Influence of Humidity on Longevity, Fecundity, and Rate of Increase of the Grain-infesting Mite Tyrophagus castellanii (Hirst) (Acarina: Acaridae) Reared on Mould Cultures

1959 ◽  
Vol 91 (1) ◽  
pp. 31-35 ◽  
Author(s):  
I. Rivard
Keyword(s):  
Constant Temperature ◽  
Immature Stages ◽  
Rate Of Development ◽  
Rate Of Increase ◽  
Innate Capacity

Results of an experiment reported previously (Rivard, 1958a) showed the influence of various humidities on mortality and rate of development of the immature stages of Tyrophagus castellanii (Hirst)reared on mould cultures at a constant temperature. Results of an experiment on the influence of humidity on the longevity and fecundity of the adult mites are reported in the present paper. Information gathered from both studies is used to calculate the innate capacity of the species for increase at different humidities.

Influence of Humidity on Mortality and Rate of Development of Immature Stages of the Grain-Infesting Mite Tyrophagus castellanii (Hirst) (Acarina: Acaridae) Reared on Mould Cultures

1958 ◽  
Vol 90 (12) ◽  
pp. 721-724 ◽  
Author(s):  
I. Rivard
Keyword(s):  
Direct Effect ◽  
Constant Temperature ◽  
Immature Stages ◽  
Food Material ◽  
Predator Prey ◽  
Rate Of Development ◽  
Fresh Food ◽  
Temperature And Humidity

It was observed that populations of Tyrophagus castellanii (Hirst) reared on cereal flakes and yeast for studies of predator-prey interactions were feeding on moulds rather than on the food material, and that an increase in humidity increased their rates of development. To discover whether this was caused by the direct effect of humidity on the mites or by a greater supply of fresh food brought about by an increase in humidity, rearings were made with a technique developed by Rivard (1958). The mites were reared exclusively on mould cultures under controlled temperature and humidity conditions. It was also possible with this technique to regdate modd growth to some extent, so that a supply of fresh food was always available to the mites. This is a report on the influence of various humidities on mortality and rate of development of the immature stages of T. castellanii at a constant temperature.

Effect of phosphorus applied as superphosphate on rate of development and spikelet number per ear of different cultivars of wheat

1977 ◽  
Vol 28 (2) ◽  
pp. 183 ◽  
Author(s):  
MS Rahman ◽  
JH Wilson
Keyword(s):  
Constant Temperature ◽  
Leaf Number ◽  
Floral Initiation ◽  
Wheat Cultivars ◽  
Main Shoot ◽  
Spikelet Number ◽  
Vegetative Phase ◽  
Rate Of Development ◽  
Elongation Phase

The effects of adding phosphorus (40 kg of phosphorus ha-1) at sowing on rate of development, spikelet number per ear, rate of spikelet initiation, apex length at floral initiation, and leaf number at ear emergence of the main shoot of seven wheat cultivars were studied under a 16 hr photoperiod at a constant temperature of 20°C. Phosphorus additions increased the spikelet number per ear, rate of spikelet initiation, and apex length significantly in all wheats, but had no effect on the duration of the vegetative phase, spikelet phase or elongation phase, or on leaf number. The increase in spikelet number was due to an increase of spikelet initiation. All wheats responded similarly to addition of phosphorus.

The effect of temperature and moisture on the Immature Stages of Aphodius tasmaniae Hope (Scarabaeidae) in the lower South-east of South Australia.

1961 ◽  
Vol 9 (2) ◽  
pp. 173 ◽  
Author(s):  
DA Maelzer
Keyword(s):  
Mortality Rate ◽  
Water Content ◽  
South Australia ◽  
Effect Of Temperature ◽  
Annual Rainfall ◽  
Field Observations ◽  
Immature Stages ◽  
Rate Of Increase ◽  
Lower South ◽  
Third Instar Larvae

The distribution and abundance of the univoltine species A. tasmaniae in the lower south-east of South Australia appears to be related to annual rainfall. The effects of moisture on the mortality rates of the immature stages were consequently studied and observations were made of the effects of variations in moisture in the field. Laboratory experiments and field observations suggested that variations in soil moisture have little effect on the eggs and the diapausing prepupae in the field. Eggs absorbed water and hatched normally within a pF range of 2.50-3.75 in a sand and in a clay loam. At pF 4.0 in both soils, eggs lost weight and did not hatch. The adults, however, tend to lay the eggs well within the pF range in which the eggs can develop, and soil samples suggested that eggs would develop with little mortality in the kinds of places in which they are usually laid. When prepupae enter diapause they have a water content of c. 77%. When desiccated in the laboratory, few prepupae died until their water content fell below 62%. The mortality rate then increased sharply, and it was estimated that 50% of the prepupae died when their water content dropped to 57%. Droughts of sufficient duration and intensity to kill 50% of the prepupae have never been recorded from the study area, and field observations suggested that few prepupae died of desiccation in summer. Unlike the two stages above, the first and third instar larvae may be markedly affected by variations in moisture in the field. The first instar larvae, after hatching, do not move to the surface of the soil and do not feed much until the soil is saturated with rain. As rainfall is variable at this time of the year, the larvae may be in dry soil for many weeks before they are stimulated to extend their burrows to the surface and search for food. Many larvae may die of starvation during this time, and the mortality rate of the larvae was related empirically to the length of the autumn "drought". Third instar larvae may be affected, on the other hand, by excessive water. In wet winters, vast numbers of larvae are drowned when extensive flooding occurs on the poorly-drained soils, and on well-drained soils a large proportion of larvae are killed by the entomophagous fungus Cordyceps aphodii. The above data have suggested that moisture is one of the major factors affecting the distribution and abundance of the species. Temperature has little effect on the rate of increase of the species.

INFLUENCE OF TEMPERATURE AND HUMIDITY ON MORTALITY AND RATE OF DEVELOPMENT OF IMMATURE STAGES OF THE MITE TYROPHAGUS PUTRESCENTIAE (SCHRANK) (ACARINA: ACARIDAE) REARED ON MOLD CULTURES

1961 ◽  
Vol 39 (4) ◽  
pp. 419-426 ◽  
Author(s):  
I. Rivard
Keyword(s):  
Sex Ratio ◽  
Indirect Effect ◽  
Food Products ◽  
Immature Stages ◽  
Direct Influence ◽  
Tyrophagus Putrescentiae ◽  
Rate Of Development ◽  
Influence Of Temperature ◽  
Temperature And Humidity ◽  
Two Factors

Tyrophagus putrescentiae (Schrank), a mite that infests stored food products, was reared individually on mold cultures at all combinations of five temperatures and four humidities. Mortality during immature stages was lowest at 72.5° F and 80% to 90% R.H. Development was usually accelerated by an increase in either of these two factors. Temperature and humidity had a direct influence on mortality and rate of development, but humidity also had an indirect effect by affecting the mold on which the mite feeds. Adults obtained at 70% R.H. were usually relatively small in size. Sex ratio of the adults was approximately one to one; the males developed faster than the females.

INFLUENCE OF HUMIDITY ON THE PREDACEOUS MITE MELICHARES DENTRITICUS (BERLESE) (ACARINA : ACEOSEJIDAE)

1962 ◽  
Vol 40 (5) ◽  
pp. 761-766 ◽  
Author(s):  
I. Rivard
Keyword(s):  
Food Product ◽  
Prey Population ◽  
Oviposition Period ◽  
Predator Population ◽  
Immature Stages ◽  
Tyrophagus Putrescentiae ◽  
Adult Females ◽  
Rate Of Increase ◽  
Predaceous Mite

The predaceous mite Melichares dentriticus (Berlese) was reared individually on larvae and protonymphs of the stored food product mite Tyrophagus putrescentiae (Schrank) at 68.0° F and 70, 80, 90, and 100% R.H. Survival and speed of development of the immature stages increased slightly with the humidity. Longevity of adult females was similar at different humidities, though the oviposition period was much shorter at 70% R.H. More eggs were laid at 100% R.H., but then the peak of laying occurred later in the oviposition period. The rate of increase of the predator population was altered very little by different humidities in comparison with that of the prey population and thus, assuming that these rates are an accurate guide to the outcome of the interaction, the population of the prey should be better controlled at lower humidities.

I. Observations on the temperature of the strata taken during the sinking of the rose bridge Colliery, Wigan, Lancashire, 1868-69

1870 ◽  
Vol 18 (114-122) ◽  
pp. 173-176
Keyword(s):  
Great Britain ◽  
Coal Seam ◽  
Constant Temperature ◽  
Average Rate ◽  
Rate Of Increase ◽  
Series Of Experiments ◽  
Experimental Researches ◽  
The Rose

In an elaborate paper by Mr. W. Hopkins, F.R.S., entitled “Experimental Researches on the Conductive Powers of various Substances,” pub­lished in the Philosophical Transactions for 1857, an account is given of a series of experiments made under the general supervision of Mr. Hopkins himself and Mr. W. Fairbairn, F.R.S., during the sinking of the Astley Pit of Dukenfield Colliery in Cheshire. At the time this paper was written the depth attained was only a little more than 1400 feet; and the rate of increase between the depths of 700 feet and 1330 feet was found to be 1° F for about 65 feet. These observations were subsequently continued until the pits had attained their full depth of 717 yards from the surface. The last observation made was in the shale overlying the coal-seam, known as the “Black Mine,” which it was the object of the proprietor, Mr. Astley, to reach, and the temperature was found to be 75°F Assuming the ‘‘stra­tum of constant temperature,” or, as it is also called by Humboidt, invariable stratum,” to be that which was reached at 16*5 feet with a temperature of 51° F., the total increase of temperature would amount.to 24° F., giving as the rate of increase 1° F. for every 88·925 feet. This is much below the average rate of increase. During a part of the period above referred to (from 1854-56) another coal-pit was being sunk at Wigan, which reached the depth of 600 yards, down to the celebrated “Cannel Mine.”At this pit similar observations on the temperature of the strata were made very carefully by the manager, Mr. Bryham, which were kindly communicated to myself for publication, and will be found in my work on the 'Coalfields of Great Britain.' The ultimate temperature attained in this pit at the depth from the surface of 600 yards was found to be 72ºF.; and assuming the invariable stratum to be the same as that at Dukenfield Colliery, the resulting rate of increase would be 1ºF. for every 61·5 feet, which accords very closely with the result obtained by Professor Phillips, F. R. S., at the Monkwearmouth Colliery.

THE RESPONSE OF TWO STRAINS OF HYLEMYA ANTIQUA (DIPTERA: ANTHOMYIIDAE) TO A CONSTANT AND AN ALTERNATING TEMPERATURE REGIME

1979 ◽  
Vol 111 (11) ◽  
pp. 1207-1217 ◽  
Author(s):  
Alan S. Robinson ◽  
G. Zurlini
Keyword(s):  
Constant Temperature ◽  
Temperature Regime ◽  
Wild Strain ◽  
Laboratory Strain ◽  
Intrinsic Rate Of Increase ◽  
Net Reproductive Rate ◽  
Hylemya Antiqua ◽  
Rate Of Increase ◽  
Weighted Mean Temperature ◽  
Alternating Temperature

AbstractThe effect of an alternating and a constant temperature regime on some aspects of the biology of two strains of Hylemya antiqua were studied. One strain was a laboratory strain, the other a newly colonized wild strain. Several population statistics were assessed and life tables constructed. Significant differences between the strains were recorded.The laboratory strain mated significantly better under both environments than the wild strain, it also oviposited earlier and lived longer. No difference between the strains was recorded for either total egg production or oviposition rate. The wild strain larvae survived significantly better than the laboratory strain larvae and produced larger pupae. As the weighted mean temperature of the alternating regime was 16.6°C compared with the constant regime of 23°C many temperature dependent processes were retarded. Nevertheless as the alternating temperature increased larval survival and increased pupal size, this temperature regime has now been adopted for the routine laboratory rearing of H. antiqua larvae. The net reproductive rate, R0, and the intrinsic rate of increase, r, were calculated for both strains in both environments. The wild flies had the highest R0 at the alternating temperature and the lowest at the constant temperature. This trend was completely reversed when r was calculated as this statistic takes into account generation time, which was much shorter in the constant temperature.The results were discussed in the framework of the quality of the laboratory stock in relation to its use in a genetic control programme.

scholarly journals MODELING DEMOGRAPHIC RESPONSE TO CONSTANT TEMPERATURE IN BRYOBIA RUBRIOCULUS (ACARI: TETRANYCHIDAE)

2014 ◽  
Vol 1 (1) ◽  
pp. 18-29
Author(s):  
Saeid Javadi Khederi ◽  
Mohammad Khanjani
Keyword(s):  
Population Growth ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Growth Potential ◽  
Distribution Model ◽  
Thermal Constant ◽  
Temperature Threshold ◽  
Immature Stages ◽  
Net Reproductive Rate ◽  
Rate Of Increase

The demographic parameters of brown mite, Bryobia rubrioculus Scheuten were carried out in order to characterize the population growth potential at five constant temperatures: 20, 22.5, 25, 27.5 and 30ºC, 60 ± 5 % RH and 16: 8 (L: D) h. The highest intrinsic rate of natural increase (rm = 0.0243/day), net reproductive rate (R0 = 2.4 ♀/♀/T) and finite rate of increase (λ = 1.0245 day-1) values were determined at 22.5°C. The mean generation time (T) of the population ranged from 22.7 days at 30°C to 45.8 days at 20°C. The maximum and minimum survival rates (lx) were recorded at 22.5ºC and 30ºC. Survivorship data (lx) of adult females were summarized and compared using the shape and scale parameters of the Weibull frequency distribution model across. The age specific fecundity data (mx) was modeled as a function of time by using Polynomial model. The lower temperature threshold (t) and thermal constant (k) of the immature stages were estimated using Ikemoto and Takai linear model to be 12.85ºC and 279.7 degree days (DD), respectively. Of the non-linear models, the Analitis-1, Analitis-2, Analitis-3 and Analitis/Allahyari models were found to be the best for the modeling development rate of immature stages of B. rubrioculus. The optimal temperature for population growth of brown mite on apple was found at 22.5°C.

FECUNDITY AND RATE OF DEVELOPMENT OF THE EUROPEAN RED MITE, PANONYCHUS ULMI (KOCH) (ACARINA: TETRANYCHIDAE), ON LEAVES FROM AN ABANDONED PEACH ORCHARD

1964 ◽  
Vol 42 (5) ◽  
pp. 719-722 ◽  
Author(s):  
Wm. L. Putman
Keyword(s):  
Population Density ◽  
Nutritional State ◽  
Panonychus Ulmi ◽  
Immature Stages ◽  
Rate Of Development ◽  
European Red Mite ◽  
Peach Orchard

The fecundity of the European red mite, Panonychus ulmi (Koch), reared on leaves from an abandoned peach orchard was equal to that of mites on leaves from a cultivated orchard, but the development of immature stages was slightly slower on leaves from the abandoned orchard. Poor nutritional state of the foliage is apparently not responsible for the very low population density of the mite in abandoned peach orchards.

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