Neozygites fresenii. [Descriptions of Fungi and Bacteria].

1984 ◽  
Author(s):  
N. Wilding
Keyword(s):  
Host Plant ◽  
Geographical Distribution ◽  
Germ Tube ◽  
Aphis Fabae ◽  
Insect Cuticle ◽  
Plant Tissues ◽  
Neozygites Fresenii ◽  
The Tropics ◽  
Aphid Populations

Abstract A description is provided for Neozygites fresenii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Aphids (Homoptera: Aphididae) especially species of the genus Aphis. GEOGRAPHICAL DISTRIBUTION: Very widespread, including Europe, N. & S. America, Asia, Africa, Polynesia. DISEASE: Capilloconidia adhere to the aphid by the sticky apical droplet. A germ tube is produced which forms an appressorium on the insect cuticle and a tube from the appressorium then penetrates it. Aphids killed by N. fresenii characteristically hang from the stems and the underside of leaves of the host plant by the proboscis inserted in the plant tissues. Aphis fabae killed by this species are orange in colour when dry and grey in moist conditions as the fungus begins to sporulate. This fungus is most frequently associated with dense populations of aphids in warm seasons and is unusual in attacking aphid populations in the tropics.

Entomophthora planchoniana. [Descriptions of Fungi and Bacteria].

1984 ◽  
Author(s):  
N. Wilding
Keyword(s):  
Geographical Distribution ◽  
Germ Tube ◽  
Common Species ◽  
The Other ◽  
Cereal Aphids ◽  
Erynia Neoaphidis ◽  
Resting Spores ◽  
Neozygites Fresenii ◽  
Aphid Populations

Abstract A description is provided for Entomophthora planchoniana. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Aphids (Hemiptera: Aphididae) including species of Cinarinae, Chaitophorinae and Drepanosiphanae which are not usually attacked by the other common species of the Entomophthorales. GEOGRAPHICAL DISTRIBUTION: Widespread, including Europe, N. & S. America, Australasia, Asia. DISEASE: Aphids become infected by a germ tube from an adhering conidium penetrating the cuticle. Naturally green aphids killed by this species are straw coloured and those filled with resting spores are grey. Black aphids turn reddish-brown. The rhizoids issuing from infected large aphids viewed from the side suggest stout supports. In N. Europe this species persists in aphid populations in warmer and drier conditions than all the other species attacking aphids except Neozygites fresenii. It frequently infects cereal aphids infesting the ears of cereals whereas Erynia neoaphidis is usually restricted to aphids on the leaves of the plant where conditions are less extreme.

Conidiobolus obscurus. [Descriptions of Fungi and Bacteria].

1984 ◽  
Author(s):  
N. Wilding
Keyword(s):  
Host Plant ◽  
Geographical Distribution ◽  
Bright Light ◽  
Plant Tissues ◽  
Stems And Leaves ◽  
Germ Tubes

Abstract A description is provided for Conidiobolus obscurus. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Aphids (Homoptera: Aphididae); one record also from Philaenus spurnarius (Homoptera: Cercopidae). GEOGRAPHICAL DISTRIBUTION: Europe, N. America, Asia, Australia. DISEASE: Infection is by germ tubes issuing from the conidia and penetrating the integument of the aphid. Dead insects characteristically hang from stems and leaves of the host plant by the proboscis inserted in the plant tissues. They are clothed in conidiophores bearing the large conidia that sparkle in bright light. In N. Europe C. obscurus occurs most frequently in the autumn and spring in relatively cool, moist weather.

Dynamics of fungal pathogens in host plant tissues

1995 ◽  
Vol 73 (S1) ◽  
pp. 1275-1283 ◽  
Author(s):  
Shigehito Takenaka
Keyword(s):  
Host Plant ◽  
Species Interactions ◽  
Fungal Biomass ◽  
Quantitative Methods ◽  
Plant Pathogens ◽  
Pathogenic Fungi ◽  
Molecular Methods ◽  
Plant Colonization ◽  
Fungal Colonization ◽  
Plant Tissues

To develop efficient control measures against fungal plant pathogens, the dynamics of host plant colonization during disease development and the interactions among fungi within host plant tissues need to be clarified. These studies require accurate quantitative estimation of specific fungal biomass in plant tissues. This has been approached by direct-microscopic methods, cultural methods, chemical determinations of fungal components, serological methods, and molecular methods. Among these methods, serological and molecular methods provide rapid, specific, and sensitive quantitative measures of fungal biomass in host plant tissues. Therefore, studies on fungal dynamics of host plant colonization using these two methods are presented. Some examples of species interactions among pathogenic fungi within host plants, such as synergism and competition, are reviewed and the usefulness of serological and molecular methods for studies on these interactions is presented. These quantitative methods will provide helpful information for understanding the ecology of plant pathogenic fungi, such as the dynamics of host plant colonization and species interactions. Key words: quantitative methods, fungal biomass, ELISA, PCR, fungal colonization, species interaction.

Effects of the Ant, Lasius niger (L.), on the Behaviour and Reproduction of the Black Bean Aphid, Aphis fabae Scop

1958 ◽  
Vol 49 (4) ◽  
pp. 701-714 ◽  
Author(s):  
C. J. Banks
Keyword(s):  
Natural Enemies ◽  
Plant Tissue ◽  
Food Supply ◽  
Aphis Fabae ◽  
Lasius Niger ◽  
Average Difference ◽  
Young Plant ◽  
Black Bean ◽  
Bean Plants ◽  
Aphid Populations

SummaryCage experiments confirmed that, in the absence of natural enemies, populations of Aphis fabae Scop., attended on bean plants (Vicia faba) by the ant, Lasius niger (L.), multiply more rapidly than otherwise similar but ant-free populations. The average difference in numbers recorded, was about one-third, the maximum being 70 per cent. No doubling or trebling of aphid numbers as claimed by an earlier worker was ever recorded.When the Aphids are attended by ants, their excretion behaviour alters and the normal dispersal of the apterae from the young apical growth of bean plants is considerably delayed.No significant differences were found between the numbers of nymphs produced by individual Aphids from ant-visited and ant-free plants, respectively, living on leaves of the same age; but the numbers were significantly affected by the age of the leaf or part of the plant on which the Aphids had developed or were then feeding.It is suggested that ant-attended aphid populations multiply more rapidly because most of the Aphids feed for a much longer time on young plant tissue where, presumably, their food supply is more nutritious.

Gibberella zeae. [Descriptions of Fungi and Bacteria].

1973 ◽  
Author(s):  
C. Booth
Keyword(s):  
Geographical Distribution ◽  
Secondary Infection ◽  
Brown Rot ◽  
Gibberella Zeae ◽  
Infested Soil ◽  
Foot Rot ◽  
Seedling Blight ◽  
Water Droplets ◽  
Ascospore Discharge ◽  
The Tropics

Abstract A description is provided for Gibberella zeae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Wheat, maize, barley, carnations and other ornamentals; also reported infecting Lycopersicon, Pisum, Trifolium and Solanum DISEASE: Seedling blight, pre-emergence and post-emergence blight, root and foot rot, brown rot, culm decay, head or kernel blight (scab or ear scab) of wheat, maize, barley and other cereals. Leaf and flower rot of carnations and other ornamentals. Also reported infecting species of Lycopersicon, Pisum, Trifolium and Solanum. GEOGRAPHICAL DISTRIBUTION: Worldwide on maize and rice in the tropics. Wheat, oats, barley and rye in temperate regions. TRANSMISSION: By planting infected or infested seeds or by planting in infested soil. Secondary infection occurs widely by water droplets under moist conditions or by ascospore discharge.

Podosphaera clandestina. [Descriptions of Fungi and Bacteria].

1975 ◽  
Author(s):  
S. M. Khairi
Keyword(s):  
Host Plant ◽  
Geographical Distribution ◽  
Secondary Infection ◽  
Pyrus Communis ◽  
Crataegus Monogyna ◽  
Terminal Buds

Abstract A description is provided for Podosphaera clandestina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Crataegus monogyna, C. pentagyna, C. punctata, Mespilus germanica, Cratoegomespilus grandiflora, C. dardari, Pyrus communis, Cydonia vulgaris, Pyrocydonia winkleri and P. danieli. DISEASE: Hawthorn mildew. Severe attacks cause defoliation and death of terminal buds on young seedlings and on soft shoots on hedges and trees. The disease has been recorded on hawthorn fruits. The host plant can be grown only from seeds. GEOGRAPHICAL DISTRIBUTION: Worldwide (Salmon, 1900; 45, 3081). Cleistothecia play no part in the disease in England. The overwintering mycelium, inside infected buds, survives until the following spring. These infected buds are the primary infections found each year. Secondary infection is by air-borne conidia.

Puccinia levis var. brachiariae. [Descriptions of Fungi and Bacteria].

2009 ◽  
Author(s):  
P. F. Cannon
Keyword(s):  
Host Plant ◽  
Geographical Distribution ◽  
Conservation Status ◽  
Leaf Lamina ◽  
Brachiaria Brizantha ◽  
Urochloa Decumbens ◽  
Urochloa Brizantha

Abstract A description is provided for Puccinia levis var. brachiariae comb. nov., which causes small lesions on young stems and leaf lamina of the host plant and, where present in quantity, could significantly reduce vigour. Some information on its dispersal and transmission and conservation status is given, along with details of its geographical distribution (Malawi, Uganda, Zambia and Brazil) and hosts (Brachiaria brizantha [Urochloa brizantha], B. decumbens [Urochloa decumbens], B. humidicola [Urochloa humidicola] and an unnamed Brachiaria sp.).

Diplocarpon earliana. [Descriptions of Fungi and Bacteria].

1976 ◽  
Author(s):  
A. Sivanesan
Keyword(s):  
South Africa ◽  
Hong Kong ◽  
North America ◽  
South America ◽  
Eastern Europe ◽  
Geographical Distribution ◽  
Canary Islands ◽  
Perfect State ◽  
Splash Dispersal ◽  
The Tropics

Abstract A description is provided for Diplocarpon earliana. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Fragaria. DISEASE: Strawberry leaf scorch. GEOGRAPHICAL DISTRIBUTION: Throughout temperate zones and extending into the tropics in Malaysia, Taiwan, Australia and New Guinea; Africa (Rhodesia, Zambia, South Africa, Canary Islands); Europe (except Ireland, Spain, Sweden, Russia); North America (Canada, USA, Jamaica); South America (Brazil, Uruguay); Asia (Armenia, Cambodia, Hong Kong, India, Israel, Japan, W. Malaysia). Appears to be most important in USA and eastern Europe (CMI Map 452, ed. 1, 1969). TRANSMISSION: Mainly by splash dispersal of conidia from infected leaves. Ascospores appear to be unimportant and in some regions (Poland; 46, 2074) where the perfect state has not been found.

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