Developmental Zero Temperature Research Articles

Effects of temperature on development, molting, and population growth of Yuukianura szeptyckii Deharveng & Weiner, 1984 (Collembola: Neanuridae)

Neanuridae is one of the most diversified families of Collembola, but its biology and ecology are poorly understood. This is, to our knowledge, the first report on the biology of the neanurid species Yuukianura szeptyckii Deharveng & Weiner. Y. szeptyckii individuals were collected near a stream in Korea, and maintained on OECD artificial soil. This species showed a better reproductive performance on an artificial soil-based substrate than on charcoal-based substrate, and thus the soil-based substrate was used for investigating its biology. The sex ratio of Y. szeptyckii was found to be biased toward females (88.0%), and its mode of reproduction was sexual. The development, survival, longevity, reproduction, molting, and life table parameters of Y. szeptyckii were evaluated at 15, 20, 25, and 30°C. Individual growth was estimated by measuring head capsule widths. Mean developmental period from egg to adult decreased with increasing temperature from 73.7 d at 15°C to 25.6 d at 30°C. In the adult stage, ovipositional periods decreased with temperature from 273 d at 15°C to 45.5 d at 30°C, but senile periods increased at temperatures above 20°C. The developmental zero temperature was estimated to be 7.88°C. Median survival time (ST50s) and mean longevity decreased with temperature from 228d at 15°C to 98.0d at 30°C and from 401 d at 15°C to 177 d at 30°C, respectively. The maximum and minimum total number of eggs produced per individual were observed at 20°C (73.8 eggs) and 30°C (6.9 eggs), respectively. The head capsule width at first oviposition was significantly smaller at 25 and 30°C (0.30–0.31mm) than that at 15 and 20°C (0.45–0.46mm), while the head capsule width at last oviposition was smaller at 30°C (0.55mm) than that at 15 to 25°C (0.63–0.64mm). The molting rate (per individual per week) increased with temperature from 0.50 at 15°C to 1.43 at 30°C, but the total number of molts during the life span varied only slightly, ranging from 29.1 at 25°C to 33.2 at 30°C. The population reared at 20°C had the highest intrinsic rate of increase (0.060) and net reproductive rate (84.5), indicating that the optimal temperature for Y. szeptyckii population growth is 20°C. This study demonstrated that temperature can profoundly affect the development, molting, and population growth of Y. szeptyckii.

Effect of temperature on life table parameters of Leptocybe invasa (Hymenoptera: Eulophidae)

AbstractLeptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae) first described in 2004, is a new eucalyptus pest of global importance. A thorough understanding of pest biology is essential for development of a reliable pest population prediction system and management strategies, but little is known about this pest. Therefore, we quantified the development, fecundity, fertility, longevity, morphometrics (length, width, and hind tibia length of adults), and other life table parameters of L. invasa in relation to temperature and to provide an experimental basis for developing an overall wasp population model. The results showed that ranging from 20 to 32°C (five constant temperatures were 20, 23, 26, 29 and 32°C, respectively), the developmental period of immatures (egg to adult) was shortest at 29°C but longest at 20°C; the number of eggs per female in the oviduct and survival rate of immatures were greatest at 29°C but smallest at 32°C. The effect of temperature on morphometrics was more pronounced for females than males. When L. invasa was fed with a 40% honey solution, maximum longevity was at 23°C (9.0 days for females and 12.8 days for males). The intrinsic rate of natural increase (rm) was largest (0.0477) at 29°C, and the sex ratio of L. invasa was extremely female‐biased. The intrinsic rate of natural increase (rm) indicates that L. invasa population growth is likely to be greatest at 29°C. The developmental zero temperature (t) and the effective cumulative temperature (k) of egg, larva and pupa were 13.0, 19.7 and 17.1°C, and 128.1, 284.2 and 201.2°C, respectively. For L. invasa, 19.1°C (t) and 563.5°C (k) were indispensable for completing development from egg to adult. Therefore, farmers or managers of forests could predict the population dynamics of the wasp and adopt physical or chemical methods to control it according to the temperature.

The impact of temperature on the bionomics of Aedes (Stegomyia) aegypti, with special reference to the cool geographic range margins.

The mosquito Aedes (Stegomyia) aegypti (L.), which occurs widely in the subtropics and tropics, is the primary urban vector of dengue and yellow fever viruses, and an important vector of chikungunya virus. There is substantial interest in how climate change may impact the bionomics and pathogen transmission potential of this mosquito. This Forum article focuses specifically on the effects of temperature on the bionomics of Ae. aegypti, with special emphasis on the cool geographic range margins where future rising temperatures could facilitate population growth. Key aims are to: 1) broadly define intra-annual (seasonal) patterns of occurrence and abundance of Ae. aegypti, and their relation to climate conditions; 2) synthesize the existing quantitative knowledge of how temperature impacts the bionomics of different life stages of Ae. aegypti; 3) better define the temperature ranges for which existing population dynamics models for Ae. aegypti are likely to produce robust predictions; 4) explore potential impacts of climate warming on human risk for exposure to Ae. aegypti at its cool range margins; and 5) identify knowledge or data gaps that hinder our ability to predict risk of human exposure to Ae. aegypti at the cool margins of its geographic range now and in the future. We first outline basic scenarios for intra-annual occurrence and abundance patterns for Ae. aegypti, and then show that these scenarios segregate with regard to climate conditions in selected cities where they occur. We then review how near-constant and intentionally fluctuating temperatures impact development times and survival of eggs and immatures. A subset of data, generated in controlled experimental studies, from the published literature is used to plot development rates and survival of eggs, larvae, and pupae in relation to water temperature. The general shape of the relationship between water temperature and development rate is similar for eggs, larvae, and pupae. Once the lower developmental zero temperature (10-14 degrees C) is exceeded, there is a near-linear relationship up to 30 degrees C. Above this temperature, the development rate is relatively stable or even decreases slightly before falling dramatically near the upper developmental zero temperature, which occurs at -38-42 degrees C. Based on life stage-specific linear relationships between water temperature and development rate in the 15-28 degrees C range, the lower developmental zero temperature is estimated to be 14.0 degrees C for eggs, 11.8 degrees C for larvae, and 10.3 degrees C for pupae. We further conclude that available population dynamics models for Ae. aegypti, such as CIMSiM and Skeeter Buster, likely produce robust predictions based on water temperatures in the 16-35 degrees C range, which includes the geographic areas where Ae. aegypti and its associated pathogens present the greatest threat to human health, but that they may be less reliable in cool range margins where water temperatures regularly fall below 15 degrees C. Finally, we identify knowledge or data gaps that hinder our ability to predict risk of human exposure to Ae. aegypti at the cool margins of its range, now and in the future, based on impacts on mosquito population dynamics of temperature and other important factors, such as water nutrient content, larval density, presence of biological competitors, and human behavior.

Temperature-Dependent Development in Capital-Breeding Lepidoptera

Temperature-dependent development is described by three variables termed thermal characteristics: the developmental zero temperature, below which no development is assumed to occur; the high cutoff temperature, above which development slows; and the developmental index, a measure of physiological time required for a given phase to develop. Physiological time in this study refers to number of degree-days, units that combine temperature and time. The phase of interest here is the entire larval stage. Degree-days track developmental progress more precisely than calendar days and better alert the observer for optimally timing planned interventions. Thermal characteristics are usually derived from simple Type I regressions fitted to the linear portion of plots of rate of development on rearing temperature, where rate is the reciprocal of duration. Existing thermal characteristics for 131 published datasets are revised here using an improved Type II regression proposed by Ikemoto & Takai (2000). These datasets represent species in 11 families and originated between 1927 and 2007 on six continents. Each dataset consists of ≥4 associated rates and temperatures. Revised developmental zero temperatures ranged from 3.9 to 16.0. They varied directly with mean annual temperatures at localities of dataset origin, forming a continuum of low to high values between cool and warm climates. Among other relations, the mathematical product of voltinism × the natural logarithm (ln) of developmental index, which encompasses multivoltinism, varied directly with developmental zeros. In 91% of datasets, number of degree-days for the larval phase calculated using official mean daily air temperatures agreed within ±2 calendar days with those using constant laboratory temperatures. Official temperatures were summarized from records at 18 mid-temperate North American weather stations. Thermal characteristics are found to be adapted to climatic regimes, and local weather-station temperatures are usually suitable for degree-day summations.

가지에서 온도별 점박이응애 발육특성 및 생명표 통계량

가지잎에서 점박이응애의 온도에 따른 발육 특성을 조사한 결과 17, 22, 27, 32, <TEX>$37^{\circ}C$</TEX>에서 점박이응애의 사충률은 <TEX>$27^{\circ}C$</TEX>를 기준으로 온도가 올라가거나 내려감에 따라 증가하였고, 부화율은 <TEX>$17^{\circ}C$</TEX>와 <TEX>$37^{\circ}C$</TEX>에서 낮았다. 발육기간은 온도가 높아짐에 따라 감소하는 경향을 보이고 <TEX>$37^{\circ}C$</TEX>에서 5.3일로 가장 짧고, <TEX>$17^{\circ}C$</TEX>에서 25.8일로 가장 길었다. 온도와 발육률의 관계를 직선회귀에 의해 분석한 결과 <TEX>$r^2$</TEX>값이 0.88 이상으로 본 실험에서 수행한 온도 <TEX>$17{\sim}37^{\circ}C$</TEX>범위에서 점박이응애의 발육은 직선회귀에 부합되었다. 발육영점온도는 전체약충기간이 암컷 <TEX>$12.5^{\circ}C$</TEX>, 수컷 <TEX>$12.8^{\circ}C$</TEX>이었고, 전체약충기간의 유효적산온도는 암컷 80.5,수컷 74.7일도였다. 성충의 수명과 산란기간은 온도가 올라감에 따라 짧아졌고, 암수의 비교에 있어서 암컷이 수컷에 비해 수명이 길었다. 온도에 따른 산란수는 <TEX>$27^{\circ}C$</TEX>에서 141.0개로 가장 많았으며, <TEX>$37^{\circ}C$</TEX>에서 78.0개로 가장 적어 온도에 따른 변이가 컸다. 온도에 따른 부화율과 암컷의 비율도 <TEX>$27^{\circ}C$</TEX>를 정점으로 온도가 높아지거나 낮아지면 감소하였다. 점박이응애의 <TEX>$R_o$</TEX> (순증가율)는 온도가 <TEX>$27^{\circ}C$</TEX>를 정점으로 온도가 높아지거나 낮아지면 감소하였고, <TEX>$r_m$</TEX> (내적자연증가율)은 온도가 높아짐에 따라 같이 높아져 <TEX>$37^{\circ}C$</TEX>에서 최고치인 0.5652였으며, <TEX>${\lambda}$</TEX> (기간증가율)도 온도가 높아짐에 따라 높아졌다. DT (배수기간)와 T (평균세대기간)는 온도가 올라감에 따라 감소하였다. Temperature dependent development of Tetranychus. urticae Koch was studied on the leaf of eggplant at 17, 22, 27, 32 and <TEX>$37^{\circ}C$</TEX>. T. urticae showed a minimum mortality at <TEX>$27^{\circ}C$</TEX> and it increased at higher or lower temperatures than <TEX>$27^{\circ}C$</TEX>. The hatchability was low at 17 and <TEX>$37^{\circ}C$</TEX>. The duration of development decreased with increasing temperatures i.e., 5.3d at <TEX>$37^{\circ}C$</TEX> and 25.8d at <TEX>$17^{\circ}C$</TEX>. Linear regression analysis of temperature vs. rate of development yielded the higher <TEX>$r^2{\geq}0.88$</TEX> resulting in a good fit of the estimated line in the range of <TEX>$17{\sim}37^{\circ}C$</TEX>. Developmental zero temperature was <TEX>$12.5^{\circ}C$</TEX> for the entire immature stage of female and <TEX>$12.8^{\circ}C$</TEX> for that of male. Thermal constants were 80.5 and 74.7 degree days for those of female and male, respectively. Adult life span and oviposition period decreased with increasing temperatures. The number of eggs laid per female peaked at 141.0 eggs at <TEX>$27^{\circ}C$</TEX>, while that was a minimum 78.0 eggs at <TEX>$37^{\circ}C$</TEX>. Rate of hatchability, ratio of female, and <TEX>$R_o$</TEX> were increased up to <TEX>$27^{\circ}C$</TEX>, and than declined thereafter. Intrinsic rate of natural increase (Rm) increased with rising temperatures and showed a maximum 0.5652 at <TEX>$37^{\circ}C$</TEX>. Also, <TEX>${\lambda}$</TEX> increased with increasing temperature. Doubling time (Dt) and generation time (T) decreased with increasing temperature.

Life cycle of a giant carnivorous caddisfly, Himalopsyche japonica (Morton) (Trichoptera: Rhyacophilidae), in the mountain streams of Nagano, Central Japan

The life cycle of a giant carnivorous caddisfly, Himalopsyche japonica (Morton), was studied in two mountain streams in Nagano Prefecture, Central Japan. Field surveys and rearing experiments in the laboratory were conducted from October 1997 to September 2001. The life cycle of H. japonica was estimated to be a complex univoltine cycle that partly includes bivoltine populations. The adults had a long flight period, from April to September, with three distinct peaks of emergence. First to third instar larvae were collected from June to February, and the last (fifth) instar larvae and pupae appeared throughout the year. In autumn, the larvae belonging to all instars were found, and younger ones overwintered in the fourth instar stage and others in the fifth instar stage. On the other hand, fifth instar larvae and pupae ceased developing in autumn even though the water temperature was higher than the developmental zero temperature. The overwintered pupae emerged as adults in April, and the overwintered fifth instar larvae pupated in May and emerged in June. The larvae which overwintered in the fourth instar stage probably emerged after June.

Possible existence of a common temperature and a common duration of development among members of a taxonomic group of arthropods that underwent spaciational adaptation to temperature.

The parameters in the law of total effective temperature, the developmental zero temperature (t) and the effective cumulative temperature (k), were estimated in several species or strains of the family Tenebrionidae. It was shown that the relationship between t and k is linear; k decreases with increasing t. Similar relationships were noted among members of the genus Periplaneta in the family Blattidae, the genus Aedes in the family Culicidae, the family Pyralidae, the family Aphididae and the family Tetranychidae. Based on analysis among groups of orders or higher categories, several researchers have found a similar relationship. The current study on a family or a genus revealed a more rigorous linearity. However, the focus of this study was the linear relationship itself and it was discovered that the t-k relationships of members within each taxonomic group of arthropods determines a common temperature (Tc) and a common duration of development (Dc). This phenomenon was mathematically deducible as a consequence of the t-k linear relation. Biologically, Tc and Dc are probably the optimum temperature and duration of development, respectively, that a group of organisms possess in common.

12 ヤブカの発育ゼロ点と地理的分布

12 ヤブカの発育ゼロ点と地理的分布

A New Linearized Formula for the Law of Total Effective Temperature and the Evaluation of Line-Fitting Methods with Both Variables Subject to Error

In the quantitative analysis of experimental data regarding temperature-dependent development, the so-called law of total effective temperature is sometimes expressed in the linearized equation 1,: 1/D = −(t/k) (1/k)T. D indicates the duration of development; T, temperature; t, the estimated developmental zero temperature; and k, the effective cumulative temperature. The method of fitting usually involves the regression of y = 1/D on x = T. Although the degree of fitting of equation 1, to data within optimum temperature ranges is fairly satisfactory, we have in the current study addressed three problems regarding the use of equation 1, and methods of fitting involving the regression of y on x. First, we found that the detection of optimum temperature ranges is frequently difficult with equation 1,. Second, in applying the method of regression of y on x with equation 1, the weights of the data points are disproportionate between those in the upper and lower parts of the line and they are not homogeneous along the temperature axis. The lower the temperature, the more disproportionate weight is burdened and the less weight is loaded. Third, in most of the data, errors in the x-variable are ignored. The second and third problems would in most cases result in a reduction in the slope of the line, a smaller t, and a larger k. Therefore, we proposed a new linearized formula: (DT) = k tD. We further propose the use of the reduced major axis, obtained as the solution of the functional model among bivariate errors-in-variables models, in the method of fitting to data. We demonstrated that the majority of the problems raised above could be unraveled under this new approach based on statistical analysis.

Biology of Ixodes Rubicundus Ticks under Laboratory Conditions: Observations on Oviposition and Egg Development

Observations on oviposition and egg development of Ixodes rubicundus were made under laboratory conditions. Engorged females were exposed to temperatures in the range 10–25°C and relative humidities (RHs) of 33 and 93%. The pre-oviposition period, oviposition period, incubation period, conversion efficiency index (CEI) values and fecundity were determined. The mean pre-oviposition period varied from 13.3 days (temperature 25°C and RH 33%) to 68.3 days (temperature 10°C and RH 93%). Oviposition extended from a mean of 39 days (temperature 25°C and RH 93%) to 201.7 days (temperature 10°C and RH 93%). The developmental zero temperature for the pre-oviposition period was 9.2°C. The mean total number of eggs produced by engorged I. rubicundus females varied from 2045.7 (temperature 10°C and RH 93%) to 3777.7 (temperature 20°C and RH 93%). Both female mass and RH significantly (p < 0.01) influenced the number of eggs produced. CEI values varied between 43.1–54.4% (RH 93%) and 34.1–42.5% (RH 33%). At 93% RH females produced between 14.2 and 17.7 eggs per mg body mass compared to the 13.2–14.6 eggs per mg body mass at 33% RH. The shortest mean incubation period recorded was 164.3 days (temperature 25°C and RH 93%). The developmental zero temperature for incubation was 6.5°C. Both the pre-oviposition and oviposition periods of I. rubicundus are more extended compared to other species of the genus. Ixodes rubicundus produces a large number of small eggs compared to other prostriate ticks.

Effect of Temperature and Photoperiod on the Larval Development and Diapause Induction in the Onion Fly, Hylemya antiqua MEIGEN : Diptera : Anthomyiidae

Larvae of the onion fly, Hylemya antiqua were reated under several combination of temperatures (10-22°C) and photoperiods (16L-8D and 12L-12D) to determine the effect of these factors on the larval development and diapause induction. Photoperiod little affected the developmental zero temperature for larva development (4.3°C under 16L-8D, and 4.6°C under 12L-12D), whereas the total effective temperature necessary for such development was a little greater in the short day (257 day-degrees under 16L-8D, and 278 day-degrees under 12L-12D). When pupae obtained from different conditions were kept at 25°C, 16L-8D, most flies emerged 9-18 days after pupation, but some were observed to emerge 40-60 days after pupation. This latter was particularly common in cultures at the lower temperatures and short photoperiod. We regarded the individuals emerging within 20 days after pupation as "non-diapausing" and the rest as "diapausing". The temperature inducing diapause in 50% of individuals was found to be significantly affected by photoperiod : 14.0°C under 16L-8D, and 18.5°C under 12L-12D.