摘要:

Abstract1In double mating experiments withDrosophila melanogasterin which one male had been irradiated, it was confirmed that sperm displacement is extensive, i.e. the second male to mate displaces most of the previously‐stored sperm.2The predominance of the second ejaculate over the first increases with the interval between the two matings, from about P2= 0.83 (second mating on the first day after the first mating) to about P2= 0.99 (interval between mating = 14 days) where P2is the proportion of offspring fathered by the second male.3A more accurate method for calculating P2values is developed for experiments in which sperm are ‘labelled’ by irradiation treatment (equation 1).4Observations of the reducing egg production of the female throughout life were also obtained. A model is examined which incorporates both the sperm competition and egg production data to predict the reproductive value to a male of a mating with a given type of female, varying in age and mating status. The relative value (in terms of probable numbers of progeny gained) of a mating with a virgin or 4 day post‐mating female is about twice that of a 14 day post‐mating female, mainly because of the fecundity difference.5Some evolutionary aspects of sperm competition and multiple mating in insects are reviewed and

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01217.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1Anthocoris confususfemales show the greatest egg production when fed on eight adultAulacorthum circumflexusper day. Prey densities below six result in a marked fall off in egg production.2Low prey densities result in reduced egg fertility and a decrease in oviposition period.3A.confususfemales oviposit on those parts of a broad bean plant which support the highest aphid densities. This increases the probability of survival of the emerging nymphs.4Females are also able to distinguish between young, fully turgid, plants and older, more flaccid, plants and oviposit preferentially in the younger ones. Thus the eggs develop before the plant dies.

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01218.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1The searching behaviour ofA.confususfemales was investigated in an artificial arena.2Females showed an increase in the frequency of turning movements following feeding and this concentrated search in a small area. As a result more prey were found in areas where prey distribution was clumped.3If no prey was encountered within 5–8 min the search track straightened out.4First and second instar nymphs searching on broad bean plants moved faster on the undersides of leaves which were the sites most likely to support aphid populations. A considerable proportion of available time was wasted in periods of inactivity.5It was concluded that while plant topography strongly influences search pattern, the underlying trend demonstrated in these experiments was of advantage to predators searching for colonial pre

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01219.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1Immature apterae of five species of cereal aphid were distinguished by ultraviolet examination of chromatograms of their fluorescent pigments.2Non‐expert examiners could identifyMetopolophium dirhodum, Sitobion fragariaeandRhopalosiphumpadiwith a mean reliability of 98, 83 and 71% respectively;Metopolophium festucaeandSitobion avenaecould be separated from the rest but not from each other.3All species gave consistent chromatograms whether reared on oats or on wheat: some species produced atypical traces if reared on certain grasse

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01220.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1Catches of male pea moths in six designs of trap, each containing (E,E)‐8,10‐dodecadienyl acetate as an attractant, were compared; triangular‐shaped traps caught most moths.2The vertical distribution of moths within a pea crop and the size of catches at different levels varied in different wind speeds. Three‐quarter crop height is probably the optimum height for monitoring.3Five trap designs (including the triangular type) captured only 20–30% of individuals landing on them; water traps were slightly more efficient.4There was an eight‐fold range in the number of moths caught depending on the sticky material used. ‘Bird‐Tanglefoot’ was most effective.5Smoke plumes, emitted from different trap designs in the field to simulate plumes of attractant, were photographed and measured. The effect of trap design on plume shape was confirmed in wind tunnel tests.6Field tests showed that the more elongated the mean plume emitted from a trap the greater the catch.7The tracks of individual moths flying to traps are discussed in relation to current views on orientation

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01221.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1Examination of 606 mammals of seventeen species and 959 birds of thirty‐three species yielded sixty‐three species or species groups of ectoparasitic arthropod. These included eighteen species of Acari, twenty‐five species or species groups of Phthiraptera, eighteen species of Diptera Pupipara, and two species of Siphonaptera. These are listed with their hosts and island localities, and host associations noted.2Host specificity amongst ectoparasitic insects is discussed, and the insects classified into four groups of decreasing specificity.3Several broad factors likely to encourage specificity are noted, and it is concluded that the wide diversity of specificity observed is caused by complex interaction of these fa

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01222.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1Subcoccinella 24‐punctata(L.) is exclusively phytophagous, and is widely distributed throughout Britain.2Under laboratory conditions the duration of pre‐adult instars is about 6 weeks. Adults appear from the end of June onwards. Many enter reproductive diapause at the end of July, but remain active till the end of October.3Reproductive diapause is determined by the interaction of photoperiod and temperature.4Hibernation is unstable, and there may be high mortality in overwintering adults. These finally die during May and June.5The cool temperate climate limits the population size, preventing it from reaching pest proporti

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01223.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1Xenylla griseaAxelson andLepidocyrtus cyaneusf.cinereusFolsom were reared on brown whole wheat flour in culture jars containing a base of plaster of paris and charcoal.2Sexes inX.griseamay be differentiated by the combination of three characters: length, colour and body shape. No parthenogenesis was observed in either species.3At room temperature (25–27°C), females ofX.griseabegan laying eggs after the fourth moult and required 10–15 days (mean of 12.6) to reach sexual maturity from the day of hatching. WithL.cyaneusf.cinereus, average periods from hatching to maturity were 16.8, 27.4 and 43.2 days at temperatures of 26.5, 22 and 15°C, respect

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01224.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1The records of migration ofAndronymus neanderin Africa are summarized and mapped.2The present known distribution suggests a possible difference between their behaviour in East and West Africa.3At Amani, in North‐East Tanzania, migrations of millions of individuals were recorded flying SW in March, April and May; their direction of flight was independent of the direction of the wind in nine different year

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01225.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Insect Ecology.By PeterW. PriceHandbuch der Schmetterllngszucht: Europäische Arten.By EkkehardFriedrichLiving Insects.By R. D. Hughes. Pp. 304, 60 plates (43 col.), 69 text‐figsKey for the Field Identification of Apterous and Alate Cereal Aphids with Photographic Illustrations.By R. N. B. PriorThe Butterflies of North America.By WilliamH. Howe, coordinating editor and illustrator, and twenty contributorsInsects, Science, and Society, edited by DavidPimentelBees and Beekeeping.By RogerA. Mo

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01226.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY