Temperature driven development of the rice brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae)

Temperature driven development of rice brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) population (biotype 4) was examined at seven constant temperatures (15, 18, 20, 25, 30, 32 and 35°C). Complete development of BPH from egg to adult was observed at constant temperatures ranging from 15 to 32°C with linear development observed till 30°C. Total immaturedevelopmental duration decreased from 74.4 days at 15°C to 22.4 days at 30°C. Linear and non-linear models fitted to describe developmental rates of life stages as a function of temperature, gave estimates of bioclimatic thresholds (lower, optimum and upper temperature thresholds). Thermal constants estimated from Campbell linear model for egg, nymph and cumulative immature development to adult were, 198.8, 275.5 and 473.9 degree days, respectively. Among empirical non-linear models, Lactin 2 model was selected for estimates of upper temperature threshold at 35°C based on higher coefficient of determination. Application of thermodynamic SSI model explained the observed nonlinear relationship of development of BPH life stages at temperatures higher than 30°C. The estimated thermal constants and bioclimatic thresholds were used in developing temperature dependent phenology model based on Campbell equation. Phenology model predicted closely the occurrence of different life stages of BPH with those observed under field conditions.

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.)

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.

Identification of the Thermal Constants of the DPL Heat Transfer Model of a Single Layer Porous Material

This paper deals with parameters’ identification of the Dual Phase Lag (DPL) thermal model of a 3D printed porous materials. The experiments were performed for two porous materials with different filling factors. The Laplace transform was applied for the heat transfer equation and together with different optimization methods it allowed to identify the thermal time constants of the DPL model. Several optimization methods were tested with known parameters in order to confirm the correctness of the parameters’ estimation.

Correlating the Cellular Network, in Foamed Concrete containing Ash, with their Physical Properties

Cellular concrete is a lightweight solid cementitious foam that is used mainly for thermal insulation and sound absorption. Either partially or wholly, when the Portland cement in the binder is replaced with ash, the environmental impact of the material is reduced. However, the resulting changes in the cell structure and their subsequent impact upon the physical properties of the material have not been well examined. In this study, cellular concrete was prepared from alkali activated fly ash binders and separately, from Portland cement binders blended with wood ash. The cell structure was photographed using laser confocal microscopy and the images were analyzed to quantify the cellular network in terms of the porosity and the fractal dimension of the porous phase. Alongside, the cellular concrete specimens were tested for their thermal constants and sound absorption. The results show that there was an increase in the fractal dimension and an associated drop in thermal conductivity for an increase in the porosity.

Study of the effect of thermal conductivity on the anti-icing performance of coated fabrics

The anti-icing property of materials can be influenced by many factors, such as mechanical forces, electrostatic forces, van der Waals interaction and so on. In this research, the effect of thermal conductivity on the anti-icing performance of coated fabrics was studied. An instrument to observe the melting process of the ice on various materials was designed, by which the melting rate of the ice on the samples could be tested. A formula for the variation of the melting rate of the ice on the samples against the thermal conductivity of the samples was deduced using a mathematical method. It was proved that the formula can be used to study the effect of thermal conductivity on the anti-icing performance of coated fabrics. A coated fabric with anti-icing performance was prepared with Nomex IIIA fabrics, PU-2540 (Polyurethane-2540), Teflon emulsion, graphite powder, SiC powder and TG-581 (fluorine-containing water and oil repellent-581) using a knife coating method. The properties of the samples were investigated by using a video optical contact angle measuring instrument (OCA15 Pro), a thermal constants analyzer (TPS2500S, Hot Disk, Sweden), an anti-icing property tester, and other devices. Results show that the coated fabrics prepared in this manner have good performance in ease of ice removal and a low interaction with water and ice, resulting in good anti-icing properties.

Predicting the Potential Invasive Range of Klambothrips myopori (Thysanopetra: Phlaeothripidae)

Temperature-driven development of myoporum thrips, Klambothrips myopori (Thysanopetra: Phlaeothripidae), was examined at seven constant temperatures (15, 17, 20, 25, 30, 34, and 35.5°C) on Myoporum laetum Forst (Lamiales: Scrophulariaceae). Thrips successfully completed development to adult stage between 15 and 35.5°C. One linear and three nonlinear models were fitted to describe developmental rates of K. myopori as a function of temperature, and for estimating thermal constants and bioclimatic thresholds (Tmin, Topt, and Tmax). The Briere-1 model performed best in describing the developmental rate of cumulative life stages. Two ecological niche models, CLIMEX and Maxent, were used to predict the geographic distribution of K. myopori in its native range and globally. Overall predictions of environmental suitability differed greatly across models. The CLIMEX model accurately predicted known invasive and native localities, while the Maxent model failed to predict the native localities and parts of the invasive range. Based on the CLIMEX model, K. myopori has the potential to establish in many regions of the globe.

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

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.

The effect of temperature on the development and reproduction of Busseola fusca (Lepidoptera: Noctuidae)

The effect of temperature on the reproduction and development of Busseola fusca was studied under laboratory conditions. Single male–female pairs were confined to oviposition chambers kept at 15, 20, 26 and 30 ± 1°C and a 14L:10D photoperiod. Data on reproduction parameters were captured daily. Oviposition occurred at all the mentioned temperatures but no fertility was recorded at 30°C. The total number of eggs laid per female moth was between 300 and 400 and the optimum temperature for oviposition and fertility was between 20 and 26°C. Larval development was studied at five different temperature regimes, i.e. 15, 18, 20, 26 and 30 ± 1°C and a 14L:10D photoperiod. The most favourable temperature as well as the upper threshold temperature for larval development was between 26 and 30°C. Total development period was 152.6–52.6 days, respectively, at 15°C, and 26–30°C. The thermal constants for B. fusca was 99.50, 536.48, 246.25 and 893.66°D and lower temperature thresholds were 10.36, 8.14, 8.99 and 8.84°C, for completion of the egg, larval, pupal and egg-to-adult stages, respectively. Results on the thermal constants and lower and upper threshold temperatures of B. fusca can be used to predict the impact of climate change on the distribution and population growth of this pest.