Impact of transient high temperature during egg development on subsequent development, reproduction, and sex ratio inOstrinia furnacalis

2016 ◽  
Author(s):  
Kang-Lai He
Keyword(s):  
High Temperature ◽  
Sex Ratio ◽  
Subsequent Development ◽  
Egg Development

scholarly journals Sex Ratios in a Warming World: Thermal Effects on Sex-Biased Survival, Sex Determination, and Sex Reversal

2021 ◽  
Vol 112 (2) ◽  
pp. 155-164
Author(s):  
Suzanne Edmands
Keyword(s):  
High Temperature ◽  
Sex Ratio ◽  
Sex Determination ◽  
Heat Tolerance ◽  
Sex Ratios ◽  
Sex Reversal ◽  
Survival Sex ◽  
Ratio Distortion ◽  
Warming World ◽  
Sex Ratio Distortion

Abstract Rising global temperatures threaten to disrupt population sex ratios, which can in turn cause mate shortages, reduce population growth and adaptive potential, and increase extinction risk, particularly when ratios are male biased. Sex ratio distortion can then have cascading effects across other species and even ecosystems. Our understanding of the problem is limited by how often studies measure temperature effects in both sexes. To address this, the current review surveyed 194 published studies of heat tolerance, finding that the majority did not even mention the sex of the individuals used, with <10% reporting results for males and females separately. Although the data are incomplete, this review assessed phylogenetic patterns of thermally induced sex ratio bias for 3 different mechanisms: sex-biased heat tolerance, temperature-dependent sex determination (TSD), and temperature-induced sex reversal. For sex-biased heat tolerance, documented examples span a large taxonomic range including arthropods, chordates, protists, and plants. Here, superior heat tolerance is more common in females than males, but the direction of tolerance appears to be phylogenetically fluid, perhaps due to the large number of contributing factors. For TSD, well-documented examples are limited to reptiles, where high temperature usually favors females, and fishes, where high temperature consistently favors males. For temperature-induced sex reversal, unambiguous cases are again limited to vertebrates, and high temperature usually favors males in fishes and amphibians, with mixed effects in reptiles. There is urgent need for further work on the full taxonomic extent of temperature-induced sex ratio distortion, including joint effects of the multiple contributing mechanisms.

The poinsettia strain of the cotton whitefly,Bemisia tabaci(Homoptera: Aleyrodidae), biological and demographic parameters on poinsettia (Euphorbia pulcherrima) in relation to temperature

1993 ◽  
Vol 83 (4) ◽  
pp. 535-546 ◽  
Author(s):  
A. Enkegaard
Keyword(s):  
Sex Ratio ◽  
Life Span ◽  
Bemisia Tabaci ◽  
Oviposition Period ◽  
Intrinsic Rate Of Increase ◽  
Euphorbia Pulcherrima ◽  
Egg Development ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
Lower Temperature

AbstractBiological characteristics of the poinsettia strain ofBemisia tabaciGennadius were investigated on poinsettia by laboratory experiments at five temperatures (range: 16°C–28°C). In addition, the effect of rearingB. tabacion the two plant species,Nicotiana tabacum(tobacco) (Solanaceae) andEuphorbia pulcherrima(Euphorbiaceae) (poinsettia) was investigated. The temperature-dependencies were established for the developmental time for eggs and egg-to-adult phase, juvenile mortality, adult female life-span, pre-oviposition period, age-specific fecundity, and sex-ratio. The lower temperature thresholds for egg-development, development from egg to adult and for ovipositional adults were estimated as well as the lower temperature threshold for oviposition. The thresholds were 12°C, 14°C, 8°C and 14°C, respectively. Egg-development required 126 day-degrees and the entire development into adults 327 day-degrees. Mortality was highest at 16°C, being 19.3% in the egg-stage and 95% from egg to adult. The pre-oviposition period and the adult life-span were 40 and 360 day-degrees. The age-specific fecundity ofB. tabaciwas described by a temperature-dependent model. The maximum daily fecundity rate was attained after 60 and 125 day-degrees forB. tabacireared on tobacco and poinsettia, respectively. The fecundity was highest forB. tabacireared on poinsettia. The sex-ratio was in favour of females at and above 19°C and increased with temperature. Estimates of the net reproductive rate, the intrinsic rate of increase, the finite rate of increase, the mean generation time and the doubling time were obtained. A positive linear relationship was found between rmand temperature, the values ranging from 0.0012 at 16°C to 0.1263 at 28°C.

scholarly journals High-temperature stress during drying improves subsequent rice (Oryza sativa L.) seed longevity

2017 ◽  
Vol 27 (4) ◽  
pp. 281-291 ◽  
Author(s):  
Katherine J. Whitehouse ◽  
Fiona R. Hay ◽  
Richard H. Ellis
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Oryza Sativa L ◽  
Subsequent Development ◽  
High Temperature Stress ◽  
Seed Longevity ◽  
In Planta ◽  
Rice Varieties ◽  
Stage Of Development ◽  
Rice Seeds

AbstractPost-harvest drying prolongs seed survival in air-dry storage; previous research has shown a benefit of drying moist rice seeds at temperatures greater than recommended for genebanks (5–20°C). The aim of this study was to determine whether there is a temperature limit for safely drying rice seeds, and to explore whether the benefit to longevity is caused by high-temperature stress or continued seed development. Seeds of two rice varieties were harvested at different stages of development and dried initially either over silica gel, or intermittently (8 h day–1) or continuously (24 h day–1) over MgCl2 at temperatures between 15 and 60°C for up to 3 days. Seeds dried more rapidly the warmer the temperature. Subsequent seed longevity in hermetic storage (45°C and 10.9% moisture content) was substantially improved by increase in drying temperature up to 45°C in both cultivars, and also with further increase from 45 to 60°C in cv. ‘Macassane’. The benefit of high-temperature drying to subsequent longevity tended to diminish the later the stage of development at seed harvest. Intermittent or continuous drying at high temperatures provided broadly similar improvements to longevity, but with the greatest improvements detected in a few treatment combinations with continuous drying. Heated-air drying of rice seeds harvested before maturity improved their subsequent storage longevity by more than that which occurred during subsequent development in planta, which may have resulted from the triggering of protection mechanisms in response to high-temperature stress.

Contabescent anthers and poor boll development in cotton in the Ord River valley

1969 ◽  
Vol 9 (36) ◽  
pp. 23
Author(s):  
JP Evenson
Keyword(s):  
High Temperature ◽  
Water Stress ◽  
Subsequent Development ◽  
Sowing Date ◽  
River Valley ◽  
Lower Percentage ◽  
Widespread Occurrence ◽  
Varietal Differences ◽  
The Relationship

Widespread occurrence in cotton of 'parrot beaked' bolls, with one or more locule empty of seed, was shown to be related to periods when anthesis takes place under conditions of high temperature and water stress. Marked sowing date effects were recorded ; cotton sown in March and April having significantly lower percentage of parrot beaked bolls than cotton sown in December. Significant varietal differences in amount of the phenomenon were also recorded. The relationship between anther contabescence, and subsequent development of the parrot beaked condition, was clearly shown, and the effects of parrot beaked bolls on yield is discussed. Limited tests of lint quality showed no difference between lint from normal and parrot beaked bolls.

Aggregations of Berried Lobsters (Homatus americanus) in Shallow Waters off Grand Manan, Eastern Canada

1990 ◽  
Vol 47 (3) ◽  
pp. 520-523 ◽  
Author(s):  
Alan Campbell
Keyword(s):  
Sex Ratio ◽  
Larval Dispersal ◽  
Shallow Waters ◽  
Eastern Canada ◽  
Egg Development ◽  
Scuba Divers ◽  
Large Numbers ◽  
Shallow Area ◽  
Newly Hatched Larvae ◽  
Trap Catches

The relative abundance, size, and sex frequencies of trap-caught lobsters were determined from five areas near the northern end of Grand Manan during August–September 1982 and August 1983. Large numbers of berried (ovigerous) females (90/100 trap hauls) and few male or nonberried female lobsters were caught in shallow (1–22 m) depths close to the shoreline in one area. The sex ratio was near 50% males in deeper areas. In the shallow area SCUBA divers observed mature lobsters excavating bowl-shaped depressions in the sand-clay substrate and confirmed the high density of berried females indicated by the trap catches. Berried females may seek and congregate in areas favourable for egg development and larval dispersal. During summer, shallow areas provide warmer water than deeper areas and therefore allow faster egg development and egg extrusion. Also, the shallow waters with strong tidal currents would allow rapid dispersal of newly hatched larvae.

Response of snake cucumber (Cucumis melo var. pubescens) to some plant regulators

1982 ◽  
Vol 99 (3) ◽  
pp. 587-590 ◽  
Author(s):  
E. El-Kholy ◽  
H. Hafez
Keyword(s):  
High Temperature ◽  
Sex Ratio ◽  
Cucumis Melo ◽  
Total Yield ◽  
Female Flower ◽  
Sex Expression ◽  
Significant Suppression ◽  
Yield Production ◽  
Male Flowers ◽  
Fruit Characters

SUMMARYTrials were conducted during the summer seasons (1978 and 1979) at the Faculty of Agriculture, Elminia University, to evaluate the effect of some growth regulators on sex expression, sex ratio and yield production of snake cucumber. The results obtained showed that both sex expression and ratio could be modified with plant regulator sprays even under the long and high temperature conditions of Elminia governorate. All plant regulators induced the formation of the first female flower at lower nodes compared with the control. There was significant suppression of male flowers in plants sprayed with plant regulators. All the treatments gave an increase in total yield and improved fruit characters.

Fertilization and egg production in the bed-bug, Cimex lectularius L.

Parasitology ◽  
1939 ◽  
Vol 31 (2) ◽  
pp. 193-199 ◽  
Author(s):  
Kenneth Mellanby
Keyword(s):  
High Temperature ◽  
Egg Production ◽  
Ovarian Development ◽  
Corpus Allatum ◽  
Cimex Lectularius ◽  
Minimum Amount ◽  
Egg Development ◽  
Bed Bug ◽  
Dry Air ◽  
Definite Period

Previous workers have described the curious method by which the female bed-bug is fertilized. They have suggested that the large quantity of sperm injected serves some function other than that of fertilizing the egg.The rate of metabolism of the virgin bug is much less than that of the fertilized female.Ovarian development never occurs until the female has been fertilized. After fertilization, egg development is apparently controlled by a hormone produced by the corpus allatum.Living sperm will always be found in the spermathecae of females which are laying fertile eggs.The so-called imperfect eggs produced when the sperm is exhausted are normal save for being unfertilized. They have been considered as malformed because of their tendency to shrivel quickly in dry air.Sperm remains viable in the female for a definite period depending on the temperature. This period is longer at low than at high temperature. Provided a certain minimum amount of sperm is introduced (this minimum is less than the quantity introduced by a well-nourished male at one copulation), the period of viability of sperm is the same no matter how many eggs are produced. The number of eggs depends only on the amount of food taken.There is no evidence that the sperm serves any nutritive function in the female.

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

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