bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of phosphorus on growth and competitive interactions of native and introduced species found in White Box woodlands
Authors: Allcock Kimberly G. 
Published: March 2003

Abstract  White Box (Eucalyptus albens Benth.) woodlands are among Australia's most endangered ecosystems and are threatened by exotic species invasion. There is evidence from other Australian communities that phosphorus enrichment can facilitate invasion, and differential growth of native and exotic species under increased phosphorus is a possible mechanism. Two glasshouse experiments were designed to test the following three questions relating to species responses to phosphorus: (i) do exotic and native species have different patterns of growth along a gradient of increasing phosphorus?; (ii) do exotic species have a greater competitive effect on native species than do conspecifics?; (iii) does phosphorus enrichment compound the competitive effect of exotic species on native species? Four native perennial species (Themeda australis (R. Br.) Staph., Bothriochloa macra (Steud.) S. T. Blake, Austrodanthonia racemosa (R. Br.) H. P. Linder and Eucalyptus albens) and two exotic annual species (Vulpia bromoides (L) Gray and Echium plantagineum L) were used. In the first experiment, plants were grown individually under six levels of soil phosphorus ranging from 0 to 60 p.p.m. In the second experiment, individuals of Eucalyptus albens and B. macra were grown alone, with a conspecific competitor, or with an exotic (V. bromoides or Echium plantagineum) competitor under low (10 p.p.m.) and high (100 p.p.m.) phosphorus. Both exotic species showed a greater positive response to increased phosphorus than the native species in experiment 1, and Eucalyptus albens seedlings grown with Echium plantagineum were significantly smaller than individuals grown alone or with Eucalyptus albens in experiment 2. There was no evidence that high phosphorus increased the competitive effect of the exotic species, but the combination of a strong positive response to phosphorus and a strong effect on growth of a native species indicates that phosphorus enrichment could favour exotic species in woodland remnants and that field studies testing the effect of phosphorus in a broader context would be appropriate.
Melbourne Vascular Surgical Association audit
Authors: Beiles C. Barry ,   the Melbourne Vascular Surgical Association Audit Committee
Published: March 2003

Background:  The formation of the Melbourne Vascular Surgical Association has led to the establishment of a vascular surgical audit programme that commenced in January 1999. This has allowed establishment of a benchmark for quality assurance in vascular surgery in Australia.Methods:  A consultative process allowed widespread adoption of the audit across all public hospital vascular units in Melbourne and the two largest regional centres in Victoria. Data were collected at two points during admission: at operation and at discharge. Risk stratification, using logistic regression and risk‐adjusted ratios for adverse events was assessed for comparison of outcomes between units for the first 3 years of data collection. There is regular contact with all participants for data feedback and quality control.Results:  The standard of vascular surgery across Victoria is consistent, and there has been excellent compliance by all academic vascular units. Private practice data are less complete, and only half of the vascular surgeons have participated.Conclusions:  A statewide audit process is feasible and viable. Coordination by the Melbourne Vascular Surgical Association is crucial for its continued success.
Predation on the slug Deroceras reticulatum by the carabid beetles Pterostichus madidus and Nebria brevicollis in the presence of alternative prey
Authors: Mair J. , Port G. R. 
Published: March 2003

Abstract1 Slugs are important pests in many agricultural crops and potential biological control agents are being studied as an alternative to molluscicides. Carabid beetles may be able to reduce slug populations, but their role as control agents may be influenced by the presence of alternative prey.2 Attacks on the pest slug Deroceras reticulatum (Müller) by the carabid beetles Pterostichus madidus (Fabricius) and Nebria brevicollis (Fabricius) were investigated in the presence of alternative prey (earthworms and Calliphora fly larvae). Consumption of slug eggs and aphids was also investigated.3 All five prey types were consumed to varying degrees during the experiments. Both beetle species showed a significant preference for Calliphora larvae over slugs. Pterostichus madidus showed a significant preference for earthworms over slugs. No preference was shown between earthworms or Calliphora larvae by P. madidus females or N. brevicollis. However, P. madidus males showed a significant preference for Calliphora larvae over worms. Pterostichus madidus showed no preference between slug eggs and aphids; N. brevicollis showed a significant preference for aphids over slug eggs.4 The results from this study indicate that generalist beetles will often attack other prey in preferences to adult slugs. Slugs may not be preferred because of their mucus. Other prey items occur frequently in arable soils and generalist carabids may ignore slugs altogether and may only feed on them when slug density is high or other prey are unavailable.
Survival, longevity and fecundity of overwintering Mesoplatys ochroptera Stål (Coleoptera: Chrysomelidae) defoliating Sesbania sesban (Leguminosae) and implications for its management in southern Africa
Authors: Sileshi G. , Kenis M. 
Published: March 2003

Abstract1 The defoliator beetle, Mesoplatys ochroptera Stål, is a serious pest of the legume tree sesbania (Sesbania sesban (L.) Merrill) in agroforestry systems in southern Africa. The survival of the overwintering stage of M. ochroptera and post‐ emergence longevity and fecundity of adults in sesbania fallows in eastern Zambia were quantified.2 Only adult M. ochroptera survived during the winter (May–August) and the dry season (September–October) hidden under weeds, plant litter, in soil cracks and under rocks. During these periods, some beetles were occasionally found feeding on S. sesban, particularly in natural stands in humid areas. The adults were parasitized by the braconid Perilitus larvicida van Achterberg at a rate of 8.5–16.4%. The beetles stayed in the winter refuges for up to 210 days and emerged with the first heavy rains in October–November. The effective survival of beetles overwintering in an insectary was 18.1% in 1998 and 37.7% in 1999, and that of beetles overwintering in the field was estimated at 0.4 and 2.8% in 1998 and 1999, respectively.3 The post‐emergence longevity and oviposition period of females in the insectary was 14–31 days and 5–29 days, respectively. The post‐emergence fecundity varied from 87 to 783.4 It is concluded that the serious M. ochroptera infestation observed every year following the rains is due to synchronous emergence of overwintered resident adult populations and their high capacity for reproduction on many species of Sesbania. Recommendations for pest management in sesbania planted‐fallows are given.
Response of natural populations of predators and parasitoids to artificially induced volatile emissions in maize plants (Zea mays L.)
Authors: Bernasconi Ockroy Marco L. , Turlings Ted C. J. , Edwards Peter J. , Fritzsche‐Hoballah Maria Elena , Ambrosetti Lara , Bassetti Paolo , Dorn Silvia 
Published: March 2003

Abstract1 In response to herbivore attack, maize plants (Zea mays L.) emit a specific blend of induced volatiles. Artificial damage and subsequent treatment of the damaged site with caterpillar regurgitant induces the same response. The induced volatile chemicals are known to be highly attractive to several parasitoids of herbivores in laboratory bioassays, but very limited information is available on how the plant odours affect entomophagous insects in the field.2 Experiments were conducted to determine if induced maize volatiles attract parasitic and predatory insects under field conditions and whether they affect their spatial distribution.3 In a preliminary field experiment with blue sticky traps near treated (damaged and treated with caterpillar regurgitant) and healthy plants, more entomophagous insects (total number of parasitic Hymenoptera, Anthocoridae and Syrphidae) were trapped near treated plants than near healthy plants.4 In a second experiment, attraction to the induced volatiles was monitored with sticky traps placed next to treated and healthy maize plants in a regular maize field. No significant differences between the two treatments were found, but significantly more insects (parasitic wasps, thrips and anthocorid bugs) were trapped near to the top of plants than on traps placed near the mid‐stem. Displacement of these insect groups within the field seemed to occur principally over the canopy, but under severe weather conditions they travelled lower in the canopy.5 In a third experiment, the effect of induced maize odours on the spatial distribution of predators and parasitoids was investigated by placing sticky traps at different distances from healthy and treated plants. The higher catches of parasitoids near treated plants and the increased presence of these insects on the downwind side of treated plants support the notion that herbivore‐induced maize odours attract natural enemies of maize pests in the field.
Response of the pine engraver, Ips pini (Say) (Coleoptera: Scolytidae), to conophthorin and other angiosperm bark volatiles in the avoidance of non‐hosts
Authors: Huber Dezene P. W. , Borden John H. , Stastny Michael 
Published: March 2003

Abstract1 Seventeen non‐host angiosperm bark volatiles, seven of which are antennally active to Ips pini (Say), the pine engraver (PE), were tested for their ability to disrupt the response of the PE to pheromone‐baited traps.2 Four green leaf volatiles (GLVs) were tested [1‐hexanol (Z)‐3‐hexen‐1‐ol, hexanal, and (E)‐2‐hexenal]. None had any disruptive effect singly, as a group or in all possible blends based on functional groups, despite the fact that the two aldehydes were antennally active. These compounds may have, in some instances, actually masked the disruptive effect of other compounds. The PE thus differs in its response from other Scolytidae, including other Ips spp.3 Eight non‐host volatiles that were antennally active to other bark beetles, but not to PEs, had no disruptive effect, validating the use of coupled gas chromatographic‐electroantennographic detection analyses to detect compounds with potential behavioural activity.4 The bicyclic spiroacetal conophthorin, (E)‐7‐methyl‐1,6‐dioxaspiro[4.5]decane, was disruptive when tested alone. When blends of two aldehydes [salicylaldehyde and nonanal] plus an alcohol and a phenol [benzyl alcohol and guaiacol] were combined with conophthorin, an enhanced disruptive effect was revealed. No single compound, other than conophthorin, disrupted the pheromone‐positive response and no blend that did not contain conophthorin was consistently disruptive to both sexes. Conophthorin seems to be a critical component in the non‐host angiosperm message for I. pini during its host selection phase.5 Combination of the repellent synomones, verbenone and ipsenol, with the five disruptive non‐host volatiles may provide a potent treatment to protect trees, logs or stands from attack by the PE.
Effects of Elatobium abietinum on nutrient fluxes in Sitka spruce canopies receiving elevated nitrogen and sulphur deposition
Authors: Stadler Bernhard , Müller Thomas , Sheppard Lucy , Crossley Alan 
Published: March 2003

Abstract1 In a field acid mist simulation experiment, Sitka spruce (Picea sitchensis) was sprayed with different pollutant treatments: N, NH4NO3; S, Na2SO4; NS Acid, NH4NO3 + H2SO4 and control, no spray. Treatment effects on the abundance of the green spruce aphid Elatobium abietinum and honeydew production were assessed. In addition, needles were sampled for phyllosphere micro‐organisms. In a manipulative experiment, shoots were established and maintained as with or without E. abietinum infestation in order to determine the effects of infestation on needle loss and throughfall nutrient fluxes.2 Aphid numbers were highest during the end of May and early June, with almost twice as many needles infested in the NS Acid treatment compared with the other treatments. Honeydew production was not affected by the treatments.3 On infested shoots, increasing numbers of yellowing and dead needles were recorded above the throughfall collectors as the season progressed. The numbers of dead needles falling into the collectors were significantly higher beneath infested shoots. There were strong positive correlations between aphid numbers above the throughfall collectors, the number of yellowing and dead needles on the shoots and the number of needles in the funnels of the throughfall collectors. Litter production was more affected by aphid number than by pollutant treatment.4 Bacteria, yeasts and filamentous fungi were more prolific on infested needles and treatment effects on colony forming units (CFUs) were most pronounced in the NS Acid treatment.5 Fluxes of inorganic nitrogen beneath infested shoots were generally lower than beneath uninfested shoots. This effect was more pronounced in those treatments that supplied N i.e. N, NS Acid. The combination of aphid infestation and N‐addition exerted the strongest influence on nutrient fluxes. The fluxes of potassium and of organic carbon (DOC) were higher beneath infested shoots in all treatments, through most of the survey period.
Using matrix models to explore the influence of temperature on population growth of arthropod pests
Authors: Bommarco Riccardo 
Published: March 2003

Abstract1 Population growth of four arthropod pests on agricultural crops, the pea aphid, the bird‐cherry oat aphid, the Mediterranean fruit fly, and the two‐spotted spider mite, was modelled using stage matrix models.2 Temperature was included as a variable in the model, affecting fecundity, mortality and growth rate. Linear temperature dependence was used to describe fecundity and individual growth rate in the matrix model. Life table data collected at various constant experimental temperatures were used to parameterize the model.3 Sensitivity analysis identified the most influential demographic parameters determining the growth rate of the population at different temperature regimes. Mortality of young adults and immature stages were found to be the most important parameters in determining population growth for all species presented. However, high temperatures increased the relative impact of individual growth rates and fecundity on the growth of the population.
Mortality of second‐instar larvae of Tuta absoluta produced by the hexane extract of Lycopersicon hirsutum f. glabratum (PI 134417) leaves
Authors: Verçosa de Magalhães Sergio Tinôco , Jham Gulab N. , Picanço Marcelo C. , Magalhães Gouvan 
Published: March 2003

Abstract1 The mortality resulting from exposure of second‐instar larvae of Tuta absoluta to a hexane extract of Lycopersicon hirsutum f. glabratum (PI 134417) leaves was evaluated in the laboratory.2 A crude hexane extract was fractionated on a silica gel column to produce 17 fractions. The toxicity of the fractions was evaluated on T. absoluta larvae at 2 and/or 6 mg/10 larvae/Petri dish along with a control.3 Only two fractions, 4.50 and 10.18% of the total hexane extract, were found to result in very high mortality of second‐instar T. absoluta.4 All the 17 fractions were analysed by capillary gas chromatography/mass spectrometry (GC/MS). The two most toxic fractions were virtually identical and contained mainly undeca‐2‐one (2‐UD) and trideca‐2‐one (2‐TD).5 A third major sub‐fraction 13 (50.73% of the total hexane extract) was further fractionated on a silica gel column to obtain five additional sub‐fractions. The toxicity of all the five sub‐fractions was evaluated using second‐instar T. absoluta at 2 mg/10 larvae/Petri dish and also analysed by GC/MS. The most toxic sub‐fractions contained mostly 2‐UD and 2‐TD.6 The results suggest that 2‐UD and 2‐TD could be related to resistance of L. hirsutum to T. absoluta.
Post hibernation dispersal of three leaf‐eating beetles (Coleoptera: Chrysomelidae) colonising cultivated willows and poplars
Authors: Sage Rufus B. , Fell David , Tucker Kenneth , Sotherton Nicolas W. 
Published: March 2003

Summary1 We studied the spring dispersal of three common chrysomelids, from overwintering habitats into cultivated willow and poplar coppices at four sites in southern England over 2 years.2 Adult Galerucella lineola, Phratora vulgatissima and P. vitellinae overwintered under the bark of mature trees or in other niches that simulated this habitat, within a few hundred metres of the coppice plantation. Relatively few beetles remained in the coppice fields during the winter.3 Phratora vitellinae at the poplar sites emerged several weeks later than G. lineola and P. vulgatissima at the willow sites, reflecting the later leafing of poplar compared to willow. For all species, dispersal was by flight, with most activity during warm periods. Dispersal continued for several weeks for the willow‐ feeding species but was shorter for P. vitellinae. 4 All three species initially colonized the edge of the coppice field. Typically, 80% or more of the beetles colonising a plantation were within 8 m of the edge. Both Phratora spp. accumulated in the plantation edge zone for several weeks before leaving this area and colonising the crop interior.5 The patterns of dispersal and colonization identified by this study may facilitate chrysomelid management practices in infested short rotation coppice that avoid the need for insecticide applications over the entire plantation. Keywords
Chrysomelidae, Galerucella lineola, Phratora vitellinae, Phratora vulgatissima, poplar, short rotation coppice, willow, winter dispersal.
Genetic variation in host susceptibility to attack by the mahogany shoot borer, Hypsipyla grandella (Zeller)
Authors: Newton A. C. , Watt A. D. , Lopez F. , Cornelius J. P. , Mesén J. F. , Corea E. A. 
Published: March 2003

Summary1 Attack by shoot borers (Hypsipyla grandella Zeller) is the main factor limiting the cultivation of Cedrela odorata and Swietenia macrophylla, two economically important members of the mahogany family. No viable methods of pest control are currently available. To assess for genetic variation in susceptibility to pest attack, a combined progeny/provenance test of C. odorata and a provenance test of S. macrophylla were established separately at CATIE, Turrialba, Costa Rica, and assessed intensively over an 84‐week period.2 Variation in height growth between provenances was highly significant in both species, provenance means varying by a factor of 2.7 and 1.2 in C. odorata and S. macrophylla, respectively. Cedrela odorata also displayed provenance variation in foliar phenology, as 94.7% of the trees from a ‘wet zone’ provenance remained foliated, whereas > 35% of trees from three ‘dry zone’ provenances abscised their leaves during the dry season.3 Both species displayed significant genetic variation in susceptibility to shoot borer attack. At the peak of attack during the second year of growth, the effect of provenance was highly significant in both species, the mean number of attacks per tree varying between 0.8–2.4 and 0.6–1.3 in different provenances of C. odorata and S. macrophylla, respectively. A provenance of C. odorata from San Carlos, Costa Rica, displayed consistently lower susceptibility to pest attack, being subjected to fewer attacks during the first year and demonstrating a higher mean height to first point of damage.4 The nitrogen, total tannin and proanthocyanidin concentration of foliage varied significantly between C. odorata provenances: nitrogen concentration was significantly lower and tannin and proanthocyanidin contents were significantly higher in trees from the San Carlos provenance, Costa Rica. This study therefore suggests that proanthocyanidins may reduce susceptibility of C. odorata to H. grandella, at least during the early period of growth.5 These results provide support for the development of plant resistance as a strategy for managing shoot borers. In particular, there may be scope for selecting for high foliar proanthocyanidin content and the ability to tolerate attack by vigorous apical growth.
Effects of previous defoliation on pine looper larval performance
Authors: Šmits Agnis , Larsson Stig 
Published: March 2003

Summary1 During outbreaks of the pine looper, Bupalus piniarius, its host, Pinus sylvestris, is severely defoliated. The larvae of this geometrid normally feed on mature needles. However, because trees are totally defoliated during outbreaks, the next generation is forced to feed on current‐year needles.2 Bupalus piniarius larvae feeding on previously defoliated trees may show lower performance either because of induced resistance or because larvae have to feed on needles not normally fed upon (current instead of mature).3 These hypotheses were tested in an experiment where larvae were reared on (i) shoots naturally defoliated the previous year, and thus, bearing only current‐year needles, (ii) non‐defoliated shoots where larvae had access only to current‐year needles, and (iii) control shoots with access to both current and mature needles.4 There was no support for the induction hypothesis. Survival was lower on naturally defoliated shoots than on control shoots (81.3 vs. 90.9%), but survival was lower also on non‐defoliated shoots where larvae had access only to current‐year needles (78.8%). Data on larval feeding distribution showed a strong preference for mature needles.5 Needle nitrogen concentration of current‐year needles was 38% higher on defoliated trees than on non‐defoliated trees.6 It is concluded that defoliation affected larval performance primarily through the removal of the preferred type of needles and not because of an induced resistance. Effects of increased concentrations of allelochemicals in defoliated shoots, if present, were probably cancelled out by increased nitrogen concentrations.
What affects the rate of gypsy moth (Lepidoptera: Lymantriidae) spread: winter temperature or forest susceptibility?
Authors: Sharov Alexei A. , Pijanowski Bryan C. , Liebhold Andrew M. , Gage Stuart H. 
Published: March 2003

Summary1 The effect of winter temperature and forest susceptibility on the rate of gypsy mothLymantria dispar(L.) range expansion in the lower peninsula of Michigan was analysed using historical data on moth counts in a grid of pheromone‐baited traps collected from 1985 to 1994 by the Michigan Department of Agriculture. The rate of spread was measured by the distance between population boundaries in consecutive years. Boundaries were estimated for population thresholds of 1, 3, 10, 30, and 100 moths per trap using a polar coordinate system.2 The average rate of spread estimated using all population thresholds was 15.8 km/yr.3 The rate of spread was higher in the northern part of the lower peninsula than in the southern part, despite lower minimum January temperatures in the north.4 The rate of spread was positively correlated with forest susceptibility, which was higher in the north than in the south.KeywordsBiological invasions, forest susceptibility,Lymantria dispar, population spread, temperature.