FORUM: INSECTS AND TEMPERATURE—A GENERAL THEORY

1996 ◽  
Vol 128 (1) ◽  
pp. 1-13 ◽  
Author(s):  
N. Gilbert ◽  
D.A. Raworth
Keyword(s):  
Genetic Variability ◽  
Low Temperatures ◽  
Growth And Development ◽  
Development Rate ◽  
Temperature Threshold ◽  
Insect Population Dynamics ◽  
Slow Development ◽  
Fast Development ◽  
Insect Predators ◽  
Effects Of Temperature

AbstractInsects are selected for slow development (but relatively fast growth) in spring, but for fast development in summer. These contrasting selection pressures explain five puzzling effects of temperature on insects: growth and development rates increase almost linearly with temperature; genetic variability in development rate is reduced at high (27°C) temperatures; genetic variability in growth rate is reduced at low (15°C) temperatures; development is very slow at the time of emergence after diapause, regardless of the temperature threshold for emergence; and growth is slow at low temperatures, but development is even slower.Insects use temperature to indicate time-of-season. Different species are geared differently to rising temperatures. Insect predators and parasitoids become more effective at high temperatures; and insect population dynamics are not stable in the conventional sense.

A unified degree day model describes survivorship of Copitarsia corruda Pogue & Simmons (Lepidoptera: Noctuidae) at different constant temperatures

2008 ◽  
Vol 99 (1) ◽  
pp. 65-72 ◽  
Author(s):  
N.N. Gómez ◽  
R.C. Venette ◽  
J.R. Gould ◽  
D.F. Winograd
Keyword(s):  
Survival Curve ◽  
The United States ◽  
Physiological Age ◽  
Alien Invasive Species ◽  
Temperature Threshold ◽  
Base Temperature ◽  
Survival Curves ◽  
Degree Day ◽  
Effects Of Temperature ◽  
Lepidoptera Noctuidae

AbstractPredictions of survivorship are critical to quantify the probability of establishment by an alien invasive species, but survival curves rarely distinguish between the effects of temperature on development versus senescence. We report chronological and physiological age-based survival curves for a potentially invasive noctuid, recently described as Copitarsia corruda Pogue & Simmons, collected from Peru and reared on asparagus at six constant temperatures between 9.7 and 34.5°C. Copitarsia spp. are not known to occur in the United States but are routinely intercepted at ports of entry. Chronological age survival curves differ significantly among temperatures. Survivorship at early age after hatch is greatest at lower temperatures and declines as temperature increases. Mean longevity was 220 (±13 SEM) days at 9.7°C. Physiological age survival curves constructed with developmental base temperature (7.2°C) did not correspond to those constructed with a senescence base temperature (5.9°C). A single degree day survival curve with an appropriate temperature threshold based on senescence adequately describes survivorship under non-stress temperature conditions (5.9–24.9°C).

The Influence of Temperature and Humidity on Instar Length in Calandra Granaria Linn

1947 ◽  
Vol 24 (1-2) ◽  
pp. 79-94
Author(s):  
L. E. S. EASTHAM ◽  
F. SEGROVE
Keyword(s):  
Growth And Development ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Food Utilization ◽  
Optimum Temperature ◽  
Atmospheric Humidity ◽  
Larval Instars ◽  
Balance Sheets ◽  
Temperature And Humidity ◽  
Effects Of Temperature

1. The effects of temperature and humidity on the duration of each instar of the life cycle of Calandra granaria Linn. have been examined. The insects were reared at temperatures ranging from 15 to 30° C. and at atmospheric humidities ranging from 40 to 80% R.H. 2. A method is described for assessing the effect of temperature as an independent factor. 3. The temperatures employed fall within the ‘vital zone’. Extrapolation indicates the threshold temperature to be approximately 11° C. for the egg and larval instars though somewhat lower for the pupa. 30° C. is below the optimum temperature. 4. The durations of the egg and pupal stages are not affected by atmospheric humidity. 5. The duration of all larval instars is affected by moisture. It is suggested that this is largely due to atmospheric humidity and that food water is of little significance. 6. Shortage of moisture acts as an obstacle to development. Evidence is presented which indicates that drier atmospheres tend to desiccate the insect and that desiccation is responsible for retarded growth and development. 7. Since much earlier work on temperature and moisture has been done on fasting insects and, therefore, on insects deficient in one of the most important environmental factors, we suggest that our results, incomplete as they are, indicate the need for new approaches to be made. More complete data on feeding insects under controlled conditions of food, temperature and moisture are required, from which can be drawn up more complete balance sheets of development involving measurements of food utilization and respiratory rates.

scholarly journals Methods for Quantification of the Decline Phenomenon and Determination of the Vulnerability Degree for the Oak Stands in Northwestern Transylvania, Romania

2017 ◽  
Vol 45 (2) ◽  
pp. 623-631
Author(s):  
Vasile ŞIMONCA ◽  
Ioan OROIAN ◽  
Dănuț CHIRA ◽  
Ioan TĂUT
Keyword(s):  
Mortality Rate ◽  
Incipient Stage ◽  
Management Measures ◽  
Slow Development ◽  
Synthetic Index ◽  
Quercus Species ◽  
Fast Development ◽  
Annual Mortality ◽  
Experimental Plots

The decline phenomenon of stands can be defined as the totality of effects that damage the normal vegetation state of trees and stands. There are two types of decline, the acute one, with fast development, and the chronical one, with slow development in space and time. The accurate capture of the phenomenon has direct implications for the forest management measures. A first step in this direction is the analysis of the development type and of its dynamics. Forests which have Quercus species in composition are affected more by this phenomenon. There were identified oak stands presenting decline phenomenon in 9 Forest Districts in Northwestern Transylvania and 22 experimental plots were analyzed. These plots were located in middle aged stands that were affected in different ways. The study was performed during 2013-2015 and focused on crown level assessments of trees, taking into consideration the shape and size, defoliations, percentage of dead or missing slender branches, number of dead thick branches, presence of epicormic branches or dormant buds on the stem, presence of pathogens or pests. These elements were used for calculating some technical indicators of the health and vegetation state: degree of dieback, damage and devitalization, synthetic index damage, annual mortality rate. In 7 out of 22 stands, the overcoming of the incipient stage and beginning of active dieback stage was observed. The strongest correlation occurred between the annual mortality rate and the synthetic index damage.

scholarly journals The Effect of Temperature on the Development of Spodoptera frugiperda (Lepidoptera: Noctuidae)

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 228 ◽  
Author(s):  
Hannalene Du Plessis ◽  
Marie-Louise Schlemmer ◽  
Johnnie Van den Berg
Keyword(s):  
Adult Development ◽  
Spodoptera Frugiperda ◽  
Far East ◽  
Fall Armyworm ◽  
Invasion Biology ◽  
Larval Survival ◽  
Development Rate ◽  
Effect Of Temperature ◽  
Temperature Threshold ◽  
Different Temperatures

The fall armyworm (Spodoptera frugiperda) is a pest of tropical origin which recently invaded Africa, the Far East and Australia. Temperature, therefore, plays an important role in its invasion biology, since this pest does not go into diapause. The aim of this study was to determine the development rate of S. frugiperda at different temperatures and to calculate the number of degree-days (°D) required for each stage to complete its development. This study was conducted at five different temperatures—18, 22, 26, 30 and 32 ± 1 °C. Larvae were reared individually in Petri dishes with sweetcorn kernels provided as food. The development rate of S. frugiperda increased linearly with increasing temperatures between 18 and 30 °C and larval survival was the highest between 26 and 30 °C. The optimal range for egg, larval and egg-to-adult development was between 26 and 30 °C. The optimum temperature with the fastest larval development rate and lowest mortality was at 30 °C. The pupal development period ranged between 7.82 and 30.68 days (32–18 °C). The minimum temperature threshold for egg and larva development was 13.01 and 12.12 °C, respectively, 13.06 °C for pupae and 12.57 °C for egg-to-adult development. Degree-day requirements for the development of the respective life cycle stages of S. frugiperda were 35.68 ± 0.22 for eggs, 204.60 ± 1.23 °D for larvae, 150.54 ± 0.93 °D for pupae and 391.61 ± 1.42 °D for egg-to-adult development.

Temperature acclimation of the caudal photoreceptor response in the crayfish Orconectes rusticus (Girard)

1988 ◽  
Vol 66 (5) ◽  
pp. 1168-1171 ◽  
Author(s):  
Jim H. Belanger
Keyword(s):  
Stimulus Intensity ◽  
Low Temperatures ◽  
Temperature Acclimation ◽  
Thermal Capacity ◽  
Maximum Frequency ◽  
Orconectes Rusticus ◽  
Temperature Dependent ◽  
Caudal Photoreceptor ◽  
Effects Of Temperature ◽  
Nerve Cords

Crayfish (Orconectes rusticus (Girard)) were acclimated for 3 weeks at 5 and 25 °C. The effects of temperature and temperature acclimation on the latency, maximum frequency, and sensitivity to stimulus intensity of the caudal photoreceptor response were examined in isolated abdominal nerve cords. Each of these components was temperature dependent. The maximum frequency of the response showed thermal capacity acclimation but latency did not. Caudal photoreceptor response was insensitive to stimulus intensity at low temperatures but acclimation improved sensitivity.

EAR LENGTH AND SPIKELET NUMBER OF WHEAT GROWN AT DIFFERENT TEMPERATURES AND LIGHT INTENSITIES

1965 ◽  
Vol 43 (3) ◽  
pp. 345-353 ◽  
Author(s):  
D. J. C. Friend
Keyword(s):  
Light Intensity ◽  
Low Temperatures ◽  
Dry Weight ◽  
High Light ◽  
Morphological Development ◽  
Spikelet Number ◽  
Light Intensities ◽  
Different Temperatures ◽  
Total Plant ◽  
Effects Of Temperature

The number of spikelets on the differentiating inflorescence and the ear at anthesis was highest at high light intensities and at low temperatures. The length of the developing inflorescence and the ear, the height of the main stem, and the total plant dry weight at the time of anthesis were also greatest under these conditions.These results are related to differential effects of temperature and light intensity on the rates and duration of apical elongation, morphological development of the ear, and spikelet formation.

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