bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of energy reserves in a viviparous skink: Does tail autotomy involve the loss of lipid stores?
Authors: Chapple David G. , Swain Roy 
Published: March 2003

Abstract  Caudal autotomy is an effective defensive strategy used by many lizards to facilitate escape during predatory encounters. However, it has several potentially severe consequences, including a range of energetic costs that are believed to result from the depletion of caudal lipid reserves during tail loss. In this study we examined the possible effect of caudal autotomy on the energetic reserves of a small viviparous skink, Niveoscincus metallicus (O'Shaughnessy 1874). Animals of each sex were collected on three occasions to assess the distribution of lipid stores. In addition, the frequency and position of naturally occurring tail breaks were determined. Both abdominal and caudal lipid stores are present in N. metallicus; however, caudal fat bodies comprise the majority (55–78%) of these fat reserves. Temporal variation in fat body mass, both abdominal and caudal, was evident. There was a significant relationship between the two fat stores, which was distorted in pregnant females, when relatively more fat was stored in the tail. Examination of the distribution of caudal fat in the tail revealed that the majority (90–95%) occurs within the proximal third of the tail. The remainder is located in the middle portion of the tail, with no reserves in the most distal tail section. During late pregnancy, females store relatively more fat closer to the body. The frequency of tail loss in a natural population of N. metallicus was extremely high (78%). Tail breaks were normally distributed along the length of the tail (i.e. most near the middle and fewer distal and proximal breaks). Thus there was a relatively high chance of some lipid depletion as a result of tail loss, but because 76% of breaks occur in the middle and distal thirds of the tail, there is a high probability that tail loss results in only minimal (i.e. <10%) lipid depletion. This is the first instance where both the energetic ‘value’ of the tail and the likelihood of lipid depletion during tail loss have been determined in a lizard. Overall, the combination of the aggregation of caudal fat reserves and position of naturally occurring tail breaks may enable N. metallicus to combine caudal fat storage and tail autotomy with minimal conflict.
Short‐term fitness benefits of physiological integration in the clonal herb Hydrocotyle peduncularis
Authors: Peterson Andrew G. , Chesson Peter 
Published: March 2003

Abstract  We test whether physiological integration enhances the short‐term fitness of the clonal herb Hydrocotyle peduncularis (Apiaceae, R. Brown ex A. Richards) subjected to spatial variation in water availability. Our measures of fitness and costs and benefits are based on the relative growth rate of fragmented genets. Physiological integration over a gradient in soil moisture resulted in a highly significant net benefit to genet growth of 0.015 g g−1 day−1. This net benefit represents a significant enhancement of the average fitness of fragmented genets spanning the moisture gradient relative to the average of those growing in homogeneous moist or dry conditions. Sections of genet fragments growing in dry conditions in spatially heterogeneous treatments had significantly higher growth than the sections they were connected to that were growing in moist conditions. Within fragments, older (parent) sections growing in moist conditions experienced significant costs from connection to younger (offspring) sections growing in dry conditions. In contrast, offspring sections with ample water did not experience any costs when connected to parent sections growing in dry conditions. However, the net benefit of physiological integration was similar for parent and offspring sections, suggesting that parent and offspring sections contributed equally to the net benefit of physiological integration to genet growth and short‐term fitness.
Thermal ecology and structural habitat use of two sympatric lizards (Carlia vivax and Lygisaurus foliorum) in subtropical Australia
Authors: Singh Sarinda , Smyth Anita K. , Blomberg Simon P. 
Published: March 2003

Abstract  The thermal ecology and structural habitat use of two closely related sympatric lizards, Carlia vivax (de Vis) and Lygisaurus foliorum de Vis, were examined in an open sclerophyll forest in subtropical Australia. Comparable mean body temperatures (Tb) and habitat temperatures (Thab) at the point of capture were recorded for both species. However, sex‐related differences in the thermal variables for C. vivax, with females displaying higher temperatures than males, resulted in some significant differences in Tb and Thab between the species. Variation in Tb and Thab within and between species was unrelated to time of capture. The difference in Thab within C. vivax suggested that females were selecting warmer thermal environments than males. Both C. vivax and L. foliorum used most structural features of their habitat randomly as indicated by a similarity in canopy, shrub, ground, log and litter cover and litter depth between habitat surveys and random surveys. However, C. vivax displayed a preference for ground vegetation (height <1 m) and litter cover with significantly higher cover recorded where these lizards were captured compared with random surveys. There was no effect of sex on structural habitat used by either species. Thus, the warmer thermal environments selected by female C. vivax may differ from those selected by males in sun/shade patterns or additional habitat features not measured in the present study. Significant associations between specific habitat features and Tb matched broad habitat descriptions for C. vivax and L. foliorum. This suggests that thermal considerations have direct interactions with the structural habitat preferences of these species. The significant association between Tb and ground cover for C. vivax corresponded with the non‐random use of ground cover by this species, whereas L. foliorum utilized all structural features randomly, despite an association between Tb and litter cover. The relative abundance or scarcity of individual structural habitat features may influence whether an association between those features and Tb is reflected in non‐random patterns of habitat use.
Habitat selection of the long‐nosed bandicoot, Perameles nasuta (Mammalia, Peramelidae), in a patchy urban environment
Authors: Chambers Lisa K. , Dickman Chris R. 
Published: March 2003

Abstract Habitat selection in an omnivorous marsupial, the long‐nosed bandicoot, Perameles nasuta Geoffroy, was investigated in an urban environment with both natural and highly modified habitats at North Head, New South Wales, Australia. Habitat use at both macro‐ and microhabitat scales was determined using live‐trapping, and P. nasuta was shown to be a habitat specialist at this site. At night, animals used open grass macrohabitats disproportionately more for foraging than other macrohabitats. Trap‐revealed macrohabitat use was supported by radiotracking three males. Lack of understorey and absence of leaf litter were the major microhabitat features affecting habitat choice, although soil type probably also had some effect. Open areas may provide a more abundant and/or accessible food supply for P. nasuta, although better manoeuvrability or increased visibility to detect predators may also be important. Diurnal nest sites, located using radiotracking, were primarily in dense scrub vegetation, often comprising introduced species of plants. The dependence of P. nasuta on: (i) dense undergrowth for diurnal nesting and temporary nocturnal sheltering; and (ii) open areas for foraging indicates the importance of conserving a mosaic of open and dense vegetation to ensure the continued persistence of this endangered population at North Head.
Host selection and performance of the giant willow aphid, Tuberolachnus salignus Gmelin – implications for pest management
Authors: Collins C. Matilda , Fellowes Mark D. E. , Sage Rufus B. , Leather Simon R. 
Published: March 2003

Abstract1 The recent increase in planting of selected willow clones as energy crops for biomass production has resulted in a need to understand the relationship between commonly grown, clonally propagated genotypes and their pests.2 For the first time, we present a study of the interactions of six willow clones and a previously unconsidered pest, the giant willow aphid Tuberolachnus salignus.3 Tuberolachnus salignus alatae displayed no preference between the clones, but there was genetic variation in resistance between the clones; Q83 was the most resistant and led to the lowest reproductive performance in the aphid4 Maternal effects buffered changes in aphid performance. On four tested willow clones fecundity of first generation aphids on the new host clone was intermediate to that of the second generation and that of the clone used to maintain the aphids in culture.5 In the field, patterns of aphid infestation were highly variable between years, with the duration of attack being up to four times longer in 1999. In both years there was a significant effect of willow clone on the intensity of infestation. However, whereas Orm had the lowest intensity of infestation in the first year, Dasyclados supported a lower population level than other monitored clones in the second year.
Host resistance in defoliated pine: effects of single and mass inoculations using bark beetle‐associated blue‐stain fungi
Authors: Långström Bo , Solheim Halvor , Hellqvist Claes , Krokene Paal 
Published: March 2003

Abstract1 In 1996, 7000 ha of pine forests were defoliated by the pine looper Bupalus piniaria in south‐western Sweden.2 The susceptibility of trees of different defoliation classes (0, 30, 60, 90 and 100% defoliation) to beetle‐vectored blue‐stain fungi was tested in inoculation experiments. Forty and 120‐year‐old Scots pine trees were inoculated with ‘single’, i.e. a few inoculations of Leptographium wingfieldii and Ophiostoma minus, two blue‐stain fungi associated with the pine shoot beetle Tomicus piniperda. The young trees were also ‘mass’ inoculated with L. wingfieldii at a density of 400 inoculation points per m2 over a 60 cm stem belt.3 Host tree symptoms indicated that only trees with 90–100% defoliation were susceptible to the mass inoculation.4 Single inoculations did not result in any consistent differences in fungal performance between trees of different defoliation classes, regardless of inoculated species or tree age class.5 Leptographium wingfieldii produced larger reaction zones than O. minus, and both species produced larger lesions in old than in young trees.6 As beetle‐induced tree mortality in the study area occurred only in totally defoliated stands, mass inoculations seem to mimic beetle‐attacks fairly well, and thus seem to be a useful tool for assessing host resistance.7 As even severely defoliated pine trees were quite resistant, host defence reactions in Scots pine seem to be less dependent on carbon allocation than predicted by carbon‐based defence hypotheses.
Potential risk of accidental introduction of Asian gypsy moth (Lymantria dispar) to Australasia: effects of climatic conditions and suitability of native plants
Authors: Matsuki M. , Kay M. , Serin J. , Floyd R. , Scott John K. 
Published: March 2003

Abstract1 The potential risk of the establishment of the Asian strain of the gypsy moth (AGM) (Lymantria dispar) in New Zealand and Australia (Australasia) was assessed from a study of the insect's host range and potential distribution. In New Zealand, viable eggs of AGM have been continuously intercepted on cargo from Asia, and therefore there is a high probability of accidental introductions of AGM to Australasia.2 We predicted potential distribution ranges of AGM based on climatic conditions. Asian gypsy moth is predicted to be able to persist in N and SE New Zealand and SE and SW Australia.3 Using three populations of AGM and 59 species (seven families) of plant (55 from Australasia and four from elsewhere), we also conducted laboratory trials to examine the ability of AGM larvae to complete development on native plants from Australasia. Asian gypsy moth was able to complete development on 26 out of the 55 native species tested. Furthermore, larval performance on at least five species of Australian native plant was as good as on AGM's preferred host species (Quercus pubescens and Q. robur).4 Larval performance of AGM was poor on all but one species of New Zealand native tree species (Nothofagus solandri), and therefore the risk of establishment in the indigenous forests of New Zealand is considered to be low.5 Given the suitability of some Australian plants and the climatic suitability for the establishment of AGM, this insect should be treated as a serious quarantine threat and managed accordingly, particularly in Australia.
Natural biological control of the pine processionary moth Thaumetopoea pityocampa (Den. & Schiff.) by the Argentine ant Linepithema humile (Mayr) in Portugal
Authors: Way M. J. , Paiva M. R. , Cammell M. E. 
Published: March 2003

Summary1 Defoliation by larvae of the pine processionary moth, Thaumetopoea pityocampa, is negligible in stands of Pinus pinaster colonized by the Argentine ant Linepithema humile which preys fiercely on the young moth larvae. In contrast, such damage is widespread where pine plantations are colonized by native ants, predominantly Tapinoma nigerrimum and Lasius niger, which seemingly disregard the larvae.2 Where L. humile‐ and native ant‐occupied sectors adjoin, there is a 20–50 m overlap in the transition area between L. humile‐ and native ant‐occupied pines. This was most evident in a > 500 ha plantation where there was severe or very severe T. pityocampa attack in native ant sectors contrasting with none in adjoining L. humile sectors.3 Predation by L. humile is no doubt enhanced by its existence as super‐colonies over very large areas, by its foraging activity and recruitment on trees throughout the time when T. pityocampa and other prey are present, and by honeydew‐ producing Homoptera which help retain foraging L. humile workers in pine tree crowns.4 The role of L. humile could be enhanced by cultivations that disturb the soil and restrain ground vegetation.
Cost‐effectiveness analysis of options within an Integrated Crop Management regime against great spruce bark beetle, Dendroctonus micans, Kug. (Coleoptera: Scolytidae)
Authors: O’neill M. , Evans H. F. 
Published: March 2003

Summary1 Great spruce bark beetle Dendroctonus micans (Kug.) (Coleoptera: Scolytidae) has been subject to an Integrated Crop Management (ICM) regime in Great Britain since its first discovery in 1982. The elements of the ICM approach are sanitation felling of the initial infestations, restriction on movement of potentially infested conifers to prevent spread to uninfested parts of the country and biological control through rearing and release of the specific predatory beetle Rhizophagus grandis Gyll. (Coleoptera: Rhizophagidae). Such a programme carries costs that have to be evaluated against the benefits to the ICM strategy.2 This paper presents a cost‐effectiveness analysis of three options – (i) continue with the current policy of restriction on movement of infested timber and use of the imported predator R. grandis, (ii) do nothing (i.e. drop all attempts to reduce the spread of D. micans), or, (iii) introduce a new east–west Dendroctonus Micans Control Area (DMCA) to define the management area. Assumptions on rates of mortality and natural spread were based on research into D. micans in Britain’s spruce forests.3 Appraisal indicated that the current policy was the most cost‐effective, even when subject to sensitivity analysis to test the limits of the assumptions included in the models. It is concluded that the current policy should remain in force.
Can Norway spruce trees be ‘vaccinated’ against attack by Ips typographus?
Authors: Christiansen Erik , Krokene Paal 
Published: March 2003

Abstract1 A field experiment was carried out to test the hypothesis that treatment of Norway spruce trees with the Ips typographus‐transmitted blue‐stain fungus Ceratocystis polonica enhances tree resistance to later mass attack by this bark beetle.2 Twenty‐five mature trees were pretreated by inoculating a non‐lethal dose of the fungus into the bark, while 18 trees served as untreated controls. Three and a half weeks after treatment a bark beetle attack was initiated by attaching dispensers with I. typographus pheromone to the tree trunks.3 A significantly larger proportion (67%) of the control trees than of the pretreated trees (36%) were killed by the beetle attack. The result is discussed in relation to recent results regarding defence mechanisms in Norway spruce trees.
Suppression of Colorado potato beetle infestation by pheromone‐mediated augmentation of the predatory spined soldier bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae)
Authors: Aldrich J. R. , Cantelo W. W. 
Published: March 2003

Summary1 Hardware and protocols were tested to enable individual growers and insectary operators to mass‐produce predatory spined soldier bugs (SSBs), Podisus maculiventris (Say) (Heteroptera: Pentatomidae: Asopinae), for augmentative biological control. Using pheromone‐based technology, an average of 1775 female SSBs (potentially as many as 1.6 million offspring) were captured each year during 2–3 weeks in early spring.2 Data for the first 2 years of a 3‐year project to use SSB for biological suppression of the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), verified earlier research showing that augmentation of SSB (∼5 nymphs/plant) can significantly suppress CPB infestations. In the third year, wild SSBs were transferred directly from pheromone traps to mid‐plot nursery cages having a mesh size chosen to retain the adult predators but allow their offspring to escape. Pheromone dispensers were placed peripherally to promote dispersal of young predators and immigration of new wild spined soldier bug adults. Pheromone‐mediated augmentation using porous nursery cages and pheromone dispensers was less labour‐intensive than earlier methods, and resulted in significantly improved potato yield.3 Trapping SSB adults early in the spring protects them from parasitization by tachinid flies and scelionid wasps that use the pheromone to facilitate host‐finding. The compatibility of pheromone‐mediated predator augmentation/conservation with implementation of transgenic plants, imidacloprid insecticide, and other biocontrol methods is discussed.
Host thermal biology: the key to understanding host–pathogen interactions and microbial pest control?
Authors: Blanford Simon , Thomas Matthew B. 
Published: March 2003

Abstract1 The role of pathogens in insect population dynamics remains poorly understood and their performance in biological control is erratic. Here we identify that temperature and host thermal behaviour, both the active interaction with environmental temperature and solar radiation via thermoregulation and the passive interception of these factors by thermal generalists, are central to understanding host–pathogen interactions.2 We demonstrate that pathogenicity, the latent period of infection and host recovery rate can all vary dramatically across and between seasons due to thermal biology of the host and changes in environmental temperature.3 Such effects have not been thoroughly explored in any previous investigations but may have major implications for disease dynamics in insects and possibly in ectotherms in general, and for development of effective biopesticides.
Pathogenicity to western larch (Larix occidentalis) of two fungi, Ophiostoma pseudotsugae and Leptographium abietinum, associated with the Douglas fir beetle (Coleoptera: Scolytidae)
Authors: Neal Tiffany A. , Ross Darrell W. 
Published: March 2003

Abstract1 Pole‐sized, live western larch Larix occidentalis Nutt. were mass‐inoculated with Ophiostoma pseudotsugae (Romb.) von Arx or Leptographium abietinum (Peck) Wingf., two blue‐stain fungi associated with the Douglas fir beetle Dendroctonus pseudotsugae Hopkins, to assess their pathogenicity.2 Inoculation with O. pseudotsugae resulted in significantly greater percentages of necrotic phloem compared with L. abietinum inoculations.3 The percentage of occluded sapwood was significantly greater after L. abietinum inoculations compared with O. pseudotsugae inoculations.4 Within the inoculation band, all trees had more than 60% functional sapwood 4 months after treatment.5 The results suggest that western larch can successfully limit colonization by O. pseudotsugae and L. abietinum.6 The inability of the fungi to thrive in live western larch may be a factor in the consistent failure of Douglas fir beetle broods in this host tree species.
Differences between attractive diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), sex pheromone lures are not determinable through analysis of emissions
Authors: Mayer M. S. , Mitchell E. R. 
Published: March 2003

Abstract1 Conjoint comparisons were made between trap captures of male diamondback moths, Plutella xylostella (L.), and gas chromatographic measures of sex pheromone emissions from grey and red rubber septa. The objective was to correlate trap captures with emissions.2 Irrespective of their composition, all mixtures that were released from grey septa effected the capture of more males than the same mixtures released from red septa. There was no difference between captures by any of the mixtures when emitted from grey septa. However, when emitted from red septa, a nominal 50 : 50 ratio of (Z)‐11‐hexadecenal (Z11–16:Al) and (Z)‐11‐hexadecenyl acetate (Z11–16:Ac) effected the capture of more males than either nominal 70 : 30 or 67 : 23 ratios. Generally, the emitted ratios of Z11–16:Al and Z11–16:Ac from both types of septa were variable, ranging between 6 : 10 to about 40 : 10.3 No statistical correlation was found between the emissions and trap captures by any single component, group or ratio of components. These results suggest that the environment substantially affects the emission of sex pheromone components from rubber septa. As a result, the demonstration of geographical biotypes of diamondback moths and other insects may be difficult.
The effects of drought upon epigeal Collembola from arable soils
Authors: Alvarez T. , Frampton G. K. , Goulson D. 
Published: March 2003

Summary1 Springtails (Hexapoda, Collembola) are usually associated with moist microhabitats. However, some species show adaptations to ecosystems subjected to periodic desiccation. This study examined the effects of short‐term drought conditions upon epigeal Collembola collected from arable fields.2 An emergence trap was used in the laboratory to investigate collembolan activity, particularly the emergence of newly hatched juveniles from soils subjected to a simulated drought and to varied levels of simulated rainfall.3 Addition of water to soils subjected to a 4‐month simulated drought resulted in synchronized emergence of juveniles ofSminthurinus elegans,Sminthurus viridisandBourletiella hortensis. As anhydrobiotic nymphs were not found in the soil, these juveniles are likely to have recently hatched from eggs in the soil.4 The same species were shown to emerge when desiccated soil samples were treated with simulated heavy rainfall. No emergence occurred in soils which received no water, whilst only a few juveniles were present under a regime of the lowest monthly rainfall recorded for the area in the spring.5 This study provides the first evidence that in northern European arable systems some epigeal Collembola can survive considerable periods of drought as eggs, emergence of which is triggered by rainfall. These findings have implications for the effects of predicted climatic changes upon collembolan populations, the recovery of collembolan communities following pesticide applications in agroecosystems, and also provide a plausible mechanism for dispersal of Collembola as wind‐blown eggs.