摘要:

SUMMARYThe performance ofAphis fabaeon an artificial diet was assessed by comparing the aphid's excretion rate on the diet with that on bean plants to investigate the possibility of using this diet in toxicological studies. No significant difference was found in the rates of honeydew excretion, but the diet‐fed aphids were noticeably smaller than those fed on bean

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1980.tb02971.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

SUMMARYField bean plants were treated with benomyl in a glasshouse and nymphs ofAcyrthosiphon pisumwere then caged on the second pinnate leaf. Soil drenches of 75 μgbenomyl/ml or above increased mortality of the aphid. The concentration of methyl benzimidazole‐2–yl carbamate (MBC = carbendazim) in leaf sap, determined by aPenicillium expansumbioassay, was proportional to the concentration of benomyl applied as a soil drench or foliar spray, but lower in sprayed plants than drenched plants. The compound persisted at high concentrations in the second leaf for 4 wk but was present in low amounts in young leaves. Nymphs were also fed through membranes on artificial diets incorporating benzimidazole compounds. In this artificial system a commercial formulation of Carbendazim (Bavistin) increased aphid mortality whereas the formulation medium was inactive. Thiabendazole (as the commercial formulation Tecto 60), 2–aminobenzimidazole and benzimidazole were also inactive. It is suggested that the carbamate moiety of carbendazim causes the aphicidal activity of the co

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1980.tb02972.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

SUMMARYObservations in mushroom houses showed that the number of larvae ofL. auripilain the casing was higher than in the compost throughout the post‐casing phase of culture. The intestines of larvae from casing contained both peat and fungal material. Choice of oviposition site was accordingly non‐specific. Females from cropping houses appeared to consist of a mixture of monogenic (predominantly unsexual) and digenic (bisexual) strains. Males matured c. 2 days before females at 20 °C; such protandry appeared to be related to sexual differences in the extent of migration undertaken by the dimorphic sexes.Sciarids were reared from egg to adult equally effectively on (a) detached sporophores or on portions of (b) pileus, (c) stipe or (d) gills, all placed on moist peat, or on detached sporophores placed on a variety of inert substrates. Development was completed where sporophore material was the only food source and also occurred on peat to which only protein, particularly egg albumin, had been added. Hence, assuming no protein metabolism by a third organism, for development in the casing layer to occur, the mushroom need contribute only such proteins. However, their replacement by amino acids was not successful in limited tests.Addition of increasing amounts of the fungal metabolites mannitol and calcium oxalate to compost delayed development, and the accumulation of these materials during fungal growth may be responsible for the antagonism between mycelial and sciarid development which results in subsequent migration of emerging ad

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1980.tb02973.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

SUMMARYSymptoms of ringspot of brassicas, caused byMycosphaerella brassicicola, rarely appeared on rapidly expanding leaves of cabbages and cauliflowers but were common on fully expanded leaves.M. brassicicolaascospores did not germinate, or germinated poorly, on expanding leaves or on recrystallised wax deposits taken from these young leaves. A high proportion germinated on expanded leaves, on waxes taken from expanded leaves and on various other surfaces in the absence of nutrients.A volatile metabolite, present in the younger leaves, appears to inhibit ascospore germination.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1980.tb02974.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

SUMMARYArtificial onion oil was evaluated as a soil treatment for control of white rot in onions caused bySclerotium cepivorum. The treatment was tested at Werribee South in a red brown earth with a sclerotial population ofc. 40–100/kg soil; and at Colac in a black clay loam withc. 180/kg soil. Treatments were applied before sowing and their effect on numbers of sclerotia, disease incidence and yield of dry bulb onions determined.At Werribee South onion oil reduced numbers of sclerotia at the 0–10 and 10–20 cm depths in soil, reduced disease incidence and increased yield in comparison with the controls. Onion oil at a concentration of 5% in water and injected (440 litredha) at 10 cm was most effective. The treatment reduced sclerotial numbers at 0–10 and 10–20 cm by 77 and 91% respectively, reduced disease from 57 to 13% and increased yield by 103%. Onion oil at 25% in water had no significant effect on populations of sclerotia or on incidence of disease.In an experiment at Colac, the application of onion oil at 5% in water reduced sclerotial numbers from 187 to 87/kg, but not incidence of

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1980.tb02975.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

SUMMARYSprays of benomyl applied during the flowering period to artificially inoculated barley heads were shown to be effective against ergot disease of male‐sterile barley. Under natural conditions, using germinating ergots as a source of ascospore inoculum, the effectiveness of benomyl was reduced — the reasons for this are discussed. Timing of fungicide application was critical as none of the fungicides tested showed marked eradicant properties. Sprays of benomyl just before and at maximum flower opening were b

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1980.tb02976.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

SUMMARYThe biological, serological and physico‐chemical properties of one isolate of artichoke yellow ringspot virus (AYRV) from Greece and another from Italy were compared.Both isolates infected 56 herbaceous species and there were few differences between them in the symptoms they caused.During purification they behaved identically and both tended to aggregate. Virus particles were isometric and measuredc. 30 nm in diameter. In CsCl, virus sedimented as mixed aggregates of empty and full particles with buoyant densities varying from 1.20–1.30 g/ml and from 1.40–1.53 g/ml, respectively.The coat protein of AYRV contains a single polypeptide of mol. wt 53000 and the genome consists of two species of single‐stranded RNA with mol. wts 2.17 × 106(RNA‐1) and 1.85 × 106(RNA‐2) daltons, estimated under denaturing conditions.The two virus isolates are serologically very closely related but are unrelated to 28 other plant viruses with isometric particles. The characteristics of AYRV suggest that it is a possible member of the ne

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1980.tb02977.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

SUMMARYParticles of six nepoviruses were detected by immunosorbent electron microscopy (ISEM) in extracts of their respective vector nematodes. This technique was at least a thousand times more sensitive than conventional electron microscopy. It was also more rapid, reliable and sensitive than infectivity tests in which extracts of nematodes were inoculated to indicator plants. The viruses were detected in extracts of single nematodes, and in the roots and leaves of infector and bait plants.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1980.tb02978.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

SUMMARYA virus causing ‘eyespot’ leaf symptoms in groundnut plants was transmitted by sap‐inoculation and byAphis craccivorain the non‐persistent manner. It infected 16 of 72 species from five of 12 families and was easily propagated inArachis hypogaeaandPhysalis floridana. The virus has particlesc. 13 × 755 nm and is serologically closely related to soybean mosaic and pepper veinal mottle viruses, and more distantly to four other potyviruses. The virus differs in host range,in vitroproperties and serological properties from previously described strains of soybean mosaic and pepper veinal mottle viruses. It seems to be a distinct member of the potyvirus group and we propose the name groundnut eyesp

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1980.tb02979.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

SUMMARYHop mosaic virus (HMV) causes severe symptoms in sensitive hop (Humulus Zupulus) cultivars, but over 90% of hop plants grown in England belong to tolerant cultivars and most of these plants are infected. HMV infected 11 herbaceous species symptomlessly but infection was systemic in only three of these:Nicotiana clevelandii, N. debneyiandUrtica urens. HMV did not infect 33 other species in 13 families. The virus was transmitted in the non‐persistent manner by the aphidsMyzus persicae, Macrosiphum euphorbiaeandPhorodon humuli. It was not seed‐borne inN. clevelandii, U. wensor hop.HMV was purified by precipitation fromN. clevelandiiextracts with polyethylene glycol followed by centrifugation in sucrose density gradients. The preparations contained filamentous particlesc. 14 × 650 nm composed ofc. 6% single‐stranded RNA of mol. wtc. 3.0 × 106and a single protein species of mol. wtc. 34 000. HMV showed distant serological relationships to carnation latent, potato M, cowpea mild mosaic and hop latent viruses but it did not react with antisera to six other carlaviruses. The cryptogram for HMV is R/1: 3.0/(6): E/E:

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1980.tb02980.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY