Autumnal moth – why autumnal?

1. As for some other spring‐feeding moths, adult flight of Epirrita autumnata (Lepidoptera: Geometridae) occurs in late autumn. Late‐season flight is a result of a prolonged pupal period. Potential evolutionary explanations for this phenological pattern are evaluated. 2. In a laboratory rearing, there was a weak correlation between pupation date and the time of adult emergence. A substantial genetic difference in pupal period was found between two geographic populations. Adaptive evolution of eclosion time can thus be expected. 3. Metabolic costs of a prolonged pupal period were found to be moderate but still of some ecological significance. Pupal mortality is likely to form the main cost of the prolonged pupal period. 4. Mortality rates of adults, exposed in the field, showed a declining temporal trend from late summer to normal eclosion time in autumn. Lower predation pressure on adults may constitute the decisive selective advantage of late‐season flight. It is suggested that ants, not birds, were the main predators responsible for the temporal trend. 5. Egg mortality was estimated to be low; it is thus unlikely that the late adult period is selected for to reduce the time during which eggs are exposed to predators. 6. In a laboratory experiment, oviposition success was maximal at the time of actual flight peak of E. autumnata, however penalties resulting from sub‐optimal timing of oviposition remained limited.     

Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate

Intrinsic processes are assumed to underlie life history expression and trade‐offs, but extrinsic inputs are theorised to shift trait expression and mask trade‐offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass‐specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade‐off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade‐offs across species.     

Phase-Shifts of Apparent Orcadian Rhythms Due to West and East Transmeridian Flights or to Corresponding Night-Shift Sleep Displacements

Phase movements of apparent circadian rhythms during 2 wk of forward or backward displacement of the sleep-wake cycle were investigated in four experimental series in a subject. The 7-hr delay or advance of sleep due to a westward or an eastward transmeridian flight was duplicated by corresponding sleep displacements during experimental night shifts. Sudden phase advances (or delays) by several hours were observed in the rhythms of continuously recorded rectal temperature and urinary excretion rates (4-hr collection intervals) of adrenaline, noradrenaline and aldosterone the first day after sleep-wake displacement. The desired 7-hr phase-shifts were reached more quickly and completely when the phase was delayed than when it was advanced. In addition, the best-fitting period of these rhythms became shorter than 24 hr when the phase was delayed, and longer than 24 hr when it was advanced. The apparent rhythms of urine flow and electrolyte excretions (potassium, sodium, zinc) were much weaker and their phase movements more irregular than those of hormonal excretion. It is concluded that the sudden phase-shifts resulted from the immediate adaptation of the exogenous components of the rhythms to the demands of the displaced sleep-wake patterns (masking effects) and that the true phase-shifts of the endogenous components followed more slowly and gradually.     

Observations on the life history of Limnodrilus hoffmeisteri (Annelida,Tubificidae) from the Little Calumet River in temperate North America

The reproductive period for L. hoffmeisteri as observed in the Little Calumet River (41°34′22″N. 87°28′30Prime;W) occurs from early fall through late spring. The period is marked by the development of the reproductive organs in the early fall months, followed by the development of sperm products within the sperm sac. The female organs appear to mature in middle to late winter with the appearance of nutritive granules followed by the developing eggs in early spring. This cycle is completed in early to late spring with the appearance of cocoons containing developing embryos. It is also apparent that a low level of reproductive activity occurs throughout the rest of the year. This is usually observed in worms with developed sperm sacs and sperm products, having matured penis and some developed egg sacs with nutritive granules. Eggs have not been observed during this low level of reproductive activity.     

A Circadian Clock of Drosophila: Effects of Deuterium Oxide and Mutations at the period Locus

Mutations at the period (per) locus (1:1.3; 3B1-2) in Drosophila melanogaster lengthen (per^L), shorten (per⁵), or abolish (per°) overt circadian rhythmi-city. Deuterium oxide lengthens the free-running circadian period. We tested the effects of deuterium on three mutants of the per gene (per⁵ per^L, and per°) and wild-type Drosophila melanogaster (per⁺) to assess interactions. With increasing concentrations of deuterium, the free-running circadian period of locomotor activity rhythms increased. The dose-response was linear in all genotypes tested. With increasing dosages ofdeuterium, circadian rhythms became weaker as evidenced by the signal-to-noise ratio (SNR). Genotype and deuterium changed circadian period length independently and additively, showing no interaction. SNRs for all genotypes converged on a low level as deuterium concentration increased. Deuterium increased life span, except at high concentrations (40 and 50%).     

The Influence of the Incubation Period on Qualitative Aspects of the Spread of AIDS

Based on a simple stochastic model the influence of the incubation period of the HIV-infection on some qualitative aspects of the spread of AIDS is studied. A critical ‘nfection rat’ is calculated in dependence on parameters of the incubation period density function.     

黑果蝇dlts品系的温度敏感时期及dlts基因多效影响的自主性研究

本文采用D.T.Suzuki的方法,研究了黑果蝇Drosophila virilis Sturt dlts品系的温度敏感时期和致死时期的相互关系.选择了31℃为限制温度,25℃为许可温度.对于成虫盘缺损的研究用了12个小时为一个脉冲或24个小时为一个脉冲的热处理,用扫描电镜技术辅助对成虫形态缺损的研究.对于成虫盘缺失和重复的关系主要在48小时为一个脉冲的热处理盘中进行,对dlts基因的表达采用了遗传嵌合性的研究,其结果如下:1. 两个不连续的温度敏感时态对致死的影响是在第1龄幼虫、第2龄幼虫、第3龄幼虫和进入蛹期后的10个小时.温度敏感时态和致死时态并不一致,而是先于致死时态几个小时.2. 温度敏感时态对成虫形态的影响是:触角的重复和复眼的缺失发生在第2龄和第3龄幼虫期.足关节融合及跗节和腿节的缩短发生在第3龄幼虫期,翅脉硬化主要发生在第3龄幼虫期即将结束进入前蛹期的这段时间.第3龄幼虫期是成虫盘发生缺陷比较集中的时期,可以明显见到足、复眼、翅和刚毛的缺陷,同源异型突变体也在这个时期发生.同源突变体的变化主要是足、触角片段及刚毛和触角片段的相互转移.3. 每一个成虫盘缺陷部有自己明显的特征,根据它们成虫盘的形态缺陷和热处理的时间性,所有的成虫盘缺陷变化都可以分为这样三类:缺失,重复,缺失和重复并存.4. 遗传镶嵌测试表明:dlts基因是自主表达的,且具有一定的时间、环境和组织的特殊性.