摘要:

Abstract1Locusta migratoriain the field feeds mainly on grasses, including cultivated species, but there are numerous reports of feeding on other monocotyledons. Feeding on dicotyledons is reported, but in many cases non‐grasses are only accepted in the absence of grasses. Previous laboratory work also indicates that grasses comprise the main food, though other plants are eaten.2Field observations on nymphal bands in Australia show that the insects select grasses within the habitat; dicotyledons are generally rejected.3The feeding response to 209 species of plants from fifty‐six families was tested. The grasses and some Cyperaceae and Juncaceae were generally fully eaten. Some other monocotyledons, such as palms, were also accepted though only small amounts were eaten; orchids and lilies were rejected. Very few dicotyledons were eaten. The dicotyledons which were eaten after 5h without food were rejected after only 1 h; the grasses were readily accepted after the shorter interval4The degree of oligophagy depends on the choice of food available and the time for which the insect has been deprived of food and water. Grass is normally eaten if available; in its absence, insects which have been without food for some hours will feed on a wide range of plants, but the amounts eaten are usually sm

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01227.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1Temperate woodland canopy as a habitat for insects is discussed.2A general account is given of the Typhlocybinae as the mesophyll‐feeding guild of canopy feeders.3Three sampling sites in South Wales are described, from which adult leaf‐hoppers were sampled regularly from twelve species of trees during 1974.4Rearing records, based on the sampling of last instar nymphs and subsequent rearing of adults, are given.5Over 20 000 adult insects of thirty‐five identified species were taken during 1974.6Results are analysed to compare species associations with different tree species. Most leaf‐hoppers show very distinct specific plant‐dependent distributions within the canopy. Many are dominantly associated with only one host plant. Others show more complicated patterns of associations. Only one species was found on all trees sampled.7The patterns of leafhopper distributions in woodland canopy are compared with previously described grassland habitats. The relative permanence and size of trees may be important factors.8Examples of groups of ecologically similar species coexisting together are

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01228.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1Four sets of experiments were devised to evaluate the absolute size of aedine larval populations. Three methods were used and compared: ‘capture‐recapture’, ‘removal’ and ‘dipping’ methods.2The results show that ‘dipping’ gives estimates of population size similar to those obtained with the two other methods, providing that a strict procedure is followed.3Since the ‘dipping’ technique is particularly easy, the results offer new possibilities for the study of population

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01229.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1The vegetation of New Jersey tidal salt marshes is composed primarily of two grasses,Spartina patens, which occupies a narrow elevational zone of high marsh and varies little in structure from site to site, andSpartina alterniflora, an intertidal species which occurs as two spacially separated growth forms (tall and short). Fulgoroids, polymorphic for wing length, inhabit these grasses.2Populations of the common fulgoroid inhabiting short formS.alterniflorawere composed of equal numbers of macropters and brachypters. Mesothoracic wings of brachypters were subequal in length to the abdomen allowing for short but inefficient flights compared to macropters.3Fulgoroidsresiding inS.patensproduced mostly brachypters having small meso‐and vestigial metathoracic wings and were incapable of flight.4Brachypter density of all fulgoroids was correlated with the seasonal increase in biomass of the host grass, while macropter density was not.5Peak macropter density occurred shortly before maximum biomass of the host grass was attained.6The production of macropterous forms was correlated with high levels of crowding incurred during nymphal stages.7Spatial and temporal variation in the structure of the host grasses and habitat reliability are suggested as important factors dictating the wing‐polymorphism strategies of fulgoro

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01230.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1Catches ofCulicoidesmade on a rocky hill and river bank in south‐western Nigeria showedCulicoides grahamiandC.distinctipennisto be dominant. The former was most active at dusk and the latter at dawn.2The number of matured eggs in the gravid femaleCulicoidescaught on the hill and riverbank was low compared with those in gravid females of the same species caught around livestock.3The fat bodies of all the dissected nulliparous and newly emergedCulicoideswere full and large; those of the parous ones were depleted and inconspicuous except in individuals caught between June and July. The crop of most of the adultCulicoidescontained colourless to dark yellowish fluid.4C.grahamiwas the most numerous of the newly‐emerged species followed byC.distinctipennis.5On the rocky hill,Culicoidesbred in rotholes and boggy ground in between the rocks; at the river bank, breeding sites were underneath partially waterlogged canoes, in crabholes and other crevices, and underneath rotten vegetation.6The influence of rainfall on theCulicoidespopulation is discussed. Most of the species had adapted themselves to nectar feeding and autogeny was common. Perhaps some species aestivate during the hot dry sea

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01231.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1In summer the sycamore aphid's responses to gravity, light direction and intensity and unidentified features of a leaf's surface result in the aphid settling and feeding on the undersurface of leaves.2At this time the petioles are a poor source of food and are not colonized.3Removal of leaf laminae results in premature abscission of the petioles. Prior to abscission the petioles become senescent and a richer food source than the laminae of mature leaves, and are colonized by aphids.

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01232.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1The timing of adult eclosion in forest zone blackflies of the Bandama cytotype of theSimulium damnosumcomplex in the Ivory Coast was investigated both in the field and laboratory.2An eclosion trap and a simple technique for keeping black‐fly pupae in the laboratory are described.3Hourly collections of newly emergedS.damnosumadults showed that there was an eclosion peak at 05.30–06.30 hours in the field and at 07.00–08.00 hours in the laboratory. Approximately 30% of the blackflies in the field emerged at 06.00–06.30 hours.4S.damnosumkept under natural light‐dark conditions in the laboratory did not show any delay in the timing of the eclosion peak, relative to that of the first day in the laboratory, until the third day of the e

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01233.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1The way in which the predatorAnthocoris confususreacts to the presence of other individuals of the same species is described.2Mutual interference between adultA.confususleads to a density‐dependent decrease in egg production, due mainly to an increased tendency to migrate from areas of high predator density.3Even when ten first instar predators were present in a 2 cm diameter cage they did not interfere with each other unless the amount of food available was inadequate for survival.4Mutual interference betweenA.confususadults promotes stability in populations of the predator and will lead to even exploitation of an unevenly distributed food sourc

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01234.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Abstract1Two hyperparasites,Cheiloneurus paralia(Walker) andMarietta exitiosaCompere, ofMicroterys flavus(Howard), a primary parasite of the brown soft scaleCoccus hesperidumL. have been studied.2The area of discovery of the hyperparasites for secondary hosts (scale insects) is greater than that of the primary parasite, indicating higher searching efficiency of the secondary parasites.3Cheiloneurushas a higher searching efficiency measured as its area of discovery for discovering both the secondary (scale insect) and the primary (Microterys) hosts, as compared withMarietta.4The searching efficiency ofCheiloneurusincreased in the presence of its own males.5In each species there is a non‐linear relationship between the searching efficiency and female density.6CheiloneurusandMariettapresent two differing searching strategies.Cheiloneurustends to exploit as many primary hosts as possible in each secondary host encountered, whereasMarietta, tends to disperse its progeny more regularly by avoiding, to a certain extent, the exploitation of more than one host in each scale insect encountere

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01235.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY

摘要:

Butterflies of Lebanon.By TorbenB. LarsenProceedings of the First International Symposium on Trichoptera, Lunz am See(Austria),September16–20, 1974. Edited by HansMalickyMosquito Ecology: Field Sampling Methods.By M. W. ServiceButterflies: their World, their Life Cycle, their Behaviour.By ThomasC. EmmelButterfly Culture: a Guide to Breeding Butterflies, Moths and Other Insects.By JohnL. S. Stoneand H. J. Midwinter, with a foreword by JohnnyMorrisAnnual Review of Entomology, Vol. 21. Edited by RayF. Smith, ThomasE. Mittlerand CarrollN. Smi

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1976.tb01236.x

出版商:Blackwell Publishing Ltd    

年代:1976

数据来源: WILEY