bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of prey‐size and predator‐instar on the predation of Daphnia by Notonecta
Authors: McARDLE B. H. , LAWTON J. H. 
Published: March 2008

Abstract. 1. Attack rates and handling times are measured by a series of separate functional response experiments for each instar of Notonecta glauca attacking four size classes of Daphnia magna as prey. The resulting attack rate and handling time surfaces are complex, with maximum attack rates for small predators attacking small prey, and large predators attacking large prey. Adult Notonecta have lower attack rates than the two previous juvenile instars (4 and 5).2. The literature on attack rates and handling times in other predator—prey interactions that involve a series of different predator and prey size or age classes is reviewed in the context of the Notonecta‐Daphnia results. The data suggest that small predator instars will usually compete with large instars for food, unless there is spatial or temporal separation between them.3. Complex attack rate and handling time surfaces are to be expected wherever a wide range of prey and predator sizes is involved.4. Size related changes in attack rates and handling times can introduce very complex dynamics into predator‐prey interactions.
Characteristics and distribution of opposition sites of the grasshopper Zonocerus variegatus (L.)
Authors: PAGE W. W. , McCAFFERY A. R. 
Published: March 2008

Abstract. 1. The dry‐season population of Zonocerus in southern Nigeria oviposits in dense aggregations under single or clumped woody plants or on the edge of tall continuous stands of vegetation. No egg pods were found oviposited singly.2. The vegetation under which oviposition occurs is the most common available at the time of the year. There seems to be no selection of particular species of plants so long as they provide good low shade.3. Oviposition can take place in a wide range of gravelly soils.4. Topography is not important as long as the oviposition site is on high ground away from damp areas subject to flooding.5. There was a mean of 618 pods per oviposition site from forty‐one sites which were dug up, and there was a significant correlation between the area of a site and the number of pods.6. There was a marked tendency for oviposition sites to be found close to cassava. At two localities of approximately 20 ha each 90% of the sites were found within 30 m of cassava.7. It is suggested that permanent shade is the most important factor in the selection of a site and this is probably related to the survival of the eggs during their 6–7 months development.
Development of Habrolepis rouxi Compere (Hymenoptera: Encyrtidae) in two armoured scale hosts (Homoptera: Diaspididae) and parasite egg encapsulation by California red scale
Authors: BLUMBERG DANIEL , DeBACH PAUL 
Published: March 2008

Abstract. 1. California red scale Aonidiella aurantii (Maskell) and oleander scale Aspidiotus nerii Bouché (Homoptera: Diaspididae) are not completely suitable for the development of the encyrtid endoparasite Habrolepis rouxi Compere.2. Mortality of parasite immatures in California red scale is caused mainly by egg encapsulation. Although oleander scale is unable to encapsulate H. rouxi, it is nutritionally unfavourable for the parasite's development.3. Some immunity to the parasite is conferred to the oleander scale by the particular host plant used.4. The parasite's rate of development is not influenced by the host species studied.5. The mortality of parasite immatures in California red scale is lower than in oleander scale. The former host also is more acceptable and preferred by the parasite for ovipositon. These characteristics of the California red scale render it more suitable than oleander scale as host for H. rouxi.6. Studies on the encapsulation of H. rouxi eggs by the California red scale indicate that (i) encapsulation does not prevent third instar host larvae from maturing and producing progeny; (ii) neither rearing temperature nor host age affect encapsulation frequency.
Abundance and reproductive strategy of the dung beetle Aphodius rufipes (L.) (Scarabaeidae)
Authors: HOLTER P. 
Published: March 2008

Abstract. 1. Adult A.rufipes invade fresh dung pats (mainly in August) and stay for a few days in each pat to feed and oviposit; maximum abundances: 0–100 beetles per cattle dung pat. Larval growth is completed within 40–55 days.2. The dispersion of beetles is contagious or seemingly random. In sunny weather, with rapid crust formation on the dung, pats deposited in the afternoon are invaded by more beetles than those deposited in the morning.3. In the field, the total number of eggs per pat is significantly less variable than the number of adult beetles; this might indicate a density‐dependent, regulatory, rate of oviposition. The subsequent larval mortality is probably density‐independent.4. Experiments confirmed that the number of eggs laid per female‐day in the pats was density‐dependent.5. The non‐opportunistic reproductive strategy of A.rufipes may have evolved as an adaptation to life in dung pats: at excessive population densities pats might disappear before completion of larval growth.6. Finally, A.rufipes in dung pats is compared with blowflies breeding in carrion.
The responses of carrot fly larvae, Psila rosae, to components of their physical enrivonment
Authors: JONES O. T. 
Published: March 2008

Abstract. 1. The responses of third instar Psila rosae (F.) larvae to light, temperature, humidity and soil moisture were investigated in the laboratory.2. Larvae were photonegative and preferred a temperature of about 15°C. Temperatures between 30 and 40°C adversely affected movement and over 40° C were lethal.3. In choice chambers, larvae preferred humidities of 70–100% r.h. and larvae in sand avoided dry conditions (2.5% field capacity). The latter response became more marked as larvae approached the pre‐pupal stage when moistures of 40% field capacity and lower were avoided.4. Most larvae were found at a depth of 8 cm in sand of uniform moisture content and temperature, but variation in moisture content could alter this preference.5. In August, most larval damage in the field occurred near the tip of the carrot tap root but was more evenly distributed over the roots in November. It is uncertain whether this was due to soil near the surface being drier in August or whether it was caused by behavioural differences between the two generations of carrot fly larvae.6. During the summer of 1975, low soil moisture levels resulted in the total absence of larval mines on the carrot roots even though pupae were found at depths of 20–30 cm in the soil. Temperature had no effect on the distribution of mines on carrot roots except at the top 2 cm of the soil profile.
Effects of constant and variable temperature extremes on sex ratio and progeny production by Aphytis melinus and A.lingnanensis (Hymenoptera: Aphelinidae)
Authors: KFIR RAMI , LUCK ROBERT F. 
Published: March 2008

Abstract. 1. Aphytis melinus DeBach and A.lingnanensis Compere were exposed to temperature extremes during development, mating, preoviposition, and opposition to assess the effect of these exposures on the progeny per female and F1 sex ratio.2. Both species showed a significant reduction in the expected proportion of F1 females when the male parent was exposed to 32°C during its development.3. The proportion of females was further reduced when mating and/or oviposition occurred at 32°C and these effects on sex ratio appeared cumulative.4. Preovipositional exposure of the females of both species to 38°C, 2°C or ‐2°C for 1 5, 4 or 7 h in most cases significantly reduced the expected proportion of females.5. In general our results showed that the sex ratios of A.melinus was less severely affected by these exposures than were those of A.lingnanensis.6. It is suggested that this difference may be one factor explaining the ability of A.melinus to exclude A.lingnanensis from the climatically more extreme areas of southern California.
A study of fungus flies (Dipteral Mycetophilidae) in beech woodland
Authors: RUSSELL‐SMITH A. 
Published: March 2008

Abstract. 1. A study was made of larval and adult Mycetophilidae in coppiced beech woodland in southern England. Adult mycetophilids were trapped throughout 1968 using sticky traps at ground level. Larvae inhabiting terrestrial fungi were collected from all sporophores from a defined area of the woodland floor between August and October 1968.2. Larval mycetophilids were extracted from only 12.6% of all sporophores collected and from fifteen of thirty‐eight species of fungi present. Some species of fungi were never inhabited by larval mycetophilids while others appeared to be highly attractive to them. Since it was not possible to identify the larvae beyond the level of tribe it was impossible to ascertain host preferences for different species. Peak numbers of larvae occurred at the beginning of September and the beginning of October.3. Adult mycetophilids had two peaks of activity, the first in March and April when the dominant species were Boletina gripha and Phronia basalis and the second in autumn when species of the genus Mycetophila were dominant. Phronia basalis is a species whose larvae inhabit dead wood and the abundance of this species (40% of all adults) probably reflects the amount of rotting wood in this type of habitat. The autumn peak of adult activity was due to species known to inhabit agaric sporophores and came about 1 month after the peak of larval numbers in fungi.4. The adult fauna was rich with 107 species representing about a quarter of the known British fauna. However, only twelve species were trapped in sufficient numbers to allow deductions concerning seasonal activity.5. The results were discussed with respect to the problems of assessing populations of insects inhabiting fungal sporophores and to the previous work on this neglected group.
Sex ratio regulation in Coccygomimus turionella Linnaeus (Hymenoptera: Ichneumonidae) and its ecological implications
Authors: SANDLAN KENNETH 
Published: March 2008

Abstract. 1. Sex regulation and its relevance to the ecology of a k‐selected pupal parasitoid was investigated in Coccygomimus turionellae.2. The ratio varied with host size, females predominating in large hosts.3. Egg transfer experiments and comparative mortality rates among the progeny of virgin and inseminated females demonstrated that the phenomenon was due to parental behaviour.4. The study of the mechanism confirmed Aubert's hypothesis of host size estimation with the addition that the host had to be exposed from the poles and had to contain the proper host kairomones.5. Host size was highly correlated to parasitoid fecundity via influences on size and longevity but not the number of ovarioles per female or daily egg production.6. Host encounters are more limiting than egg production and host size had no effect on host acceptance.7. Sex regulation allows a maximal host encounter rate at the same time that it maximizes the reproductive potential of female progeny.8. Low host density increased the production of female progeny resulting in more offspring searching for the limited resource. Concealed hosts and a high host density resulted in a shift towards a Fisher 1:1 sex ratio.
Environmental control of pupal colour in swallowtail butterflies (Lepidoptera: Papilioninae): Battus philenor (L.) and Papilio polyxenes Fabr.
Authors: HAZEL WADE N. , WEST DAVID A. 
Published: March 2008

Abstract. 1. Some swallowtail butterflies produce both green and brown pupae. The phenotypes result from the joint action of genotype and environment and usually make the pupae cryptic in their habitats.2. The major environmental cues influencing pupal colour in two swallowtail species were determined to be textural and optical.3. Differences in the usage of these kinds of cues in the two species are thought to have evolved because of major differences in the pupation habitats. P.polyxenes, which usually pupates on slender stems amidst vegetation, responds more strongly to optical cues. B.philenor, which usually pupates on exposed surfaces of tree trunks and cliffs, responds more strongly to textural cues.4. Differences in the overall tendency to produce brown pupae (‘sensitivity’: Hazel, 1977) are thought to be related to the frequency of brown pupation sites utilized by these two species: high average sensitivity in philenor, which often uses brown sites, and lower average sensitivity in polyxenes, which often uses green sites.
A preliminary study of dispersal and survival of Anopheles culicifacies in relation to the possibility of inhibiting the spread of insecticide resistance
Authors: CURTIS C. F. , RAWLINGS P. 
Published: March 2008

Abstract.

Blood‐fed Anopheles culicifacies were collected in a cow‐baited hut, marked with fluorescent powder and released in the same hut. Captured mosquitoes were checked for the presence of marks from the previous day's releases. These checks were carried out on those captured in the release hut and in three similar huts at distances of up to 500 m away.
By dividing the percentage found to be marked in the outlying huts by the percentage marked found on the same day in the release hut, estimates were made of the extent of ‘overlap’ between the populations sampled by the different huts.
Evidence from the rate of build‐up in the percentage marked, from the daily loss rate when a ‘pulse’ of a different colour mark was used, and from the parity rate, gave information on mosquito survival and the interval between marking and recapture. This was notably high in view of earlier field work on the same species in India and of the fact that all houses on the site of the present experiment had been sprayed with malathion.
A population study in Jamaica on adult Sceliphron assimile (Dahlbom) (Hymenoptera: Sphecidae)
Authors: FREEMAN B. E. 
Published: March 2008

Abstract.

A mark–recapture study on the sphecid wasp Sceliphron assimile (Dahlbohm), analysed by Jolly's stochastic method (1965), was made from 3 December 1974 to 22 February 1975 at Green Bay, St Catherine, Jamaica.
Population levels in an 18.2 ha study area fluctuated about a mean of 281 for males, 259 for total females and 87 for reproducing females, while the probable carrying‐capacity for these reproductives was about 104.
Mean estimated daily survival rates were 0.903 for males, 0.924 for total females and 0.945 for reproducing females. For the first two categories these rates decreased (p < 0.02) during the study, probably reflecting increasing emigration. Reproducing females probably do not emigrate and their survival did not significantly decrease.
Minimum age was linearly related to wing wear (r=+0.69, P < 0.001) and the latter associated with the progressive maturation and ageing of the ovaries. All surviving females become parous by middle age.
The mean rate of fecundity in the field was dependent on female age and was reduced during prolonged drought. Curves of total achieved fecundity appropriate to realistic survival rates give 4.2–16.8 eggs/female. The Jamaican mean was 9.6 ± 2.3 and that for Green Bay 8.6.
The proportion of females in the Green Bay population was 0.48 ± 0.03 while 0.55 was expected at emergence.
A cyclic budget is used to estimate immigration and emigration, and these were important causes of population change.
For Jamaica, only an estimated 28% of females survived to nest.
Interpopulation quality in gypsy moths with implications for success of two pupal parasitoids: Brachymeria intermedia (Nees) and Coccygomimus turionellae (L.)*
Authors: GREENBLATT J. A. , BARBOSA P. 
Published: March 2008

Abstract.

Gypsy moth egg masses were collected from innocuous, release and outbreak populations and reared in the laboratory on synthetic diet under identical conditions.
Outbreak population gypsy moths hatched sooner, were smaller and less fecund than innocuous or release gypsy moths, but had a higher concentration of total carbohydrates in their haemolymph.
Pupae from each population source were submitted to parasitization by two pupal parasitoids. Emerging B.intermedia, an established parasitoid of the gypsy moth associated with outbreak populations, were largest on outbreak source gypsy moths. C. turionellae, not a usual parasitoid of the gypsy moth, were largest when emerging from innocuous or release population gypsy moths. Implications for population dynamics of the gypsy moth are discussed.
The effects of prey density on survival and growth of damselfly larvae
Authors: LAWTON J. H. , THOMPSON B. , THOMPSON D. J. 
Published: March 2008

Abstract.

Instar 10, 11 and 12 Ischnura larvae were maintained throughout the instar on a constant food supply (Daphnia magna of a standard size).
A very narrow range of prey availability separated cohorts in which all the larvae successfully moulted to the next instar, from those in which all the larvae died (less than one Daphnia per day in the case of instar 10).
Larvae were able to survive long periods without food at 16°C.
Prey availability had a marked effect on development rates, which continued to increase at prey densities well in excess of 100% survival by the larvae.
The data on Ischnura survival and development rates are compared with previously published general models of these two components of the predators' rate of increase.
We conclude that starvation is very unlikely to be a significant cause of mortality in the field for Ischnura (or indeed most other Odonata larvae), but that prey availability undoubtedly influences development rates. Natural selection should therefore favour larvae that forage optimally to minimize development times.
The effect of nectar abundance on foraging patterns of bumble bees
Authors: MORSE DOUGLASS H. 
Published: March 2008

Abstract.

Bumble bees (Bombus spp.) fed more on previously screened, nectar‐rich plots of cow vetch (Vicia cracca) and white clover (Trifolium repens), and remained longer on inflorescences there, than on continually‐exploited plots of these flowers. No significant differences between previously screened and continually available plots occurred in the number of individuals visiting these two areas, the number of inflorescences per visit, the number of florets visited per inflorescence, and the percentage of inflorescences rejected.
Individual bees were analysed in greater detail. They visited more inflorescences and spent longer times on cow vetch in the previously‐screened plots, whether moving from previously‐screened to continually available areas, or vice versa. On white clover the same pattern held for bees moving from previously screened to continually available plots, but not for those moving from continually available to previously‐screened areas.
Quantitative studies on the eggs of Simulium (Simulium) ornatum Meigen and Simulium (Wilhelmia) equinum L. in a chalk stream in southern England
Authors: WELTON J. S. , BASS J. A. B. 
Published: March 2008

Abstract.

The egg masses of Simulium ornatum, S.equinum and S.vernum are described and information is given on numbers of eggs per egg mass and the size and number of batches laid by individual females.
The oviposition sites were studied in relation to water velocity, wind speed and direction.
The incubation periods at different river temperatures and the effects of desiccation on percentage hatch and incubation times were investigated.
The numbers of eggs laid were assessed for the winter generations of S. ornatum and S.equinum. The relevance of these to the overall production estimates is discussed
Insect–fern interactions: macrolepidopteran utilization and species–area association
Authors: AUERBACH MICHAEL J. , HENDRIX STEPHEN D. 
Published: March 2008

Abstract.

The generalization that ferns are under‐utilized by phytophagous insects in comparison to angiosperms may be invalid because of biases involving plant growth form, plant range, and unequal sampling efforts.
Comparison of nineteen fern species with 652 herb species, the angjosperm growth form most similar to the ferns, indicates no significant difference in the mean number of supported macrolepidopteran species. When the herbs are subdivided into annuals, biennials and perennials, only the annual herbs are significantly different than the ferns.
Comparisons of the occurrence distributions for ferns and the herb categories also demonstrate that only the annual herbs support more macrolepidopteran species than the ferns. The same results are obtained when random assemblages of herbs are created that are the same size as the fern assemblage.
Both the occurrence distributions and the species–area relationship for the ferns indicate that host records for insects feeding on ferns may be grossly incomplete.
The similarity of exploitation of ferns and perennial herbs by the Macro‐lepidoptera suggests that other foliage feeding insects may also use ferns at levels equivalent to angiosperms.
The distribution and abundance of the coccid leery a seychellarum Westw. on Aldabra atoll
Authors: HILL M. G. , NEWBERY D. McC. 
Published: March 2008

Abstract. Icerya seychellarum, a polyphagous phloem feeding coccid, was discovered on Aldabra atoll in 1968. It was not recorded by early expeditions to the atoll, and is probably a recent introduction. Its infestation rose to a peak density around 1975, and thereafter declined, as revealed by a comparison of fifty‐one woody taxa common to three surveys. In 1975, twenty‐one taxa were ‘heavily’ infested and twenty‐one ‘lightly’/‘moderately’ infested. By the end of 1978, no taxa remained ‘heavily’ infested and thirty‐seven were ‘lightly’/‘moderately’ infested. The state of vegetation showed negligible change between the 1976/77 and 1978 surveys, refuting an earlier prediction that it would be substantially modified by the Icerya infestation.The subsequent decline in infestation cannot here be attributed to the development of natural enemies. Possible reasons, which are discussed, include changes in the quality of the coccid or its host.
Nerium oleander as an alternative host plant for south Florida milkweed bugs, Oncopeltus fasciatus
Authors: KLAUSNER EDWARD , MILLER ELIZABETH RUTH , DINGLE HUGH 
Published: March 2008

Abstract.

Life history data were gathered for south Florida Oncopeltus fasciatus reared from eggs on Nerium oleander seeds and milkweed seeds in the laboratory.
Milkweed seeds were found to be a superior food source since O.fasciatus grew faster, laid more clutches, and has a higher total fecundity on milkweed seeds.
Fruiting N.oleander was found to be a better food source than nonfruiting milkweeds in a summer field study in south Florida since no nymphs survived to the adult stage on nonfruiting milkweeds but some did on N.oleander.
O.fasciatus adults and nymphs are abundant on N.oleander in the summer in south Florida when N.oleander is fruiting; no O.fasciatus nymphs are found in the summer on the milkweeds which are not fruiting.
O.fasciatus leave N.oleander in the autumn when milkweeds start to fruit and can then be found on fruiting milkweeds.