摘要:

Abstract.1Individual supercooling points ranged from ‐2 to ‐44°C for six species of springtails, five species from the Swiss Alps and one from lowland Britain. Individuals ofIsotomurus alticola(Carl) andIsotoma viridisBourlet without gut contents had substantially lower supercooling points than those containing food material.2Juveniles were more cold resistant than adults in bothI.alticolaandIsotoma hiemalisSchött, both with respect to supercooling point and to their survival at prolonged subzero temperatures.3Temperature and acclimation time affected the degree of supercooling of four of the Alpine species especiallyI.hiemalis.4Duration of culture period had no consistent influence on the supercooling potential of all the species.5Tests for glycerol in the body fluids of the five Alpine springtails were negative, but the presence of a sugar, probably glucose, together with a five carbon polyhydric alcohol was indicated by chromatog

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1980.tb01118.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract.1Blood‐fedAnopheles culicifacieswere 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.2By 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.3Evidence 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 w

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1980.tb01119.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract.1A mark–recapture study on the sphecid waspSceliphron 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.2Population 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 104.3Mean 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.4Minimum 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.5The 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 8.6.6The proportion of females in the Green Bay population was 0.48 ± 0.03 while 0.55 was expected at emergence.7A cyclic budget is used to estimate immigration and emigration, and these were important causes of population change.8For Jamaica, only an estimated 28% of females survived

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1980.tb01120.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract.1Gypsy moth egg masses were collected from innocuous, release and outbreak populations and reared in the laboratory on synthetic diet under identical conditions.2Outbreak 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.3Pupae from each population source were submitted to parasitization by two pupal parasitoids. EmergingB.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.

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1980.tb01121.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract.1Instar 10, 11 and 12Ischnuralarvae were maintained throughout the instar on a constant food supply (Daphnia magnaof a standard size).2A 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 oneDaphniaper day in the case of instar 10).3Larvae were able to survive long periods without food at 16°C.4Prey availability had a marked effect on development rates, which continued to increase at prey densities well in excess of 100% survival by the larvae.5The data onIschnurasurvival and development rates are compared with previously published general models of these two components of the predators' rate of increase.6We conclude that starvation is very unlikely to be a significant cause of mortality in the field forIschnura(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

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1980.tb01122.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract.1Bumble bees (Bombusspp.) 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.2Individual 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, orvice 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‐scree

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1980.tb01123.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract.1The distribution and abundance of fiveDrosophilaspecies breeding in fungi are examined by attracting adult flies to baited traps and collecting fungal fruit bodies containing the larval stages.2Changes in species frequency follow a temporal (seasonal and yearly), rather than a spatial (between and within woods) pattern.3There is a regular diurnal pattern of activity inD.subobscurabut not inD.phalerata.Temperature, light intensity, humidity and wind speed have no effect upon the daily activity ofD.phalerata.Only temperature affects the activity ofD.subobscura.4Out of 125 species of fungi collected, only forty‐eight species producedDrosophila.However, the flies are even more selective, since only five species of fungi (Phallus impudicus, Polyporus squamosus, Amanita rubescens, Pluteus cervinusandLactarius quietus) produce 80% of allDrosophilareared.5The commonest species,D.phalerata, has two or three generations per year with a winter diapause. An outline of the yearly life cycle is given, with the major breeding sites for each generation indicated.6Measures of niche overlap calculated from the data on individual fruit bodies are very low, suggesting that the five species are effectively isolated during the larval period. This ecological isolation is achieved by a summation of several niche dimensions, woodlands, seasons, fungal species, and individual fruiting body difference

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1980.tb01124.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract.1Three species ofEupteryx, E.aurata, E.cyclopsandE.urticaeare regularly found on stinging nettles in South Wales.2E.auratahost alternates between nettles in spring and autumn, andHeraclewn, EupatoriumandMenthaspecies in summer.E.cyclopsandE.urticaeattack only nettles.3All species are host specific during oviposition and show preferences to lay eggs in discrete plant regions.4A Mymarid egg parasite of the genusAnagruswas reared more commonly from eggs laid in nettles than from eggs laid in alternative hosts.

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1980.tb01125.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Abstract.1The egg masses ofSimulium ornatum, S.equinumandS.vernumare described and information is given on numbers of eggs per egg mass and the size and number of batches laid by individual females.2The oviposition sites were studied in relation to water velocity, wind speed and direction.3The incubation periods at different river temperatures and the effects of desiccation on percentage hatch and incubation times were investigated.4The numbers of eggs laid were assessed for the winter generations ofS. ornatumandS.equinum.The relevance of these to the overall production estimates is discussed

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1980.tb01126.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Book reviewed in this article:THE POLLINATION OF FLOWERS BY INSECTS. Edited by A. J. Richards.THE DYNAMICS OF ARTHROPOD PREDATOR–PREY SYSTEMS. By Michael P. Hassell.HONEYBEE PESTS, PREDATORS, AND DISEASES. Edited by Roger A. Morse.FUNDAMENTALS OF APPLIED ENTOMOLOGY, 3rd edn. Edited by Robert E. Pfadt.CASTE AND ECOLOGY IN THE SOCIAL INSECTS. By George F. Oster and Edward O. Wilso

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1980.tb01127.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY