bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lepidopteran pest populations and crop yields in row intercropped broccoli
Authors: Hooks Cerruti R. R. , Johnson Marshall W. 
Published: March 2003

Abstract

To determine how the presence of non‐host plants impact populations of lepidopteran pests and yield of broccoli, Brassica oleracea var. italica L., broccoli was intercropped with tomato, Lycopersicon esculentum Miller, or yellow sweetclover (YSC), Melilotus officinalis L., and compared with broccoli monoculture grown at two densities (high and low).
During a 1997 study, numbers of early instar imported cabbageworm, Artogeia rapae L., were greater in broccoli monoculture compared with intercropped plantings. In contrast, late instar A. rapae numbers were significantly higher in intercropped broccoli during most of the season, indicating greater survival of early instar stages in intercropped habitats.
Cabbage looper, Trichoplusia ni Hübner, eggs and larvae were more abundant in broccoli monoculture than intercropped broccoli in 1997. In addition, T. ni populations were found at significantly lower levels in broccoli‐YSC compared with broccoli‐tomato habitat throughout the season.
During a 1998 study, numbers of early and late A. rapae instars were greater in intercropped broccoli on most sampling dates.
The mean percentages of harvested broccoli heads infested with insects and associated frass were higher in monocultures than intercropped treatments in 1997. Additionally, a significantly lower number of contaminants were found in the crowns of broccoli harvested from broccoli‐YSC (YSC) compared with broccoli‐tomato (tomato) habitat. However, broccoli heads were significantly smaller in intercropped habitats.
Variations in insect responses and challenges to using crop diversification as a management tool are discussed.
Selective toxicity of some pesticides to Pullus mediterraneus Fabr. (Coleoptera: Coccinellidae), a predator of Saissetia oleae Bern. (Homoptera: Coccoideae)
Authors: Ba M'hamed T. , Chemseddine M. 
Published: March 2003

Abstract

To contribute to the development of IPM strategies in olive groves, the selectivity of several insecticides to Pullus mediterraneus Fabr. (Coleoptera: coccinellidae) was investigated in the laboratory. The study assessed the toxicity of seven chemical pesticides and one bacteriological insecticide to adult P. mediterraneus.
The LC50 was estimated by applying the pesticides on the dorsal side of adults. Lambda‐cyhalothrin, methomyl and cypermethrin resulted in the highest toxicity followed, in decreasing order of toxicity, by malathion, fenthion and dimethoate. Parathion had the least effect on the coccinellid.
Consumption of Bacillus thuringiensis bacteria (applied as a commercial formulation), over a period of 10 consecutive days, resulted in low mortality of adult P. mediterraneus.
The results of these laboratory experiments indicate that the most widely used chemical pesticides were toxic to P. mediterraneus. Their use in olive groves must take account of the activity period of this predator. In contrast, B. thuringiensis seemed to be a suitable candidate to be included in pest management systems.
Insecticidal activity of Piper tuberculatum Jacq. extracts: synergistic interaction of piperamides
Authors: Scott I. M. , Puniani E. , Durst T. , Phelps D. , Merali S. , Assabgui R. A. , Sánchez‐Vindas P. , Poveda L. , Philogène B. J. R. , Arnason J. T. 
Published: March 2003

Abstract

The insecticidal activity of the neotropical pepper Piper tuberculatum Jacq. and its isolated piperamides was studied. Bioassays with the mosquito Aedes atropalpus L. assessed the relative toxicity of the whole extract of Piper tuberculatum and four of the piperamides, which were isolated and identified, then prepared synthetically.
The results confirm that P. tuberculatum leaf extracts are as effective as black pepper seed extract and provide an alternative pepper insecticide from a more convenient source, the leaves.
Experiments with piperamides showed that the tertiary and quaternary mixtures have greater‐than‐additive toxicity compared to single compounds or binary mixtures. One of the four amide compounds, 4,5‐dihydropiperlonguminine, was the most acutely toxic in mosquito larvae bioassays.
A study of piperamide levels from different P. tuberculatum populations in Costa Rica determined that they were relatively homogeneous. Piper tuberculatum from only one of the five sites had higher levels of one piperamide, 4,5‐dihydropiperine, in both leaf and stem parts. One explanation for differences in the amide concentrations between populations is that one site is ecologically unique compared to the other four.
Sex pheromone of apple fruit moth Argyresthia conjugella (Lepidoptera: Argyresthiidae)
Authors: Jaastad Gunnhild , Bengtsson Marie , Anderson Peter , Kobro Sverre , Knudsen Geir , Witzgall Peter 
Published: March 2003

Abstract

The apple fruit moth Argyresthia conjugella Zell. (Lepidoptera: Argyresthiidae) is the most important pest of apple in Scandinavia. It invades apple orchards and can destroy an entire crop during years of poor flowering and fruitsetting of its principal host, mountain ash Sorbus aucuparia. We investigated the female sex pheromone of apple fruit moth in order to develop a reliable lure, which can be used to detect migration of apple fruit moth into orchards and thus to avoid preventive insecticide sprays.
Pheromonal compounds obtained by solvent extraction of excised A. conjugella female pheromone glands were identified by coupled gas chromatography/electroantennography and gas chromatography/mass spectrometry. Two compounds (Z)‐11‐hexadecenyl acetate, and the analogous alcohol (Z)‐11‐hexadecen‐1‐ol, elicited a strong response from male antennae. (Z)‐11‐hexadecenyl acetate was highly attractive in field trapping tests, whereas as little as a 1%‐addition of (Z)‐11‐hexadecen‐1‐ol strongly reduced male attraction.
(Z)‐13‐octadecenyl acetate, a previously reported sex attractant, had no effect on A. conjugella male attraction.
Mating disruption of the pine sawfly Neodiprion sertifer (Hymenoptera: Diprionidae) in isolated pine stands
Authors: Martini Antonio , Baldassari Nadia , Baronio Piero , Anderbrant Olle , Hedenström Erik , Högberg Hans‐Erik , Rocchetta Gabriella 
Published: March 2003

Abstract

Previous applications of the mating disruption technique to Neodiprion sertifer resulted in decreased numbers of males caught in the treated area but no effect on sex ratio or overall population density.
The present study assessed the efficacy of mating disruption against N. sertifer outbreaks in pine stands surrounded by agricultural areas or pasture, and therefore isolated from other infested areas.
Pine stands were treated by placing dispensers with an erythro‐mixture of the acetate ester of 3,7‐dimethyl‐2‐pentadecanol every 10 m in a grid.
The efficacy of this technique was evaluated by comparing the number of males caught in sticky traps baited with synthetic pheromone, and by comparing the sex ratio and the population density of the sawfly in the subsequent generation between treated and control pine stands.
The number of males caught within treated areas was significantly lower than in the control area.
In the treated pine stands 46% of the egg clusters resulted in male cocoons only, compared to 3% of the clusters in the control stand.
A significant reduction of the sawfly population was observed in the treated pine stands. The results contrast to the earlier mating disruption attempts with N. sertifer and can probably be ascribed to the isolation of the experimental stands.
Oviposition behaviour and response ofMonochamus scutellatus(Coleoptera: Cerambycidae) to conspecific eggs and larvae
Authors: Peddle Shawna , De Groot Peter , Smith Sandy 
Published: March 2003

Abstract The oviposition behaviour of white‐spotted sawyer beetleMonochamus scutellatus(Say) (Coleoptera: Cerambycidae) females was studied under laboratory and field conditions. Females walked over the bark surface and stopped to palpate it with their labial and maxillary palpi. Once a potential oviposition site was located, the female excavated a scar in the bark with her mandibles, deposited an egg and brown plug in the scar and inserted her mandibles again into the scar prior to leaving the area. FemaleM. scutellatuspreferred to lay eggs on bolts containing no eggs (control) to those containing eggs from other females, but did not show this preference when provided with control bolts and those containing their own eggs. When females were provided with bolts containing their own eggs and bolts containing eggs from other females, they laid more eggs on bolts containing their own eggs. Females laid more eggs on control bolts than on bolts containing their own larvae or larvae from other females. The brown plug in the oviposition scar may provide a protective barrier to the egg, a chemical message that the site is occupied, or both.
Asymmetric plant‐mediated cross‐effects between a herbivorous insect and a phytopathogenic fungus
Authors: Rostás Michael , Hilker Monika 
Published: March 2003

Abstract

Cross‐effects between a herbivorous insect and a phytopathogenic fungus on their common host plant were examined. Specifically, we addressed the questions whether (i) infection of Chinese cabbage leaves by the fungus Alternaria brassicae affects the development and host selection behaviour of the leaf beetle Phaedon cochleariae and (ii) whether herbivory influences host suitability of Chinese cabbage for A. brassicae.
Feeding on fungus‐infected leaves prolonged larval development and reduced pupal weight of P. cochleariae. Adult beetles avoided feeding and egg deposition on fungus‐infected leaves. In contrast to these local effects, no systemic effect of phytopathogenic infection on the herbivore was detected.
Herbivory did not influence fungal growth neither locally nor systemically.
Thus, our results demonstrate an asymmetric relationship between herbivore and fungus. Whereas herbivory had no visible impact on fungal growth, fungal infection of the plant induced local resistance against P. cochleariae.
Biology of Centistes delusorius, a parasitoid of adult apple blossom weevil
Authors: Zijp Jan‐Piet , Blommers Leo H. M. 
Published: March 2003

Abstract

Natural control of apple blossom weevil, Anthonomus pomorum (L.), deserves attention, as the pest is regaining importance with the declining use of non‐selective pesticides in apple and pear orchards. In this study the biology of Centistes delusorius (Förster), a specific parasitoid of adult apple blossom weevil, is investigated.
The parasitoid hibernates as young larva in an adult weevil, and juvenile development is resumed in early spring. The fully grown parasitoid larvae leave their hosts during full bloom at the end of April and early May, to pupate. The adults emerging in May oviposit into the newly emerged weevils, which initially feed on apple leaves.
Centistes delusorius was detected in six out of 15 host‐weevil infested orchards, but was only common in two with larger apple trees standing in grass. There, parasitism levels of around 30% were usual in hosts taken from treebands in winter.
The delicate larva is vulnerable, and the thin cocoon provides little protection against either desiccation or drowning on a weedless orchard floor. Observations indicate that successful pupation of C. delusorius demands stable humid conditions and some shelter, such as that found in grass or woodland soils.
Parasitoid females, provided with honey, lived for a mean of 6.3 ± 2.1 days under outdoor conditions in June. Their life span was similar whether they had access to and oviposited in hosts, or not. The species is pro‐ovigenic, and potential fecundity is about 40 eggs. Oviposition usually takes a few seconds. Parasitized female hosts do not reproduce.
Up to 95% of the parasitoid eggs laid in May develop into a second generation, the adults of which appear in July, when the host has entered aestivation. Older (British) records of C. delusorius outside orchards suggest that some parasitized hosts, like the healthy ones, leave the orchard prior to aestivo‐hibernation, so that the latter do not escape parasitoid attack in July.
A trapping sample in late June, when most non‐parasitized weevils have gone into aestivo‐hibernation, is probably the most efficient method to detect parasitized weevils.
The (near‐)absence of C. delusorius in many orchards is probably due not only to pesticide side‐effects, or scarcity of its host, but also to the absence of suitable pupation sites for the wasp.
The effect of cold temperature exposure and long‐day photoperiod on the termination of the reproductive diapause of newly emerged female Pissodes strobi (Coleoptera: Curculionidae)
Authors: Trudel Richard , Lavallée Robert , Bauce É ric , Guertin Claude 
Published: March 2003

Abstract

There is confusion in the literature concerning a possible reproductive diapause in the adult white pine weevil Pissodes strobi.
We evaluated the effects of temperature, photoperiod, feeding substrate and mating status on the sexual maturation and oviposition of female white pine weevils.
Less than 30% of female P. strobi became sexually mature and laid eggs without experiencing dormancy under a temperature regime of 2 °C for 4 weeks.
Among the females that experienced a cold temperature treatment after emergence, 80% laid eggs after dormancy when exposed to a long‐day (LD 16 : 8 h) photoperiod and 17.6% laid eggs when exposed to a short‐day (LD 8 : 16 h) photoperiod.
Significantly more eggs were laid by all the females (with and without a cold treatment) when subjected to a long‐day photoperiod compared with a short‐day photoperiod.
A period of cold temperature followed by exposure to a long‐day photoperiod with warmer temperatures is required to break reproductive diapause and to obtain a good oviposition response in female P. strobi.
This study reveals the existence of much intraspecific variation in the response of the white pine weevil to temperature and photoperiod with respect to the induction and termination of reproductive diapause.
Oviposition strategies employed by the western spruce budworm: tests of predictions from the phylogenetic constraints hypothesis
Authors: Leyva Kathryn J. , Clancy Karen M. , Price Peter W. 
Published: March 2003

Abstract1 Predictions from the Phylogenetic Constraints Hypothesis were tested for the first time in an eruptive forest Lepidopteran species, the western spruce budworm.2 In previous work, we established that western spruce budworm females exhibit oviposition preferences with regard to tree age, tree vigour and host species. However, there was no evidence to support a link between oviposition preference and larval performance, which supports the Phylogenetic Constraints Hypothesis.3 Our preference data led us to test whether female budworms use oviposition strategies to select the sites where they lay their egg masses. Our experiments were designed to make direct comparisons between latent and eruptive insect herbivores with respect to two oviposition behaviours: egg retention and avoidance of conspecifics. This type of research has not previously been conducted on any eruptive forest Lepidopteran.4 Female budworms retained eggs instead of laying them on less preferred hosts in two of three experiments, but the percentage of eggs they retained was significantly less compared to latent insect herbivores.5 In addition, female budworms actively avoided oviposition in areas with the highest density of conspecific egg masses, but they laid egg masses in all the other locations provided. This contrasts with the pattern seen in latent insect herbivores, which consistently avoid laying their eggs near any sites already used by conspecifics.6 Our research indicates that there are extreme differences between latent and eruptive insect herbivores with respect to egg retention and avoidance of conspecifics, thus supporting the Phylogenetic Constraints Hypothesis.
Tree killing by Ips typographus (Coleoptera: Scolytidae) at stand edges with and without colonized felled spruce trees
Authors: Hedgren Per Olof , Schroeder L. Martin , Weslien Jan 
Published: March 2003

Abstract 1 To maintain biodiversity in managed spruce forests in Sweden more wind‐felled trees must be retained. However, there is concern among forest owners that this may result in higher tree mortality caused by the spruce bark beetle, Ips typographus (L.) (Col. Scolytidae).2 To simulate wind‐felled trees, living spruce trees were cut at spruce stand edges bordering fresh clear‐cuttings. Treatments comprised edges with zero, one or five cut trees colonized by I. typographus. Edges with naturally wind‐felled trees colonized by I. typographus were also included in the analyses.3 During the two following summers, the number of trees killed by I. typographus did not differ between edges with and without felled trees, or between edges with one or five felled trees.4 Within edges with felled trees, there were more killed trees close to the felled trees than at other parts of the edges. Thus, felled trees provided focal points for attacks within edges.5 It is concluded that small numbers of wind‐felled trees colonized by I. typographus may be left near spruce stand edges without increasing the risk of beetle‐induced tree mortality.
The changing utilization of a children’s emergency department
Authors: Boyle Robert , Smith Craig , McIntyre John 
Published: March 2003

ABSTRACT Objective To assess the changing pattern of attendance at an emergency department in a children’s hospital. Design A retrospective review of the attendance register from 1 September 1986 to 31 August 1998. Setting Derbyshire Children’s Hospital, Derby, serving a mixed urban and rural population within the National Health Service. Measurement Total number of attendances and admissions each year. For one week in February and August each year: age and case mix assessed. For the period 1994–98: the source of the referral and the outcome of patients referred by their General Practitioner (GP). Results Over the study period: a rise in attendances from 4853 to 8796; no change in the total number admitted to hospital. A decline in the proportion admitted from 56 to 32%. For the period 1994–98: no change in the number of patients referred by their GP; an increasing number of self‐referrals. Overall age mix: age < 1 year, 27%; age 1–4 years, 42%; age 5–12 years, 26%; age > 13 years, 5%. Overall case mix: medical, 73%; surgical, 9%; trauma/minor injuries, 18%. Conclusion An important change has occurred in the utilization of our paediatric emergency department with increasing numbers of children seeking hospital assessment, largely via self‐referrals, but not requiring hospital admission. Implications for practice Future planning and deployment of paediatric resources need to take account of the change in use of hospital emergency services.
The paediatrician’s role in ambulatory health care of the older child in Switzerland
Authors: Carrel Rebecca , Klingler Jean , Ryffel Meinrad , Tschanz Urs , Vuille Jean‐Claude , Westkämper Reinhard , Zumstein Matthias 
Published: March 2003

ABSTRACT Objective Data selected from a larger study, ‘Schoolchildren in the Paediatric Practice’, were analysed to examine the role of the practising paediatrician in providing care to the older child/adolescent. Design For the base study, paediatricians in private practice collected data on schoolchildren during two year‐long research segments. At the end of the study, each paediatrician was interviewed. To assist the focused analysis of this paper, statistics on physician utilization patterns and diagnoses were obtained from two external sources. Setting and Sample Thirty‐four paediatricians practising in the canton of Bern, Switzerland received a sample of 5971 schoolchildren, aged 6–16. Results The paediatricians saw a decreasing number of children with increasing ages. Other medical specialities showed no comparable decline. The length of time a paediatrician had been practising was related to having more older patients. The paediatricians expressed mixed opinions about the decline in older patients, with 59% stating this to be normal or not a problem. A minority felt the situation was a serious threat to the profession. Issues concerning the paediatricians included the image of the profession, the medical and administrative management of adolescent visits, and inadequate reimbursement. Implications for practice To take the lead in assuring adequate care for the country’s older children, Swiss paediatricians need to clarify their desired role and address the questions of competence, training needs, personal barriers to offering services, and manpower coverage.
An evaluation of a home palliative care programme for children
Authors: Dangel Tomasz , Fowler‐Kerry Susan , Karwacki Marek , Bereda Joanna 
Published: March 2003

ABSTRACTObjective To measure the quality of a paediatric hospice home care programme and to assess the needs and concerns, both met and unmet, of parents who received hospice services.Sample One hundred and thirty‐six questionnaires were sent to parents or primary caretakers of 87 children who had died under the hospice home care. Eighty questionnaires (59%) were returned, representing 54 patients.Methods Responders were asked about: (1) their decision to choose hospice care, (2) difficult problems experienced during hospice care, (3) communication with their children, (4) how parents and children experienced dying, and (5) evaluation of the specific service components.Results The majority of responders decided to bring their child home from hospital because further hospital care was not considered beneficial, and because they wanted the whole family to be together. Also, the child wished to be at home. Feelings of helplessness and fear were the most common and difficult problems reported. The majority of responders were not able to speak honestly with their child about their death. Most of the children died peacefully and did not suffer. Satisfaction with the hospice home care programme was high. Satisfaction with the hospice home care programme was not explained solely by the presence or absence of financial support from the hospice programme.Conclusion The questionnaire developed for evaluation of this paediatric home care programme has yielded valuable information directed at improving the care of terminally ill children and their families.Implications for practice The data obtained from this study may be used to improve the quality of service delivery, and also to provide useful documentation for institutions involved with the development of health care policy, education, and funding, such as the ministry of health, foundations, and health insurance companies.