bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short‐term correlation properties of R–R interval dynamics at different exercise intensity levels
Authors: Hautala Arto J. , Mäkikallio Timo H. , Seppänen Tapio , Huikuri Heikki V. , Tulppo Mikko P. 
Published: December 2004

SummaryMethods based on non‐linear heart rate (HR) dynamics have been suggested to probe features in HR behaviour that are not easily detected by the traditional HR variability indices. This study tested the hypothesis that analysis of correlation properties of R–R intervals provides useful information on HR fluctuation during exercise. High‐ (HF) and low‐frequency (LF) spectral components and a short‐term scaling exponent (α1) of HR variability, were analysed for nine healthy subjects at rest, during incremental and steady‐state exercise, during atropine infusion and during incremental exercise after atropine administration. During the incremental exercise test α1 increased from rest to an intensity level of ∼40% of (from 1·07 ± 0·24 to 1·50 ± 0·25, P<0·001) and thereafter decreased linearly until the end of exercise (from 1·50 ± 0·25 to 0·38 ± 0·10, P<0·001). Atropine infusion increased the scaling exponent α1 value from 0·91 ± 0·23 to 1·37 ± 0·31 (P<0·001). During exercise after atropine infusion, a linear reduction was observed in the scaling exponent α1 from 1·37 ± 0·23 to 0·25 ± 0·08 (P<0·001). Analogous changes in α1 were seen during long‐term steady‐state exercise compared to incremental exercise. Conventional HR variability indices did not show any significant changes during exercise at high exercise intensity levels. α1 correlated with the LF/HF ratio at rest (r = 0·90, P<0·001), but the correlation was weaker after atropine (r = 0·71, P<0·05) and during exercise (e.g. r = 0·33, P = NS at the level of 40% of ). In conclusion, incremental exercise test until exhaustion results in bidirectional changes in correlation properties of R–R interval dynamics. These changes can be explained by the intensity of vagal and sympathetic input to the sinus node during the different intensity levels of exercise. Changes in α1 values can be detected also in high intensity levels, when the conventional measures of HR variability can not be applied.
Disruption of the odour‐mediated mating behaviour of Plodia interpunctella using high‐frequency sound
Authors: Svensson Glenn P. , Skals Niels , Löfstedt Christer 
Published: December 2004

Abstract Indian meal moths, Plodia interpunctella Hübner (Lepidoptera: Pyralidae), have ears which are sensitive to high‐frequency calls produced by echolocating, insectivorous bats. The influence of artificially generated, high‐intensity, ultrasound signals (25 kHz, 106 dB SPL at 1 m distance) on different parameters involved in the odour‐mediated mating behaviour of this species and its potential use in population control was investigated. All moths flying towards olfactory cues in flight tunnel experiments reacted strongly to a 1 s ultrasound pulse by cessation of flight and falling out of the odour plume. The source contact proportion of both male moths orienting towards the female‐produced sex pheromone and of mated female moths orienting towards an oviposition cue was reduced by 40%, compared to unexposed moths. Calling females responded to the sound by retraction of the ovipositor or by falling to the ground. Long‐term exposure to repetitive pulses of ultrasound suppressed female calling by up to 27%. Furthermore, mating in plastic tents was disrupted by up to 58% in ultrasound‐treated tents using different sound regimens, compared to control tents. The results are discussed in relation to the potential use of ultrasound technology for the population control of pyralid stored product pests.
Different bioassays for investigating orientation responses of the banana weevil, Cosmopolites sordidus, show additive effects of host plant volatiles and a synthetic male‐produced aggregation pheromone
Authors: Tinzaara William , Dicke Marcel , Van Huis Arnold , Van Loon Joop J. A. , Gold Clifford S. 
Published: December 2004

Abstract Three different bioassay methods to investigate the orientation behaviour of the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae), to host plant volatiles and a synthetic pheromone (cosmolure+) were compared. A locomotion compensator was used to separately record walking tracks in response to three odour sources. The data show that C. sordidus uses odour‐conditioned anemotaxis in its orientation to the odour sources tested. Of the two olfactometers tested, a dual port olfactometer using a continuous airflow showed stronger discrimination by C. sordidus to the different odours compared with a double pitfall olfactometer. The results of all three bioassays indicate that C. sordidus responds in an additive way to the combination of fermentation plant volatiles and the synthetic pheromone.
The effect of Fusarium verticillioides on oviposition behaviour and bionomics of lepidopteran and coleopteran pests attacking the stem and cobs of maize in West Africa
Authors: Ako Mouhoubè , Schulthess Fritz , Gumedzoe Mawuena Y. D. , Cardwell Kitty F. 
Published: December 2004

Abstract The effect of Fusarium verticillioides Sacc. (Nirenberg) in maize stem and grain on the oviposition behaviour and bionomics of lepidopteran and coleopteran pests in West Africa was studied in olfactometer, greenhouse, and field trials in Benin. In a choice experiment, the pyralid Eldana saccharina (Walker) laid on average 31.9 eggs on inoculated maize stems vs. 9.2 and 7.8 on stems from plants, grown from hot‐water or fungicide treated seeds, respectively. For the pyralid Mussidia nigrivenella (Ragonot) the values were 42.1 in the inoculation and 7.8 eggs in the fungicide treatment. The survival of E. saccharina larvae was significantly higher from the inoculation than the hot‐water or fungicide treatments. Fecundity in the three treatments was 494, 307, and 268 eggs per female, respectively. In an olfactometer experiment, no significant differences were found in the time spent by the curculionid Sitophilus zeamais Motschulsky between the odor field with Fusarium‐infected grain and with uninfected grain, but both were significantly different from the controls. Significant differences were obtained for the nitidulid Carpophilus dimidiatus (Fabricius) with 50.5 and 35.8%, respectively, of the time spent in the Fusarium‐infected and non‐infected odor field. For both species, no differences were found between sexes. For S. zeamais, development time was significantly higher when reared on infected (37.2 days) than on non‐infected grain (34.4 days), whereas fecundity, expressed as number of progenies during the first 4 weeks, was lower on the inoculated grain (11 vs. 16 offspring per female). For C. dimidiatus the situation was the reverse: development time was shorter and fecundity was higher on infected grain (32.4 vs. 34.4 days, and 18 vs. 13 offspring per female, respectively). It was concluded that the higher pest densities found in the stem and ear of field grown maize was due to a higher attraction to and higher immature survival and adult fecundity on F. verticillioides infected plants.
Effect of leaf surface extraction on palatability of romaine lettuce to Diabrotica balteata
Authors: Huang Juan , McAuslane Heather J. , Nuessly Gregg S. 
Published: December 2004

Abstract The leaf surface of a plant, especially its chemical components, constitutes the first line of resistance to herbivores and other pests. Our previous research indicated that ‘Valmaine’ (Val) romaine lettuce, Lactuca sativa L., was highly resistant to feeding by adult banded cucumber beetle, Diabrotica balteata LeConte, while ‘Tall Guzmaine’ (TG) was highly susceptible. We investigated the leaf surface chemistry of these two cultivars for its possible role in their resistance to D. balteata. Three solvents with different polarity (hexane, methylene chloride, and methanol) were tested to remove leaf surface chemicals, but only methylene chloride and methanol extracts were used in feeding bioassays. Adult D. balteata consumed much more of the leaf tissue of Val and TG when their surface chemicals were removed with methylene chloride, but not methanol, compared to nonextracted leaf tissue, leading us to hypothesize that methylene‐chloride extractable leaf surface chemicals may have a role in the expression of lettuce resistance. However, leaf surface chemicals extracted from Val with methylene chloride were not a deterrent to adult D. balteata when applied to palatable lima bean leaf surfaces at various concentrations in dual‐choice tests. Furthermore, the application of surface extracts from TG did not stimulate beetle feeding in similar choice tests. In a no‐choice feeding test, there was no significant difference in leaf area consumption on lima bean leaves sprayed with extracts of Val or TG. These results suggest that leaf surface chemicals in romaine lettuce do not explain the resistance of Val to adult D. balteata, and that factors inside the leaf may play a role in resistance. We discuss the possibility that the solvent may have increased the palatability of lettuce leaves to D. balteata by causing enzymatic browning and cellular damage, which is likely to have degraded internal feeding deterrents and impaired the plant's ability to emit latex.
Geographical variation in photoperiodic induction of larval diapause in the bruchid beetle, Bruchidius dorsalis: polymorphism in overwintering stages
Authors: Kurota Hiroyuki , Shimada Masakazu 
Published: December 2004

AbstractThe bruchid beetle, Bruchidius dorsalis Fahraeus (Coleoptera: Bruchidae), has a multivoltine life cycle and shows geographical variation of overwintering stages in Japan. Our previous study found that B. dorsalis enters larval diapause in the final instar under short photoperiods. In cooler areas, we observed that most individuals overwinter in the final larval stage in diapause, whereas beetles at different developmental stages (non‐diapausing young instars, diapausing instars, and adults) were overwintering in warmer areas. In this study, we investigated geographical variation in the photoperiodic response for induction of larval diapause at 20 °C (three populations) and 24 °C (two populations) to clarify the overwintering strategy of B. dorsalis. We observed that (1) diapause incidence at 20 °C changed sharply from ca. 100% to 0% with a change in photoperiod in all the populations, (2) critical photoperiod was longer at 20 °C in populations from cooler areas, and (3) critical photoperiod at 24 °C was shorter than at 20 °C and a fraction of the larvae did not enter diapause, even under short photoperiods. Overwintering stages estimated from these results were consistent with those actually observed in the field. This study indicates that the geographical variation of overwintering stages is likely to reflect adaptive diapause induction in each local environment.
Larval distributions of the ectoparasitoid wasp Eurytoma robusta relative to the host tephritid gall fly Urophora cardui
Authors: Johannesen Jes , Seitz Alfred 
Published: December 2004

AbstractParasitism may explain the patchy distributions of host populations. The present paper is a study of larval distributions of the parasitoid Eurytoma robusta in galls of the tephritid gall fly Urophora cardui. It focuses on E. robusta's choice of U. cardui gall and whether this changes relative to the rate of parasitism. Oviposition patterns were inferred by direct counts of larvae in galls and genetically, for both species, using indirect relatedness estimates between gall‐members. Furthermore, rates of parasitism in four populations were monitored for 4 years. The modal distribution of E. robusta larvae per gall was one and independent of the level of parasitism. The mean number of E. robusta per gall did not differ from Poisson distributions at different parasitism rates. We were not able to demonstrate a parasitoid preference for gall size. In contrast, parasitoids may have a negative effect on gall growth. Relatedness estimates showed that E. robusta gall members were often unrelated, whereas U. cardui were siblings. Thus, larval distributions of E. robusta suggest that oviposition behaviour is generally constrained and density independent. In four populations monitored over 4 years, parasitism was initially high (up to 70%), but suddenly declined with no apparent effect on fly (gall) abundance.
Interhabitat differences in ant activity on plant foliage: ants at extrafloral nectaries ofHibiscus pernambucensisin sandy and mangrove forests
Authors: Cogni Rodrigo , Freitas André V. L. , Oliveira Paulo S. 
Published: December 2004

AbstractThe association between visiting ants and the extrafloral nectaries (EFN)‐bearing shrubHibiscus pernambucensisArruda (Malvaceae) was investigated in two different coastal habitats – a permanently dry sandy forest and a regularly inundated mangrove forest. In both habitats the frequency of plants with ants and the mean number of ants per plant were much higher onH. pernambucensisthan on non‐nectariferous neighbouring plants. In the sandy forest the proportion of live termite baits attacked by ants onH. pernambucensiswas much higher than on plants lacking EFNs. In the mangrove, however, ants attacked equal numbers of termites on either plant class. Ant attendance to tuna/honey baits revealed that overall ant activity in the sandy forest is higher than in the mangrove area. The vertical distribution (ground vs. foliage) of ant activity also differed between habitats. While in the mangrove foraging ants were more frequent at baits placed on foliage, in the sandy forest ant attendance was higher at ground baits. Plants housing ant colonies were more common in the mangrove than in the sandy forest. Frequent flooding in the mangrove may have resulted in increased numbers of ant nests on vegetation and scattered ant activity across plant foliage, irrespective of possession of EFNs. Thus plants with EFNs in the mangrove may not experience increased ant aggression towards potential herbivores relative to plants lacking EFNs. The study suggests that the vertical distribution of ant activity, as related to different nest site distribution (ground vs. foliage) through a spatial scale, can mediate ant foraging patterns on plant foliage and probably affect the ants’ potential for herbivore deterrence on an EFN‐bearing plant species.
Effects of methoxyfenozide‐treated surfaces on the attractiveness and responsiveness of adult leafrollers
Authors: Hoelscher Jennifer A. , Barrett Bruce A. 
Published: December 2004

Abstract The attractiveness and responsiveness of the adult redbanded leafroller, Argyrotaenia velutinana (Walker), and obliquebanded leafroller, Choristoneura rosaceana (Harris), exposed to surfaces treated with the ecdysteroid agonist methoxyfenozide were investigated in wind tunnel and orientation tube assays. For both species, when males were exposed to water‐treated surfaces for 48 h, and regardless of what treatment surfaces the females had been exposed to, the mean percentage recaptures of such treated males in the wind tunnel assays were always significantly greater than the recaptures of males that had been exposed to methoxyfenozide. However, exposure to surfaces treated with surfactant (Latron B‐1956) also negatively affected the responsiveness (or attractiveness) of both moth species. In the orientation tube assays, males exposed to methoxyfenozide‐treated surfaces always had significantly lower mean levels of individuals exhibiting sexual excitability, and the mean distances traveled upwind, regardless of females’ exposure. In addition, exposure to surfactant‐treated surfaces did not affect mean levels of sexual excitibility and distances traveled upwind. The two bioassays demonstrated that male A. velutinana and C. rosaceana exposed to methoxyfenozide‐treated surfaces were not as responsive to calling females (treated and non‐treated) as were the non‐treated males. Conversely, females exposed to methoxyfenozide‐treated surfaces were just as attractive to non‐treated males as water‐treated females. It appears that a male's ability to respond to a calling female is more negatively affected by the ecdysone agonist than a female's ability to call and attract males.
Diel activity pattern and predation rate of the generalist predator Dicyphus hesperus
Authors: VanLaerhoven Sherah L. , Gillespie David R. , Roitberg Bernard D. 
Published: December 2004

Abstract This study examined the diel activity pattern and the effect of diel activity pattern on predation rate and prey finding of Dicyphus hesperus Knight (Heteroptera: Miridae). To determine the diel activity pattern of D. hesperus, starved females were placed on tomato leaflets Lycopersicon esculentum Mill. (Solanaceae) under zero, low, or high light intensities at 02:00, 08:00, and 14:00 h, respectively, and the amount of time spent walking or resting during a 30‐min interval was recorded. Predation rates of D. hesperus females on Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) egg patches were determined under either a L16:D8 (long day) or L8:D16 (short day) diel period. Egg patches were removed from D. hesperus females after either 8 or 16 h of dark or 16 or 8 h of light, and the number of eggs consumed was counted. Dicyphus hesperus females spent more time searching for prey at night than during the day. Females ate eggs at a higher rate during the night than during the day. Overall, D. hesperus females had higher predation rates when reared under a long day diel cycle compared with females reared under a short day diel cycle. More females reared at the L16:D8 diel cycle found the egg patch during the night than during the day. There was no difference in egg patch finding between night and day for females reared at L8:D16. Overall, L16:D8 reared females found more egg patches than females reared at L8:D16. Therefore, D. hesperus females are more active and find and consume prey at a higher rate at night than day.
Life history characteristics ofFrankliniella occidentalison cucumber leaves with and without supplemental food
Authors: Hulshof Jan , Ketoja Elise , Vänninen Irene 
Published: December 2004

AbstractThe development time, fecundity, longevity, and resultant intrinsic growth rate of the western flower thripsFrankliniella occidentalis(Pergande) [Thysanoptera: Thripidae] encaged on a cucumber leaf were compared among seven types of food supplied: six pollen species and a mixture of milk powder and yeast. The rationale was to find a food source that offers the least benefit for thrips and could therefore be considered as a food source for the preventative introduction of thrips predators. With the exception of the mixture of milk powder and yeast, all the food sources tested offered a nutritional benefit for the thrips. The addition of pollen increased fecundity and reduced development time, mainly during the larval stage.Betula pubescensandCorylus avellanapollen also increased adult longevity. The nutritional benefit ofPinus sylvestrispollen was greater than that of the other five pollen species, as manifested by its significantly greater positive effect on fecundity. The other pollen species could not be ranked in terms of nutritional benefit toF. occidentalis. The negative effect of the milk powder plus yeast mix on the life‐table parameters ofF. occidentalisprobably only occurs in an encaged situation where thrips cannot escape from the unfavorable environment. The crude estimate of the intrinsic growth rate ofF. occidentalisincreased from 0.163 on the plain cucumber leaf to 0.240 whenP. sylvestrispollen was added to the leaf. The differences in intrinsic growth rate mainly reflect the differences in fecundity among the food sources. Thus, the peak oviposition rate may be used as a measure of the nutritional benefitF. occidentaliscan obtain by feeding on supplemental food sources. The positive effect of a supplemental food source on thrips does not necessarily mean it is unsuitable for the preventative introduction of thrips predators, because the supplemental food can also affect the population dynamics of the predator and the predator–prey interaction and, hence, the outcome of biological control.
Evidence for single gene resistance in apple to brownheaded leafroller, Ctenopseustis obliquana, and implications for resistance to other New Zealand leafrollers
Authors: Wearing C.H. , Colhoun K. , McLaren G.F. , Attfield B. , Bus V.G.M. 
Published: December 2004

AbstractThe survival and development rate of Ctenopseustis obliquana (Walker) (Lepidoptera: Tortricidae) larvae, and weight of pupae were measured on detached mature leaves of two apple (Malus domestica Borkh.) progenies derived from the resistant (R) parent ‘Prima’ crossed with the susceptible (S) cultivars ‘Liberty’ (n = 44) and ‘Red Delicious’ (n = 35). The R:S ratio in both these modified backcross families did not differ significantly from the 1:1 expected in the case of monogenic resistance, carried in a heterozygous condition in the resistant parent. The survival to pupation on the individual seedlings was either zero/very low (R) or high (S). With all resistant seedlings being heterozygous, this indicates that the resistance allele shows complete dominance over the susceptible allele. We have named this putative gene Cob1. The expression of the resistance was found to be influenced by both the colony of C. obliquana used and the time of the season when resistance was assessed. In a separate experiment with another tortricid, there was no survival of Planotortrix octoDugdale larvae on the apple cultivar ‘Prima’ and high survival on the cultivars ‘Liberty’ and ‘Red Delicious’. The similarity of the responses of the two leafroller species to these cultivars, and other published evidence concerning Planotortrix excessana (Walker) and Ctenopseustis herana(Felder and Rogerhofer), suggest that the resistance discovered to C. obliquana may be effective against all four endemic tortricid species. The implications of these findings for apple breeding and leafroller control in New Zealand are discussed.
Sexual selection in a tropical fruit fly: role of a plant derived chemical in mate choice
Authors: Raghu S. , Clarke A.R. 
Published: December 2004

AbstractThe specific mechanisms by which selective pressures affect individuals are often difficult to resolve. In tephritid fruit flies, males respond strongly and positively to certain plant derived chemicals. Sexual selection by female choice has been hypothesized as the mechanism driving this behaviour in certain species, as females preferentially mate with males that have fed on these chemicals. This hypothesis is, to date, based on studies of only very few species and its generality is largely untested. We tested the hypothesis on different spatial scales (small cage and seminatural field‐cage) using the monophagous fruit fly, Bactrocera cacuminata. This species is known to respond to methyl eugenol (ME), a chemical found in many plant species and one upon which previous studies have focused. Contrary to expectation, no obvious female choice was apparent in selecting ME‐fed males over unfed males as measured by the number of matings achieved over time, copulation duration, or time of copulation initiation. However, the number of matings achieved by ME‐fed males was significantly greater than unfed males 16 and 32 days after exposure to ME in small cages (but not in a field‐cage). This delayed advantage suggests that ME may not influence the pheromone system of B. cacuminata but may have other consequences, acting on some other fitness consequence (e.g., enhancement of physiology or survival) of male exposure to these chemicals. We discuss the ecological and evolutionary implications of our findings to explore alternate hypotheses to explain the patterns of response of dacine fruit flies to specific plant‐derived chemicals.