Effect of neem on the growth and development of the obliquebanded leafroller, Choristoneura rosaceana

Neem, Azadirachta indica A. Juss. (Meliaceae), seed oil (NSO) added to meridic diet at concentrations as low as 0.016% reduced pupation and prevented adult eclosion of obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). At a rate of 0.0016%, NSO reduced the fitness of C. rosaceana, resulting in longer developmental times, lower adult eclosion rates, and reduced egg production compared with controls. The neem insecticide Margosan-O ^TM produced comparable results based on concentrations of the most biologically active constituent, azadirachtin. Pupation was completely inhibited at concentrations of 0.25% and 1.0% for larvae exposed at 5th or 6th instar, respectively; rates as low as 0.016% reduced pupal weights and adult eclosion rates. For larvae transferred to treated diet at 5th instar, physical abnormalities in the wings of adults occurred at a rate of 0.004% NSO and increased with increasing treatment rates. NSO at concentrations as high as 2.0% was not antifeedant to neonate larvae, based on 24 and 48 h choice test bioassays, when incorporated into a meridic diet.     

Toxicity of insecticides to obliquebanded leafroller, Choristoneura rosaceana, larvae and adults exposed previously to neem seed oil

Adult and sixth instar obliquebanded leafroller, Choristoneura rosaceana (Harris), exposed previously as fifth instar larvae to sub-lethal concentrations of neem, Azadirachta indica A. Juss., seed oil contained in artificial diet were more susceptible to topically applied pyrethroid, carbamate and organophosphate insecticides than C. rosaceana reared on control diets. Increased susceptibility to insecticides did not result from reduced vigour, as measured by reductions in adult or larval weights, but is instead correlated with previously demonstrated reductions in detoxication enzyme activities. The modest increases in susceptibilities, not exceeding ca. 4.5-fold, for C. rosaceana exposed to neem were achieved with subjects from a susceptible laboratory colony; a larger response could be expected for resistant field populations having elevated detoxication enzyme levels. Neem-based insecticides could be useful tools for the management of orchard pests that have developed resistance to synthetic neurotoxins. These findings also contribute to a better understanding of the numerous physiological changes that occur in larval Lepidoptera following exposure to neem extracts.     

Investigations of Mechanisms of Pheromone Communication Disruption of Choristoneura rosaceana (Harris) in a Wind Tunnel

Although atmospheric treatment with synthetic pheromone is used commercially to control several lepidopteran pests, little is known about how mate-finding behavior is altered by this procedure. Mechanisms of disruption of the mate-finding behavior of Choristoneura rosaceana (Lepidoptera: Tortricidae) were examined in wind tunnel bioassays. Male moths were exposed to synthetic sex pheromone or pheromone components prior to or during upwind flight to a calling virgin female. The proportion of males successfully contacting a calling female was reduced only when the synthetic pheromone treatment was presented simultaneously. A synthetic source of the attractive four-component pheromone placed upwind of a calling female was more effective than a less attractive two-component blend in achieving disorientation. Habituation of the central nervous system does not appear to be a significant factor in disruption of mate-finding behavior of male C. rosaceana, as exposure to pheromone prior to the bioassay did not alter the proportion of males that achieved subsequent upwind flight. Disruption of mate-finding behavior of C. rosaceana in a wind tunnel is probably the result of a combination of mechanisms including adaptation of antennal receptors, camouflage of the female-produced plume, and false-trail following which contributed to the additive disruption effect observed with the most attractive four-component pheromone.     

Effects of different male remating intervals on the reproductive success of Choristoneura rosaceana males and females

The mass of the spermatophore transferred by a previously mated Choristoneura rosaceana male increases with time elapsed since the last mating but, even after 4 days, it never reaches the mass of the spermatophore of a virgin male. However, spermatophore mass is clearly not a good indicator of the male reproductive investment as the quantity of sperm in the second ejaculate of a previously mated male is the same as that of his first, if he is allowed a 2 (eupyrene sperm) to 3 day (apyrene sperm) recovery period. The interval between the first two matings had no influence on female fecundity or longevity but significantly affected fertility if the male had only 1 day to recover. The length of the post-copulatory refractory period was also shorter in females mated with previously mated males than in those mated with virgins, regardless of the male's remating interval. Furthermore, a significant variation in the eupyrene sperm content of the spermatophore transferred by virgin males had no influence on the length of the female refractory period. Globally, these results support the hypothesis that a factor, other than sperm numbers in the spermatheca, is responsible for maintaining the inhibition of pheromone production in this species.     

Recognition and avoidance of previously laid egg masses by the oblique-banded leafroller (Lepidoptera: Tortricidae)

Investigations were conducted on oviposition by laboratory-reared oblique-banded leafrollers, Choristoneura rosaceana Harris. In paperbag oviposition chambers, females deposited their egg masses in a significantly nonrandom, uniform manner in 16 of 20 replicates. Inpetri dish oviposition chambers, gravid females were exposed to egg masses recently deposited by other females. As determined by the magnitude of the mean direction vector of the second egg mass in relation to the first, females detected and avoided egg masses laid by other females. In addition, they avoided waxed paper from which a recently oviposited egg mass had been removed. This phenomenon is most likely due to a pheromone laid down with each egg mass.     

Effect of male and female age on the mating success of the obliquebanded leafrollerChoristoneura rosaceana (Lepidoptera: Tortricidae) under different ecological conditions

The present study was undertaken to test the hypothesis that male and female age, as well as temperature, can affect the mating success ofChoristoneura rosaceana, given the role that these two factors play in the pheromone biology of this species. In the laboratory, the mating success of females generally declined linearly with age, whereas in males, it increased during the first 3 days and then decreased. The decline in female mating success was more pronounced under warm than cool thermocycles, while the changes observed in males were greater under fluctuating than constant temperature regimes. The onset time of mating was unaffected by male age, however, older females always mated earlier than younger ones, with the advance being more pronounced at cool than warm temperatures. Similar results were also obtained under field conditions. When a single 3-day-old male was provided with 0-, 3-, and 5-day-old females simultaneously, older females obtained mates significantly more often than younger individuals at all temperatures, indicating that calling earlier may afford a reproductive advantage to older females. At both constant temperatures, the time spent mating was longer in older than in younger females, but not under fluctuating thermocycles. Very young and very old males generally spent more time in copula than middle-aged individuals both at constant temperatures and under the warm thermocycle. Under the cool thermocycle, the duration of mating was considerably prolonged at all ages, which could increase the risk of predation.     

The influence of constant and fluctuating temperatures on development rate and survival of pupae of the Australian sheep blowfly Lucilia cuprina

Functions describing instantaneous development rates in constant and natural temperature regimes were obtained for pupae of the Australian sheep blowfly, Lucilia cuprina (Wiedemann). These were derived using a technique that directly calculates rate functions from development-time observations made under any temperature regime. The functions indicated similar instantaneous development rates for constant and natural temperatures up to 30°C. At 30° the constant-temperature function reached a plateau which was maintained to the constant-temperature thermal limit. The natural-temperature function, however, continued its ascending phase to 34°, and then fell sharply to zero at 42°.The median survival temperatures of pupae for single 7-h exposures, daily 7-h exposures, and continuous exposures to high temperatures were 44.7, 39.2, and 34.4°, respectively. Development was completed at constant 15° but not at 10°. Median survival times at constant 10, 5, 0 and-5° were 4.3, 4.2, 2.5 and 1.5 days. Mortality was slight for single or daily 7-h exposures to-5°, but was complete for all except brief single exposures to-10°.

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Influence des températures constantes et de la thermopériode sur le taux de développement et la survie des pupes de Lucilia cuprina

Résumé Des fonctions associant les taux de développement aux températures en conditions constantes et en thermopériodes naturelles ont été établies pour les pupes de L. cuprina. La fonction pour les conditions naturelles décrit les taux de développement immédiat-c'est-à-dire les taux de développement existant en réponse à la température pour chaque laps de temps (en réalité, pour un court intervalle), plutôt que le taux moyen pour une gamme de températures. La fonction pour les températures constantes décrit à la fois les taux de développement instantané et moyen (ceux-ci étant équivalents, en ne supposant pas de réponses spécifiques suivant l'âge en conditions constantes). Les fonctions ont été dérivées en utilisant une technique qui calcule directement les fonctions des taux à partir des observations sur les durées de développement faites dans chaque condition de température.Les fonctions ont révélé des taux de développement instantanés semblables pour les températures jusqu'à 30°C. A 30°C la fonction pour la température constante a atteint un plateau qui s'est maintenu jusqu'à la limite thermique. La fonction pour les thermopériodes naturelles a continué de s'élever jusqu'a 34°C, et alors a chuté brutalement jusqu'à zéro à 42°C. Dans la région d'où les lots de pupes ont été obtenus les températures subies par les pupes dans les zones non ombragées dépassent fréquemment 50°C pendant l'été. Les taux de développement des pupes aux températures au dessus de 30°C, où les fonctions avec températures constantes et thermopériodes deviennent différentes, sont cependant cohérent avec les expériences dans la nature avec L. cuprina. Les températures médianes de survie des pupes pour une exposition unique de 7 h, pour des expositions quotidiennes de 7 h et pour une exposition constante à haute température étaient respectivement de 44,7; 39, 2 et 34,4°C. Par comparaison avec des températures estivales du sol de 50°C et plus, il semble vraisemblable que la mortalité nymphale est un facteur important de déclin des populations de L. cuprina au milieu de l'été.

     

Changes in calling behaviour and mating success in the European corn borer (Ostrinia nubilalis), caused by relative humidity

We examined the calling behaviour of O. nubilalis virgin females, held at three different constant conditions of relative humidity from the time of emergence through their sixth night of calling, as well as the incidence of mating over time at low or high relative humidity conditions. The mean age at which females initiated calling in their life was independent of relative humidity conditions, although more variable at low humidity. On successive nights of calling, fewer virgin European corn borer females called under low compared with high humidity conditions, and those that did began later in scotophase, had fewer calling bouts, and spent less time calling. These changes in the female prereproductive behaviour were reflected on the incidence of mating which, in the first two days following emergence, was significantly less at low than at high humidity conditions. The ecological significance of these results is discussed in relation with the susceptibility of O. nubilalis to desiccation.

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Résumé Nous avons étudié le comportement d'appel des femelles vierges d'Ostrinia nubilalis maintenues sous trois conditions constantes d'humidité relative, depuis l'émergence jusqu'à la sixième nuit d'appel, ainsi que l'incidence d'accouplement d'individus placés en milieu sec ou humide pour diverses périodes de temps. Les conditions d'humidité n'ont pas significativement affecté l'âge moyen auquel les femelles ont commencé à appeler au cours de leur vie, bien qu'il ait été plus variable à 53% h.r. Les nuits subséquentes, le comportement d'appel des femelles maintenues à basse humidité a débuté plus tard dans la nuit, s'est exprimé pour une période de temps plus courte avec moins de séquences d'appel que celui de leurs congénères placés en milieu humide, et la proportion de femelles en appel a toujours été plus faible à 53% h.r. Ces changements du comportement préreproducteur des femelles se sont répercutés sur l'incidence d'accouplement qui, les deux premiers jours suivant lémergence, a été significativement plus faible à basse humidité qu'elle ne l'a été en milieu humide. Ces résultats seront discutés en relation avec l'écologie de O. nubilalis et associés à sa susceptibilité à la dessication.

     

Orientation of males of sorghum midge,Contarinia sorghicola to sex pheromones from virgin females in the field

The orientation of males of the sorghum midge,Contarinia sorghicola Coq. (Diptera: Cecidomyiidae) towards virgin female baited sticky traps was studied in the field. Male response increased linearly with an increase in the number of virgin females in the sticky traps. Five females per vial were optimum for monitoring midge populations in the field. Numbers of males trapped were significantly greater in traps placed at 0.5 and 1.5 m above ground level compared with those placed at 2.5 m. Peak trap catches occurred at 0900 h. The number of males trapped decreased significantly after 1400 h; male catches continued till sunset. Trap catches followed the same pattern as the number of ovipositing females on sorghum panicles at the half-anthesis stage. Midge activity decreased with an increase in temperature and a decrease in relative humidity. Peak midge density was observed during the second fortnight of October in the rainy season and during February-March in the post-rainy season. Sex pheromones can be used to monitor midge population dynamics for integrated pest management and to screen for host plant resistance to this insect.     

Thermal constraints to successful development of the Queensland fruit fly in regimes of constant and fluctuating temperature

Temperature can affect the survival rate through each immature stage of life history and hence the rate of survival from egg to adult emergence. This phenomenon was investigated experimentally by using both regimes of constant temperature and ones in which temperatures fluctuated on a daily basis with rates of heating and cooling approximating to those found in the field. In fluctuating regimes, the highest temperatures tolerated for a few hours on a daily basis were higher than those tolerable on a constant basis. The highest tolerable daily maximum was influenced to some extent by the daily minimum. Regimes near the tolerable threshold that were experienced during one stage of the life history adversely affected the survival rate during the next stage, even if the latter experienced optimal conditions. The results in dicate that, in nature, survival from egg to adult is unlikely if daily maxima prevail in the region of 38–40°C for more than 7 days.

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Affectien de température sur le développement couronné de succès chez Dacus tryoni dans des régimes à des températures constantes et fluctuantes

Résumé La température peut affecter le taux de survie, pour chaque stade d'immaturité, dans l'histoire d'une vie et d'où le taux de survie de l'oeuf à son apparition adulte. Ce phénomène a été étudié à titre expérimental en utilisant les deux régimes à une température constante et l'un d'eux à des températures variées sur une base journalière avec un taux approximatif de chauffage et refroidissement comme ceux que l'on trouve dans ce domaine.Dans un régime de fluctuation, les températures les plus élevées pendant quelques heures sur une base journalière étaient plus fortes que celles tolérées sur une base constante.La maximum journalier de la température la plus élevée supportable était influencé, jusqu'à un certain point, par le minimum journalier.Les régimes qui ont fait l'expérience proche du seuil du supportable au cours d'un stade, dan l'histoire d'une vie, on affecté défavorablement le taux de survie du stade suivant, même si ce dernier a expérimenté les conditions optimal.Les résultats indiquent que, dans la nature, la survie d'oeuf à adulte est improbable si le maxima journalier de 38–40°C prédomine dans la région pendant plus de 7 jours.

     

Incubation period, spore egestion and horizontal transmission of Nosema fumiferanae (Microsporidia: Nosematidae) in spruce budworm (Choristoneura sp., Lepidoptera: Tortricidae): the role of temperature and dose

Various instars of Choristoneura occidentalis were fed with a range of doses of Nosema fumiferanae and reared at 20, 24 and 28 degrees C to determine the influence of temperature and dose on the time to spore egestion and the number of spores egested in the frass. When larvae were fed in the third stadium, as few as 10(2) spores per larva initiated infection, and both onset of spore egestion and the number of spores egested were affected by a complex relationship between temperature and inoculation dose. Onset of spore egestion varied from 11 to 15 days postinoculation. At 20 degrees C, the onset was delayed and spore production decreased with increasing inoculation dose whereas at higher temperatures spores were first egested at the lowest dose and spore production increased with dose. When larvae were fed spores in the fifth and sixth stadium, no spores were egested because pupation occurred before completion of the incubation period. To assess the effect of temperature on horizontal transmission, Choristoneura fumiferana larvae fed with 10(4) N. fumiferanae spores per larva were reared with uninfected larvae at 15, 20 and 25 degrees C. At 15 degrees C, we observed the highest degree of horizontal transmission, defined by the largest change in N. fumiferanae prevalence, even though the density of spores available for horizontal transmission was the lowest. Infected adults eclosed later than uninfected adults and the time to eclosion was also dependent on sex and temperature. We relate our experimental findings to consequences for horizontal and vertical transmission of N. fumiferanae in spruce budworm populations.     

Age and Sex-Based Differences in the Use of Prey Sensory Cues in Wolf Spiders (Araneae: Lycosidae)

Differences in foraging patterns mediated by sensory cues were examined between adult and juvenile male and female wolf spiders (Schizocosa rovneri; Lycosidae). Patch residence time for thirty-one spiders were tested among juveniles and adults in artificial foraging patches. Patches varied in sensory information provided by live prey (crickets) as follows: visual stimuli alone; vibratory stimuli alone; visual and vibratory stimuli together; and control (no stimuli). Spiders moved between patches for one hour, but could not feed. Adult Schizocosa rovneri use primarily visual information to determine patch residence time, but juveniles use vibratory cues as well. Significant age and sex-based differences in the use of sensory cues suggest that observed divergent foraging strategies are partly due to the use of different perceptual cues in prey detection.     

Host instar, body size and fitness in the koinobiotic parasitoid Aphidius nigripes

In aphidiine parasitoids, resources for growth and adult body size increase with host instar used by ovipositing females, but the fitness consequences of body size on fitness are poorly documented. We compared the fitness of male and female A. nigripesadults that varied in size as a consequence of developing in different instars of their host Macrosiphum euphorbiae. When reproductive fitness was measured without considering time, female wasps from small and large hosts performed similarly, contributing 125–175 foundresses plus 100–180 sons to the next generation. However, when expressed as the innate capacity for increase (r _m), female fitness correlated with host-induced variation of wasp size, indicating that micropopulations initiated by large wasps would increase faster. In a wind-tunnel, a sex pheromone plume from large female wasps induced more males to fly upwind when released at a distance of 50 cm downwind than small females, indicating that large females were sexually more attractive. With respect to male body size effects on fitness, large individuals performed similar to small ones, whether fitness was measured by lifetime mating frequency, fertile inseminations, or proportion of daughters among progeny born from their mates. When young naive males of unequal size were directly competing for mating with a virgin female, small and large males had equal mating success, and large individuals were no more successful than small ones at displacing a competitor already positioned on a receptive female. In a wind-tunnel test where males were scored on their ability to reach a female pheromone source, small and large males were equally affected by wind speed but reached the source located 50 cm downwind in equal proportions, suggesting similar capacity for finding mates by flying upwind. Our results indicate that despite host resources not being fixed at the time of attack for the koinobiont A. nigripes, fitness consequences of resource limitation by the mother may be perceived to be greater for daughters than sons, which would explain male-biased sex ratio in early-instar hosts.     

Growth,growth efficiency,and assimilation efficiency of the Tahoe sucker in cyclic and constant temperature

Synopsis Tahoe sucker, Catostomus tahoensis, were fed at three ration levels (starvation, 50% of repletion, and repletion) at three constant and cyclic temperature regimes (4–12°, 8°, 8–18°, 13°, and 13°–23°, 18° C) to examine growth rate and gross growth efficiencies. Growth rates increased with increasing temperature and ration level. Growth rates were not different between cyclic temperatures and the constant temperature equivalent to the mean of the cycle. Growth efficiencies were similar for cyclic and constant temperature regimes. Maintenance rations increased from 0.9% of the initial wet weight per day at low temperatures to 2.0 and 1.7% at intermediate and high temperatures, respectively. Assimilation efficiencies (not measured at low temperatures) did not differ between constant and cyclic temperatures. Tahoe sucker growth rates and assimilation efficiencies may not be enhanced in small streams because of this species' inability to mediate temperature cycles through behavioral thermoregulation.     

Age and growth of the ajime-loach,niwaella delicata, in the yura river, kyoto, japan

The age of the Ajime-loach,Niwaella delicata (a species endemic to Japan), was determined from the number of concentric rings appearing on the cross-sectional surface of the erectile spine (peculiar to Cobitidae). The ages of loaches caught in the Yura River, Kyoto, were determined and growth rates for each sex estimated. It was found that size dimorphism in this species was due to different growth patterns between the sexes, 2.5 years old males being larger than females and usually sexually mature, unlike the latter. Females older than 3.5 years were sexually mature and larger than males of equivalent age.     

Lysozyme gene expression and hemocyte behaviour in the Mediterranean mussel, Mytilus galloprovincialis, after injection of various bacteria or temperature stresses

The aim of the present study was to evaluate the expression of the Mytilus galloprovincialis lysozyme gene in different in vivo stress situations, including injection of bacteria Vibrio splendidus LGP32, Vibrio anguillarum or Micrococcus lysodeikticus, as well as heat shock at 30 degrees C and cold stress at 5 degrees C. Injection of V. splendidus LGP32 resulted in: (i) a general down-regulation of lysozyme gene expression, as quantified by Q-PCR; (ii) reduction in the number of circulating hemocytes; (iii) decrease in the percentage of circulating hemocytes expressing lysozyme mRNA which was now restricted to only small cells, as observed by ISH; and (iv) accumulation of hemocytes expressing lysozyme in the muscle sinus where injection took place. Injection of V. anguillarum or M. lysodeikticus induced significant up-regulation of lysozyme gene expression, but only 2-3days post-injection, with no change in the total hemocyte counts but an increased percentage of hemocytes expressing lysozyme mRNA. Neither the control injection of PBS-NaCl nor temperature stress modified the lysozyme expression pattern. Consequently, the hemocyte population appears to be capable of discriminating between stress factors, and even between 2 Vibrio species.     

Growth of various ecotypes ofLemna paucicostata in Japan under various temperature conditions,and their wintering forms

Lemna paucicostata in Japan is classified into 4 types, N-1, N-2, K and S types. S type strains which are distributed in southern Japan grew more rapidly than other strains at the temperatures of both 27 and 17C. With the extension of the culture period at 17 C to which the plants had been transferred from 25C, the growth rate increased greatly in S type strains, while it decreased in N-1 type strains which are distributed widely from Hokkaido to Kyushu, and particularly in those distributed in the northern area. S type strains survived winter mostly in the form of normal fronds under natural conditions at Kyoto (minimum temperature is lower than OC), while most of the fronds of N-1 type strains died after producing seed before winter. Thus S type strains are considered to have adapted to the climate of southern Japan so as to survive winter in the form of fronds, while N-1 type strains overwinter in the form of seed. N-2 type strains which are distributed in the northern part of the area adjacent to the Japan Sea produced turion-like fronds during winter under natural conditions, while none of the other strains did. The K type strain which was found only at the campus of Kyoto University overwintered only in the form of fronds which produce no seed.     

Pheromone-like substances affecting host-related behaviour of larvae and adults in the dry bean weevil, Acanthoscelides obtectus

Males and females of the dry bean weevil, Acanthoscelides obtectus deposit chemically unknown substance(s) on beans during various activities (most probably during defecation), under laboratory conditions. The marking results in avoidance of these beans by other females for oviposition. Also, first-instar larvae are influenced to disperse more by the deposited substance(s), so that they are more likely to find unmarked beans to enter. No specific marking behaviour by adults was noted. That the deterring substance(s) might originate from microorganismic activity after deposition has occurred, is improbable. Possible explanations for sources of marking substance(s) and the significance of the corresponding behaviour in this species are discussed.

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Résumé Les mâles et les femelles d'A. obtectus déposent des substance(s) encore non-identifiées sur les grains du haricot au cours de leurs diverses activités. Ce comportement de marquage fait que les autres femelles hésitent à pondre des ufs sur ces grains. De plus, les substance(s) déposée(s) poussent les larves du 1^er stade à se disperser plus vigoureusement, par conséquent, elles sont enclines positivement à entrer dans les grains sans marque. On n'a observé aucun comportement marqueur spécifique chez les adultes. La possibilité d'une origine microbiologique des substance(s) répulsive(s) a été eliminée. Les origines possibles des substance(s) de marquage et la signification de ce comportement sont discutés.

     

Seasonal and daily rhythms of body temperature in the European hamster (Cricetus cricetus) under semi-natural conditions

Body temperature of five European hamsters exposed to semi-natural environmental conditions at 47° N in Southern Germany was recorded over a 1.5-year period using intraperitoneal temperature-sensitive radio transmitters. The animals showed pronounced seasonal changes in body weight and reproductive status. Euthermic body temperature changed significantly throughout the year reaching its maximum of 37.9±0.2°C in April and its minimum of 36.1±0.4°C in December. Between November and March the hamsters showed regular bouts of hibernation and a few bouts of shallow torpor. During hibernation body temperature correlated with ambient temperature. Monthly means of body temperature during hibernation were highest in November (7.9±0.8°C) and March (8.2±0.5°C) and lowest in January (4.4±0.7°C). Using periodogram analysis methods, a clear diurnal rhythm of euthermic body temperature could be detected between March and August, whereas no such rhythm could be found during fall and winter. During hibernation bouts, no circadian rhythmicity was evident for body temperature apart from body temperature following ambient temperature with a time lag of 3–5 h. On average, hibernation bouts lasted 104.2±23.8 h with body temperature falling to 6.0±1.7°C. When entering hibernation the animals cooled at a rate of -0.8±0.2°C·h^-1; when arousing from hibernation they warmed at a rate of 9.9±2.4°C·h^-1. Warming rates were significantly lower in November and December than in January and February, and correlated with ambient temperature (r=-0.46, P<0.01) and hibernating body temperature (r=-0.47, P<0.01). Entry into hibrnation occured mostly in the middle of the night (mean time of day 0148 hours ±3.4 h), while spontaneous arousals were widely scattered across day and night. For all animals regression analysis revealed free-running circadian rhythms for the timing of arousal. These results suggest that entry into hibernation is either induced by environmental effects or by a circadian clock with a period of 24 h, whereas arousal from hibernation is controlled by an endogenous rhythm with a period different from 24 h.Abbreviations bw body weight - CET central European time - T _a ambient temperature - T _b body temperature - TTL transistor-transistor logic     

Functional and spectral characterization of the respiratory chain of Chloroflexus aurantiacus grown in the dark under oxygen-saturated conditions

In this paper we attempt a functional and spectral characterization of the membrane-bound cytochromes involved in respiratory electron transport by membranes from cells of Chloroflexus aurantiacus grown in the dark under oxygen saturated conditions. We conclude that the NADH-dependent respiration is carried out by a branched respiratory chain leading to two oxidases which differ in sensitivity to CN^- and CO. The two routes also show a different sensitivity to the ubiquinone analogue, HQNO, the pathway through the cytochrome c oxidase being fully blocked by 5 M HQNO, whereas the alternative one is insensitive to this inhibitor. The cytochrome c oxidase containing branch is composed by at least two c-type haems with E _m 7.0 of +130 and +270 mV ( bands at 550/553 nm and 549 nm, respectively), plus a b-type cytochrome with E _m 7.0 of +50 mV ( band at 561 nm). From this, and previous work, we conclude that respiratory and photosynthetic electron transport components are assembled together and function on a single undifferentiated plasma membrane.Abbreviations HQNO heptylhydroxy-quinoline-N-oxide - UHDBT undecyl-hydroxydioxobenthiazole - Q/b-c ubiquinol/cytochrome c oxidoreductase complex - BChl bacteriochlorophyll