摘要:

Abstract.1. Estimates of worker populations ofFormica lugubrisZett. nests in Irish plantation woods were obtained using capture—mark—recapture methods. Forager numbers were estimated by paint‐marking individuals on the foraging routes and ‘recapturing’ by traffic counts. Colony‐size was estimated using Stradling's (1970)32P‐radiolabelling technique. Worker brood was estimated by excavation and direct count.2. Forager numbers ranged from 6906 to 64 686 (eleven nests), colony‐size ranged from 9797 to 71 052 (five nests) and worker brood ranged from 9809 to 16 269 (four nests).3. Forager number was highly correlated with the average traffic on individual routes and the nest forager populations declined rapidly in>30

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1979.tb00556.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.1. This paper describes field observations on diel changes in the nectars ofCrataegus, TiliaandEchiumin relation to microclimate and insect visits.2. Nectar concentration is highly correlated with ambient relative humidity, but the concentrative properties of the nectars differ from those of pure sugar solutions in ways that could be accounted for by microclimate or chemical effects.3. The microclimate inside flowers may influence the rate of equilibration of nectar with the relative humidity of the air, or the equilibrium concentration itself.4. The vapour pressure relationships of nectars may be influenced by the presence of components with lowr/Pvalues (that is, solutes in which solution show a relatively large lowering of vapour pressure,P, for a small change in refraction,r). Such components might be released by micro‐organisms in the nectar.5. The quantity of sugar per flower depends on the relative rates of secretion and reabsorption, among other things. The flowers we studied showed evidence for morning and evening peaks of secretion, and inCrataegussubstantial quantities of sugar were ‘sequestered’ around midday.6. The pattern of visits by bumblebees to the flowers ofTiliaandEchiumcan be related to the changing concentration of sugar in the nectar; caloric reward was probably not limiting for bumblebees visiting

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1979.tb00557.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.1. A line transect density index for small wolf spiders is described and shown by means of regression analysis to provide adequate accuracy and excellent reproducibility.2. A review of the literature discloses numerous regression and replication studies of other catch per unit effort methods possessing equal precision and reliability.3. Such methods, when used judiciously, can provide accuracy and reproducibility as good as those obtainable using the statistical methods now in wider use, and deserve serious consideration in many kinds of sampling situations.

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1979.tb00558.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.1. The number of common carabid beetles trapped‐irr a wheat field on a clay with flint soil from May to October in.1971–77 differed greatly:Harpalus rufipesandPterostichus melanariuswere numerous every year; but the appearance ofH.aeneus, P.madidus, Agonum dorsale, Nebria brevicollis, Notiophilus biguttatus, Bembidion lamprosandTrechus quadristriatuswas much more variable.2. The numbers caught were not correlated with rainfall. Catches of the large species were positively correlated with accumulated temperature above an assumed activity threshold of 5°C, whereas the smaller beetles were negatively correlated with accumulated temperature, suggesting that the danger of desiccation at high temperatures limits their activity.3. The egg‐laying periods of the commonest species were:B.lamprosandA.dorsalefrom late April to June; overwinteredP.melanarius, H.rufipesandH.aeneusin May and June, with the summer generation of these species and ofP.madidusfrom July to September;T.quadristriatusduring August and September;N.brevicollisfrom September to November;N.biguttatusandC.fossorlaid in the early summer and again in the autumn.4. A few male and femaleH.rufipesandH.aeneus, and one femaleP.melanariusandN.brevicolliswere each parasitized by a single tachinid larva; oneP.melanariuswas infested with a mermithid pa

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1979.tb00559.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.1. The relationship between the parasiteMuscidifurax raptorand its host, puparia of the Mediterranean fruit flyCeratitis capitatawas studied. Emphasis was placed on quantitative descriptions of parasite responses and behaviour.2. Female parasites ‘paralyse’ the host prior to oviposition. This treatment is not essential for larval development but crucial when oviposition took place in fully developed pupae. When having the choice females preferred to parasitize older hosts.3. Parasite efficiency was affected by temperature, and reached its greatest value at 28°C. Increasing parasite density reduced the searching efficiency when it exceeded a certain level. A stronger effect of similar type was obtained by increasing the number of males per female. Apart from affecting efficiency of search, increasing parasite density caused an increasing proportion of males in the progeny.4. Parasites responded to host density by weak functional response followed by reduction in efficiency of search due to egg limitation.5. The parasites responded to host distribution by aggregating on high host densities. Such aggregation is antagonistic to the tendency to disperse due to mutual interfer

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1979.tb00560.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.1.Ladoga CamillaL. underwent a striking expansion of range in the 1930s and early 1940s. The study was undertaken to investigate the reasons for this expansion.2. A life table study in Monks Wood, Cambridgeshire, analysed by thekfactor method, showed the key factor to be late larval and pupal mortality. The mortality of these stages, believed to be due to bird predation, was dependent on the duration of the stages. At low temperatures the stages were prolonged and mortality high. Due to this relationship mean June temperature was closely correlated with adult numbers.3. Information from entomological journals from 1900 to 1977 was used to identify the timing of the expansion of range as precisely as possible. A good agreement was found between June temperatures over the period and the timing of the expansion.4. Although weather conditions determine year‐to‐year fluctuations it is likely that long‐term habitat changes also have an impact onL.camillapopulations. The abandonment of traditional coppice management of woodland is considered to have increased the area of woodland suitable for the species and so played a role in its expa

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1979.tb00561.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.1.Callaspidia defonscolombeiwas found to be a common, solitary, thelytokous parasitoid of aphidophagous syrphid larvae. In 1977 it was bivoltine with adults being most numerous in early August and late September. It is probably polyphagous.2. An analysis of host searching behaviour suggests that females respond to an aphid odour bringing them to the region of an aphid colony.3. Syrphid hosts are located within the aphid colony by response to a contact chemical. There is a host size preference, only larger second and third instar larvae being attacked.4. Females inject a venom, which temporarily paralyses host larvae, and place the egg inside a cerebral ganglion.

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1979.tb00562.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.1. Population size as well as the absolute and relative frequencies of thephegeaandfilipendulaemimetic complexes have been estimated in an area of Central Italy selected because it is: (a) little affected by man, (b) representative of many others in the Central Appennines, and (c) containing an abundant population ofZygaena ephialtes.2. This distasteful polymorphic species belongs, in Central Italy as in other Southern areas, to thephegeacomplex (Zygaena ephialtes, yellow ephialtoid form), while in Northern and Central Europe it belongs to thefilipendulaecomplex (Z.ephialtes, red peucedanoid form).3. In the Southern areas thephegeacomplex is much more abundant than thefilipendulaeone, which gives the yellow ephialtoid form ofZ.ephialtesa strong mimetic advantage over the red peucedanoid.4. In addition,Amata phegeagreatly outnumbers the other distasteful members of its complex and emerges first.5. Throughout its flight periodZ.ephialtes, which emerges about 20 days later thanA.phegea, never attains a frequency higher than 0.03 in this complex. It is suggested that in such a situation the protection that this species gains as a mimic would be very high regardless of its unpalatability.6. These findings and others discussed in the present paper, such as the degree of unpalatability, the genetics of the mimetic form as well as the polymorphism for colour and pattern, are examined according to the hypothesis of divergent evolutionary strategies in Batesian and Müllerian mimicry. It is suggested that these are meaningful concepts but that individual mimics, of whichZ.ephialtesis one, can fall between them

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1979.tb00563.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Abstract.1. Three experimental stream bed sections were established in areas of similar depth and current velocity to examine the effect of rock size upon the distributionof Baetis intercalarisand Orthocladiinae. Each section was composed of one rock size with the diameters (mm) of the three rock classes being 30–70, 90–140 and 160–190.2. Colonization was measured at 2 week intervals over an 8 week period, and these data were used to calculated abundance or the number of individuals per unit area of stream bed and density or the number of individuals per unit area of rock surface.3. Statistical analyses reveal that rock size was of secondary importance in determining Orthocladiinae abundance and density among the experimental bed sections. Rock size differences had a more pronounced effect uponB. intercalarissince on every sampling date both abundance and density increased with rock size.4. Rock size differences appeared to have little effect on the response of Orthocladiinae to silt deposition, whereas the reverse was true forB.interca

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1979.tb00564.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

BIOLOGICAL CONTROL BY AUGMENTATION OF NATURAL ENEMIES, INSECT AND MITE CONTROL WITH PARASITES AND PREDATORS. Edited by R. L. Ridgway and S. B. Vinson.ATLAS OF THE CARABID BEETLES OF THE NETHERLANDS. Edited by H. Turin, J. Haeck and R. Hengeveld.THE BIOLOGY OFTRIBOLIUMWITH SPECIAL EMPHASIS ON GENETIC ASPECTS. By A. Sokoloff.ANT RESEARCH 1954–76. By Michael Brian and others.EVOLUTION OF INSECT MIGRATION AND DIAPAUSE. Edited by Hugh Dingle.THE COCKROACH, Volume 2. By P. B. Cornwell.OVERLAYS OF ENVIRONMENTAL AND OTHER FACTORS FOR USE WITH BIOLOGICAL RECORDS CENTRE DISTRIBUTION MAP

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1979.tb00565.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY