scholarly journals Thermal Requirements of Ooencyrtus submetallicus (Hym.: Encyrtidae) and Telenomus podisi (Hym.: Platygastridae) Parasitizing Euschistus heros Eggs (Hem.: Pentatomidae)

Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 924
Author(s):  
Valeria Freitas Chaves ◽  
Fabricio Fagundes Pereira ◽  
Jorge Braz Torres ◽  
Ivana Fernandes da Silva ◽  
Patrik Luiz Pastori ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Thermal Constant ◽  
Cycle Duration ◽  
Base Temperature ◽  
Thermal Requirements ◽  
Euschistus Heros ◽  
Different Temperatures ◽  
Telenomus Podisi ◽  
And Behavior ◽  
Number Of Individuals

Temperature is one of the abiotic factors that strongly influences the biology and behavior of insects. In this study, we assessed the development of egg parasitoids Ooencyrtus submetallicus and Telenomus podisi parasitizing Euschistus heros eggs at different temperatures, and estimated the average number of generations for seven representative soybean-producing regions in Brazil. A comparative biology study was conducted, where the percentage of parasitism and emergence, life cycle duration (egg–adult), and longevity were found to be similar between O. submetallicus and T. podisi. The sex ratio and the number of individuals emerged from parasitized egg were higher in O. submetallicus in all regions. In the study of thermal requirements, temperatures of 16, 19, 22, 25, 28, 31, and 33 °C were tested. O. submetallicus and T. podisi developed at temperatures between 16 and 31 °C. The base temperature (Tb) for O. submetallicus and T. podisi was 9.3 and 6.7 °C, respectively; the thermal constant (K) was 336.9 and 272.7 degree-days, respectively. The estimated average number of annual generations of both parasitoids was higher than the host. O. submetallicus and T. podisi have the same ability to parasitize and develop in eggs of E. heros under the conditions studied. Both parasitoids exhibited satisfactory development and parasitism at temperatures between 19 and 31 °C. The development of both parasitoids was faster than their host, and the number of generations was higher for the seven studied localities.

scholarly journals Thermal requirements of Dermanyssus gallinae (De Geer, 1778) (Acari: Dermanyssidae)

2008 ◽  
Vol 17 (2) ◽  
pp. 67-72
Author(s):  
Edna Clara Tucci ◽  
Angelo P. do Prado ◽  
Raquel Pires de Araújo
Keyword(s):  
Developmental Stages ◽  
Sao Paulo ◽  
The State ◽  
Regression Equation ◽  
Dermanyssus Gallinae ◽  
Thermal Constant ◽  
Base Temperature ◽  
São Paulo ◽  
Determination Coefficient ◽  
Thermal Requirements

The thermal requirements for development of Dermanyssus gallinae were studied under laboratory conditions at 15, 20, 25, 30 and 35°C, a 12h photoperiod and 60-85% RH. The thermal requirements for D. gallinae were as follows. Preoviposition: base temperature 3.4ºC, thermal constant (k) 562.85 degree-hours, determination coefficient (R²) 0.59, regression equation: Y= -0.006035 + 0.001777 x. Egg: base temperature 10.60ºC, thermal constant (k) 689.65 degree-hours, determination coefficient (R²) 0.94, regression equation: Y= -0.015367 + 0.001450 x. Larva: base temperature 9.82ºC, thermal constant (k) 464.91 degree-hours, determination coefficient R² 0.87, regression equation: Y= -0.021123+0.002151 x. Protonymph: base temperature 10.17ºC, thermal constant (k) 504.49 degree-hours, determination coefficient (R²) 0.90, regression equation: Y= -0.020152 + 0.001982 x. Deutonymph: base temperature 11.80ºC, thermal constant (k) 501.11 degree-hours, determination coefficient (R²) 0.99, regression equation: Y= -0.023555 + 0.001996 x. The results obtained showed that 15 to 42 generations of Dermanyssus gallinae may occur during the year in the State of São Paulo, as estimated based on isotherm charts. Dermanyssus gallinae may develop continually in the State of São Paulo, with a population decrease in the winter. There were differences between the developmental stages of D. gallinae in relation to thermal requirements.

scholarly journals Congregating behavior and response to resource distribution of the Green House Millipede, Oxidus gracilis

2016 ◽  
Author(s):  
Gregory Bulpitt
Keyword(s):  
Environmental Factors ◽  
Abiotic Factors ◽  
Environmental Parameters ◽  
Field Recording ◽  
Litter Cover ◽  
Rock Cover ◽  
Oxidus Gracilis ◽  
Experimental Trials ◽  
And Behavior ◽  
Number Of Individuals

Background. Congregating behaviors, though common among many animal species, are little studied among millipedes. It is also unclear to what extent abiotic factors influence the distribution and behavior of millipedes. The species Oxidus gracilis was surveyed around several streams on the island of Mo’orea along with soil moisture, leaf litter cover, and rock cover. Experiments were designed in order to determine how an innate congregating behavior may affect their distributions. Methods. Fifteen transects were performed in the field, recording O. gracilis abundances and the three environmental factors every 1 m. Forty trials were performed using covered bins filled with soil and five fruits of the Tahitian chestnut tree (Inocarpus fagifer). Ten millipedes were placed in the box and left for an hour, after which the number of individuals per fruit was recorded. Results. It was found that while none of the three environmental factors were strong indicators of the distribution of O. gracilis , individuals did in fact demonstrate a tendency to congregate in the experimental trials. Discussion. The lack of significant relationships with the three environmental parameters suggests a generalist behavior of this millipede species, potentially benefitting its invasive nature. The congregating behavior could potentially be for the purposes of mating or defense. Although not studied in this paper, it is possible that conspecific chemical cues are responsible.

scholarly journals Thermal requirements and estimates of the annual number of generations of Lobiopa insularis on strawberry crop

2018 ◽  
Vol 36 (1) ◽  
pp. 54-58
Author(s):  
Simone Andzeiewski ◽  
Sabrina Lerin ◽  
Ligia C. Bortoli ◽  
Aline Nondillo ◽  
Daniel Bernardi ◽  
...  
Keyword(s):  
Temperature Increase ◽  
Artificial Diet ◽  
Development Time ◽  
Development Rate ◽  
Annual Number ◽  
Thermal Constant ◽  
Base Temperature ◽  
Biological Cycle ◽  
Thermal Requirements ◽  
Direct Damage

ABSTRACT Lobiopa insularis is one of the main pests of strawberry crop, causing direct damage to fruit, making them unfeasible for consumption and commercialization. This study aimed to estimate, under laboratory conditions, base temperature and thermal requirements of the eggs, larvae, pupae and the biological cycle (from egg to adult) of L. insularis. Insects were reared on artificial diet based on strawberry fruits, at temperatures of 16, 19, 22, 25, 28 and 31°C, using air-conditioned chambers (70±10% R.H.; 12 h photophase). The number of annual generations of L. insularis was estimated for eight municipalities belonging to the main strawberry growing regions in Brazil, considering base temperature and thermal constant. Development time of L. insularis was proportional to the temperature increase. The best development rate was obtained when insects were reared at 22 and 25ºC. Based on thermal requirements of L. insularis, the number of annual generations was estimated between 5 and 7 per year, according to the studied region.

scholarly journals Biological Characteristics and Parasitism Capacity of Telenomus podisi (Hymenoptera: Platygastridae) on Eggs of Euschistus heros (Hemiptera: Pentatomidae)

2018 ◽  
Vol 10 (8) ◽  
pp. 210 ◽  
Author(s):  
Gabriela Vieira Silva ◽  
Adeney De Freitas Bueno ◽  
Pedro Manuel Oliveira Janeiro Neves ◽  
Bruna Magda Favetti
Keyword(s):  
Biological Characteristics ◽  
Biological Potential ◽  
Euschistus Heros ◽  
Different Temperatures ◽  
Telenomus Podisi ◽  
F1 Generation

We evaluated the effects of adult mating and temperature on the biological potential and parasitism of Telenomus podisi (Ashmead) (Hymenoptera: Platygastridae) on Euschistus heros (Fabricius) (Hemiptera: Pentatomidae). Females were isolated and the characteristics of the F1 generation were compared with those of females previously copulated. The parasitism capacity of T. podisi on E. heros eggs at 20, 25, 30, 35, and 40 °C was evaluated. The longevity of parental females (days), egg-adult period (days) of the F1 generation, parasitism of parental females (%), and parasitoid emergence (%) were not influenced by the lack or not of the copulation. The offspring of non-copulated females were males, and arrhenotokous parthenogenesis occurred. The temperatures most favorable to the parasitoid were 25 and 30 °C. Even previously copulated females generated mostly males after a few days of oviposition. Therefore, the biological characteristics and reproduction of T. podisi were impacted by adult mating prior to parasitism and by different temperatures. Although parasitism of T. podisi was not affected by mating parasitoid permanence in the field, it may be affected when unmated females are released.

scholarly journals Thermal requirements and estimate number of generations of Palmistichus elaeisis (Hymenoptera: Eulophidae) in different Eucalyptus plantations regions

2011 ◽  
Vol 71 (2) ◽  
pp. 431-436 ◽  
Author(s):  
FF Pereira ◽  
JC Zanuncio ◽  
HN Oliveira ◽  
ELV Grance ◽  
PL Pastori ◽  
...  
Keyword(s):  
Control Programme ◽  
Thermal Constant ◽  
Mato Grosso ◽  
Thermal Requirements ◽  
Minas Gerais State ◽  
Eucalyptus Plantations ◽  
Number Of Individuals ◽  
Mato Grosso Do Sul ◽  
Threshold Of Development ◽  
Estimate Number

To use Palmistichus elaeisis Delvare and LaSalle, 1993 (Hymenoptera: Eulophidae) in a biological control programme of Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), it is necessary to study thermal requirements, because temperature can affect the metabolism and bioecological aspects. The objective was to determine the thermal requirements and estimate the number of generations of P. elaeisis in different Eucalyptus plantations regions. After 24 hours in contact with the parasitoid, the pupae was placed in 16, 19, 22, 25, 28 and 31 °C, 70 ± 10% of relative humidity and 14 hours of photophase. The duration of the life cycle of P. elaeisis was reduced with the increase in the temperature. At 31 °C the parasitoid could not finish the cycle in T. arnobia pupae. The emergence of P. elaeisis was not affected by the temperature, except at 31 °C. The number of individuals was between six and 1238 per pupae, being higher at 16 °C. The thermal threshold of development (Tb) and the thermal constant (K) of this parasitoid were 3.92 °C and 478.85 degree-days (GD), respectively, allowing for the completion of 14.98 generations per year in Linhares, Espírito Santo State, 13.87 in Pompéu and 11.75 in Viçosa, Minas Gerais State and 14.10 in Dourados, Mato Grosso do Sul State.

scholarly journals Congregating behavior and response to resource distribution of the Green House Millipede, Oxidus gracilis

2016 ◽  
Author(s):  
Gregory Bulpitt
Keyword(s):  
Environmental Factors ◽  
Abiotic Factors ◽  
Environmental Parameters ◽  
Field Recording ◽  
Litter Cover ◽  
Rock Cover ◽  
Oxidus Gracilis ◽  
Experimental Trials ◽  
And Behavior ◽  
Number Of Individuals

Background. Congregating behaviors, though common among many animal species, are little studied among millipedes. It is also unclear to what extent abiotic factors influence the distribution and behavior of millipedes. The species Oxidus gracilis was surveyed around several streams on the island of Mo’orea along with soil moisture, leaf litter cover, and rock cover. Experiments were designed in order to determine how an innate congregating behavior may affect their distributions. Methods. Fifteen transects were performed in the field, recording O. gracilis abundances and the three environmental factors every 1 m. Forty trials were performed using covered bins filled with soil and five fruits of the Tahitian chestnut tree (Inocarpus fagifer). Ten millipedes were placed in the box and left for an hour, after which the number of individuals per fruit was recorded. Results. It was found that while none of the three environmental factors were strong indicators of the distribution of O. gracilis , individuals did in fact demonstrate a tendency to congregate in the experimental trials. Discussion. The lack of significant relationships with the three environmental parameters suggests a generalist behavior of this millipede species, potentially benefitting its invasive nature. The congregating behavior could potentially be for the purposes of mating or defense. Although not studied in this paper, it is possible that conspecific chemical cues are responsible.

scholarly journals Biology and thermal requirements of Telenomus remus reared on fall armyworm Spodoptera frugiperda eggs

2008 ◽  
Vol 38 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Regiane Cristina Oliveira de Freitas Bueno ◽  
Tatiana Rodrigues Carneiro ◽  
Dirceu Pratissoli ◽  
Adeney de Freitas Bueno ◽  
Odair Aparecido Fernandes
Keyword(s):  
Sex Ratio ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Thermal Constant ◽  
Degree Days ◽  
Thermal Threshold ◽  
Thermal Requirements ◽  
Different Temperatures ◽  
Males And Females ◽  
Telenomus Remus

This research aimed at studing Telenomus remus Nixon biology reared on Spodoptera frugiperda (J.E. Smith) eggs at different temperatures. Based on the development of the cycle (egg-adult), the thermal requirements and the number of parasitoid generations at constant temperatures were determined. Initially, 24-hour-old S. frugiperda eggs were submitted to parasitism by T. remus during 5 h, being then transferred to acclimatized chambers regulated at 15, 20, 25, 28, 31, and 35°C. The cycle (egg to adult) was influenced by temperature varying from 8.3±0.01 to 47.2±0.01 for females and 8.1±0.01 to 46.8±0.01 days for males at 31 and 15°C, respectively. The emergency (%) was also influenced by temperature. A reduction in emergency was observed at 15°C and no emergency at 35°C. T. remus sex ratio was not influenced by temperature. Sexual rate was not changed by temperature. Regarding to thermal requirements, thermal constant (K) and inferior thermal threshold (Tb) were higher for T. remus females (158.88 degree-days and 12.5°C) when compared to males (154.12 degree-days and 12.6°C). The estimated number of T. remus generation per year for males and females at laboratory conditions was 5.6 and 5.6, 16.9 and 17.3, 28.3 and 29.0, 35.1 and 36.0, 39.6 and 40.7 at 15, 20, 25, 28, and 31oC, respectively.

scholarly journals Creation and Validation of a Temperature-Based Phenology Model for Meloidogyne incognita on Common Bean

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 240
Author(s):  
Ariadna Giné ◽  
Patricia Monfort ◽  
Francisco Javier Sorribas
Keyword(s):  
Life Cycle ◽  
Meloidogyne Incognita ◽  
Egg Production ◽  
Thermal Constant ◽  
Base Temperature ◽  
Degree Days ◽  
Thermal Requirements ◽  
Soil Temperatures ◽  
Phenology Model ◽  
Accumulated Degree Days

The thermal requirements of Meloidogyne incognita on Phaseolus vulgaris in a set of constant soil temperatures were determined and the phenology model was validated at fluctuating soil temperatures. The base temperature (Tb) and the thermal constant (S) from nematode inoculation to females starting to lay eggs were 11.3 °C and 323 accumulated degree days (DD), respectively; Tb = 10.5 °C and S = 147 DD from egg production to emergence of juveniles; and Tb = 11.1 °C and S = 476 DD for life cycle completion. At fluctuating soil temperatures in pots with the minimum lower than Tb and the maximum higher than To (optimal temperature), the DD calculation was carried out by the average daily temperature–Tb (ADTb) and the single sine method over Tb (SSTb) with horizontal, intermediate, and vertical cutoffs. The most accurate were the ADTb and the SSTb with horizontal and intermediate cutoffs (93–106% of the predicted value) but the vertical underestimated the accumulated DD (75–82% of the predicted value). When fluctuating soil temperatures were between Tb and To in a plastic greenhouse, only the ADTb method was used. Life cycle completion was observed around 465 DD (accuracy between 0.95 and 0.99) at four different transplanting dates.

scholarly journals The Effects of Biotic and Abiotic Factors on the Community Dynamics in a Mountain Subtropical Forest

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 427
Author(s):  
Tianyang Zhou ◽  
Jiaxin Zhang ◽  
Yunzhi Qin ◽  
Mingxi Jiang ◽  
Xiujuan Qiao
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Forest Dynamics ◽  
Community Dynamics ◽  
Abiotic Factors ◽  
Subtropical Forest ◽  
Above Ground Biomass ◽  
Short Term ◽  
Forest Ecosystem Services ◽  
Number Of Individuals

From supporting wood production to mitigating climate change, forest ecosystem services are crucial to the well-being of humans. Understanding the mechanisms that drive forest dynamics can help us infer how to maintain forest ecosystem services and how to improve predictions of forest dynamics under climate change. Despite the growing number of studies exploring above ground biomass (AGB) dynamics, questions of dynamics in biodiversity and in number of individuals still remain unclear. Here, we first explored the patterns of community dynamics in different aspects (i.e., AGB, density and biodiversity) based on short-term (five years) data from a 25-ha permanent plot in a subtropical forest in central China. Second, we examined the relationships between community dynamics and biodiversity and functional traits. Third, we identified the key factors affecting different aspects of community dynamics and quantified their relative contributions. We found that in the short term (five years), net above ground biomass change (ΔAGB) and biodiversity increased, while the number of individuals decreased. Resource-conservation traits enhanced the ΔAGB and reduced the loss in individuals, while the resource-acquisition traits had the opposite effect. Furthermore, the community structure contributed the most to ΔAGB; topographic variables and soil nutrients contributed the most to the number of individuals; demographic process contributed the most to biodiversity. Our results indicate that biotic factors mostly affected the community dynamics of ΔAGB and biodiversity, while the number of individuals was mainly shaped by abiotic factors. Our work highlighted that the factors influencing different aspects of community dynamics vary. Therefore, forest management practices should be formulated according to a specific protective purpose.

Preparation and Characterization of NTC NiMn2O4-La1-xCaxMnO3 (0≤x≤0.3) Composite Ceramics

2013 ◽  
Vol 716 ◽  
pp. 78-83 ◽  
Author(s):  
Hui Min Zhang ◽  
Fang Guan ◽  
Ai Min Chang ◽  
Li Jun Zhao
Keyword(s):  
Electrical Resistivity ◽  
Perovskite Structure ◽  
Spinel Structure ◽  
Thermal Constant ◽  
Inrush Current ◽  
Composite Ceramics ◽  
Sem Images ◽  
Conventional Solid State Reaction ◽  
Different Temperatures ◽  
Xrd Patterns

Composite ceramics made of spinel structure NiMn2O4 and CaO-doped perovskite structure LaMnO3 were prepared by a conventional solid state reaction and sintered at different temperatures. The XRD patterns have shown that the major phases presented in the sintered samples are NiMn2O4 compounds with the spinel structure, La1-xCaxMnO3 with the perovskite structure and NiO with a monoclinic structure. SEM images show that the density and grain size of the composite ceramics increases with sintered temperature increasing. The electrical resistivity of the composite ceramics at 25°C is found to change significantly depending on the CaO content, while the thermal constant B is still reasonably large in the range of 2400 to 3000 K. For the composition x = 0.1, the composite with a low electrical resistivity (ρ25°C=4.46Ω·cm) and moderate B value (B25/50=2762K) was obtained. These composites could be applied as potential candidates for NTC thermistors in the suppression of the inrush current.

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