Rethinking our Work with Leaders: Using Developmental Threshold Zones in Coaching

2021 ◽  
Author(s):  
David B. Drake
Keyword(s):  
Developmental Threshold

Influence of temperature on the development and reproduction of Cinara cedri (Hemiptera: Aphidoidea: Lachninae)

2021 ◽  
pp. 1-6
Author(s):  
Yingchao Ji ◽  
Guohua Li ◽  
Chenggang Zhou ◽  
Shuyan Yin
Keyword(s):  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Threshold Temperature ◽  
Reproduction Rate ◽  
Cedrus Deodara ◽  
Developmental Threshold ◽  
Factors Affecting ◽  
Rate Of Increase ◽  
Influence Of Temperature On ◽  
Development Duration

Abstract Temperature is one of the main factors affecting insect growth, development and reproduction. The effects of temperatures (10, 15, 20, 25 and 30°C) on the development and reproduction of Cinara cedri Mimeur (Hemiptera: Aphidoidea: Lachnidae) fed on Cedrus deodara (Roxb.) G. Don were evaluated in this study. With the increase of temperature from 10 to 30°C, the development duration at different development stages gradually shortened. There was a significant positive correlation between the developmental rates and temperature, following a quadratic regression model. The lower developmental threshold temperature (C) and effective accumulated temperatures (K) for completing a generation were 4.13°C and 263.4 degree-days, respectively. The highest fecundity was observed at 20°C with 25.74 first-instar nymphs/female. Both the highest intrinsic rate of increase (r, 0.11 ± 0.03) and net reproduction rate (R0, 19.06 ± 2.05) were observed at 20°C, whereas the lowest values of r (0.05 ± 0.01) at 10°C and R0 (5.78 ± 0.88) at 30°C were observed. The results suggest that temperature significantly affects the biology of C. cedri and the optimal temperature for its development is 20°C.

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.

THE BIOLOGY AND ECOLOGY OF THE COTTONWOOD LEAF BEETLE, CHRYSOMELA SCRIPTA (COLEOPTERA: CHRYSOMELIDAE), ON TISSUE CULTURED HYBRID AIGEIROS (POPULUS × EURAMERICANA) SUBCLONES IN WISCONSIN

1979 ◽  
Vol 111 (5) ◽  
pp. 551-556 ◽  
Author(s):  
T.R. Burkot ◽  
D.M. Benjamin
Keyword(s):  
Biological Control ◽  
Leaf Beetle ◽  
Coleomegilla Maculata ◽  
Third Generation ◽  
Biological Control Agents ◽  
Developmental Threshold ◽  
Populus Euramericana ◽  
The Third ◽  
Chrysomela Scripta ◽  
Cottonwood Leaf Beetle

AbstractAdults and larvae of the cottonwood leaf beetle, Chrysomela scripta Fab., defoliated tissue cultured Aigeiros (Populus × euramericana (Dode) Guinier) subclones and destroyed apical tips. Fecundity was 510 ± 153 eggs . Four generations occurred between May and September in southern Wisconsin. Maximal insect numbers and damage occurred in the third generation. The minimal developmental threshold was 10.8 °C with a mean 257 ± 26 day-degree (°C) required per generation. Important biological control agents included Coleomegilla maculata, which consumed up to 25% of the eggs, and Shizonatus latus, a pteromalid parasite, which destroyed up to 26% of the pupae.

Temperature-dependent life history of Eutetranychus africanus (Acari: Tetranychidae) on papaya

2020 ◽  
Vol 25 (3) ◽  
pp. 479-490
Author(s):  
Ming-ying Lin ◽  
Chin-hsing Lin ◽  
Yen-po Lin ◽  
Ching-tzu Tseng
Keyword(s):  
Life History ◽  
Immature Stage ◽  
Invasive Pest ◽  
Intrinsic Rate Of Increase ◽  
Reproduction Rate ◽  
Developmental Duration ◽  
Developmental Threshold ◽  
Rate Of Increase ◽  
History Of ◽  
Net Reproduction

This study was conducted to further understand the biology of Eutetranychus africanus Tucker, a newly invasive pest mite in Taiwan that can cause serious damage to papaya. We report the life history of E. africanus on papaya in laboratory conditions at 12, 17, 22, 27 and 32 ± 0.5 °C, with 70 ± 5 % relative humidity and a photoperiod of L12: D12. Eggs did not hatch at 12 °C. Both developmental duration and longevity were significantly shortened with the increase of temperature. The longest and shortest developmental durations of the immature stage were 37.28 days at 17 °C and 8.70 days at 32 °C, respectively. The longevity of both sexes varied similarly with the change in temperature, with shorter lifespan in males: Females survived for 3.64 days (shortest) at 32 °C to 17.50 days (longest) at 17 °C, whereas males survived for 11.00 days (longest) at 17 °C to 2.57 days (shortest) at 32 °C. The differences in fecundity were significant among all tested temperatures, with 17.61 eggs/female at 27 °C being the highest. The low developmental threshold and thermal summation of the full immature stage were 11.48 °C and 163.93 degree-days, respectively. In two-sex life table analysis, population parameters were significantly affected by temperature except the net reproduction rate. The highest intrinsic rate of increase was 0.1221 day−1 at 27 °C; the average generation time was the shortest (12.61 days) at 32 °C and the longest (48.70 days) at 17 °C. The highest net reproduction rate was 5.06 eggs/female at 27 °C. This report contributes background knowledge to the management of the damage caused by E. africanuson papaya.This study was conducted to further understand the biology of Eutetranychus africanus Tucker, a newly invasive pest mite in Taiwan that can cause serious damage to papaya. We report the life history of E. africanus on papaya in laboratory conditions at 12, 17, 22, 27 and 32 ± 0.5 °C, with 70 ± 5 % relative humidity and a photoperiod of L12: D12. Eggs did not hatch at 12 °C. Both developmental duration and longevity were significantly shortened with the increase of temperature. The longest and shortest developmental durations of the immature stage were 37.28 days at 17 °C and 8.70 days at 32 °C, respectively. The longevity of both sexes varied similarly with the change in temperature, with shorter lifespan in males: Females survived for 3.64 days (shortest) at 32 °C to 17.50 days (longest) at 17 °C, whereas males survived for 11.00 days (longest) at 17 °C to 2.57 days (shortest) at 32 °C. The differences in fecundity were significant among all tested temperatures, with 17.61 eggs/female at 27 °C being the highest. The low developmental threshold and thermal summation of the full immature stage were 11.48 °C and 163.93 degree-days, respectively. In two-sex life table analysis, population parameters were significantly affected by temperature except the net reproduction rate. The highest intrinsic rate of increase was 0.1221 day−1 at 27 °C; the average generation time was the shortest (12.61 days) at 32 °C and the longest (48.70 days) at 17 °C. The highest net reproduction rate was 5.06 eggs/female at 27 °C. This report contributes background knowledge to the management of the damage caused by E. africanus on papaya.

Developmental Threshold

2008 ◽  
pp. 1201-1201
Author(s):  
Jeffrey M. Cumming ◽  
Bradley J. Sinclair ◽  
Charles A. Triplehorn ◽  
Yousif Aldryhim ◽  
Eduardo Galante ◽  
...  
Keyword(s):  
Developmental Threshold

Seasonal trends in the rate of population increase of Frankliniella occidentalis (Thysanoptera: Thripidae) on cucumber

1997 ◽  
Vol 87 (5) ◽  
pp. 487-495 ◽  
Author(s):  
V. Jarošík ◽  
M. Koliáš ◽  
L. Lapchin ◽  
J. Rochat ◽  
A.F.G. Dixon
Keyword(s):  
Population Growth ◽  
Frankliniella Occidentalis ◽  
First Generation ◽  
Developmental Rate ◽  
Exponential Phase ◽  
Population Increase ◽  
Developmental Threshold ◽  
Sum Of Effective Temperatures ◽  
Lower Developmental Threshold ◽  
Effective Temperatures

AbstractThe developmental rate of Frankliniella occidentalis (Pergande) was determined on cucumber Cucumis sativus cv. Sandra over a range of constant temperatures. The lower developmental threshold (LDT) and the sum of effective temperatures (SET) for the pre-imaginal development were 10.7°C and 231.1°C, respectively. The rate of population increase was assessed as the sum of effective temperatures above the lower developmental threshold by monitoring the numbers of thrips on individual leaves of cucumber under commercial greenhouse conditions. Population growth was characterized by an early stochastic phase, corresponding to pre-imaginal development of the first generation, and followed by an exponential phase starting with the second generation, the rate of which did not vary between plants. Throughout the exponential phase, the rate of population growth increased with time/age of plant. As significant damage to cucumber may occur during the exponential phase of population increase, the sum of effective temperatures of 231°C can be used to predict when damage is likely to start to occur.

Survival and development of different life stages of three Ceratitis spp. (Diptera: Tephritidae) reared at five constant temperatures

2002 ◽  
Vol 92 (6) ◽  
pp. 461-469 ◽  
Author(s):  
P.F. Duyck ◽  
S. Quilici
Keyword(s):  
Simulation Models ◽  
Fruit Fly ◽  
Thermal Constant ◽  
Immature Stages ◽  
Developmental Threshold ◽  
Laboratory Rearing ◽  
Larval Stages ◽  
Survival And Development ◽  
Lower Developmental Threshold ◽  
Computer Simulation Models

AbstractFruit flies (Diptera: Tephritidae) are the most damaging pests on fruit crops on Réunion Island, near Madagascar. Survival and development of the Mediterranean fruit fly, Ceratitiscapitata (Wiedemann), the Natal fruit fly, C. rosa Karsch and the Mascarenes fruit fly, C. catoirii Guérin-Mèneville were compared at five constant temperatures spanning 15 to 35°C. Durations of the immature stages of C. capitata, C. rosa and C catoirii ranged from 14.5–63.8, 18.8–65.7 and 16.8–65.8 days, respectively, at 30–15°C. The lower developmental threshold and thermal constant were calculated using the temperature summation model. The thermal constant for total development of the immature stages of C. capitata, C. rosa and C. catoirii were 260, 405 and 356 DD, respectively. Species differed mainly during the larval stages and ovarian maturation period, with smaller differences in the egg stage. Ceratitis rosa appeared to be better adapted to low temperatures than the two other species as it showed a lower larval developmental threshold of 3.1°C compared to 10.2°C for C. capitata and 8.9°C for C. catoirii. Overall, C. catoirii had a low survival rate within the range of temperatures studied. The different responses of the three Ceratitis species to various temperatures explain to some extent their distribution on the island. The results obtained will be used for optimizing laboratory rearing procedures and for constructing computer simulation models to predict fruit fly population dynamics.

Laboratory comparison of twoAphelinus maliclades for control of woolly apple aphid from Hebei Province, China

2017 ◽  
Vol 108 (3) ◽  
pp. 400-405
Author(s):  
M. Su ◽  
X. Tan ◽  
Q. Yang ◽  
C. Zhao ◽  
F. Wan ◽  
...  
Keyword(s):  
Shandong Province ◽  
Hebei Province ◽  
Threshold Temperature ◽  
Host Searching ◽  
Eriosoma Lanigerum ◽  
Developmental Threshold ◽  
Woolly Apple Aphid ◽  
Effective Accumulated Temperature ◽  
Aphelinus Mali ◽  
Accumulated Temperature

AbstractAphelinus mali(Haldeman) is an effective natural enemy of woolly apple aphid (WAA),Eriosoma lanigerum(Hausmann). Previous studies have found that, with WAA from Shandong Province (Qingdao) as the host, there are significant differences in various biological characteristics between a Shandong clade and Liaoning clade ofA. mali. The ability of the Shandong clade to control this aphid was significantly higher than that of the Liaoning clade in Shandong Province. In order to determine whether differences were caused by better adaptation of the Shandong parasitoid clade to the population of the host in that province or if it represents a more general fitness of this clade to control the host regardless of location, we compared the same parasitoid clades with hosts from Hebei Province. We found no significant differences in the developmental threshold temperature, effective accumulated temperature, fecundity, longevity, and oviposition period of the two clades, but the duration of host searching of the Shandong clade was significantly longer than that of the Liaoning clade. The instantaneous attack rate, the control ability (a/Th), the search parameter (Q) of the Shandong clade (0.0946, 0.543, 0.0725) ofA. maliwere higher than that of the Liaoning clade (0.0713, 0.382, 0.0381), and therefore, with WAA from Hebei Province as the host, the host adaptability of the Shandong clade ofA. maliwas not worse than that of the Liaoning clade, while the pest control ability of the Shandong clade was still greater than that of the Liaoning clade.

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