scholarly journals Effect of elevated CO2 and temperature on thermal constants and lower threshold temperatures of maize aphid, Rhopalosiphum maidis (Fitch.) (Aphididae:Hemiptera) on maize, Zea mays (Linn.)

2021 ◽  
Vol 22 (2) ◽  
pp. 116-123
Author(s):  
D. MOUNICA ◽  
M. SRINIVASA RAO ◽  
P.V. KRISHNAYYA ◽  
A.K. PATIBANDA ◽  
V. SRINIVASA RAO
Keyword(s):  
Zea Mays ◽  
Elevated Co2 ◽  
Temperature Threshold ◽  
Nymphal Instar ◽  
Rhopalosiphum Maidis ◽  
Temperature Thresholds ◽  
Thermal Constants ◽  
Lower Temperature Threshold ◽  
The Mean ◽  
Lower Temperature

The objective of this study was to examine the development of corn leaf aphid,Rhopalosiphum maidis Fitch (Aphididae: Hemiptera) on maize Zea mays Linnaeus at elevated and ambient concentrations of CO2 (550 and 380ppm ± 25 ppm, respectively) at six temperatures (20, 25, 27, 30, 33 and 35°C) and to estimate thermal constants and lower temperature thresholds for the forecasting models based on heat accumulation units which could be developed for use in forecasting. The duration of different growth stages of R.maidis were reduced with an increase of temperature from 20°C to 35°C under both ambient and elevated CO2 conditions. The lower development threshold for first nymphal instar,second nymphal instar, third nymphal instar, fourth nymphal instar, adult duration and total development period required 10.1, 5.04, 13.42, 26.96, 10.9, 23.22 and 20.20°C under eCO2 whereas it was 13.32, 9.41, 19.13, 30.48, 16.38, 22.88 and 20.89°C under aCO2 conditions,respectively. The mean lower temperature threshold for nymph was slightly higher (16.38°C) at aCO2 compared to that of eCO2 (10.90°C) whereas for adult the mean lower temperature threshold was slightly higher (23.22°C) at eCO2 compared to that of aCO2 (22.88°C). The thermal requirement of R. maidis from first nymphal instar to adult (total development period) was found to be 100.00 degree days (DD) under eCO2 conditions as against 111.11degree days under aCO2 conditions. These estimated temperature thresholds and thermal constant can predict the pest scenarios and population dynamics of R. maidis.

THERMAL CONSTANTS FOR DEVELOPMENT OF THE PEA APHID (HOMOPTERA: APHIDIDAE) AND SOME OF ITS PARASITES

1977 ◽  
Vol 107 (4) ◽  
pp. 419-423 ◽  
Author(s):  
A. Campbell ◽  
M. Mackauer
Keyword(s):  
First Generation ◽  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Aphidius Ervi ◽  
Temperature Threshold ◽  
Thermal Constants ◽  
Lower Temperature Threshold ◽  
Lower Temperature ◽  
The Relationship ◽  
Generation Offspring

AbstractThe relationship between the temperature and the speed of development is described for the Kamloops ‘biotype’ of the pea aphid, Acyrthosiphon pisum, and some of its associated hymenopterous parasites. The primary parasites are: Aphidius ervi ervi, A. ervi pulcher, A. smithi, and Praon pequodorum; and the secondary parasites are: Asaphes lucens and Dendrocerus niger. For each species the lower temperature threshold for development and the time-to-adult was determined under constant laboratory conditions using field-grown alfalfa as a host plant for the pea aphid and the first-generation offspring of field-collected aphids and parasites. The thermal constants enable the prediction of aphid and parasite population growth, as influenced by temperature, on a physiological time-scale.

Fish growth and degree-days II: selecting a base temperature for an among-population study

2014 ◽  
Vol 71 (9) ◽  
pp. 1303-1311 ◽  
Author(s):  
Kyle A. Chezik ◽  
Nigel P. Lester ◽  
Paul A. Venturelli
Keyword(s):  
Growth Rates ◽  
Spatial Scales ◽  
Fish Growth ◽  
Temperature Threshold ◽  
Base Temperature ◽  
Degree Days ◽  
Thermal Range ◽  
Lower Temperature Threshold ◽  
Lower Temperature ◽  
Statistical Artifact

The degree-day (DD) is a method of describing the thermal opportunity for growth and development and is becoming increasingly popular when comparing fish growth over large spatial scales (e.g., counter-gradient growth). Temperatures too cold to permit growth are excluded in the DD equation by incorporating a lower temperature threshold (To). However, there is no convention for choosing To, and unknown is the effect of an incorrect To on how growth is perceived. We simulate data to demonstrate how an incorrect To may lead to differences in temperature-corrected growth rates among populations. These differences increase with the error in To and the thermal range among simulated populations. We then show the same relationships in an analysis of length-at-age data from 81 walleye (Sander vitreus) populations in North America. Together, our results demonstrate that differences in temperature-corrected growth rates among populations can be a statistical artifact rather than a biological phenomenon, especially when populations are distributed over a large thermal gradient.

scholarly journals The effect of temperature on the development of Nephus includens (Kirsch) and Nephus bisignatus (Boheman) (Coleoptera: Coccinellidae), predators of Planococcus citri Risso (Homoptera: Pseudococcidae)

2017 ◽  
Vol 15 ◽  
pp. 3
Author(s):  
D.C. Kontodimas ◽  
D.C Lykouressis ◽  
M.G. Karandinos ◽  
P. Katsouannos ◽  
G.J. Stathas ◽  
...  
Keyword(s):  
Survival Rate ◽  
Linear Model ◽  
Cucurbita Pepo ◽  
Effect Of Temperature ◽  
Planococcus Citri ◽  
Sour Orange ◽  
Biological Cycle ◽  
Temperature Thresholds ◽  
Thermal Constants ◽  
Lower Temperature

The effect of temperature οη the development of the predators Nephus includens (Kirsch) and Ν. bisignatus (Boheman) (Coleoptera: Coccinellidae), was studied. The development time of immature stages and the pre-oviposition period of adult females for the two predators was recorded at eight constant temperatures (10, 15, 20, 25, 30, 32.5, 35 and 37.5°C). The beetles were reared on eggs, nymphs and female adults of Planococcus citri (Risso) (Homoptera: Pseudococcidae) that had developed on squash (Cucurbita pepo) and on sour orange leaves (CΊtrus aurantium). Using the linear model for the biological cycle of Ν. includens on squash and on sour orange leaves, the developmental zeros (lower temperature thresholds) were estimated to be 10.9 and 11.0°C respectively and the thermal constants, 490.5 and 472.8 day-degrees respectively. Using the Lactin model the lower thresholds were estimated to be 11.1 and 11.2°C respectively and the upper thresholds 36.1 and 36.0°C respectively. For the biological cycle of Ν. bisignatus, using the linear model, the lower thresholds were estimated to be 9.4°C on squash and 9.3°C on sour orange leaves and the thermal constants were 614.3 and 647.9 day-degrees respectively. Using the Lactin model the lower thresholds were estimated to be 9.9 and 1O.0°C respectively and the upper thresholds, 34.7 and 35.0°C respectively. The survival rate of Ν. includens in­stars at 10, 15, 20, 25, 30, 32.5, 35 and 37.5°C on squash and on sour orange leaves was respectively 0.0, 34.9, 63.2, 70.6, 63.3, 54.5, 19.8, 0.0, and 0.0, 32.2, 61.0, 68.0, 68.3, 56.6, 17.6, 0.0%. The survival rate of Ν. bisignatus instars at 10, 15, 20, 25, 30, 32.5 and 35°C on squash and on sour orange leaves was respectively, 0.0, 39.9, 61.1, 60.7, 47.2, 26.4, 0.0 and 0.0, 35.7, 65.7, 68.0, 44.2, 29.1, 0.0%. The results show that Ν. includens has a shorter biological cycle than Ν. bisignatus, whereas the latter species has lower temperature thresholds.

scholarly journals Nonlinear models for describing development and fecundity of the pseudococcid predators Nephus includens and Nephus bisignatus

2017 ◽  
Vol 21 (1) ◽  
pp. 13 ◽  
Author(s):  
Dimitrios Ch. Kontodimas
Keyword(s):  
Mathematical Models ◽  
Goodness Of Fit ◽  
Nonlinear Models ◽  
Planococcus Citri ◽  
Temperature Threshold ◽  
Optimum Temperature ◽  
Biological Features ◽  
Lower Temperature Threshold ◽  
Lower Temperature

Among several mathematical models used to describe the development or the fecundity of insects the equations of Enkegaard, Analytis, Bieri 1 and Bieri 2 could describe both biological features. In the current study these equations used to describe the development and fecundity of two pseudococcid predators [Nephus includens (Kirsch) and Nephus bisignatus (Boheman) (Coleoptera: Coccinellidae)] preying on Planococcus citri (Risso) (Hemiptera: Pseudococcidae) at constant temperatures (15oC - 35oC). All models have goodness of fit to data especially for development [R2 adj, RSS and AIC ranged 0.9908-0.9996, 0.0019-89.1752 (x10-4), and (-75.43) – (-31.07) respectively]. Optimum temperature (Topt) and upper threshold (Tmax) were calculated accurately by all models (Topt ranged 32.6-34.0oC for N. includens and 30.0-30.6oC for N. bisignatus and Tmax ranged 35.0-38.8oC for N. includens and 33.1-36.0oC for N. bisignatus, respectively). Lower temperature threshold (Tmin) was calculated accurately by Bieri-1 model (11.0 and 10.0oC for N. includens and N. bisignatus respectively) whereas Analytis model underestimated it (8.0 and 4.9oC). As far as fecundity is concerned the respective values were better fitted near the optimum temperature (25oC) [R2 adj, RSS and AIC ranged 0.8246-0.9704, 9.2729-24.0736 and (-246.82) – (-115.34) respectively]. Conclusively, from the tested models the Bieri-1 equation was proved as the most appropriate for the reason that could estimate correctly all the requested parameters concerning the development (Tmin, Topt, Tmax) as well as it could describe sufficiently the fecundity trend of the two predators.

scholarly journals Temperature dependent development of Phenacoccus solenopsis under laboratory conditions

2017 ◽  
Vol 21 (1) ◽  
pp. 25 ◽  
Author(s):  
Sanjeev Kumar ◽  
Ch. Kontodimas
Keyword(s):  
Nonlinear Models ◽  
Thermal Constant ◽  
Temperature Threshold ◽  
Critical Temperatures ◽  
Phenacoccus Solenopsis ◽  
Developmental Threshold ◽  
Cotton Mealybug ◽  
Lower Temperature Threshold ◽  
Lower Temperature ◽  
The Relationship

Cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is an important cotton pest in Punjab, India. Development of the immature stages (four instars in female and five in male) of P. solenopsis was observed at nine constant temperatures (15, 18, 20, 25, 30, 34, 35, 38, 40°C). Using the linear model, the lower temperature threshold (tmin) for development was estimated to be 4.93 and 2.95°C and the thermal constant (K) was 333.33 and 454.54 degree days for female and male, respectively. In addition, three nonlinear models (Lactin, Bieri-1 and 3rd order polynomial) were tested to describe the relationship between temperature and development rate and to estimate the upper developmental threshold (tmax) and the optimum temperature for development (topt). Our results proved that the Bieri-1 and Lactin models and provided the best fit (r2 = 93,4 – 99,9%) and estimated accurately all the three critical temperatures, ranged tmin = 5.06 – 5.25°C, topt = 33.55 – 33.60°C, tmax = 39.99 – 40.00°C, for the total development of females and tmin = 2.82 – 3.16°C, topt = 34.01 – 34.04°C, tmax =40.00 – 40.10°C, for the total development of males.

FECUNDITY OF THE ROOT WEEVILS BRACHYRHINUS SULCATUS AND SCIOPITHES OBSCURUS ON STRAWBERRY IN THE LABORATORY AND OUTDOORS

1965 ◽  
Vol 45 (2) ◽  
pp. 169-176 ◽  
Author(s):  
W. T. Cram
Keyword(s):  
British Columbia ◽  
Relative Humidity ◽  
Coastal Area ◽  
Temperature Threshold ◽  
Night Temperature ◽  
Nocturnal Species ◽  
Root Weevils ◽  
Black Vine Weevil ◽  
Lower Temperature Threshold ◽  
Lower Temperature

The effects of laboratory and outdoor conditions on fecundity were compared between the introduced black vine weevil, Brachyrhinus sulcatus (F.), and the native obscure strawberry root weevil, Sciopithes obscurus Horn. Both species are economic pests of strawberry in the coastal area of British Columbia, Washington, and Oregon.Though B. sulcatus is much more fecund than S. obscurus both in the laboratory at a constant 20 °C and outdoors, it is not so well adapted to British Columbia conditions as S. obscurus which has a lower temperature threshold for oviposition and, therefore, a longer oviposition period.When the night temperature in cabinets at diurnal temperature programs is minimal at 8 °C, the fecundity of these nocturnal species is maximal at day temperatures of 20° for S. obscurus and 25 °C for B. sulcatus. Under these diurnal conditions B. sulcatus is the more fecund of the two and survives better in continuously high rather than variable relative humidity. S. obscurus is comparatively indifferent to humidity fluctuations.

scholarly journals Using daily air temperature thresholds to evaluate snow melting occurrence and amount on Alpine glaciers by <i>T</i>-index models: the case study of the Forni Glacier (Italy)

2014 ◽  
Vol 8 (5) ◽  
pp. 1921-1933 ◽  
Author(s):  
A. Senese ◽  
M. Maugeri ◽  
E. Vuillermoz ◽  
C. Smiraglia ◽  
G. Diolaiuti
Keyword(s):  
Air Temperature ◽  
Energy Budget ◽  
Snow Depth ◽  
Lapse Rate ◽  
Positive Energy ◽  
Temperature Threshold ◽  
Snow Melting ◽  
Air Temperatures ◽  
Temperature Thresholds ◽  
The Mean

Abstract. Glacier melt conditions (i.e., null surface temperature and positive energy budget) can be assessed by analyzing data acquired by a supraglacial automatic weather station (AWS), such as the station installed on the surface of Forni Glacier (Italian Alps). When an AWS is not present, the assessment of actual melt conditions and the evaluation of the melt amount is more difficult and simple methods based on T-index (or degree days) models are generally applied. These models require the choice of a correct temperature threshold. In fact, melt does not necessarily occur at daily air temperatures higher than 0 °C. In this paper, we applied both energy budget and T-index approaches with the aim of solving this issue. We start by distinguishing between the occurrence of snowmelt and the reduction in snow depth due to actual ablation (from snow depth data recorded by a sonic ranger). Then we find the daily average temperature thresholds (by analyzing temperature data acquired by an AWS on Forni Glacier) which, on the one hand, best capture the occurrence of significant snowmelt conditions and, on the other, make it possible, using the T-index, to quantify the actual snow ablation amount. Finally we investigated the applicability of the mean tropospheric lapse rate to reproduce air temperature conditions at the glacier surface starting from data acquired by weather stations located outside the glacier area. We found that the mean tropospheric lapse rate allows for a good and reliable reconstruction of glacier air temperatures and that the choice of an appropriate temperature threshold in T-index models is a very important issue. From our study, the application of the +0.5 °C temperature threshold allows for a consistent quantification of snow ablation while, instead, for detecting the beginning of the snow melting processes a suitable threshold has proven to be at least −4.6 °C.

Biology at Different Temperatures, Thermal Requirements, and Ecological Zoning of Opogona sacchari (Lepidoptera: Tineidae)

2019 ◽  
Vol 112 (4) ◽  
pp. 1676-1682
Author(s):  
Lucas Fonseca Lacerda ◽  
Aloisio Coelho ◽  
Adriano Gomes Garcia ◽  
Paulo Cesar Sentelhas ◽  
José Roberto Postali Parra
Keyword(s):  
Temperature Threshold ◽  
Life Stages ◽  
Southern Brazil ◽  
Consumer Market ◽  
Actual Distribution ◽  
Thermal Requirements ◽  
Different Temperatures ◽  
Lower Temperature Threshold ◽  
Lower Temperature ◽  
Main Consumer

Abstract The banana moth, Opogona sacchari (Bojer, 1856), is a polyphagous pest that causes serious damage to different crops around the world, particularly to bananas in southern Brazil. The insect is designated a quarantine pest in several countries including Argentina, the main consumer market for bananas produced in southern Brazil. To provide support for the management of O. sacchari, the present study investigated the biology and thermal requirements at eight temperatures (18, 22, 25, 28, 30, 32, 33, and 34 ± 1°C) and constructed a fertility life table at five temperatures (18, 22, 25, 28, and 30 ± 1°C). Above 30°C, the mortality of all life stages was 100%; the best temperature for development was 25°C. Based on this information, an ecological zoning of the pest was developed for Brazil. The lower temperature threshold was 8.6°C. The zoning indicated that the pest does not occur in regions with warmer climates, corresponding to the actual distribution of this pest in Brazil.

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