scholarly journals GROWTH THRESHOLD AND DEGREE DAYS REQUIREMENT FOR DEVELOPMENT AND GROWTH OF CITRUS MEALYBUG Planococcus citri (Risso), HEMIPTERA : PSEUDOCOCCIDAE

2017 ◽  
Vol 48 (2) ◽  
Author(s):  
Al-Shammari & Al-Zubaidy
Keyword(s):  
Growth Rate ◽  
Growth And Development ◽  
Developmental Time ◽  
Thermal Constant ◽  
Planococcus Citri ◽  
Degree Days ◽  
Developmental Threshold ◽  
Citrus Mealybug ◽  
Mealy Bug ◽  
The Impact

Laboratory studies was conducted in Biocontrol unit- Faculty of Agriculture- University of Baghdad in order to determine the impact of different temperatures  15,  20,  25, 30 and 35 ±2 C°  on the development and growth rate of  different stages of mealy bug P.citri. The results showed that the total developmental time from (egg - adult)of the mealy bug were  24.0, 28.08, 39.67 and 73.31 days  respectively. With significant rearing differences on temperatures 15, 20, 25 and 30 ±2  C°  respectively, while no development and growth rate on temperature  35±C°. the developmental threshold for the mealy bug stages  eggs,  crawlers, 2nd  and 3rd nymphal instars as well as the duration of the egg to adult were different, being 7.1, 7.26, 7.08, 7.12 and 7.15C° respectively, while 116.27, 136.98 and 172.4 thermal units for  degree days required for growth and development while the thermal constant for the period from egg to adult was 526.31. Optimum temperature was 27.85C ͦ  while Upper threshold was 33.64 C° for P.citri  Which refers to the lack of suitable high temperature for growth and development .

scholarly journals GROWTH THRESHOLD AND DEGREE DAYS REQUIREMENT FOR DEVELOPMENT AND GROWTH OF CITRUS MEALYBUG Planococcus citri (Risso), HEMIPTERA : PSEUDOCOCCIDAE

2017 ◽  
Vol 48 (2) ◽  
Author(s):  
Al-Shammari & Al-Zubaidy
Keyword(s):  
Growth Rate ◽  
Growth And Development ◽  
Developmental Time ◽  
Thermal Constant ◽  
Planococcus Citri ◽  
Degree Days ◽  
Developmental Threshold ◽  
Citrus Mealybug ◽  
Mealy Bug ◽  
The Impact

Laboratory studies was conducted in Biocontrol unit- Faculty of Agriculture- University of Baghdad in order to determine the impact of different temperatures  15,  20,  25, 30 and 35 ±2 C°  on the development and growth rate of  different stages of mealy bug P.citri. The results showed that the total developmental time from (egg - adult)of the mealy bug were  24.0, 28.08, 39.67 and 73.31 days  respectively. With significant rearing differences on temperatures 15, 20, 25 and 30 ±2  C°  respectively, while no development and growth rate on temperature  35±C°. the developmental threshold for the mealy bug stages  eggs,  crawlers, 2nd  and 3rd nymphal instars as well as the duration of the egg to adult were different, being 7.1, 7.26, 7.08, 7.12 and 7.15C° respectively, while 116.27, 136.98 and 172.4 thermal units for  degree days required for growth and development while the thermal constant for the period from egg to adult was 526.31. Optimum temperature was 27.85C ͦ  while Upper threshold was 33.64 C° for P.citri  Which refers to the lack of suitable high temperature for growth and development .

scholarly journals Thermal requirements and estimated number of generations of Neopamera bilobata (Say) in strawberry-producing regions of Brazil

2017 ◽  
Vol 48 (1) ◽  
Author(s):  
Taciana Melissa de Azevedo Kuhn ◽  
Alci Enimar Loeck ◽  
Marcos Botton
Keyword(s):  
Adult Stage ◽  
Thermal Constant ◽  
Rio Grande Do Sul ◽  
Degree Days ◽  
Climate Chamber ◽  
Thermal Threshold ◽  
Developmental Threshold ◽  
Thermal Requirements ◽  
Developmental Thresholds ◽  
The Mean

ABSTRACT: The thermal threshold and thermal requirements of Neopamera bilobata were determined, and the number of generations that this species may produce in the main strawberry-producing regions of Brazil was estimated. In a climate chamber (70±10% RH and 12h photophase) at 16, 19, 22, 25, 28, or 30±1°C, the development of 120 eggs was monitored until the adult stage, at each temperature. Nymphs were maintained in individual cages and fed on strawberry fruits of the cultivar Aromas. The mean duration and viability of the egg and nymph stages were calculated by estimating the lower and upper developmental thresholds and the thermal constant, and this information was used to estimate the number of generations per year in different strawberry-producing regions of Brazil. The egg-to-adult duration decreased as temperatures increased, up to 28°C (93.4, 83.2, 43.9, and 31.4 days at 19, 22, 25, and 28°C, respectively). Viability of nymphs was highest between 22 and 28°C. At 30°C, the egg-to-adult duration increased (36 days), while the viability decreased (11.11%). The lower egg-to-adult developmental threshold was 15.2°C and the thermal constant was 418.4 degree-days. Calculating the number of generations indicated that the largest number (5.1 generations yr-1) was obtained for the municipality of Jaboti, Paraná, and the smallest for Caxias do Sul, Rio Grande do Sul (1.9 generations yr-1). Our findings demonstrated that important strawberry-producing regions in Brazil are suitable for the development of N. bilobata.

scholarly journals Determination of thermal constant and development threshold of Bihar hairy caterpillar, Spilarctia obliqua Walker

2014 ◽  
Vol 6 (2) ◽  
pp. 644-648 ◽  
Author(s):  
K. Selvaraj ◽  
B. S. Gotyal ◽  
V. Ramesh Babu ◽  
S. Satpathy
Keyword(s):  
Development Rate ◽  
Developmental Period ◽  
Adult Survival ◽  
Thermal Constant ◽  
Regression Equations ◽  
Small Larva ◽  
Degree Days ◽  
Large Larva ◽  
Developmental Threshold ◽  
Spilarctia Obliqua

Effect of six constant temperatures viz., 18±1, 21±1, 24±1, 27±1, 30±1 and 33±10C was studied on the egg hatchability, larval pupal development and adult survival of Spilarctia obliqua. Development rate of egg, larva and pupa gradually increased with increase in temperature, while total developmental period decreased. Mean developmental period of the pest decreased from 93.73 days at 18±10C to 31.20 at 33±10C. The lowest and the highest temperatures at which no development took place were found to be 12±10C and 39±10C, respectively. Regression equations between development rate and temperature were found to be Y= 0.0189 X -0.1998 (R2=0.88) for egg, Y=0.00122 X -0.0248 (R2=0.84) for small larva (1-3rd instar), Y=0.0058 X -0.0675 (R2=0.76) for large larva (4-6th instar), Y=0.0074 X-0.1075 (R2=0.94) for pupa and Y=0.0142 X-0.4363 (R2=0.79) for adults. Developmental threshold were determined to be 10.57, 11.27, 11.55, 15.28 and 10.92oC for egg, small larva, large larva, pupa, and adult respectively with corresponding thermal constant being 52.91, 344.82, 243.90, 142.85 and 70.42 degree days (DD). Thermal constant to complete a generation was found to be 854.90 DD. This was the first studies on this aspects, these estimated thermal thresholds and degree days could be used to predict the S. obliqua activity in the field for their effective management through pest forecasting.

EFFECTS OF PHOTOPERIOD AND TEMPERATURE ON DIAPAUSE OF TWO APHEL1NUS SPP. (HYMENOPTERA: APHELINIDAE) PARASITIZING THE RUSSIAN WHEAT APHID

1992 ◽  
Vol 124 (5) ◽  
pp. 853-860 ◽  
Author(s):  
D.S. Yu
Keyword(s):  
Developmental Rate ◽  
Developmental Time ◽  
Russian Wheat Aphid ◽  
Lower Threshold ◽  
Maximum Sensitivity ◽  
Thermal Constant ◽  
Degree Days ◽  
Temperature Dependent ◽  
C 50 ◽  
Aphelinus Varipes

AbstractThe effects of photoperiod and temperature on the diapause of Aphelinus varipes (Focrster) from Kazakhstan and Apheiinus near varipes from Alberta, which both attack Russian wheat aphid, were studied in the laboratory. At 20 °C, 50% of A. varipes entered diapause when the photoperiod was between 12.5L:11.5D and 13L:11D whereas 50% of A. nr. varipes entered diapause when the photoperiod was around 14L:10D. Diapause induction was close to 100% at 11.5L:12.5D for both species. Maximum sensitivity to photoperiod occurred 2 days alter parasitization for A. varipes and 3 days after parasitization for A. nr. varipes. At 30 °C, the proportion of wasps entering diapause was reduced to 40 and 72% for A. varipes and A. nr. varipes, respectively. Exposing diapausing mummies to temperatures from 10 to −10 °C for 4–20 weeks shortened the postdiapause developmental time. Survival was lowered by exposing mummies to −10 °C for over 8 weeks. Postdiapause developmental rate was directly temperature dependent. The lower threshold and thermal constant for postdiapause development were estimated to be 10.3 °C and 189 degree-days (DD) for A. varipes and 7.41 °C and 204 DD for A. nr. varipes.

Reciprocal crosses between two populations ofTrissolcus vassilievi(Mayr) (Hymenoptera: Scelionidae) reveal maternal effects on thermal phenotypes

2015 ◽  
Vol 105 (3) ◽  
pp. 355-363
Author(s):  
S. Iranipour ◽  
P. BenaMolaei ◽  
S. Asgari ◽  
J.P. Michaud
Keyword(s):  
Maternal Effect ◽  
Developmental Time ◽  
Adult Survival ◽  
Thermal Constant ◽  
Temperature Threshold ◽  
Degree Days ◽  
Sunn Pest ◽  
Female Progeny ◽  
Reciprocal Crosses ◽  
Two Populations

AbstractThe egg parasitoidTrissolcus vassilievi(Mayr) (Hymenoptera: Scelionidae) is a significant natural enemy of the sunn pest,Eurygaster integricepsPuton (Hemiptera: Scutelleridae), the most important pest of wheat in Iran. This study examined the developmental time and egg-to-adult survival of two geographically separate populations ofT. vassilievion two corresponding host populations at five constant temperatures ranging from 15.0 to 35.0±1°C. No wasps of either population emerged at 15.0°C and the temperature threshold for development was similar between populations, ranging from 13.1±0.3 to 13.8±0.4°C for males and 12.2±0.1 to 12.6±0.1°C for females, but the thermal constant varied with gender and parasitoid population. Development of wasps from the colder Tabriz location was slower, with thermal constants for males and females of 172.6±3.1 and 204.1±1.2 degree-days, respectively, compared to Varamin wasps with 164.7±3.0 and 195.6±1.3 degree-days, respectively. Based on genetic inheritance patterns, reciprocal crosses between the two populations were expected to result in females with thermal phenotypes intermediate to their parental populations, and males that resembled their mothers. However, female progeny of crosses more closely resembled their maternal population, indicating a maternal effect on thermal phenotype. Furthermore, the magnitude of the maternal effect on the thermal constant was asymmetric and was more strongly expressed by Varmin than Tabriz females. These results suggest the possibility of using selective crosses between wasp populations, in combination with artificial selection in the laboratory, to tune the thermal phenotype of parasitoids to specific regions prior to augmentative releases.

scholarly journals Вплив кормових добавок із морських гідробіонтів на продуктивність каченят-бройлерів

2018 ◽  
pp. 176-179
Author(s):  
Н. І. Данкевич
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Weight Gain ◽  
Growth And Development ◽  
Body Weight Gain ◽  
Animal Origin ◽  
Relative Growth ◽  
Conservation Rate ◽  
Mineral Additive ◽  
The Impact

Представлено результати досліджень кормових добавок  із морських гідробіонтів, білково-мінераль-ної та мінеральної, виготовлених за розробленими нами технологіями, які підтверджені патентами України на корисну модель:  № 42687 «Спосіб одержання кормової добавки з морських гідробіонтів для птиці» від 10.07.2009;  № 34634 «Спосіб одержання кормової добавки з морських гідробіонтів для птиці» від 11.08.2008. Їх використанні в кількості 10 % у раціоні каченят-бройлерів позитивно впливає на продуктивність каченят, не знижує приріст живої маси, сприяє збереженню каченят при вирощуванні та незначним середньодобовим приростам живої маси. Recently the production of livestock production has decreased in the country. It accounts for the reduction of animal and bird livestock, fodder production, the proportion of protein-mineral food of animal origin. In this regard the problem of surching alternative animal feed resources is becoming particularly important. Sea hydrobionts possessing sustainable proteins and valuable biodiversity crucial for growth and development of animals and birds are suggested to be one of such precious sources. Using sea hydrobiont forage in poultry farming is of crucial importance as it is one of the fastest-growing branches of animal industry. The purpose of the research in view of the above, the tusk is to consider the impact sea hydrobiont additives on broiler ducks productivity. The study focuses on sea hydrobiont additives both protein-mineral and mineral produced according to our own designed technology by means of shredding mussels primary processing and agrarian wastes (iodine). The study of sea hydrobionts impact on broiler ducks productivity was carried out under existing instructions and regulatory documents. In accordance with the study methodology control and test groups of ducks were provided with staple ration for 8 days (aged from 12 to 20 days). From the 21st day till the end of the period (60 days in total) their ration was enreached by paste-like additives in the amount of 10 % to the staple ration. We used the additives in 2 ways: 10 % replacement of the staple ration with additives and adding extra 10 % of additives to enreach the staple ration. In the course of the study it was found that using protein-mineral hydrobiont additives has a positive effect on broiler ducks growth regardless the way used. The 10 % replacement of the staple ration with hydrobiont additive does not reduce body weight gain which made up 100.4 % in the test group of ducks. Adding extra 10 % of protein-mineral additive to the ration increases the intensity of body weight gain by 6.9 %, relative growth rate and survival rate of ducks by 5.6 %. The  impact of mineral additive on ducks productivity when raised them according to our scheme is less but at the same time it contributes to ducks growth and development. The 10 % replacement of the ration with mineral additive does not have a big impact on growth and development. But adding extra 10 % of mineral to the ration increases the intensity of live body weight gain by 4.9 % compared to the control group of ducks. The growth rate and conservation rate are also increased by 3.9 %. Sea hydrobiont additives produced according to our own technology can be used when raising broiler ducks as non-traditional source of proteins and minerals for staple ration. Enreaching the ration of ducks by protein-mineral additive in the amount of 10 % or replacing the ration by the same amount of the additive allows to increase their body weight gain by 6.9 % as well as relative growth and conservation rate. Enreaching the ration by mineral additive increases body weight gain of ducks by 4.9 %. The 10 % replacement with such an additive does not effect their productivity.

Growth and Development Planning in India

2021 ◽  
Author(s):  
K. L. Datta
Keyword(s):  
Economic Growth ◽  
Growth Rate ◽  
Development Strategy ◽  
Growth And Development ◽  
Poverty Reduction ◽  
Development Planning ◽  
Reform Process ◽  
The People ◽  
Standards Of Living ◽  
The Impact

The central theme of this book is to appraise the role of planning to maximize the rate of economic growth, and improve the standards of living and quality of life of the people in India since Independence. The book addresses four core areas. First, it delves into the circumstances which led to the adoption of planning and presents a comprehensive analysis of the economic scenario that unfolded in the six decades between 1951 and 2011, documenting shifts in growth and development strategy. Second, it explores the rate and pattern of economic growth, and traces reasons behind the shortfall in growth rate from the target. Third, the book contextualizes the backdrop against which economic reform measures were introduced to understand how different areas and sectors of the economy were integrated with the reform process. Fourth, it analyses the transition from growth measures pursued until the 1970s, to a mix of growth and redistribution from the 1980s, and then to inclusive growth in the 2000s, and finds out how income, especially of the poor and marginalized sections of the population increased. It makes an assessment of the level and change in poverty over time, and the impact of economic growth on poverty reduction. These four thematic areas of the book are essential to understand the process of economic growth and its impact on the lives of the people in India's rapidly changing socio-economic environment. Finally, it assesses the economic scenario in the 2010s, when planning was abandoned, and pinpoints the reasons behind dipping growth rate, and suggests measures for its revival.

International trade: Research of the reasons for the fall

2019 ◽  
pp. 79-91 ◽  
Author(s):  
V. S. Nazarov ◽  
S. S. Lazaryan ◽  
I. V. Nikonov ◽  
A. I. Votinov
Keyword(s):  
Growth Rate ◽  
International Trade ◽  
Exchange Rate ◽  
Global Economy ◽  
Structural Changes ◽  
Global Value Chains ◽  
Value Chains ◽  
Negative Contribution ◽  
Basic Commodity ◽  
The Impact

The article assesses the impact of various factors on the growth rate of international trade. Many experts interpreted the cross-border flows of goods decline against the backdrop of a growing global economy as an alarming sign that indicates a slowdown in the processes of globalization. To determine the reasons for the dynamics of international trade, the decompositions of its growth rate were carried out and allowed to single out the effect of the dollar exchange rate, the commodities prices and global value chains on the change in the volume of trade. As a result, it was discovered that the most part of the dynamics of international trade is due to fluctuations in the exchange rate of the dollar and prices for basic commodity groups. The negative contribution of trade within global value chains in 2014 was also revealed. During the investigated period (2000—2014), such a picture was observed only in the crisis periods, which may indicate the beginning of structural changes in the world trade.

Sign in / Sign up

Export Citation Format

Share Document