bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plant structure and the foraging success of Aphidius rhopalosiphi (Hymenoptera: Aphidiidae)
Authors: GARDNER SARAH M. , DIXON A. F. G. 
Published: March 2008

Abstract. 1. A study of searching behaviour on wheat and host preference of Aphidius rhopalosiphi (DeStefani‐Perez) is described.2. Parasitoids divided their time equally between the leaves but spent very little time on the ear.3. After contact with honeydew or an aphid host, parasitoids were arrested in a particular area and increased the time spent searching.4. Aphids feeding on the ear were parasitized less successfully, since their position between the grains protected them from parasitoid attacks.5. A.rhopalosiphi exhibited no preference for Metopolophium dirhodum (Walker) or Sitobion avenae (Fabricius), although the handling time for the latter was significantly longer; this resulted in fewer S.avenae being parasitized when it was abundant. Parasitoids did not switch between hosts in these experiments.6. As a result of its searching behaviour, A.rhopalosiphi will encounter and parasitize M.dirhodum feeding on the leaves more frequently than S.avenae, which feeds on the ear. This will limit the parasitoid's ability to regulate populations of the cereal aphid S. avenae.
Egg weight variation in relation to egg mortality and starvation endurance of newly hatched larvae in some satyrid butterflies
Authors: KARLSSON BENGT , WIKLUND CHRISTER 
Published: March 2008

Abstract. 1. Egg weights decrease over the oviposition period in all of the five satyrid butterflies that have been studied, viz Parage aegeria L., Lasiommata petropolitana F., L.maera L., L.megera L. and Lopingaachine Scop. However, within each species, no correlation was found between variation in egg weight and egg mortality in 30% relative humidity or the ability of newly hatched larvae to survive without food for 1–4 days.2. Although egg weights of Papilio machaon L. were similar to the highest satyrid egg weights, newly hatched larvae of P.machaon showed significantly higher mortality after 1 day of starvation when compared to all of the satyrid larvae. This indicates that the capability of newly hatched larvae to endure starvation is not necessarily correlated with egg weight, and consequently that this character trait of satyrid larvae has been selected for (i.e. should be regarded as an adaptation). It is noteworthy that this ability of satyrid larvae to endure starvation is coupled with the habit of many satyrid butterflies not to deposit their eggs directly on the larval host plants.3. In 30% relative humidity, egg mortality of L.achine was 100% and that of P.aegeria 29.2%, whereas that of the three Lasiommata spp. was significantly lower. At 100% relative humidity egg mortality in L.achine dropped to 8%. Since egg weights are higher in L.achine than in the other four satyrids this indicates that egg resistance to desiccation is not necessarily correlated with egg size (as might be expected due to the area to volume ratio which is negatively correlated with egg size). Thus the resistance to desiccation which is found in the three Lasiommata spp. should be regarded as an adaptation to the habit of these three butterflies to deposit their eggs in relatively dry microhabitats. This resistance to desiccation is not found in eggs of the two forest‐dwelling satyrids P.aegeria and L.achine which lay their eggs in microhabitats where the relative humidity is high.
Oviposition preferences in relation to larval growth rates and survival in the pine beauty moth, Panolis flammea
Authors: LEATHER SIMON R. 
Published: March 2008

Abstract. 1. Adult female pine beauty moths, Panolis flammea (D & S), when given a choice of whole plants or needle pairs of four provenances of Lodgepole pine, Pinus contorta (Douglas), laid most eggs on that provenance on which the larvae attained their greatest growth rates.2. When presented with a greater number of Lodgepole pine provenances and Pinus sylvestris L, P.flammea oviposition preferences reflected the trade‐off between growth rate and survival.3. There is some evidence to suggest that the moths are responding to the monoterpene composition of the plants.4. Adult moths showed no preference for Lodgepole pine needles of a range of ages (1–4 years), ovipositing uniformly on all age classes.
The use of fluorescent pigments to study insect behaviour: investigating mating patterns in a butterfly population
Authors: WHEYE DARRYL , EHRLICH PAUL R. 
Published: March 2008

Abstract. 1. Mating patterns in a natural population of checkerspot butterflies, Euphydryas editha Boisduval, were investigated by dusting male external genitalia with fluorescent dyes and examining mated females under UV light.2. These dyes may have diverse applications in studies of insect populations.
Geographical variation in food web structure in Nepenthes pitcher plants
Authors: BEAVER R. A. 
Published: March 2008

Abstract. 1. Relative to Nepenthes species in West Malaysia near the evolutionary centre of the genus, outlying species of Nepenthes in the Seychelles, Sri Lanka and Madagascar have fewer species of both prey and predator living in them, fewer and smaller guilds of species, much apparently empty niche space, less complex food webs, and a greater connectance. The ratios of prey to predators, and of connectance (C1) to the total number of trophic types present remain approximately constant.2. Differences between the food webs appear to be related in a complex way to the size of the country and its degree of spatial and temporal isolation, the size of the local species pool capable of colonizing the pitchers, and the number of Nepenthes species present. However, the maximal length of food chains in the richest and most complex food webs is probably limited by energetic constraints or environmental predictability.3. The data may illustrate how food webs change to become more complex, both by the addition of new guilds of species and the addition of species to existing guilds, while at the same time certain properties of the food web are kept approximately constant.
Seasonal abundance of macropterous Nilaparvata lugens and Sogatella furcifera based on presumptive macroptery in fifth‐instar nymphs
Authors: COOK A. G. , PERFECT T. J. 
Published: March 2008

Abstract. 1. The seasonal changes in abundance of macropterous N. lugens (Stal) and S. furcifera (Horvath) (Homoptera: Delphacidae) are described based on observed numbers of adults and presumptive macroptery in fifth‐instar nymphs occurring in rice crops in the Philippines.2. Percentage presumptive macroptery in fifth‐instar nymphs was correlated with nymphal density over the range of 0–20 nymphs per hill for females of both species and 5–20 nymphs per hill for male N. lugens.3. Lunar phase had no effect on wingmorph expression in either species.4. Comparison of the percentage macroptery in fifth‐instar nymphs with subsequent percentage macroptery in N. lugens adults for one season showed net emigration occurred from 60 DAT (days after transplanting) to harvest except for a period of net immigration lasting 7–10 days at approximately 95 DAT for both sexes.
Radar observations of moths migrating in a nocturnal low‐level jet
Authors: DRAKE V. A. 
Published: March 2008

Abstract. 1. Radar observations of insects migrating at night over central‐western New South Wales have detected an instance of migration in a low‐level wind jet.2. From the characteristics of the radar echoes, and from the catches obtained in traps at ground level and at the altitude of migration, the migrants can be identified as noctuid and pyralid moths of a number of different species.3. The migration, which was in a downwind direction, started at dusk and ended at about dawn. During the period immediately before first light, a large proportion of the migrants were concentrated into a 100m deep layer at an altitude of about 250m; this layer had not been present during the first half of the night.4. The boundary layer wind profile at dawn exhibited a clear low‐level jet structure, with a wind maximum between 100 and 300m, and strong shear in the wind direction below 300m. A strong surface temperature inversion, but not a wind‐speed maximum, had been present the previous evening.5. The formation of the layer concentration in the upper part of the jet may be accounted for in terms of previously described responses of nocturnally migrating insects to a surface temperature inversion. It is not therefore necessary to assume that the migrants were responding specifically to the presence of a wind‐speed maximum.
The effects of body size on mating and reproduction in Brachinus lateralis (Coleoptera: Carabidae)
Authors: JULIANO STEVEN A. 
Published: March 2008

Abstract.1. The causes and reproductive consequences of body size variation of Brachinus lateralis Dejean, a parasitic carabid beetle, were investigated.2. Body size variation occurs within and between sites. Host size has a major influence on body size of the adult.3. Fecundity is positively correlated with body size. Egg size is not correlated with body size.4. Mating males tend to be larger than non‐mating males. There is a positive correlation of body sizes in mating pairs.5. Limited opportunity for host choice may maintain size variation despite the advantages of large size.6. The non‐random patterns of mating for a species without obvious intrasexual aggression suggest that subtle means of male‐male competition or female choice may be important.
Pollen‐feeding and the host specificity and fecundity of flower thrips (Thysanoptera)
Authors: KIRK WILLIAM D. J. 
Published: March 2008

Abstract. 1. Flower thrips could feed on pollen of a wide range of sizes and were unaffected by exine spines. One species of thrips was unable to feed on very adhesive grains.2. The proportion of time spent feeding on each species of pollen (in seconds per minute of exposure) reflected the known host specificities. Host‐specific thrips could distinguish their host pollen, apparently without probing.3. Kakothrips pisivorus (Westwood) appeared to have a higher rate of ingestion of a host pollen than of four non‐host pollens.4. In cages in the laboratory, Thrips fuscipennis Haliday laid significantly more eggs over 48h when given pollen than when given other floral tissues or no food. K. pisivonis and Ceratothrips ericae (Haliday) also laid significantly more eggs over 48h in the presence of pollen than in its absence.5. In comparisons between pollen diets, T. fuscipennis, a generalist, laid similar numbers of eggs with each species of pollen, but K. pisivorus and C. ericae laid significantly more eggs with their respective host pollens. The differences in oviposition rate between pollen diets reflected the differences in the proportion of time spent feeding.
Host plant toxins and unpalatability of Neacoryphus bicrucis (Hemiptera: Lygaeidae)
Authors: McLAIN DENSON K. , SHURE DONALD J. 
Published: March 2008

Abstract. 1. Host plant choice of the seed bug, Neacoryphus bicrucis Say (Hemiritera, Lygaeidae), was evaluated in four different Georgia habitats. N. bicrucis utilized only species of Senecio as host plants at a granite outcrop and at old fields on the coastal plain, in the piedmont, and in the Blue Ridge Mountains.2. In laboratory tests N. bicrucis is distasteful to the green anole lizard, Anolis carolinensis Voight. Only six of ninety field‐collected bugs were eaten in palatability trials while eighty‐four of the remaining ninety attacked bugs were rejected by lizards without apparent harm. However, the bugs were palatable to Fowler's toads, Bufo woodhousei fowleri Hinckley, which ate all thirty‐six bugs offered to them.3. N. bicrucis selectively sequesters pyrrolizidine alkaloids from Senecio spp. These may cause the insects' distastefulness to green anoles. In palatability trials, lizards ate all twenty insects reared on sunflower seeds, Helianthus annus, but rejected all twenty reared on Senecio smallii.
Specializations and polyphagy of Plebejus argus (Lepidoptera: Lycaenidae) in North Wales
Authors: THOMAS C. D. 
Published: March 2008

Abstract. 1. The polyphagous butterfly, Plebejus argus L., was found to have specialized requirements: eggs are laid along vegetation/bare ground margins, larvae specialize on tender meristematic and reproductive growth, larvae and pupae are tended by Lasius ants, and warm microclimates are favoured.2. These requirements are met in early successional habitats within several bio topes. These habitats are locally distributed, as is P. argus.3. Populations on limestone, heathland and mossland biotopes did not differ greatly in ecologies. Given a choice of foodplants in captivity, larvae from heathland and limestone did show slight differences in preference, selecting some of the hostplants they normally encounter in the wild. Regardless of biotope, all these larvae were plant taxa generalists (on three plant families), but specialists on plant parts.4. The decline of P. argus in Britain is attributed to loss of biotopes and to declining traditional management of them. Fewer habitats are available, and the distances between them are greater than formerly. As some of these habitats are short lived, and P. argus rarely flies far, the butterfly's decline is a compound effect of reduced areas of habitat and inability to colonize them.
Ovariole number and fecundity for the two emigrating generations of the bird cherry‐oat aphid (Rhopalosiphum padi) in Sweden
Authors: WIKTELIUS S. , CHIVERTON P. A. 
Published: March 2008

Abstract. 1. The number of ovarioles and the potential fecundity in first (fundatrigenia) and second generation emigrants of Rhopalosiphum padi (L.) was investigated.2. The relationships between weight and host quality on ovariole number were investigated.3. The first generation of emigrants had a greater number of ovarioles and a higher fecundity than the second.4. There was a positive relationship between ovariole number and weight.5. The number of ovarioles and weight decreased with decreasing host quality.6. The results do not agree with a recently proposed reproductive strategy of aphids where the number of ovarioles are supposed to be independent of weight and host quality.7. In years with a high initial population on bird cherry, the migration to grasses, e.g. cereals, will be earlier, probably larger and, to a greater extent, consists of aphids which have a higher reproductive rate than in years with a small initial number on bird cherry.
Humidity responses and water balance of riparian species of Bembidiini (Col., Carabidae)
Authors: ANDERSEN JOHAN 
Published: March 2008

Abstract. 1. The humidity responses of Asaphidion pallipes (Duftschmid) and Bembidion spp. were studied at various temperatures in choice chambers.2. Several species initially showed a hygropositive or indifferent response. Other species had a hygronegative reaction which later changed to a hygropositive one. The duration of the hygronegative reaction varied with species, age, temperature and relative humidity. B.litorale (Olivier) and B.semipunctatum (Donovan) change response when they have lost 8–9% of their initial body weight as water.3. The survival time of species of Bembidion under dry conditions was short compared with that reported for many other carabid beetles. Newly emerged adults of B.argenteolum Ahrens that had been kept away from sand for 3 weeks had lower transpiration rates than any other species. Young adult Bembidion had lower transpiration rates than those in the breeding phase, larvae and dead adults. Transpiration rate appeared to be inversely proportional to the relative humidity whereas there was a non‐linear increase in weight loss with increasing temperature.4. The species gain most water by drinking and/or from food.5. There was no correlation between humidity response and transpiration rate or ability to tolerate dry conditions of the species. There was, however, a correlation between behaviour/habitat affinity and humidity response. Diurnal species, living in sandy or silty, half shady‐exposed habitats had an initial hygronegative response, whereas those which hide among gravel/stones, leaves or vegetation were indifferent or hygropositive.
Population dynamics of Mallophaga and Acari on reed buntings occupying a communal winter roost
Authors: FOWLER J. A. , WILLIAMS L. R. 
Published: March 2008

Abstract. 1. Mallophaga and Acari were collected from 324 reed buntings (Emberiza schoeniclus (Linnaeus)) captured in a communal winter roost between October 1980 and March 1981.2. Frequency distributions of one of the mallophagan species, (Philopterus docophorulus (Zlotorzycka)), of the aggregated Mallophaga, and of the aggregated Acari, conform well with a negative binomial model. The remaining three mallophagan species collected were not present in sufficient numbers to describe a frequency distribution.3. The ratio of nymphs to adults in the mallophagan community increased significantly in the second half of the roosting period (January–March) indicating the onset of increased reproductive activity.
Patchiness, aggregation, and the coexistence of competitors for ephemeral resources
Authors: KNEIDEL KENNETH A. 
Published: March 2008

Abstract. 1. A laboratory experiment was conducted to determine the outcome of competition between two species of carrion‐breeding Diptera for food at two levels of resource patchiness.2. Adults of Fannia howardi Malloch (Muscidae) and Megaselia scalaris Loew (Phoridae) were released into a large population cage and were given access to three 2g sections of pork kidney in one treatment (low patchiness) and to twelve 0.5g sections in the other (high patchiness).3. Increasing the patchiness of the resource resulted in reduced overlap in the distribution of the two species, and therefore less interspecific competition. However, this did not result in improved survival of the poorer competitor, F.howardi. Both species aggregated their eggs at high patchiness, and therefore suffered from increased levels of intraspecific competition.4. The experiment shows that increasing patchiness in this way could lead to prolonged coexistence, as has been predicted in other studies.
Some aspects of overwintering in southern England of the mosquitoes Anopheles atroparvus and Culiseta annulata (Diptera: Culicidae)
Authors: RAMSDALE C. D. , WILKES T. J. 
Published: March 2008

Abstract. 1. Overwintering of the mosquitoes Anopheles atroparvus van Thiel and Culiseta annulata Schrank, both of which feed on blood throughout the year, is compared.2 The aquatic stages, males and gonoactive females of A.atroparvus disappear before winter, leaving a generation of inseminated, nulliparous, diapausing females to overwinter. Blood meals taken by diapausing females merely serve to maintain fat reserves. After re‐activation in March–April, gonoactive life expectancy appears to be rather short. Aquatic development at this season is slow and eggs laid in the spring do not significantly affect adult densities until June.3. Aquatic stages, males and gonoactive females of C.annulata are present throughout the year. This species appears to be able to overwinter without recourse to diapause, females passing the winter in alternating, or lasting, states of cold‐induced quiescence or normal gonoactivity.
The relationship between feeding specialization and host plants to aldrin epoxidase activities of midgut homogenates in larval Lepidoptera
Authors: ROSE H. A. 
Published: March 2008

Abstract. 1. Aldrin epoxidase activities of midgut homogenates in fifty‐eight species of phytophagous lepidopterous larvae, were determined.2. There were no significant differences in mean activities amongst monophagous, oligophagous and polyphagous feeders. These results question the widely held view that there is a correlation between mixed function oxidase activity and feeding specialization.3. Aldrin epoxidase activity depended largely on the host which was consumed. Larvae with high activity invariably fed on hosts containing monoterpene compounds.4. The proposal that mixed function oxidases provide polyphagous insects with an effective biochemical defence against diverse allelochemicals is discussed.
Development, fecundity and survival of the herbivore Lymantria dispar and the number of plant species in its diet
Authors: BARBOSA P. , MARTINAT P. , WALDVOGEL M. 
Published: March 2008

ABSTRACT.

Larval gypsy moth Lymantria dispar (L.) mortality depends upon the number and type of plant species consumed as well as the sequence in which they are consumed.
When a two‐species diet is composed of a favourable and an unfavourable species, larval mortality is higher on the two‐species diet than on the diet of the favourable species alone.
When a two species diet is composed of a favourable and unfavourable coniferous species, larval mortality is higher on the single conifer species diet than on the two‐species diet.
Two‐species diets, in which one species is a conifer, produce individuals with a greater fecundity than diets of either species alone.
The influence of diets composed of two favourable species, on development, size and fecundity, depends both on the relative quality of each of the two plant species and which of the two is consumed by older instars.
Reproductive strategies of female butterflies: variation in and constraints on fecundity
Authors: BOGGS CAROL L. 
Published: March 2008

ABSTRACT.

This study first examines the reproductive strategy of female Speyeria mormonia Edwards (Lepidoptera: Nymphalidae):
Egg weight and number laid per day decrease with age.
Survival and daily egg number may be affected by temperature; mean daily egg weight is not affected by temperature.
Daily egg number is not correlated with body size. In the central range of body size, egg weight is also not correlated with body size. However, exceptionally large or small females lay respectively heavier or lighter eggs than average.
A simple trade‐off between offspring size and number does not occur within females on a daily basis, or among females averaged over their lifespans.
Fat body resources are depleted at a rate independent of body size.
Females are essentially monogamous.
Age‐specific fecundity data reported here for S.mormonia are next compared with data for other Lepidoptera with different adult feeding habits and egg maturation patterns, and hence different possibilities for adult feeding to play a role in egg production. Based on these comparisons, I propose that the shape of the age‐specific fecundity curve for each species under optimal conditions is constrained by the potential importance of adult nutrients in egg production.
Is the Iberian lacewing Chrysopa regalis a semivoltine species?
Authors: CANARD M. 
Published: March 2008

ABSTRACT.

Adults of the lacewing Chrysopa regalis Navás were caught in north Spain, Huesca province, Aragon.
Their progeny reared in the laboratory under short‐ and long‐day light conditions at 20°C, entered a long diapause as prepupae within the cocoon.
Transferred outdoors after spinning up, only a few (12%) became active again in the following spring, whereas the rest remained in diapause for one more year and waited for the end of the second spring to resume their morphogenetic development. Thus most of the studied strain exhibited a 2–year life cycle. This semivoltine strategy is new to chrysopid biology.
The predaceous larval phase did not exceed 3% of the total individual lifespan, though the duration of the free‐living larval instars averaged 19.9±1.1 (SD) days.
During the extended diapause, weight loss was very small, no more than 6.6% of the initial weight, 16.9±2.7 (SD) mg, at the end of diapause, and 8.8% at the time of pupal ecdysis.