Developmental Threshold Temperature Research Articles

Survival and development of the forensically important blow fly, Calliphora varifrons (Diptera: Calliphoridae) at constant temperatures.

The influence of temperature on the development of the forensically important blow fly, Calliphora varifrons Malloch 1932 (Diptera: Calliphoridae), was investigated at seven constant temperatures ranging from 12 to 30°C. C. varifrons completed development between 12 and 27°C. At 30°C larvae formed pupae but did not successfully emerge. Temperature significantly influenced development time, mortality, maximum larval length, and adult body size. Development time (larviposition to adult emergence) ranged from 16.65±0.17days at 27°C to 49.93±0.26days at 12°C. Development rate was essentially linear throughout the 12-27°C temperature range. Linear estimates of lower developmental threshold and thermal requirement (K) for development of C. varifrons were 4.20°C and 368.46±26.38K. At 30°C, a slight inhibitory effect of high temperature on third instar development rate was observed followed by a rapid decline when subsequent development and survival ceased. Nonlinear estimates of lower developmental threshold for third instar development were comparatively higher (6.29°C). Nonlinear estimates of optimal developmental temperature and upper lethal developmental threshold were 25.94 and 32.13°C respectively. Mortality was high at both temperature extremes (12 and 27°C) and lowest between 18 and 24°C. Maximum larval length was inversely related to temperature. Adult body size was significantly smaller at 12°C, peaked at 18°C, and declined as temperatures increased. The species-specific development data presented are the first available for C. varifrons for use by forensic practitioners for estimation of minimum time since death.

Bahasa Indonesia

Rice stem borer abundance are largely influenced by climate. This research aims to (i) develop a population dynamic model of yellow stem borer (YSB) and (ii) to assess the model’s ability to predict abundance and population peak of YSB under climate change scenario SRES A1FI and B1. Modeling the YSB requires two major components: climate parameter and lower developmental threshold temperatures (To) to describe life cycle of YSB from the egg, larva, pupa, and adult stages. The research utilized DYMEX software to describe development, mortality, transfer of individuals from one to the next life stages, fecundity and reproduction of YSB. The coefficient of determination (R2) of calibration models between predictions and observations showed a strong positive correlation of 0.65. Model validation could well predict the peak population, with R2 = 0.42. The simulations showed that the trend of population peak occur at high rainfall i.e. in March to April, July to September, and November to December. The model predicted YSB population in the Sukamandi reaches 3 generations per year, while in Kuningan 2 generations per year. Simulation models under climate change scenarios SRES A1FI and B1 showed differences in the sensitivities. Trend of YSB population is increasing in the regions Kuningan and decreasing in region Sukamandi. Under changing climate, environment conditions in Kuningan become more suitable for the proliferation of YSB, allowing an increase in the number of generations per year.

Effects of Temperature on Snow Crab (Chionoecetes opilio) Larval Survival and Development under Laboratory Conditions

To understand more fully the larval dispersal and settlement of the snow crab Chionoecetes opilio in natural habitats, we tested the effects of temperatures ranging from ∼1–20°C and ∼1–18°C on the survival and developmental period of snow crab larvae in the zoeal and megalopal stages, respectively, through laboratory experiments. The survival rates of second zoeae and megalopae were significantly greater at 5–16°C and 5–14°C, respectively. There were no statistically significant differences among the survival rates of megalopae reared at 3–16°C, although greater survival rates were observed at 5–14°C. The mean numbers of days from hatching to second zoeae and megalopae and from megalopae to reach first crab instar were significantly shorter at warmer temperatures. Moreover, the relationships between mean temperatures and larval periods were well described by the heat summation theory equations. The threshold temperatures for larval development were estimated to be -2.24–0.63°C; they decreased with larval development as an adaptation for deeper vertical distributions in later larval stages. On the basis of larval distribution with respect to water temperature in natural habitats as well as the heat summation theory equations, the entire larval duration from hatching to first crab instar was estimated to be 74.4–123.4 days, which is similar to that in natural habitats inferred on the basis of the time lags in the occurrence of peak abundance between each larval stage.

温度对柑橘始叶螨实验种群生长发育繁殖的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 温度对柑橘始叶螨实验种群生长发育繁殖的影响 DOI: 10.5846/stxb201210081389 作者: 作者单位: 西南大学植物保护学院 重庆 400716,西南大学植物保护学院 重庆 400716,西南大学植物保护学院,西南大学植物保护学院 重庆 400716 作者简介: 通讯作者: 中图分类号: 基金项目: 重庆市自然科学基金资助项目（cstcjjA80009）；中央高校基本科研业务费资助项目（XDJK2011C010） Effects of different temperatures on the growth and development of Eotetranychus Kankitus (Ehara) Author: Affiliation: College of Plant Protection,Southwest University,College of Plant Protection,Southwest University,,College of Plant Protection,Southwest University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:通过室内试验研究了温度对柑橘始叶螨Eotetranychus kankitus（Ehara）生长发育和繁殖的影响，组建了柑橘始叶螨在7种温度下（18、21、24、27、30、33℃和36℃）的实验种群生命表。结果表明，柑橘始叶螨的生长发育、繁殖和生命表参数在不同温度之间有显著差异。卵在36℃条件下不能正常孵化，其他6个温度对该螨的种群适合度有显著影响；发育历期与温度基本呈负相关；整个世代温度（T）和发育速率（V（G））拟合的线性日度方程和Logistic模型分别为V（G）=-0.037+0.004 T（R2=7.879）和V（G）=0.080/（1+EXP（7.402 - 0.363T））（R2=0.973）；世代发育起点温度和有效积温分别为12.38℃和220.00d·℃；每雌产卵总量在27℃下最高，为73.4粒，18℃下最低，为35.3粒；卵的孵化率、幼、若螨的存活率在27℃下最大，分别为99.75%、96.18%和97.54%，18℃下最小，分别为99.01%、94.05%和93.15%；在6种温度下内禀增长力rm值分别为0.0372、0.0757、0.1024、0.1195、0.1469、0.1427；净增值率Ro分别为9.3241、16.0162、16.6874、20.4564、21.1958、8.8142。由此推断，21-30℃是柑橘始叶螨生长发育和繁殖的最适温度范围。 Abstract:In order to explore the effects of temperatures on the growth, development and reproduction of Eotetranychus Kankitus (Ehara) in the laboratory, the experimental population life tables of Eotetranychus Kankitus at seven different temperatures (18℃, 21℃, 24℃, 27℃, 30℃, 33℃, and 36℃) were established in laboratory. The results showed that the growth, development, reproduction, and life table parameters of Eotetranychus Kankitus were significantly affected by different temperatures. Eggs cannot hatch at 36℃, and other six temperatures had significant influence on the population fitness of Eotetranychus Kankitus. The developmental period was negatively correlated with the temperature. The relationship between temperature (T) and developmental rate (V(G)) for whole generation could be described by the linear model V(G)=-0.037+0.004 T (R2=0.879) and Logistic model V(G)=0.080/(1+EXP(7.402 - 0.363T)) (R2=0.973). The developmental threshold temperature and effectively accumulated temperature for the whole generation were 12.38℃ and 220.00 degree day, respectively. The highest eggs laid per female was 73.4 at 27℃, while the least was 35.3 at 18℃; The greatest hatching rates (99.75%), survival rate of larva (96.18%) and nymph (97.54%) were,all observed at 27℃., whereas the least were 99.01%, 94.05% and 93.15% at 18℃, respectively, The rm under six different temperatures were 0.0372, 0.0757, 0.1024, 0.1195, 0.1469 and 0.1427, while the R0 were 9.3241, 16.0162, 16.6874, 20.4564, 21.1958 and 8.8142, respectively. It was concluded that temperature had a great effect on the development of Eotetranychus kankitus and the optimum temperature range for the mite is from 21℃ to 30℃. 参考文献 相似文献 引证文献

Effects of temperature on the development and population growth of the melon thrips, Thrips palmi, on eggplant, Solanum melongena.

The effects of temperature on the melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae), preimaginal development, survival, fecundity, longevity of females and males, and population growth were investigated at 16, 19, 22, 25, 28, and 31° C, 70–80% RH, and a photoperiod of 12:12 L:D. The results indicated that the duration of egg, larval, and pupal stages was significantly influenced by increased temperature. The egg-to-adult developmental period of T. palmi declined from 35.7 to 9.6 days as the temperature increased from 16 to 31° C. The developmental threshold temperature estimated for egg-to-adult was 11.25° C, with a thermal constant of 196.1 degreedays. The developmental threshold temperature was 13.91, 11.82, 9.36, and 10.45° C for adult preoviposition period, total preoviposition period, female longevity, and male longevity, respectively. The thermal constants for completing the adult preoviposition period, total preoviposition period, female longevity, and male longevity were 29.3, 227.3, 454.6, and 344.8 degreedays, respectively. Female longevity was found to be shortest at 31° C (18.7 days) and longest at 16° C (56.7 days), and male longevity was shortest at 31° C (15.5 days) and longest at 16° C (50.7 days). Fecundity was highest at 25° C (64.2 eggs/female) and lowest at 16° C (23.4 eggs/female). The population trend index of T. palmi was highest at 25° C (31.3) and lowest at 16° C (7.6). The optimal developmental temperature for T. palmi in eggplant, Solanum melongena L. (Solanales: Solanaceae), was determined to be 25° C.

温度对香蕉花蓟马发育和存活的影响

通过在人工气候箱内饲养香蕉花蓟马，测定了14、18、22、26℃和30℃ 5个温度下香蕉花蓟马不同虫态的发育历期，分析了温度与香蕉花蓟马发育速率的关系，计算了其发育起点温度、有效积温及存活率。结果表明：香蕉花蓟马各虫态的发育历期随温度的升高而缩短，发育速率和温度之间有很大的相关性；香蕉花蓟马卵、一龄若虫、二龄若虫、预蛹、蛹及世代的发育起点温度分别为8.26、10.56、7.92、9.17、9.53、8.69℃ ，世代的有效积温为153.81d·℃。26℃下香蕉花蓟马的世代存活率最高，为63.16%；30℃下的存活率最低，为46.34%。;<em>Thrips hamaiiensis</em> (Morgan) was tested at five contest temperature (14,18,22,26℃ and30℃) in the laborary to investigate the development periods of their different development stages and calculate their development threshold temperature、effective accumulated temperature and survival rate. The results showed that the development period of different development stages shortened with the temperature increasement, the relationship between temperature and development speed of each life stage fitted with liner model. The development start temperature of Egg,NymphaeⅠ,NymphaeⅡ,Prepupa,Pupae and Whole generation was 8.26,10.56,7.92,9.17,9.53,8.69℃. The effective accumulative temperature of Whole generation was 153.81d·℃. The Generation survival rate at 25℃ was high, being 63.16%, while at 30℃was lower, only 46.34%.

Adaptation of the egg of the desert beetle, Microdera punctipennis (Coleoptera: Tenebrionidae), to arid environment.

Microdera punctipennis Kaszab (Coleoptera: Tenebrionidae) is an endemic species in Guerbantonggut desert in China. To explore the ways that M. punctipennis egg adapts to dry desert environment, morphological characteristics of the egg was investigated along with the egg of the nondesert beetle Tenebrio molitor (Coleoptera: Tenebrionidae). Water loss rate and survival rate of these eggs under different dry treatments (relative humidity0, 10, and 20%) were measured to evaluate the desiccation resistance of the eggs at different developmental stages (day 0, 2, and 5 eggs). Our results showed that the 50-egg weight in T. molitor was heavier than M. punctipennis , while the 50-first-instar larva weight in T. molitor was almost the same as in M. punctipennis . The water loss rate of M. punctipennis egg under dry conditions was significantly lower than T. molitor , and the egg survival rate was significantly higher than T. molitor . The estimated developmental threshold temperature of M. punctipennis egg was 18.30°C, and the critical thermal maximum of M. punctipennis egg is above 39°C. These features partly account for the adaptability of M. punctipennis to desert environment in egg stage.

Temperature-driven models of Aculops pelekassi (Acari: Eriophyidae) based on its development and fecundity on detached citrus leaves in the laboratory

This study was carried out to develop temperature-driven models for immature development and oviposition of the pink citrus rust mite Aculops pelekassi (Keifer). A. pelekassi egg development times decreased as the temperature increased, ranging from 6.6days at 16°C to 1.9days at 35°C. Total nymph development times decreased from 8.2days at 16°C to 3.3days at 35°C. The egg-to-adult development durations were 14.8, 11.6, 9.7, 8.0, 7.3, 6.1, and 5.2days at 16, 20, 24, 26, 28, 32, and 35°C, respectively. The lower developmental threshold temperatures for eggs, nymphs, and total egg-to-adult development were calculated as 9.3, 4.3, and 6.9°C, respectively. The thermal constants were 54.0, 101.8, and 153.8degree days for each of the above stages. The non-linear biophysical model fitted well for the relationship between the development rate and temperature for all stages. The Weibull function provided a good fit for the distribution of development times of each stage. Temperature affected the longevity and fecundity of A. pelekassi. Adult longevity decreased as the temperature increased and ranged from 24.2days at 16°C to 14.6days at 35.0°C. A. pelekassi had a maximum fecundity of 33.1 eggs per female at 28°C, which declined to 18.8 eggs per female at 16°C. In addition, three temperature-dependent components for an oviposition model of A. pelekassi were developed with sub-models estimated: total fecundity, age-specific cumulative oviposition rate, and age-specific survival rate. The oviposition model, coupled with the stage emergence model, should be useful to construct a population model for A. pelekassi in the future.

갈색거저리(Tenebrio molitor L.) 유충의 온도발육 모형

The developmental times of mealworm beetle larvae, Tenebrio molitor were studied at six temperatures ranging from 15 to with 60~70% RH, and a photoperiod of 14L:10D. Mortality of larval period was very low at 17 and but did not die over . Developmental time of larva was decreased with increasing temperature. The total developmental time of T. molitor larvae was longest at (244.3 days) and shortest at (110.8 days). Egg and larvae were not developed at . The lower developmental threshold and effective accumulative temperatures for the total larval stages were and 2564.1 degree-days, respectively. The relationship between developmental rate and temperature was fitted by a linear model and nonlinear model of Logan-6(

발육영점온도에서 파밤나방 5령 유충의 유전자 발현 저하

파밤나방(Spodoptera exigua)의 발육을 일으키는 최저온도를 결정하고, 이 상태의 생리적 특성을 서로 다른 기능군(대사, 신경, 면역 및 스트레스) 유전자의 발현 양상을 이해하기 위해 본 연구를 수행하였다. 알부터 번데기까지 파밤나방의 발육영점온도는 <TEX>$5.5{\sim}11.6^{\circ}C$</TEX>로 다양하였다. 유충은 알과 번데기에 비해 비교적 낮은 온도에서 발육이 가능하였다. 5령충의 경우 생리적 발육영점온도가 추정치(<TEX>$10.3^{\circ}C$</TEX>)와 다르게 이보다 높은 <TEX>$15^{\circ}C$</TEX>에서 관찰되었다. 정량적 RT-PCR로 분석된 유전자의 발현양상은 유충 영기가 진행됨에 따라 모든 기능군의 대부분 유전자의 발현량이 증가하였고, 또한 5령 시기에서도 처리온도가 증가함에 따라 이들 유전자의 발현량도 증가하였다. 비록 동일한 갓 탈피한 5령이라 하더라도 이전에 노출된 외부 온도에 따라 발현량이 상이하였다. 5령충의 생리적 발육영점온도인 <TEX>$15^{\circ}C$</TEX>에서 대부분의 유전자 발현량은 저하되었다. 그러나 높은 온도에서와 마찬가지로 발육기간이 증가함에 따라 이들 유전자의 발현량이 증가하였다. 이상의 결과는 발육영점온도에서 파밤나방의 발육 관련 유전자의 발현이 전체적으로 수준은 낮지만 지속적으로 진행되고 있다는 것을 의미한다. This study aimed to understand the physiological status of the beet armyworm, Spodoptera exigua at low developmental threshold temperature (LTT) through analysis of gene-expression patterns associated with different functions (metabolism, nervous system, immune, and stress). The estimated LTTs for egg, larval, and pupal developments varied with <TEX>$5.5{\sim}11.6^{\circ}C$</TEX>. Larvae were able to develop at the lower temperatures than eggs and pupae. However, the physiological LTT (<TEX>$15^{\circ}C$</TEX>) in the fifth instar was much higher than the estimated LTT (<TEX>$10.3^{\circ}C$</TEX>). Gene expression patterns estimated by a quantitative RT-PCR (qRT-PCR) indicate that most genes in different functional groups increased their expressions with increase of larval instars. In the same fifth instar, as the treatment temperatures increased, the gene expression levels increased. Moreover, the newly molted fifth instar larvae were different in their gene expression rates according to their previous culturing temperatures. Most gene expressions were suppressed in the fifth instar larvae at the physiological LTT (<TEX>$15^{\circ}C$</TEX>). However, the larvae at <TEX>$15^{\circ}C$</TEX> gradually exhibited significant increase in the gene expression rates with rearing time just like those at the higher temperature. These results suggest that S. exigua at LTT exhibits a typical gene expression pattern with maintaining significantly suppressed levels.

A temperature-based phenology model for predicting development, survival and population growth potential of the mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae)

The temperature-dependent population growth potential of Phenacoccus solenopsis Tinsley, a highly polyphagous and invasive mealybug species, was studied on sprouted potatoes under laboratory conditions at six constant temperatures (15–40 °C). Several non-linear equations were fitted to the obtained data to model temperature-dependent population growth and species life history. The established equations for each life age/stage of the species were compiled to obtain an overall temperature-dependent phenology model. The life table parameters of P. solenopsis were estimated using stochastic simulation centred on a rate summation and cohort up-dating approach. The theoretical lower development threshold temperatures estimated using linear regressions applied to mean development rates were 11.2, 8.9, 9.8 and 12.7 °C, and the thermal constants for development were 93.7, 129.8, 97.1 and 100.0 degree days (DD) for nymph 1, nymph 2, nymph 3 and male pupa stages, respectively. The developed phenology model predicted temperatures between 25 and 35 °C as the favourable range for P. solenopsis development, survival and reproduction. P. solenopsis population attained a maximum net reproductive rate (107–108 females/female/generation) and total fecundity (216.6–226.5 individuals/female/generation) at temperatures between 25 and 30 °C. Mean length of generations decreased from 75.6 days at 15 °C to 21 days at 40 °C. The maximum finite rate of increase (1.12–1.16 females/female/day) and shortest doubling time (4.3–6.1 days) were also observed at temperatures between 25 and 35 °C. The simulation of phenology model at fluctuating temperatures indicated that P. solenopsis populations might potentially increase with a finite rate of 1.06 females/female/day with an average generation time of 58.7 days and a doubling time of 12.1 days. The obtained life table parameters were reasonably similar when compared with literature data. The present model can be simulated spatially for estimating the pest risk and undertaking agro-ecoregion specific pest management strategies.

Development characteristics of the box‐tree moth Cydalima perspectalis and its potential distribution in Europe

AbstractThe box‐tree moth Cydalima perspectalis (Walker) is an invasive pest causing severe damage to box trees (Buxus spp.). It is native to Japan, Korea and China, but established populations have been recorded in a number of locations across Europe since 2007 and the spread of the insect continues. The developmental investigations suggest that larvae overwinter mainly in their 3rd instar in Europe and that diapause is induced by a day length of about 13.5 h. One and a half to 2 months in the cold are necessary to terminate diapause. Threshold temperatures for development and number of degree‐days to complete a generation are slightly different from those calculated in previous studies in Japan. A bioclimatic (CLIMEX®) model for C. perspectalis in Europe was developed, based on climate, ecological and developmental parameters from the literature and new field and laboratory studies on diapause termination, thermal requirements and phenology. The model was then validated with actual distribution records and phenology data. The current distribution and life history of C. perspectalis in Europe were consistent with the predicted distribution. The climate model suggests that C. perspectalis is likely to continue its spread across Europe, except for Northern Fenno‐Scandinavia, Northern Scotland and high mountain regions. The northern distribution of C. perspectalis is expected to be limited by a number of degree‐days above the temperature threshold insufficient to complete a generation, whereas its southern range is limited by the absence of a cold period necessary to resume diapause. The model predicts relatively high Ecoclimatic Indices throughout most of Europe, suggesting that the insect has the potential of becoming a pest in most of its predicted range. However, damage is likely to be higher in Southern and Central Europe where the moth is able to complete at least two generations per year.

An empirical predictive model for the flight period of Platypus koryoensis (Coleoptera: Platypodinae)

Between 2007 and 2009, field studies were conducted in four Quercus mongolica Fischer ex Ledebour forests in Korea to develop an empirical degree-day model for the flight period of the ambrosia beetle, Platypus koryoensis (Murayama). The lower developmental threshold temperature was estimated using an iterative method based on field trap catches and temperatures. The pooled proportion of the total number of beetles found in the traps at the end of the experiment was plotted against the accumulated degree-days at selected baseline temperatures, and these plots were fitted by the Weibull function. The baseline temperature with the highest coefficient of determination was considered the lower developmental threshold temperature, and this was estimated to be 5.8 °C. The explanatory power of the model was 89 %. Moreover, the model accurately predicted the time distributions of P. koryoensis flights in 2011 and 2012 at one of the sites. The estimated median flight dates in 2011 and 2012 were 4 days earlier and 5 days later than the corresponding observed flight dates, respectively. The estimated median date of flight advanced progressively during 1970–2010 by a total of 9 days due to an increase in annual mean temperature.

The effects of temperature on the development of the moth Athetis lepigone, and a prediction of field occurrence.

Athetis lepigone (Möschler) (Lepidoptera: Noctuidae) is an important insect pest of corn crops in China. To determine the effect of temperature on A. lepigone growth, and to provide a forecasting model for this pest, the development and fecundity of A. lepigone under five different temperatures (18, 21, 24, 27, 30° C) was investigated, and an experimental population life table was constructed based on the obtained results. The results showed that the duration of development of A. lepigone decreased as the temperature increased from 18 to 30° C. Approximately 95% of mature larvae stopped pupating at 18° C, and about 70% of mature larvae stopped pupating at 21° C. When the growth chamber temperature was above 24° C, no growth arrest was observed. The results indicated that the optimum growth temperature of A. lepigone was about 26.47° C. In this study, the highest survival rate, fecundity per female, and population index trend were observed when the temperature was set at 27° C. The percentages of larvae that could spin cocoons after the 5th or 6th instar differed at the different temperatures. The developmental threshold temperatures for A. lepigone eggs, larvae, pre-pupae, pupae, preoviposition females, and the whole generation (i.e., egg to oviposition) were 11.03, 9.04, 15.08, 11.79, 11.63, and 10.84° C, respectively, and their effective accumulative temperatures were 63.51, 339.42, 30.04, 118.41, 35.06 and 574.08 degree-days, respectively. Based on the effective accumulative temperature law, this pest insect can have four generations in most of the Huang-Huai region of China, and two to three generations annually in some cold regions. Athetis lepigone may have four generations in the mid-southern part of Hebei Province. This prediction matches the field survey results.

Threshold temperature and heat unit requirements for the development of the granary weevil, Sitophilus granarius (L.)

The objective of the present investigation was to determine the effects of temperature on the granary weevil, Sitophilus granarius L., in the laboratory so that forecasting models based on heat accumulation units could be developed for the pest. Development of S. granarius reared on wheat grains was studied at three constant temperatures (15, 20 and 25 °C) and relative humidity of 70 ± 5%. The developmental time was significantly decreased with the increase in temperature. The developmental threshold temperatures estimated for egg, larva, pupa and from egg to adult were 7.79, 7.31, 14.08 and 9.97 °C, respectively. Based on these thresholds, the developmental stages, respectively, needed 92.75, 393.78, 45.04 and 562.36 day degrees to complete their development. Also, about nine generations were calculated for the pest per year under Assiut prevailing conditions. It seems that temperature of 25 °C is the most favourable developmental temperature.

Adult behavior of an ambrosia gall midge Illiciomyia yukawai (Diptera: Cecidomyiidae) and synchronization between its emergence and host plant phenology

AbstractThe adult behavior of an ambrosia gall midge Illiciomyia yukawai (Diptera: Cecidomyiidae) that induces leaf galls on Illicium anisatum (Illiciaceae) was studied at the population level from 1977 to 1995 in Kagoshima, Japan. Most males emerged between 0:00 and 08:00 h and females between 05:00 and 11:00 h. Males swarmed around the host trees between 05:00 and 11:00 h. Mating occurred on the host leaves mainly between 06:00 and 08:00 h. Females then left the host trees for somewhere else, possibly to collect symbiont fungal conidia. From 08:00 to 16:00 h, females were observed ovipositing into the host shoots. The low development threshold temperature for overwintered larvae was 14°C, while the thermal constant for emergence differed with individuals. Thermal totals above 14°C up to the 50% emergence date varied yearly from 33.1 to 68.7 degree‐days. The 50% emergence date varied from 9 to 18 May. The thermal totals significantly correlated with the 50% emergence date but did not correlate with the date when 50% of shoots became suitable for oviposition. Thus, the host‐plant responded to thermal effects differently from the gall midge. Illiciomyia yukawai has been synchronizing well with the host‐plant phenology but will suffer from asynchrony when global warming becomes more conspicuous.

흰띠명나방의 온도발육 모형

The Hawaiian beet webworm (Spoladea recurvalis) is one of the serious insect pests found on red beet (Beta vulgaris var. conditiva) in Korea. The study was conducted to investigate the development period of S. recurvalis at various constant temperatures, 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 32.5 and , with RH and a photoperiod of 16L:8D. The developmental period from egg to pre-adult was 51.0 days at and 14.6 days at . The developmental period of S. recurvalis was decreased with increasing temperature. The relationship between the developmental rate and temperature was fitted well by linear regression analysis (). The lower developmental threshold and effective accumulative temperature of the total immature stage were and 384.7 degree days, respectively. The nonlinear relationship between the temperature and developmental rate was well described by the Lactin model. The relationship between the cumulative frequency and normalized distributions of the developmental period for each life stage were fitted to the Weibull function with $R^2

Diapause development in early and late emerging phenotypes ofDelia floralis

The turnip fly, Delia floralis Fallén (Diptera: Anthomyiidae) is an important insect pest of brassica vegetable crops in the holarctic region. Different populations have strongly varying temperature requirements for fly emergence, a challenge for accurate prediction of activity. This study focused on diapause development in one early and one late emerging phenotype. The physiological state after various treatments was deduced from emergence data. Our results showed a slow diapause progression at chilling conditions for both populations and diapause ended about 7 months after pupae were formed for the early population. For the late population held at 4°C diapause did not end, no matter how long the duration of chilling. These pupae required a period with elevated temperatures above 6°C to continue development. At constant non-chilling conditions (18°C) from the time pupae were formed both populations completed diapause most rapidly. These results indicate that chilling delayed, rather than accelerated development and was not a prerequisite for diapause development. For post-diapause, results indicated a linear relationship between rate of development and temperature within the range of 6-18°C and a theoretical base temperature for development of about 2°C for both populations. In conclusion, D. floralis pupae are in diapause throughout a long winter period, and delayed emergence of the late population appears to be caused by prolonged diapause regulated by a developmental temperature threshold. The study has added information on the biology of turnip fly populations, a prerequisite for improved pest control.

Oviposition and larval development of a stem borer, Eoreuma loftini, on rice and non‐crop grass hosts

AbstractA greenhouse study compared oviposition preference and larval development duration of a stem borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), on rice, Oryza sativa L. cv Cocodrie (Poaceae), and four primary non‐crop hosts of Texas Gulf Coast rice agroecosystems. Rice and two perennials, johnsongrass, Sorghum halepense (L.) Pers., and vaseygrass, Paspalum urvillei Steud. (both Poaceae), were assessed at three phenological stages. Two spring annuals, brome, Bromus spec., and ryegrass, Lolium spec. (both Poaceae), were assessed at two phenological stages. Phenological stages represented the diversity of plant development stages E. loftini may encounter. Plant fresh biomass, dry biomass, and sum of tiller heights were used as measures of plant availability. Accounting for plant availability, rice was preferred over non‐crop hosts, and intermediate and older plants were preferred over young plants. Johnsongrass and vaseygrass were 32–60% as preferred as rice when considering the most preferred phenological stages of each host. Brome and ryegrass received few or no eggs, respectively. Eoreuma loftini larval development (in degree days above developmental threshold temperatures) was fastest on rice and slowest on johnsongrass and vaseygrass. Development duration was only retarded by plant stage on young rice plants. Foliar and stem free amino acid concentrations were determined to help provide insights on the mechanisms of E. loftini oviposition preference and developmental performance.

Effects of Temperature on the Development of Chinese Windmill Butterfly, Atrophaneura alcinous (Lepidoptera: Papilionidae)

The Chinese windmill butterfly, Atrophaneura alcinous, is an important butterfly for exhibition in butterfly garden. The objective of this study was to determine the effect of temperature on A. alcinous in the laboratory. Development of A. alcinous reared on leaves of Aristolochia contorta was investigated at five constant the laboratory condition (20, 22.5, 25, 27.5 and <TEX>$30^{\circ}C$</TEX>) and at relative humidity of 60% with a photoperiod of 14:10 (L:D). Temperatures have been suggested as an important determinant of developmental rate, lifespan and mortality in invertebrates. As the temperature increased, the length of the developmental period gradually decreased. The developmental time (pupation) from egg hatching to pupation was respectively 25.8, 23.6, 19.6, 15.5, and 12.9 days at the temperatures of 20, 22.5, 25, 27.5 and <TEX>$30^{\circ}C$</TEX>. And pupation was respectively 40.0, 30.0, 63.4, 50.0, 23.3% at the temperatures of 20, 22.5, 25, 27.5 and <TEX>$30^{\circ}C$</TEX>. The developmental threshold temperature estimated for egg-to-pupae was 10.8, with a thermal constant of 230.4 degree-days. Therefore, the optimal developmental temperature for A. alninous was determined to be <TEX>$25^{\circ}C$</TEX>. To compare the effects of the total duration of chilling on the termination of diapause, larvae were subjected to a temperature of <TEX>$8^{\circ}C$</TEX> from 60 to 120 days. The rate of termination of diapause was significantly higher at 60 days compared to other incubation period.