摘要:

Abstract.(1) One hundred and two plants were offered to locust nymphs after a 5 h period without food. Large meals were only taken on grasses and onJuncus.Most dicotyledons were totally rejected.(2) All the plants which were relatively unpalatable yielded an extract which reduced the amount eaten, but no inhibition of feeding was induced by extracts of plants which were freely eaten. Very few of the extracts increased the amount eaten.(3) Over 100 chemicals, mostly non‐nutritional, known to occur in leaves, were tested for their inhibitory effect on feeding. Some had no effect, but most progressively inhibited feeding as their concentration was increased until no feeding at all occurred. Chemicals of many classes had this effect, but alkaloids and monoterpenoids were the most consistently deterrent at the lowest concentrations.(4) It is concluded that the failure to eat most plants results from the presence in the leaves of one or more chemicals in amounts which inhibit feeding. Grasses and a few other plants are readily acceptable because they do not contain deterrent chemicals in sufficient quantity to limit feedin

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1977.tb00861.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Abstract.1. Field host plants of the six British species ofOncopsisare described.O. avellanaeis unusual in being associated with bothCorylusandAlnus.2. Laboratory experiments on nymphal feeding preferences, nymphal and adult survival, and adult oviposition preferences are described for all species, usingCarpinus, Corylus, AlnusandBetulaspecies as test plants.3. All experiments demonstrated considerable specificity in feeding, and especially oviposition.4. It is suggested that discriminative oviposition behaviour is the major determinant of observed field distribution patterns.

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1977.tb00862.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Abstract.(1) 6449 chalcids representing 212 species, ninety‐six genera and eleven families were collected. The frequency of species and individuals did not fit a logarithmic series and Yule's index was chosen as a suitable index of diversity.(2) Species diversity of the total chalcid fauna in a zone was directly related to the number of flowering plants in the zone. However, Jaccard's coefficient of similarity between pairs of zones showed that there was little correlation between the similarity of zones based on the occurrence of plants and the presence of chalcids.(3) The Eulophidae and Pteromalidae showed two peaks of occurrence, the other families had only one. The times of peak occurrence varied on different zones and presumably reflected the main flowering period or some other seasonal aggregating factor.(4) Overall there was a higher female to male ratio. In a majority of the more common species the males were more aggregated than the females.(5) The overall sex ratio varied throughout the year, with a high female ratio at the beginning and end of the season. The Pteromalidae showed a greater fluctuation through the season and over the zones than the other families.(6) Several species were collected on the sand‐dunes although their known hosts were absent.(7) Thirteen rare species were captu

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1977.tb00863.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Abstract.1. On lime,Blepharidopterus angulatusis parasitized by a braconid,Peristenussp., which is attacked by an ichneumonid hyperparasite,Mesochorussp. The emergence and oviposition behaviour of the adult parasites and the growth of the larvae are described.2. ParasitizedB. angulatusare considerably heavier at maturity than normal, and nymphs parasitized byPeristenusconsume, during their fifth instar, 2.1 times more in dry weight of prey (lime aphids). The growth efficiency ofPeristenusis 30–37%.3. An inverse relationship between percentage parasitism and host density on different trees may have been due to differences in synchronizatio

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1977.tb00864.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Abstract.1. Capture efficiency was determined chiefly by insect type: Diptera 79–98%, Hymenoptera 60–83%, Homoptera 32–76%, Thysanoptera 27–62%, Acarina 12–40%.2. Grass length also affected efficiency, but to a lesser degree.3. Prolongation of the sampling period increased the proportions of some groups more than others.4. Capture efficiency for any group was not affected by the number of individuals present.5. Catch size did not vary with time of day.6. The method was unsatisfactory for

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1977.tb00865.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Abstract.1. Observations were made in Mexico on the subsocial behaviour and biology of some membracids. An attempt was made to quantify the amount of violence to which the female ofBilimekia broomfieldicould be subjected without causing it to abandon its eggs or larvae.2. The brooding behaviour of females of different species can be very dissimilar, even within the same genus, e.g.Polyglypta.3. The females of many species exhibit a striking reversal of behaviour when they begin to tend eggs. When not tending eggs or larvae they take evasive action, often flying away, when a large predator approaches closely. However, once they are brooding the female stays with the eggs when a large predator approaches and may behave in a manner that in a higher animal might be described as a purposeful counter‐attack.4. Brooding females ofBilimekia broomfieldiwere killed and other brooding females were used as surrogate mothers for the orphaned eggs and larvae. The surrogate mothers appeared to behave towards the strange eggs and larvae as if they had been their own.5. Observations were made on the way in which some membracids defend themselves against attacks by ants.6. During development, membracids of most species undergo morphological colour changes. The significance of the change from black aposematic in first instar larvae to bright yellow and black aposematic in later instars, a change which appears not to be reversed in any species, is discussed.7. The aposematic pattern of the larvae of some species of bothMembracisandAcanophorapartly consists of a white encrustation secreted in patches or stripes over the epicuticle. The encrustation reflects ultraviolet light, so perhaps the aposematic pattern confers some protection against other insects as well as vertebrates.8. A new species of membracid,Bilimeki broomfieldi, is describe

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1977.tb00866.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Abstract.(1) The immigration of spiders into the Lauwerszeepolder (constructed in 1969) was studied during four years in four areas. The spider fauna was sampled weekly and 65 000 specimens of eighty‐four species were caught using strip traps, window traps, simple pitfall traps and fences.(2) About sixty species from all kinds of habitats were caught rarely; nineteen species were caught in numbers that suggest that they had established populations in the study areas.(3) The four successful pioneer species, plus two marsh‐dwelling species, were most abundant during 1969 and 1970. The 1971 catch was dominated by species from saline habitats; they became less abundant in 1972 when species from non‐saline habitats increased. Only halotolerant species established populations.(4) No evidence was found that dispersing spiders select certain areas. The differences between the spider fauna of the differennt study areas arise from degrees of success in colonization by immigrants. Pioneer species are least influenced by the abiotic environment.(5) A greater aeronautic dispersal power is found in species inhabiting unstable habitats than in species from stable habitats.(6) Aeronautic activity in adult linyphiids (s.l.) is not restricted to a special season, but is related to definite phases of the phenology.(7) Male and female erigonids are equally active in aeronautic behaviour. In erigonids and linyphiids intense aeronautic activity coincides with great ground activity; on the ground males are more active than fe

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1977.tb00867.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Abstract.(1)Heteronyx obesusswarmed about twice annually on evenings when relative humidity was>80% and temperature was at or above 20°C at 19.30 hours local time.(2) Swarms were characterized by the frenzied, random flight of their component insects, and the clustering of males about females on vertical structures.(3) Early the following morning beetles searched for pasture containing favoured food plants, and then burrowed into the soil near them.(4) Adults did not ingest food before, during or for several days after swarming; the oesophagus and crop of all insects dissected was distended with gas, probably air. This condition appeared to be associated with pre‐flight behaviour of individuals.(5) The post‐swarm activity was concerned with feeding, dispersal, maturation of eggs and oviposition.(6) The distribution of individuals of the next generation was strongly influenced by presence in the sward of favoured food (sorrel,Rumexspecies) of the ad

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1977.tb00868.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Book reviewed in this article:MITES OF MOTHS AND BUTTERFLIES. By Asher E. Treat.THE SWALLOWTAIL BUTTERFLIES OF NORTH AMERICA. By Hamilton A. Tyler.APHIDS. By Roger Blackman.APHID PARASITES (HYMENOPTERA, APHIDIIDAE) OF THE MEDITERRANEAN AREA. By Petr Stary.MAN'S PLAGUE. INSECTS AND AGRICULTURE. By V. G. Dethier.STUDIES IN BIOLOGICAL CONTROL. Edited by V. L. Delucchi.

ISSN:0307-6946    

DOI:10.1111/j.1365-2311.1977.tb00869.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY