scholarly journals Morphometry of the reproductive system of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera, Pentatomidae) when submitted to different temperatures

2020 ◽  
Vol 50 (12) ◽  
Author(s):  
Ítala Tainy Barreto Francisco dos Santos ◽  
Heloisa Safira Santos Pinheiro ◽  
Júlio César Melo Poderoso ◽  
Vancleber Batista dos Santos ◽  
Thiago Xavier Chagas ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Reproductive System ◽  
Adult Stage ◽  
Mass Rearing ◽  
Developmental Duration ◽  
Temperature Variations ◽  
Temperature Conditions ◽  
Controlled Conditions ◽  
Different Temperatures ◽  
Ovariole Number

ABSTRACT: In order to manipulate the mass rearing of natural enemies, temperature variations can be used. The effects are widely studied for their survival and developmental duration; however, there is little information about their reproductive system in the literature. Therefore, the purpose of this study was to evaluate the effects of different temperatures on the reproductive system of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae). The predator was kept at temperature conditions of 17, 21, 25, and 29 °C until reaching 15 days of age, the adult stage. The insects were then killed, measured for both weight and size, dissected, and then evaluated for the following parameters: length of the most developed ovariole; number of ovarioles per ovary; number of oocytes per the more developed ovarioles; number of oocytes per P. nigrispinus female; and the total area of the testicles was measured in the male insects. Results showed that as the temperature increased, the parameters were positively affected. These temperature variations can be used to manipulate the mass rearing of P. nigrispinus under controlled conditions.

scholarly journals The Effects of Temperature on the Development, Morphology, and Fecundity of Aenasius bambawalei (=Aenasius arizonensis)

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 833
Author(s):  
Juan Zhang ◽  
Yayuan Tang ◽  
Jun Huang
Keyword(s):  
High Temperature ◽  
Natural Enemies ◽  
Morphological Changes ◽  
Insect Pest ◽  
Hind Tibia ◽  
Developmental Rate ◽  
Female Offspring ◽  
Developmental Duration ◽  
Phenacoccus Solenopsis ◽  
Different Temperatures

The effects of high temperature on the developmental, morphological, and fecundity characteristics of insects, including biological invaders and their accompanying natural enemies, are clear. Phenacoccus solenopsis (Homoptera: Pseudococcidae) is an aggressive invasive insect pest worldwide. Aenasius bambawalei (=Aenasius arizonensis Girault) (Hymenoptera: Encyrtidae) is a predominant accompanying parasitoid of this mealybug. Our previous studies showed that temperature change induced an increase in the female offspring ratio of A. bambawalei. However, whether this increase is the result of a shortened or enhanced development period of the reproductive systems of A. bambawalei remains unknown. Here, we compared the pupal development, hind tibia of female adults, and fecundity of A. bambawalei under different temperatures to clarify the development and morphological changes induced by high temperature and to better understand its potential as an accompanying natural enemy. Our results showed that, at a high temperature (36 °C), the pupal developmental duration of A. bambawalei was only 0.80 times that of the control, and the length of the hind tibia was 1.16 times that of the control. Moreover, high temperature accelerated the developmental rate of gonads and increased the numbers of eggs and sperm. These results indicated that experimental warming shortened the pupal developmental duration, altered the hind tibia length of female adults, and facilitated the fecundity of A. bambawalei. These findings will help to understand the adaptation mechanisms of accompanying natural enemies. Furthermore, these findings will help to make use of this behavior to effectively control invasive pests.

scholarly journals Conidia sporulation of Pyricularia oryzae in segments of wheat plants under six different temperatures

2020 ◽  
Vol 50 (4) ◽  
Author(s):  
Marcos Kovaleski ◽  
João Leodato Nunes Maciel ◽  
Gustavo Bilibio dos Santos ◽  
Alieze Nascimento da Silva ◽  
Carolina Cardoso Deuner
Keyword(s):  
High Temperature ◽  
Petri Dish ◽  
Pyricularia Oryzae ◽  
Causal Agent ◽  
Temperature Conditions ◽  
Wheat Blast ◽  
Conidia Production ◽  
Different Temperatures

ABSTRACT: Wheat blast is known for developing itself more intensely under relatively high temperature conditions but many aspects related to its epidemiology remain unknown. The objective of this research was to evaluate the sporulative capacity of Pyricularia oryzae Triticum (Pot), the causal agent of wheat blast, in tissues of wheat plants under different temperatures degrees. Wheat plants of the cultivar Anahuac 75, susceptible to blast, were inoculated in the stage of flowering with conidial suspensions (105 conidia/mL) of the Pot isolates Py 12.1.209 and Py 12.1.132. Seven days after the inoculation, plants were cut in the following segments: leaves, stems and rachis (with blast severity ranging from 40 to 60%). Groups of each one of the three plant segments with the lesions were disposed in Petri-dish moist chambers, that were submitted to six different temperature treatments (18, 21, 24, 27, 30 and 33 °C). The most appropriate model that related the conidia production with temperature was identified in the evaluations conducted with stems. The established equations allowed identifying that the highest production of conidia of Pot occurs between 24 and 27 °C.

Bottom-up Effects on Tri-trophic Interactions: Plant Fertilization Enhances the Fitness of a Primary Parasitoid Mediated by Its Herbivore Host

2020 ◽  
Vol 113 (6) ◽  
pp. 2619-2626
Author(s):  
Apostolos Pekas ◽  
Felix L Wäckers
Keyword(s):  
Natural Enemies ◽  
Nitrogen Concentration ◽  
Mass Rearing ◽  
Reproductive Capacity ◽  
Biological Pest Control ◽  
Tobacco Plants ◽  
Primary And Secondary Metabolites ◽  
Food Quantity ◽  
Nitrogen Treatment ◽  
The Impact

Abstract Plants play a pivotal role in interactions involving herbivores and their natural enemies. Variation in plant primary and secondary metabolites not only affects herbivores but, directly and indirectly, also their natural enemies. Here, we used a commercial NPK fertilizer to test the impact of three fertilizer, namely 50, 100, and 200 ppm nitrogen, and one control (i.e., water) treatments, on the weight of the nymphs of the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Subsequently, the whitefly parasitoid Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) was reared on the different groups of whitefly nymphs and upon parasitoid emergence, the number of oocytes was determined as a measure of reproductive capacity. Trials were done on tomato and tobacco plants. The level of nitrogen concentration in tobacco leaves was directly correlated with the fertilizer applications, thus confirming the effect of our fertilizer treatments. Both in tomato and tobacco plants, healthy as well as parasitized whitefly nymphs, were heaviest in the 200 ppm nitrogen treatment. The highest number of oocytes per female parasitoid was recorded in the 200 ppm nitrogen treatment in tomato (31% more oocytes as compared with the control) and in the 100 and 200 ppm nitrogen treatments in tobacco (200% more oocytes). We suggest that the increase in oocytes was the result of the enhanced size (food quantity) and/or nutritional quality of the whitefly host. The practical implications of these results for the mass rearing of whitefly parasitoids and for biological pest control are discussed.

A METHOD FOR REARING VARIOUS SPECIES OF SOCIAL WASPS OF THE GENUS POLISTES (HYMENOPTERA: VESPIDAE) UNDER CONTROLLED CONDITIONS

1977 ◽  
Vol 109 (7) ◽  
pp. 1013-1015 ◽  
Author(s):  
David L. Gibo
Keyword(s):  
Social Behaviour ◽  
Simple Technique ◽  
Mass Rearing ◽  
Colony Growth ◽  
Social Wasps ◽  
Colony Founding ◽  
Rearing Method ◽  
Modified Method ◽  
Controlled Conditions ◽  
Caste Differences

Wasps of the genus Polistes have a number of characteristics that make them particularly suitable for studies on insect social behaviour. The females construct nests with exposed combs, have a reasonably complex social behaviour, and usually lack obvious morphological caste differences. In addition, the adults of many species establish colonies as groups of siblings (foundress associations), a method which is intermediate between colony founding by swarming, and colony founding by individual queens (Wilson 1971). Because of these characteristics, Polistes have been of interest to biologists who are concerned with the evolution of social behaviour in insects (e.g. Alexander 1974, Gibo 1974, Lin and Michener 1972, West 1967, West Eberhard 1969, 1975). Consequently, there is a need for a simple technique for rearing various species of Polistes under controlled conditions. Gibo (1974) briefly described modifications of Gillaspy's (1971) rearing method for P. apachus which made mass rearing of P. fascatus possible. This note describes the modified method in greater detail, and includes improvements that have resulted in increased yield and greater synchrony of colony growth. The improvements have been developed over 3 years and the method has been used to rear more than 100 colonies of various species of Polistes, including P. fuscatus, P. apachus, and P. dorsalis.

scholarly journals Pyroelectric Energy Harvesting: With Thermodynamic-Based Cycles

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Saber Mohammadi ◽  
Akram Khodayari
Keyword(s):  
Energy Harvesting ◽  
Single Crystal ◽  
Ferroelectric Materials ◽  
Temperature Variations ◽  
Thermodynamic Cycles ◽  
Sensor Applications ◽  
Different Temperatures

This work deals with energy harvesting from temperature variations using ferroelectric materials as a microgenerator. The previous researches show that direct pyroelectric energy harvesting is not effective, whereas thermodynamic-based cycles give higher energy. Also, at different temperatures some thermodynamic cycles exhibit different behaviours. In this paper pyroelectric energy harvesting using Lenoir and Ericsson thermodynamic cycles has been studied numerically and the two cycles were compared with each other. The material used is the PMN-25 PT single crystal that is a very interesting material in the framework of energy harvesting and sensor applications.

scholarly journals Peculiarities of surface layer response to local and global variations of temperature field at water-air boundary

2021 ◽  
Vol 1 (395) ◽  
pp. 155-161
Author(s):  
S. Zenchenko ◽  
Keyword(s):  
Surface Layer ◽  
Temperature Field ◽  
Water Surface ◽  
Thermal Conditions ◽  
Simulation Data ◽  
Temperature Variations ◽  
Low Intensity ◽  
Water Surface Temperature ◽  
Different Temperatures ◽  
Qualitative Changes

Object and purpose of research. This paper discusses surface layer at water-air boundary. The purpose of this work to investigate, in controllable conditions, the dynamics of surface layer properties depending on temperature variations. Materials and methods. Contact multi-channel tools for temperature and humidity control, as well as infrared tools for water surface temperature monitoring. Simulation of different thermal conditions at water-air boundary and low-intensity hydrophysical disturbances on the free surface. Main results. The study yielded simulation data and experimental confirmation of humidity fluctuations in the surface layer at different temperatures at water-air boundary in the conditions of low-intensity disturbances. Conclusion. This study yielded the data on qualitative changes in surface layer humidity based on the calculations as per simultaneously measured temperatures of water in the surface layer and near water-air boundary.

scholarly journals Impact of Outdoor Temperature Variations on Thermal State in Experiments Using Immersive Virtual Environment

2021 ◽  
Vol 13 (19) ◽  
pp. 10638
Author(s):  
Girish Rentala ◽  
Yimin Zhu ◽  
Neil M. Johannsen
Keyword(s):  
Virtual Environments ◽  
Thermal Sensation ◽  
Outdoor Temperature ◽  
Temperature Variations ◽  
Immersive Virtual Environments ◽  
Temperature Conditions ◽  
In Situ Experiments ◽  
Potential Impact ◽  
Thermal States

Recent studies have established immersive virtual environments (IVEs) as promising tools for studying human thermal states and human–building interactions. One advantage of using immersive virtual environments is that experiments or data collection can be conducted at any time of the year. However, previous studies have confirmed the potential impact of outdoor temperature variations, such as seasonal variations on human thermal sensation. To the best of our knowledge, no study has looked into the potential impact of variations in outdoor temperatures on experiments using IVE. Thus, this study aimed to determine if different outdoor temperature conditions affected the thermal states in experiments using IVEs. Experiments were conducted using a head mounted display (HMD) in a climate chamber, and the data was analyzed under three temperature ranges. A total of seventy-two people participated in the experiments conducted in two contrasting outdoor temperature conditions, i.e., cold and warm outdoor conditions. The in situ experiments conducted in two cases, i.e., cooling in warm outdoor conditions and heating in cold outdoor conditions, were used as a baseline. The baseline in-situ experiments were then compared with the IVE experiments conducted in four cases, i.e., cooling in warm and cold outdoor conditions and heating in warm and cold outdoor conditions. The selection of cooling in cold outdoor conditions and heating in warm outdoor conditions for IVE experiments is particularly for studying the impact of outdoor temperature variations. Results showed that under the experimental and outdoor temperature conditions, outdoor temperature variations in most cases did not impact the results of IVE experiments, i.e., IVE experiments can replicate a temperature environment for participants compared to the ones in the in situ experiments. In addition, the participant’s thermal sensation vote was found to be a reliable indicator between IVE and in situ settings in all studied conditions. A few significantly different cases were related to thermal comfort, thermal acceptability, and overall skin temperature.

scholarly journals An experimental study of PMMA precision cryogenic micro-milling

2021 ◽  
Vol 1 (1) ◽  
pp. 15-21
Author(s):  
Ying Yan ◽  
Yujia Sun ◽  
Bo Li ◽  
Ping Zhou
Keyword(s):  
Processing Parameters ◽  
Polymer Materials ◽  
Micro Milling ◽  
Dominant Factor ◽  
Processing Temperature ◽  
Shape Accuracy ◽  
Optical Components ◽  
Temperature Conditions ◽  
Different Temperatures ◽  
Cryogenic Method

Polymethyl methacrylate (PMMA) has been used more and more widely in the fields of microfluidic devices and high-precision optical components due to its excellent mechanical and optical properties. Micro-milling is one of the methods that has been used in the machining of polymer materials. The machinability of PMMA is highly dependent on temperature, and the cryogenic method is also applied to control the processing temperature. In this work, the PMMA was milled with different processing parameters at the temperature of -55℃ and 25℃. The influence of each milling parameter on the surface quality under different temperature conditions were investigated. According to the results, the cutting depth is the dominant factor that influenced the surface roughness. The shape accuracy of the rectangular microgroove processed under low-temperature conditions is better. The material removal mechanism under different temperatures was also discussed, and the material is cut in a brittle way under low temperatures.

Development of Hydrotaea spinigera (Diptera: Muscidae) at Constant Temperatures and Its Significance for Estimating Postmortem Interval

2020 ◽  
Author(s):  
Yu Wang ◽  
Yingna Zhang ◽  
Man Wang ◽  
Guoliang Hu ◽  
Yangfan Fu ◽  
...  
Keyword(s):  
Body Length ◽  
Adult Stage ◽  
Postmortem Interval ◽  
Larval Body ◽  
Developmental Threshold ◽  
Development Models ◽  
Different Temperatures ◽  
Development Duration ◽  
Lower Developmental Threshold ◽  
Length Changes

Abstract Hydrotaea spinigera Stein is a necrophagous species, widely distributed in Oriental and Australasian regions. Considering that the postfeeding larvae or puparia of this species can still be found in abundance at the advanced decomposition stage or even the skeleton stage of remains, it can serve as a good supplementary indicator for estimating the minimum postmortem interval (PMImin). This could also extend the range of PMImin when the primary colonizers are no longer associated with the corpse or have emerged as adults. This study investigated the development duration, accumulated degree hours, and larval body length changes of H. spinigera at seven constant temperatures ranging from 16 to 34°C, and established three development models for estimating PMImin, including isomorphen diagram, isomegalen diagram, and thermal summation model. At 16, 19, 22, 25, 28, 31, and 34°C, the development durations of H. spinigera from egg to adult stage were 1,412.6 ± 62.9, 867.4 ± 14.9, 657.1 ± 22.9, 532.3 ± 10.1, 418.8 ± 21.3, 379.8 ± 16.6, and 340.0 ± 20.3 h, respectively. The lower developmental threshold L0 was estimated as 10.50 ± 0.20°C, and the thermal summation constant K was 7,648.83 ± 146.74 degree hours. Using regression analysis, equations were obtained modeling the change of larval body length with time after hatching at different temperatures. This study provided basic data based on the growth and development of H. spinigera for the estimation of PMImin in forensic science.

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