DIFFERENCES IN POST-DIAPAUSE THERMAL REQUIREMENTS FOR EGGS OF TWO RANGELAND GRASSHOPPERS

1987 ◽  
Vol 119 (7-8) ◽  
pp. 653-661 ◽  
Author(s):  
William P. Kemp ◽  
Norma E. Sánchez
Keyword(s):  
Laboratory Experiments ◽  
Field Observations ◽  
Degree Days ◽  
Egg Hatching ◽  
Grasshopper Species ◽  
Thermal Requirements ◽  
Diapause Development ◽  
Species Specific ◽  
Oviposition Sites ◽  
Accumulated Degree Days

AbstractA study was conducted to examine the springtime hatching characteristics of Melanoplus sanguinipes (F.) and Aulocara elliotti (Thomas) eggs on rangeland. Laboratory experiments showed that eggs of M. sanguinipes required fewer accumulated degree days (DD) to complete post-diapause development than those of A. elliotti at a constant temperature of 23.3°C. Springtime field observations revealed that A. elliotti nymphs emerged prior to or concurrent with M. sanguinipes. Additionally, results suggest that A. elliotti nymphs emerge over a shorter interval than M. sanguinipes. Much of the variation in springtime emergence could be attributed to species-specific oviposition sites, pod depth, and pod orientation that resulted in A. elliotti eggs accumulating heat more rapidly than M. sanguinipes eggs. Results help explain some of the variation found in egg hatching of these two grasshopper species on rangeland.

EFFECTS OF TEMPERATURE ON DEVELOPMENTAL RATE OF THE IMMATURE STAGES OF CRIOCERIS ASPARAGI (COLEOPTERA: CHRYSOMELIDAE)

1978 ◽  
Vol 110 (1) ◽  
pp. 57-62 ◽  
Author(s):  
R.G. Taylor ◽  
D. G. Harcourt
Keyword(s):  
Developmental Rate ◽  
Immature Stages ◽  
Degree Days ◽  
Thermal Requirements ◽  
Three Generations ◽  
Survival And Development ◽  
Developmental Rates ◽  
Effects Of Temperature ◽  
Accumulated Degree Days

AbstractWhen the immature stages of Crioceris asparagi (L.) were reared at 10 constant temperatures, differential rates of survival and development were observed. The duration of all stages decreased with increase in temperature up to 32°C. The eggs tolerated a wider range of temperatures (8°–34°C) than larvae and pupae (10°–34°C). Developmental rates plotted against temperature did not deviate significantly from fitted curves of the form 1/y = K/1 + ea−bx. During three generations, accumulated degree-days above a base of 10° during development of C. asparagi in the field did not differ significantly from stage thermal requirements as calculated.

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.

EFFECTS OF TEMPERATURE ON DEVELOPMENTAL RATE OF THE IMMATURE STAGES OF THE ALFALFA WEEVIL, HYPERA POSTICA (COLEOPTERA: CURCULIONIDAE)

1974 ◽  
Vol 106 (1) ◽  
pp. 93-100 ◽  
Author(s):  
J. C. Guppy ◽  
M. K. Mukerji
Keyword(s):  
Developmental Rate ◽  
Hatching Rate ◽  
Immature Stages ◽  
Optimum Temperature ◽  
Degree Days ◽  
Hypera Postica ◽  
Thermal Requirements ◽  
Developmental Rates ◽  
Effects Of Temperature ◽  
Accumulated Degree Days

AbstractWhen Hypera postica (Gyll.) was held at 11 constant temperatures, the hatching rate for eggs increased with rise in temperature from 8° to 20 °C and remained maximal to 32 °C. None hatched at 6 °C. Larvae survived at 10° to 35 °C with high mortality only at these limits. Pupae survived at all temperatures above 10 °C but at 35 °C half of the adults were deformed. Duration of all stages decreased with rise in temperature up to 32 °C. Developmental rates plotted against temperature did not deviate significantly from fitted curves of the form 1/y = K/(1 + ea−bx).The optimum temperature, based on maximal rates of development and survival, for eggs and young larvae was near 32 °C and for older larvae and pupae, 30 °C. Accumulated degree-days above a base of 10 °C during development of H. postica at two Ontario locations did not differ significantly from thermal requirements calculated.

scholarly journals Hydraulic transmissivity inferred from ice-sheet relaxation following Greenland supraglacial lake drainages

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ching-Yao Lai ◽  
Laura A. Stevens ◽  
Danielle L. Chase ◽  
Timothy T. Creyts ◽  
Mark D. Behn ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Ice Sheet ◽  
Drainage System ◽  
Greenland Ice Sheet ◽  
Field Observations ◽  
Surface Uplift ◽  
Drainage Networks ◽  
Order Of Magnitude ◽  
Lake Drainage ◽  
Magnitude Increase

AbstractSurface meltwater reaching the base of the Greenland Ice Sheet transits through drainage networks, modulating the flow of the ice sheet. Dye and gas-tracing studies conducted in the western margin sector of the ice sheet have directly observed drainage efficiency to evolve seasonally along the drainage pathway. However, the local evolution of drainage systems further inland, where ice thicknesses exceed 1000 m, remains largely unknown. Here, we infer drainage system transmissivity based on surface uplift relaxation following rapid lake drainage events. Combining field observations of five lake drainage events with a mathematical model and laboratory experiments, we show that the surface uplift decreases exponentially with time, as the water in the blister formed beneath the drained lake permeates through the subglacial drainage system. This deflation obeys a universal relaxation law with a timescale that reveals hydraulic transmissivity and indicates a two-order-of-magnitude increase in subglacial transmissivity (from 0.8 ± 0.3 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 to 215 ± 90.2 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 ) as the melt season progresses, suggesting significant changes in basal hydrology beneath the lakes driven by seasonal meltwater input.

Temperature as a Proximate Factor in Orientation Behavior

1977 ◽  
Vol 34 (5) ◽  
pp. 734-739 ◽  
Author(s):  
William W. Reynolds
Keyword(s):  
Temperature Response ◽  
Biotic Interactions ◽  
Niche Differentiation ◽  
Behavioral Thermoregulation ◽  
Size Segregation ◽  
Ecological Value ◽  
Thermal Requirements ◽  
Prey Location ◽  
Proximate Factor ◽  
Species Specific

Temperature serves as a proximate factor (cue, guidepost, sign stimulus, or directive factor) affecting locomotor responses of fishes. Although temperature can also serve as an ultimate ecological factor, as in behavioral thermoregulation, nonthermal factors may in some cases provide the ultimate adaptive or ecological value of a temperature response; some examples are habitat selection, intraspecific size segregation, interspecific niche differentiation, isolating mechanisms, predator avoidance, prey location, escape reactions, and migrations (thermoperiodic, diel, seasonal, spawning). Conversely, nonthermal variables such as light intensity or water depth may act as accessory proximate factors in thermoregulation. In spawning migrations, thermal requirements of eggs and larvae may take precedence over the (often different) preferenda or optima of adults. Although thermal responses of fishes are largely innate and species specific, ontogenetic and other changes can occur. Since temperature can serve as an unconditioned reinforcer in operant conditioning, thermal responses are not limited to simple kineses or taxes. Nonthermal factors such as photoperiod, circadian rhythms, currents, social and biotic interactions, stresses, infections, or chemicals can affect thermal responses, and may account for some lack of conformity between laboratory preferenda and field distributions and behaviors. Key words: thermoregulation, orientation, preferendum, selection, preference, avoidance, behavior, temperature, fish, responses

scholarly journals Interactions Between Chill-Hours and Degree-Days Affect Carpogenic Germination in Monilinia vaccinii-corymbosi

2001 ◽  
Vol 91 (1) ◽  
pp. 77-83 ◽  
Author(s):  
H. Scherm ◽  
A. T. Savelle ◽  
P. L. Pusey
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Degree Days ◽  
Carpogenic Germination ◽  
Conditioning Period ◽  
Low Degree ◽  
Heating Degree Days ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship

The relationship of cumulative chill-hours (hours with a mean temperature <7.2°C) and heating degree-days (base 7.2°C) to carpogenic germination of pseudosclerotia of Monilinia vaccinii-corymbosi, which causes mummy berry disease of blueberry, was investigated. In two laboratory experiments, pseudosclerotia collected from rabbiteye blueberry in Georgia were conditioned at 5 to 6°C for 26 to 1,378 h prior to placement in conditions favorable for germination and apothecium development. The number of chill-hours accumulated during the conditioning period affected the subsequent proportion of pseudosclerotia that germinated and produced apothecia, with the greatest incidence of carpogenic germination occurring after intermediate levels of chilling (≈700 chill-hours). The minimum chilling requirement for germination and apothecium production was considerably lower than that reported previously for pseudo-sclerotia from highbush blueberry in northern production regions. The rate of carpogenic germination was strongly affected by interactions between the accumulation of chill-hours and degree-days during the conditioning and germination periods; pseudosclerotia exposed to prolonged chilling periods, once transferred to suitable conditions, germinated and produced apothecia more rapidly (after fewer degree-days had accumulated) than those exposed to shorter chilling periods. Thus, pseudosclerotia of M. vaccinii-corymbosi are adapted to germinate carpogenically following cold winters (high chill-hours, low degree-days) as well as warm winters (low chill-hours, high degree-days). Results were validated in a combined field-laboratory experiment in which pseudosclerotia that had received various levels of natural chilling were allowed to germinate in controlled conditions in the laboratory, and in two field experiments in which pseudosclerotia were exposed to natural chilling and germination conditions. A simple model describing the timing of apothecium emergence in relation to cumulative chill-hours and degree-days was developed based on the experiments. The model should be useful for better timing of field scouting programs for apothecia to aid in management of primary infection by M. vaccinii-corymbosi.

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.

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