bluuebunny/crossref_metadata_2025_split huggingface dataset:
How nutritionally imbalanced is phloem sap for aphids?
Authors: Sandström Jonas , Moran Nancy 
Published: October 2003

AbstractAphids harbour intracellular symbionts (Buchnera) that provide their host with amino acids present in low amounts in their diet, phloem sap. To find out the extent to which aphids depend on their symbionts for synthesis of individual essential amino acids, we have evaluated how well phloem sap amino acid composition matches the aphids' needs. Amino acid compositions of the ingested phloem sap were compared to amino acids in aphid body proteins and also to available information about optimal diet composition for other plant feeding insects. Phloem sap data from severed stylets of two aphid species, Rhopalosiphum padi (L.) (Homoptera: Aphididae) feeding on wheat, and Uroleucon sonchi (L.) (Homoptera: Aphididae) feeding on Sonchus oleraceus (L.), together with published information on phloem sap compositions from other plant species were used.Phloem sap has in general only around 20% essential amino acids, with a range from 15–48%. Aphid body proteins and optimal diets for two other plant feeding insects have around 50%. The phloem sap of early flowering S. oleraceus ingested by U. sonchi contained 48%, which seems to be exceptional. Aphids feeding on different plants appear to be very differently dependent on their symbionts for their overall essential amino acid synthesis, due to the large variation in proportion of essential amino acids in phloem sap from different plants.The profile of the essential amino acids in phloem sap from different plant species corresponds rather well to profiles of both aphid body proteins and optimal diets determined for plant feeding insects. However, methionine and leucine in phloem sap are in general low in these comparisons, suggesting a higher dependence on the symbiont for synthesis of these amino acids. Concentrations of several essential amino acids in phloem from different plant species seem to vary together, suggesting that levels of symbiont provisioning of different amino acids are adjusted in parallel.
Using hybrid and backcross larvae of Papilio canadensis and Papilio glaucus to detect induced phytochemical resistance in hybrid poplar trees experimentally defoliated by gypsy moths
Authors: Scriber J. Mark , Weir Kirsten , Parry Dylan , Deering Jessica 
Published: October 2003

AbstractSub‐plots of hybrid poplars were experimentally defoliated using 10 million gypsy moth larvae. Half of the defoliated (and undefoliated control) plots were fertilized to see if this would ameliorate the predicted induction of carbon‐based phenolic defenses in the regrowth leaves. In order to bioassay the leaves of the four different treatments, we employed a continuum of genotypes (different hybrids and backcrosses of two different species of tiger swallowtail butterflies) with different abilities to detoxify these allelochemicals. Based on our previous studies with phytochemicals from the Salicaceae plant family, Papilio canadensis was likely to consume and process all Populus spp treatments, whereas P. glaucus predicted to either not consume or else quickly die on all Populus treatment leaves. Hybrid and backcross larvae of these two butterfly species are known to have intermediate levels of esterase detoxication enzymes and would therefore be likely to provide a continuum or at least varying degrees of sensitivity in bioassays for even the most subtle induction responses in the regrowth leaves. This presumption was supported in the feeding and growth studies conducted at different times post‐defoliation during the 1997 growing season in Michigan.
Genetic basis for established and novel host plant use in a herbivorous ladybird beetle, Epilachna vigintioctomaculata
Authors: Ueno Hideki , Fujiyama Naoyuki , Irie Kiyoshi , Sato Yuji , Katakura Haruo 
Published: October 2003

AbstractGenetic trade‐offs in host plant use are thought to promote the evolution of host specificity. Experiments on a range of herbivorous insects, however, have found negative genetic correlation in host plant use in only a limited number of species. To account for the general lack of negative genetic correlation, recent hypotheses advocate that different stages in evolution of host use must be distinguished: initial performance on a novel host in comparison with the established host, and performance on both hosts after the insect population has interacted with both hosts for a long time. The hypotheses suggest that genetic correlation may not necessarily be negative at the initial stage. The present study examines growth performance on both the established and a novel host in a herbivorous ladybird beetle, Epilachna vigintioctomaculata Motschulsky (Coccinellidae, Epilachninae). The results show that traits of growth performance across hosts were positively or neutrally correlated, but there was no evidence of a negative genetic correlation. In addition, significant genetic variance of growth performance on each host was detected, suggesting that E. vigintioctomaculata can potentially respond to selection for increased performance on both plant species. These results and similar results from experiments on other herbivores suggest that host expansion may not be constrained genetically, at least at the initial stage of host range evolution.
Host‐plant choice and larval growth in the cinnabar moth: do pyrrolizidine alkaloids play a role?
Authors: Vrieling Klaas , de Boer Nico J. 
Published: October 2003

AbstractWitte et al. (1992) described two distinct chemotypes of Senecio jacobaea L. Asteraceae, a chemotype with jacobine as one of the major pyrrolizidine alkaloids (PAs) and a chemotype with erucifoline as one of the major PAs. We hypothesized that the presence of erucifoline might be the factor responsible for the lack of success of the cinnabar moth on Senecio erucifolius L. Asteraceae and the S. jacobaea erucifoline chemotype. We performed a survey of the distribution of the two chemotypes in the Netherlands and compared this with the distribution map of Tyria jacobaeae L. Lepidoptera, Arctiidae. The distribution of the two chemotypes in the Netherlands is poorly correlated with the distribution of the cinnabar moth. The jacobine chemotype occurs along the coast and the erucifoline chemotype predominantly inward.An oviposition experiment showed that the cinnabar moth did not discriminate between the two chemotypes of S. jacobaea and S. erucifolius. Larval performance did not differ between the two chemotypes and species. Although the distribution of S. jacobaea jacobine chemotype is loosely associated with the abundance of the cinnabar moth the oviposition and growth experiments indicate that other factors than the presence of erucifoline play a role in this association.The absence of recordings of S. erucifolius as a foodplant for the cinnabar moth might be explained by the phenology of the foodplant. Ovipositing females of the univoltine cinnabar moth prefer flowering plants for oviposition. S. erucifolius starts flowering about 1–2 month later than S. jacobaea just after the peak density of moths.
The effects of mating, age at mating, and plant stimuli, on the lifetime fecundity and fertility of the generalist herbivore Epiphyas postvittana
Authors: Foster S.P. , Howard A.J. 
Published: October 2003

AbstractThe effects of mating, age at mating, the presence or absence of a plant leaf, and the deprivation of a suitable ovipositional substrate during when the first ovipositional bout after mating would normally take place, on the lifetime fecundity and fertility (percentage of fertile eggs laid) of female Epiphyas postvittana were investigated. Mating had a significant effect on lifetime fecundity, with mated females laying 2.5 times more eggs than virgin females. Age at mating had a significant effect on both fecundity and fertility, both declining with increasing age when the female was mated. In the presence of a leaf of C. japonica, mated females had a greater lifetime fecundity than when no leaf was present; females in the presence of a C. japonica leaf consistently laid more eggs each day during the first 4–6 days after mating than females without a leaf. When females were deprived of a suitable ovipositional substrate, for the first 22 h after mating, they were significantly less fecund over their lifetime than were control females. Finally, in no‐choice tests with three plants of different acceptability to females, the fecundity of females differed in the order C. japonica > Urtica ferox > Tibouchina multiflora. This different fecundity appeared to be inversely related to the pubescence of the leaves, suggesting that leaf texture may be a suitable antixenotic resistance factor for crops to be protected from this insect. These results suggest that strategies whereby mating is delayed or oviposition reduced within a critical period after mating, may result in significant reductions in pest populations.
Effectiveness of Trichogramma ostriniae and T. nubilale for controlling the European corn borer Ostrinia nubilalis in sweet corn
Authors: Wang Baode , Ferro David N. , Hosmer David W. 
Published: October 2003

AbstractSeven field releases of Trichogramma ostriniae and T. nubilale (Hymenoptera: Trichogrammatidae) were made separately and in combination in a sweet corn field to compare the level of parasitism in sentinel eggs of the European corn borer, Ostrinia nubilalis (Lepidoptera: Pyralidae). The results indicate that the levels of egg parasitism among different release dates differed mainly because of changes in weather and plant architecture within the season. The level of egg parasitism by releasing T. ostriniae alone was found to be 15% higher than that by releasing T. nubilale alone, and 20% higher than by releasing the combination of the two species. Further analyses using the logistic regression model for independent and correlated data indicated T. ostriniae to be more efficient at discovering host egg masses and to have higher levels of egg parasitism than T. nubilale. Mutual interference between T. ostriniae and T. nubilale was the main factor for the lower level of egg parasitism when T. ostriniae and T. nubilale were released together. The results suggest that T. ostriniae is the better candidate for augmentative releases for control of the European corn borer, and the two species should not be released into a corn field at the same time.
Oviposition bioassay responses of Culex tarsalis and Culex quinquefasciatus to neem products containing azadirachtin
Authors: Su Tianyun , Mulla Mir S. 
Published: October 2003

AbstractNeem (Azadirachta indica A. Juss) products have been shown to exert pesticidal properties against a variety of insect species. In mosquito control programs, such products may have the potential to be used successfully as larvicides. In exploring other advantages of neem products, we studied the oviposition responses of Culex tarsalis Coquillett and Cx. quinquefasciatus Say to two experimental azadirachtin (AZ) formulations, wettable powder Azad™ WP10 (WP) and emulsifiable concentrate Azad™ EC4.5 (EC). Gravid Cx. tarsalis exhibited a distinct preference for the neem suspension of the WP, where significantly more egg rafts were collected from the treatment than from the control. The minimum effective AZ concentration for this activity was 0.5 ppm. The aged suspensions from 1–7 days at 0.5 and 1 ppm AZ were more active in eliciting oviposition responses in Cx. tarsalis than the fresh preparations. This activity of the aged suspensions lasted up to 14 and 21 days at 0.5 and 1 ppm AZ, respectively. Negative ovipositional responses were indicated in the tests of the EC vs. Cx. tarsalis, as well as both neem formulations vs. Cx. quinquefasciatus. In the tests of the EC formulation, significantly less gravid females were trapped by oviposition cups in the treatment than in the control, and in the tests of the WP significantly less egg rafts were collected from the treatment than from the control. The minimum effective concentrations for oviposition avoidance activity were 5 ppm AZ for Cx. tarsalis and 10 ppm AZ for Cx. quinquefasciatus, which lasted up to 1 and 4 days for these two species respectively. Neem products potentially used as mosquito larvicides may have many additional benefits in mosquito control programs, the oviposition modification noted in the current studies is one such example.
Specificity of a Y‐linked gene in the flea beetle Phyllotreta nemorum for defences in Barbarea vulgaris
Authors: Nielsen Jens Kvist 
Published: October 2003

AbstractA Y‐linked gene (R‐gene) in the flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) confer the ability of larvae to survive on types of the plant Barbarea vulgaris R.Br. (Brassicaceae) which are immune to attack by susceptible conspecifics. Two near‐isogenic flea beetle lines were developed. The YE‐line contained the Y‐linked R‐gene, and male larvae from this line survived on B. vulgaris. The ST‐line did not contain the gene and did not survive on the plant. The YE‐line had been developed through 8–9 generations of backcrosses (YE‐males with ST‐females) and the two lines were considered to be isogenic except for genes located on the Y‐chromosome.A single copy of the Y‐linked gene is sufficient to transfer a susceptible genotype (ST) into a resistant genotype (YE) which is able to utilize a plant that is immune to attack by specimens without R‐genes. The Y‐linked gene had no effects on survival on other plant species tested. The gene did not have any effect on developmental times and weights of adult beetles reared on other plants than B. vulgaris. Developmental times of larvae with the Y‐linked gene were longer on B. vulgaris than on normal host plants, R. sativus and S. arvensis, but the adults obtained the same size on these plant species. No trade‐offs of the Y‐linked gene were discovered. The results suggest that the occurrence of the Y‐linked gene is a derived trait which has enabled the flea beetle to expand its host plant range. The evolution of a host shift to B. vulgaris seems not to be favoured by the presence of this single gene.
Alaska Native Mortality, 1979–1998
Authors: Day Gretchen Ehrsam , Lanier Anne P. 
Published: October 2003

Objectives. This study compares mortality patterns for the Alaska Native population and the U.S. white population for 1989–1998 and examines trends for the 20-year period 1979–1998. Methods. The authors used death certificate data and Indian Health Service population estimates to calculate mortality rates for the Alaska Native population, age-adjusted to the U.S. 1940 standard million. Data on population and mortality for U.S. whites, aggregated by 10-year age groups and by gender, were obtained from the National Center for Health Statistics, and U.S. white mortality rates were age-adjusted to the U.S. 1940 standard million. Results. Overall, 1989–1998 Alaska Native mortality rates were 60% higher than those for the U.S. white population for the same period. There were significant disparities for eight of 10 leading causes of death, particularly unintentional injury, suicide, and homicide/legal intervention. Although declines in injury rates can be documented for the period 1979–1998, large disparities still exist. Alaska Native death rates for cancer, cerebrovascular disease, chronic obstructive pulmonary disease, and diabetes increased from 1979 to 1998. Given decreases in some cause-specific mortality rates in the U.S. white population, increased rates among Alaska Natives have resulted in new disparities. Conclusions. These data indicate that improvements in injury mortality rates are offset by marked increases in chronic disease deaths.
Adaptation to Labour Market Change in France and the UK: Convergent or Parallel Tracks?
Authors: Daguerre Anne , Taylor‐Gooby Peter 
Published: October 2003

Abstract France and the UK are markedly different welfare states, both in terms of regime type and in terms of the varying degree of state responsibility for reconciling work and family life. One recent theoretical strand suggests that welfare states will tend to grow more similar since they face broadly similar pressures. This paper discusses the policy responses in France and the UK to labour market pressures resulting from enhanced international competition, technological development and family change during the past decade. These responses are set in the context of European debates about the desirability of greater flexibility, up‐skilling and the activation of unemployed people, about the childcare needs of women workers and about the importance of paid work in reducing poverty and inequality. The analysis shows that trends to convergence are limited.
Convergence in the Social Welfare Systems in Europe: From Goal to Reality
Authors: Bouget Denis 
Published: October 2003

AbstractThe history of the social welfare systems in Europe in the postwar period appears as autonomous national processes because the construction of Europe which imposed common rules in many areas was equally consistent with the national development of social welfare systems, within each national culture. However, the idea of a common system of social protection has always remained linked to political and economic European construction which would create a more cohesive society. Many studies have analysed the trend of specific social policies and their convergence or divergence in Europe. Therefore, global convergence is often conceived as resulting from the domestic dynamics of each social risk. The paper focuses on one specific topic: the quantitative evaluation of convergence among the EU and OECD countries at the macroeconomic level. In the first part we explain the construction of social indicators which can assess the convergence or divergence of social expenditure in EU and OECD countries. In the second part we show many methodological problems and difficulties of interpretation of the social indicators. Then we see that the analysis of national trajectories of social expenditure and the link with economic development can enrich the analysis of convergence in social protection. Finally, the empirical analysis supports the idea of “adjustment” reforms rather than radical changes in a transitional period.
An Empirical Study of Cash Payments
Authors: Kippers Jeanine , van Nierop Erjen , Paap Richard , Franses Philip Hans 
Published: October 2003

Anytime an individual makes a cash payment, he or she needs to think about the amount to be paid, the coins and notes which are available, and the amount of change. For central banks and retail stores, it is of interest to understand how this individual choice process works. The literature of currency use concerns primarily theory, in the sense that, given certain assumptions, one can derive an optimal denomination range.There is no empirical study which deals with the actual use of coins and notes, given a specific denomination range. In this paper we present such a study, which is based on two rather unique data sets. We use descriptive statistics and a sophisticated model, which is designed for this specific purpose, to see whether two basic premises of the theories on optimal ranges are valid. In contrast to the widely accepted assumptions, we find that individuals appear not to pay efficiently and that they are also not indifferent to the use of coins and notes. In other words, some notes and coins are used less often than expected given the payment situation.
The Kingdom of Sicily and the Kingdom of England, 1066–1266
Authors: Loud G. A. 
Published: October 2003

AbstractThis article looks back from the political crisis in England in the 1250s to examine English and Anglo‐Norman perceptions of southern Italy and Sicily, and contacts between the two regions, over the previous two centuries. Although some at least were conscious of a common Norman heritage, commentators from England knew relatively little of the southern kingdom; certainly less than the Norman chroniclers, Orderic Vitalis and Robert of Torigni, and even they were less well informed than has been suggested in the past. There was a period of increased diplomatic contact for a generation or so after 1160, in which the Becket dispute played a part, culminating in the visit of Richard I to Sicily during the Third Crusade although that episode did nothing to increase the warmth of Anglo‐Sicilian relations. Thereafter there was relatively little contact for the next half‐century, in spite of Frederick II's marriage to the sister of Henry III of England in 1235. Furthermore, Sicily was always perceived as an exotic and alien region indicating that the perceptions found in the 1250s had been anticipated at an earlier period.
The Fourth Duke of Newcastle, the Ultra‐Tories and the Opposition to Canning's Administration
Authors: Gaunt Richard A. 
Published: October 2003

AbstractThis article explores the Ultra‐Tory opposition to the formation of George Canning's administration in March–April 1827 and subsequent events leading up to the beginning of the duke of Wellington's ministry in January 1828. It concentrates, in particular, upon the role of Henry, fourth duke of Newcastle (1785–1851) who emerged as the leading Ultra‐Tory in the period. The article re‐examines the events of the year with two considerations in mind: first, the effect of Canning's appointment on the position of the king and the ‘open’ status of Catholic Emancipation (given Canning's sympathies for a settlement of that question); secondly, the potential for the formation of a united ‘Protestant’ party in parliament out of the materials provided by Canning's opponents. It concludes that the events of the year were pivotal in transforming the Ultra‐Tories from grumbling, but acquiescent, backwoodsmen into a political group and in demonstrating, well before the repeal of the Test and Corporation Acts and Catholic Emancipation, that they were unlikely to find a receptive following from either George IV, Wellington or Peel.
‘On Account of their Disreputable Characters’: Parish‐Assisted Emigration from Rural England, 1834–1860
Authors: Howells Gary 
Published: October 2003

AbstractNineteenth‐century assisted emigration has long been associated with the phrase ‘shovelling out paupers’. This view is challenged by the actions and attitudes of the sponsors of parish‐assisted emigration who invested considerable time and energy in supporting the emigration of their poor. Close investigation of the policy that was applied at the local level for the rural counties of Bedfordshire, Northamptonshire and Norfolk suggests that assisted emigration was seen as a policy in which rich and poor interacted to secure mutual benefits. Assisted emigration was conceived as a way of helping individual paupers while simultaneously displaying a continued concern for the labouring population. Faced with the challenges of the New Poor Law, the farming class viewed assisted emigration as part of an older tradition of paternalistic help for the ‘deserving poor’. Sponsors were well aware of the ambivalence of the subject and sought to develop a conscious ideology of assisted emigration, which focused on the hope of a better life, for those who left and for those who remained.