AbstractRates of development of selected stages and complete development of the carrot weevil, Listronotus oregonensis (LeConte), were determined in the laboratory at controlled temperatures ranging from 17.5 to 30°C. Within that range of temperature, rates of development increased with temperature. Fitting the data to a cubic polynomial function provided an excellent description of the relationship between temperature and rate of development for all stages as shown by R2 values of at least 0.98.

2013 ◽  
Vol 671-674 ◽  
pp. 758-767
Author(s):  
Wei Sun ◽  
Shi Yan ◽  
Shao Fei Jiang

This paper presents an experimental method to investigate the attenuation performance of stress waves in concrete structures embedded in piezoelectric ceramics. To get the research objective, a series of test were hold. The relationship curve between the frequency and the attenuation coefficient was fit. The calculation method for propagation distances of stress waves with constant amplitudes and frequencies in the concrete medium was proposed. The research results show that the relationship curve of attenuation coefficient and frequency conform to the cubic polynomial function approximately. The attenuation performance for the concrete structure embedded into piezoelectric ceramics is relevant to the frequency, the amplitude and the medium character, and the frequency is the main factor. The research results of this paper can provide an effective evidence for correctly placing transducers.


It is shown that, when two superposed fluids of different densities are accelerated in a direction perpendicular to their interface, this surface is stable or unstable according to whether the acceleration is directed from the heavier to the lighter fluid or vice versa. The relationship between the rate of development of the instability and the length of wave-like disturbances, the acceleration and the densities is found, and similar calculations are made for the case when a sheet of liquid of uniform depth is accelerated.


2020 ◽  
Vol 152 (3) ◽  
pp. 374-388
Author(s):  
Suzanne Blatt ◽  
Deney Augustine Joseph ◽  
G. Christopher Cutler ◽  
A. Randall Olson ◽  
Scott White

AbstractCarrot weevil, Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae), is a pest of carrot (Daucus carota var. sativus Hoffmann; Apiaceae) throughout eastern Canada. Carrot weevil emergence and oviposition were monitored in commercial carrot fields in Nova Scotia. Cumulative degree days were calculated using a base temperature of 7 °C (DD7), and models were developed to predict cumulative emergence and oviposition using nonlinear regression. Cumulative emergence and oviposition were adequately explained as functions of DD7 by a three-parameter sigmoidal Hill equation. Our emergence model predicted initial and peak adult emergence at 35 and 387 DD7, respectively, with oviposition on carrot baits occurring as early as 42 DD7. Models were then validated to evaluate how well they performed. Oviposition on carrot plants began at the fourth true-leaf stage (342 DD7) and continued until eleventh true-leaf stage. Growers using these models can identify their window of opportunity to manage their carrot weevil populations targeting the majority of emerged adults before oviposition begins in the field.


1989 ◽  
Vol 256 (1) ◽  
pp. H21-H31 ◽  
Author(s):  
M. Bernier ◽  
M. J. Curtis ◽  
D. J. Hearse

The relationship between heart rate and ischemia-induced and reperfusion-induced arrhythmias was studied using 573 isolated rat hearts. Hearts (12/group), subjected to 7 min of coronary occlusion and 10 min reperfusion, were paced at 300, 330, 360, 390, 420, 480, or 540 beats/min. Pacing either throughout the experiment or during ischemia alone led to a rate-dependent increase in the incidence of reperfusion-induced ventricular fibrillation (VF) from 25% in the unpaced hearts to greater than 90% when the rate was 420 beats/min or higher. However, pacing during reperfusion alone did not increase the incidence of reperfusion-induced VF. In separate hearts, the right atrium was removed to permit examination of both low and high rates (167 +/- 2, 240, 336 +/- 3, or 480 beats/min throughout the experiment) over a wide range of durations of occlusion (3, 5, 7, 10, 15, 20, or 40 min). Ischemia-induced VF incidence was critically dependent on heart rate, low rates being protective. During reperfusion, the incidence of VF was also highly rate dependent if reperfusion was initiated within 10 min of the onset of ischemia (ranging from 8% when rate was 167 +/- 2 beats/min to 100% when rate was 480 beats/min) but was unrelated to heart rate when reperfusion occurred at later times (ranging from 33 to 50% when ischemia duration was 40 min). Heart rate can therefore influence susceptibility to ischemia- and reperfusion-induced arrhythmias, probably as a result of an effect on the rate of development of ischemic injury.


Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4635
Author(s):  
Angel de la Torre ◽  
Santiago Medina-Rodríguez ◽  
Jose C. Segura ◽  
Jorge F. Fernández-Sánchez

In this work, we propose a new model describing the relationship between the analyte concentration and the instrument response in photoluminescence sensors excited with modulated light sources. The concentration is modeled as a polynomial function of the analytical signal corrected with an exponent, and therefore the model is referred to as a polynomial-exponent (PE) model. The proposed approach is motivated by the limitations of the classical models for describing the frequency response of the luminescence sensors excited with a modulated light source, and can be considered as an extension of the Stern–Volmer model. We compare the calibration provided by the proposed PE-model with that provided by the classical Stern–Volmer, Lehrer, and Demas models. Compared with the classical models, for a similar complexity (i.e., with the same number of parameters to be fitted), the PE-model improves the trade-off between the accuracy and the complexity. The utility of the proposed model is supported with experiments involving two oxygen-sensitive photoluminescence sensors in instruments based on sinusoidally modulated light sources, using four different analytical signals (phase-shift, amplitude, and the corresponding lifetimes estimated from them).


Parasitology ◽  
1976 ◽  
Vol 73 (2) ◽  
pp. 223-238 ◽  
Author(s):  
L. F. Le Jambre ◽  
J. H. Whitlock

Vulvar phenotypes and the rate of development of eggs over a range of temperatures were used to compare Haemonchus contortus populations in New York State and Ohio. These parameters indicated that the westernmost boundary of the subspecies Haemonchus contortus cayugensis is the Chautauqua valley in New York. The Haemonchus ecotype in Ohio had a vulvar phenotype formula similar to that described for the subspecies Haemonchus contortus contortus. The relationship between slope and intercept of the regression of rate of egg hatch on temperature was different for morphs within ecotypes as well as between the New York and Ohio ecotypes. Linguiform-A appeared to be the cold-adapted morph in both ecotypes. Smooth was the warm-adapted morph in New York with linguiform-B filling that niche in Ohio.


1987 ◽  
Vol 77 (4) ◽  
pp. 629-635 ◽  
Author(s):  
Y. K. Aalbersberg ◽  
F. Du Toit ◽  
M. C. Van Der Westhuizen ◽  
P. H. Hewitt

AbstractThe rate of development, fecundity and lifespan of apterae of Diuraphis noxia (Mordvilko) were determined at five sets of temperature and daylength conditions. The time required to complete pre-imaginal growth at mean daily temperatures of 10, 13, 14, 17·25 and 20°C was 19·70, 12·09, 11·25, 9·88 and 8·17 days, respectively. The threshold for development was estimated to be 0·54°C and the number of day-degrees C required to complete development was 158·73.


1961 ◽  
Vol 93 (5) ◽  
pp. 380-384 ◽  
Author(s):  
H. J. Herbert

The predacious mites of the subfamily Phytoseiinae are common predators of the phytophagous mites in apple orchards in Nova Scotia. There is little information in the literature on the value of these predators in the control of phytophagous mites or on the food necessary for their development and reproduction. Ballard (1953) found that at 78°F. at least two males of Tetranychus bimaculatus Har. were required daily by Typhlodroms fallacis (Garm.) to complete the protonymphal or the deutonymphal instar. The males and mated females consumed daily an average of 3.9 and 7.5 males respectively from the larva1 to the adult stage. Chant (1960) found that T. pyri required 25 larvae of Panonychus ulmi (Koch), during 26 days to complete development at 64°F. in the absence of plant material or free water. These authors did not study the effects of different amounts of food on the development of these two species of phytoseiids.


1976 ◽  
Vol 108 (9) ◽  
pp. 931-934 ◽  
Author(s):  
P. Martel ◽  
H. J. Svec ◽  
C. R. Harris

AbstractLaboratory studies on the biology of the carrot weevil, Listronotus oregonensis (LeConte), were performed at 21° and 27 °C. At 21 °C females laid eggs for 88 days on carrot slices and 94 days on foliage. Egg production per female averaged 156 and 175 on slices and leaves respectively. Eggs hatched after 8.3 days incubation and the larval stage comprising four instars was completed in 19.1 days. The prepupal and pupal stages lasted 3.7 and 9.4 days respectively. The complete life cycle including an average preoviposition period of 17 days was 57.6 days. Development was more rapid at 27 °C, with the complete life cycle taking only 37 days.


1997 ◽  
Vol 129 (1) ◽  
pp. 187-194 ◽  
Author(s):  
A.B. Stevenson ◽  
E.S. Barszcz

AbstractThe carrot weevil, Listronotus oregonensis (LeConte), was monitored at 11 research or commercial carrot plantings at Holland Marsh, Kettleby, Ontario, using three methods, i.e. wooden plate (Boivin) traps to capture adults, carrot root sections placed in the soil to detect oviposition, and recording the numbers of adults present on carrot root sections. All three methods provided similar records of the seasonal pattern of adult activity. At most sites, thresholds used to determine the need for insecticide applications were reached or exceeded soon after the beginning of monitoring.There were significant linear relationships among the seasonal activity parameters generated by the three methods and between those parameters and percentage injury at harvest. Control programs that would have resulted from the use of each method are discussed.


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